Phẫu Thuật Tạo Hình (Tập 4): Chi Dưới, Thân Mình Và Bỏng – Neligan (2018)

17
The thigh
Fig. 1.13  Muscles of the thigh. (From: Netter; © Elsevier Inc. All rights reserved.)
Superficial dissection: posterior view
Iliac crest
Gluteus maximus muscle
Semitendinosus muscle
Biceps femoris muscle (long head)
Adductor magnus muscle
Iliotibial tract
Semimembranosus muscle
(short head)
Gracilis muscle
Biceps femoris muscle
Semimembranosus muscle
Semitendinosus muscle
Popliteal vessels and tibial nerve
Common fibular (peroneal) nerve
Plantaris muscle
Gastrocnemius muscle
Inguinal ligament
Pubic tubercle
Iliopsoas muscle
Tensor fasciae latae muscle
Pectineus muscle
Adductor longus muscle
Gracilis muscle
Sartorius muscle
Rectus femoris muscle
Vastus lateralis muscle
Vastus medialis muscle
Patellar ligament
Sartorius tendon
Gracilis tendon
Tibial tuberosity
Semitendinosus tendon
Lateral patellar retinaculum
Medial patellar retinaculum
Patella
Pes anserinus
Rectus femoris tendon
Superficial dissection: anterior view
Anterior superior iliac spine
Iliacus muscle
Psoas major muscle
A
B

18
SECTION I
CHAPTER 1 • Comprehensive lower extremity anatomy
an independent, longitudinal manner, allowing for muscle
subdivision when necessary.18,19 As opposed to the gracilis, the
remainder of the adductor muscles do not lend themselves
easily for flap transposition due to their position and muscular
structure.
The tensor fascia latae is not classically designated in the
previously described compartments but is included in the
discussion of the thigh because of its intimate relation to thigh
musculature and utility in reconstructive surgery. The tensor
fascia latae lies on the proximal lateral aspect of the thigh
originating from the iliac crest. As it descends distally it is
enveloped by the two layers of the iliotibial band (Figs. 1.8 &
1.10). The tensor fascia latae muscle usually ends in the proxi-
mal third of the thigh but can extend down to the lateral
femoral condyle. Its blood supply is from the ascending or
transverse branch of the lateral circumflex femoral arterial
The adductor compartment contains the adductor magnus,
brevis, and longus, as well as the gracilis and pectineus
muscles (Fig. 1.14). All five muscles cross the hip joint, but
only the gracilis crosses the knee. The gracilis is also the most
superficial muscle of the adductor compartment. It begins
from its origin on the pubic bone as a flat, broad muscle that
tapers down into a narrow tendon that inserts into the pes
anserinus. The gracilis is often harvested for wound coverage
and can be transferred as a pedicled flap for local coverage or
a free flap for distant reconstruction. It can also be harvested
with its nerve supply for functional upper extremity recon-
struction or facial reanimation. The gracilis has a type II
vascular supply, perfused from a dominant medial circumflex
femoral artery pedicle, with three to six muscular branches
entering the muscle on the deep surface adjacent to a branch
of the obturator nerve and each branch proceeding distally in
Fig. 1.14  Muscles of the thigh, deep dissection: anterior view. (From:
Netter; © Elsevier Inc. All rights reserved.)
Pectineus m. (cut and reflected)
Superior ramus of pubis
Adductor longus m.
(cut and reflected)
Adductor
brevis m. (cut)
Pubic
tubercle
Gracilis m. (cut)
Obturator
externus m.
Quadratus
femoris m.
Adductor
magnus m.
(Adductor
minimis m.)
Openings for
perforating
branches of
deep femoral a.
Medial
epicondyle of
femur
Gracilis m. (cut)
Tibial collateral
ligament
Medial patellar
retinaculum
Sartorius tendon (cut)
Semitendinosus tendon
Tuberosity of tibia
Patellar ligament
Head of fibula
Lateral patellar retinaculum
Fibular collateral ligament
Patella
Lateral epicondyle of femur
Rectus femoris tendon (cut)
Vastus lateralis m. (cut)
Vastus medialis m. (cut)
Femoral a. and v.
passing through
tendinous hiatus of
adductor magnus m.
Adductor longus m.
(cut and reflected)
Vastus intermedius m.
Adductor brevis m.
(cut and reflected)
Pectineus m.
(cut and reflected)
Iliopsoas m. (cut)
Greater trochanter
of femur
Capsule of hip joint
Anterior inferior
iliac spine
Anterior
superior
iliac spine
Muscles of Hip and Thigh
Anterior view: deep dissection

19
The thigh
through the femoral sheath, a short canal composed of the
continuation of the transversalis fascia anteriorly and the iliac
fascia posteriorly. These fascial layers fuse with the vascular
adventitia approximately 4 cm inferior to the inguinal liga-
ment. The femoral artery crosses beneath the sartorius muscle
and enters Hunter’s canal, a fibromuscular canal bounded
laterally by the vastus medialis, inferiorly by the adductor
longus and magnus, and anteromedially by the sartorius. The
femoral artery exits Hunter’s canal through the adductor
hiatus, entering the popliteal fossa, at which point it is referred
to as the popliteal artery.
In the proximal thigh, the femoral artery bifurcates
4 cm inferior to the inguinal ligament into the profunda
femoris (also called the deep femoral artery) and the superfi-
cial femoral artery (SFA). Although there is some debate over
the terminology of the femoral artery’s origin and distal
progression, it is usually described as follows: the external
iliac artery becomes the femoral artery after it crosses the
inguinal ligament, and the femoral artery then branches into
the profunda femoris and the SFA. The profunda femoris
usually branches from the posterolateral aspect of the femoral
artery, then passes deep to the adductor longus muscle,
between the insertions of the lateral and the medial intermus-
cular septa, and runs posterior to the linea aspera of the femur
(Figs. 1.9 & 1.16).
Profunda femoris
In the thigh, the profunda femoris is the predominant blood
supply source. There are some important contributions to
thigh musculature by the SFA (the adductors, sartorius, and
the vastus medialis), but the main vascular distribution for
the three thigh compartments arises from the profunda
femoris. The majority of the pedicles to thigh musculature
arise in the proximal two-thirds of the thigh from the six major
branches of the profunda femoris: the lateral and medial cir-
cumflex arteries and four perforating arteries (Fig. 1.16).
Lateral circumflex femoral arterial system
The lateral circumflex femoral arterial system is particularly
relevant to the reconstructive surgeon due to the popularity
of flap options that can be harvested on it. Classically, the
lateral circumflex femoral artery (LCFA) is described as the
second major branch off the profunda femoris, splitting into
the ascending, transverse, and descending branches (Fig.
1.16). The ascending branch travels along the intertrochanteric
line, supplying the greater trochanter, tensor fascia latae,
anterior iliac crest, and skin overlying the hip, before connect-
ing with the superior gluteal and deep circumflex iliac vessels.
The transverse branch passes through the vastus lateralis
and curls posteriorly around the femur, joining with the
medial circumflex artery. The descending branch usually
travels in the intermuscular septum between the vastus
intermedius and the overlying rectus femoris. From these
branches, cutaneous perforators either travel through the
musculature (musculocutaneous perforators) or between the
musculature along the intervening fibrous septa (septocutane-
ous perforators).
There is great variability in the LCFA system, and the clas-
sical description of the location of the vessels and their courses
does not always hold. In 20% of cases, the take-off of the LCFA
system. This allows the muscle and fascia to be included with
other flaps based off the same system, if such a composite
reconstruction is required.
Thigh vasculature
The primary blood supply to the lower extremity is the
femoral artery (Fig. 1.15). It courses with the femoral vein
Femoral artery
Deep artery of thigh
First perforating artery
Second perforating artery
Third perforating artery
Descending branch of
lateral circumflex
femoral artery
Descending genicular artery
Articular branch of
descending genicular artery
Saphenous branch of
descending genicular artery
Superior medial genicular artery
Inferior medial genicular artery
Circumflex peroneal
branch of posterior
tibial artery
Anterior tibial artery
Anterior medial malleolar artery
Anterior lateral
malleolar artery
Lateral tarsal artery
Dorsal pedis artery
Medial tarsal artery
Arcuate artery
Posterior tibial artery
Superior lateral
genicular artery
Inferior lateral
genicular artery
Popliteal artery
Peroneal artery
Medial circumflex femoral artery
Ascending branch
of lateral circumflex
femoral artery
Transverse branch
of lateral circumflex
femoral artery
Fig. 1.15  Femoral and profunda arteries.

20
SECTION I
CHAPTER 1 • Comprehensive lower extremity anatomy
Fig. 1.17  Lateral circumflex femoral artery (LCFA) system. ALT, anterolateral thigh;
TFL, tensor fasciae latae. (Courtesy of Lawrence Gottlieb.)
Rectus
femoris
TFL
for
tongue
Lateral
Femoral
Circumflex
Lateral
Iliac Crest
ALT
Fig. 1.16  Lateral circumflex femoral artery (LCFA).
Femoral artery
Deep artery of thigh
Tensor fasciae latae
Descending branch of
lateral circumflex
femoral artery
Rectus femoris
Vastus lateralis
Vastus intermedius
Ascending branch
of lateral circumflex
femoral artery
Lateral circumflex
femoral artery
Transverse branch
of lateral circumflex
femoral artery
is from a different source vessel than the profunda femoris. It
can arise from the common femoral artery itself, present as a
split artery traveling from the femoral artery and the profunda
femoris separately, from a common origin for the profunda
femoris and the medial circumflex femoral artery (MCFA),
from the MCFA, or even from the external iliac artery.20 In
spite of this multiplicity of anatomic variations, the LCFA
system provides a robust interconnected blood supply to skin,
muscle, fascia, and bone. This can be exploited for a plethora
of flap compositions in a variety of orientations. The numer-
ous independent branches of the LCFA system allow for
construction of chimeric flaps with multiple tissue types,
including anterolateral thigh skin, fascia lata, vastus lateralis,
rectus femoris, tensor fascia latae, and lateral iliac crest
(Fig. 1.17).
Clinical correlation – anterolateral thigh flap
The anterolateral thigh (ALT) flap, based on the LCFA system,
is one of the most popular soft-tissue flaps for microvascular
tissue transfer in reconstructive surgery. There is considerable
variability in the arterial anatomy of the ALT flap. Most com-
monly, perforators from the descending branch of the LCFA
supply the ALT flap. However, in up to 44% of cases, there is
an oblique branch, arising most commonly from the descend-
ing branch of the LCFA or, less frequently, from the transverse
branch of the LCFA, which provides the dominant perforator
supply to the ALT flap.20,21 When an oblique branch is present,
in over 90% of cases it will supply an additional codominant
pedicle to the rectus femoris muscle.22 The implication of this
is that an ALT flap can be reliably harvested on either pedicle
without compromising perfusion to the rectus femoris.
The superior-most cutaneous perforator is reliably located
approximately 17 cm inferior to the ASIS along a line from the
ASIS to the lateral patella.23 The majority of cutaneous perfo-
rators will be found within a 3 cm radius around the midpoint
of this line.24,25 Septocutaneous perforators to the ALT flap,
which allow for more efficient dissection than musculocuta-
neous perforators, can be expected to be present in nearly 20%
of cases and are more common in the proximal thigh. A major
benefit of the ALT flap is the potential for a long vascular
pedicle. With a proximal harvest, the pedicle ranges from 4 to
8 cm; however, when harvested distally, the pedicle can reach
20 cm in length.20

21
The thigh
and cutaneous regions. Branches of the MCFA are typically
smaller than those of the LCFA. However, patients with small
or absent LCFA perforators tend to have larger branches from
the MCFA, suggesting a reciprocal dominance of blood
supply.26
Profunda femoris perforating branches
There are typically four perforating branches of the profunda
femoris that arise distal to the circumflex arteries. Their name
is derived from the course of the vessels traveling posteriorly
near the linea aspera of the femur. These vessels perforate the
tendon of the adductor magnus under small tendinous arches
to supply the posterior thigh. The first perforating branch
emerges from the profunda femoris above the adductor
brevis, the second from in front of the adductor, and the third
immediately below it. The distal aspect of the profunda
becomes the fourth perforator (Fig. 1.18). The first perforating
branch supplies the adductor brevis, adductor magnus, biceps
femoris, and gluteus maximus. The second perforating branch
is larger than the first and divides into an ascending and
descending branch. These branches supply the posterior
compartment muscles and the endosteal blood supply to the
femoral bone. The third and fourth perforating branches also
supply the posterior femoral muscles and join with branches
of the MCFA and the popliteal artery.
Innervation of the thigh
Motor innervation
The nerve supply of the compartments in the thigh follows a
“one compartment, one nerve” pattern. The femoral nerve
supplies the anterior compartment, the obturator nerve sup-
plies the medial compartment, and the sciatic nerve supplies
the musculature of the posterior compartment. Innervation to
the thigh is derived originally from the lumbosacral plexus.
The femoral nerve, arising from the L2–L4 nerve roots, passes
beneath the inguinal ligament and splits into anterior and
posterior divisions around the lateral femoral circumflex
artery (Fig. 1.19). The anterior division supplies motor inner-
vation to the sartorius and gives off the intermediate and
medial cutaneous nerves of the thigh. The posterior division
of the femoral nerve provides motor innervation to the quad-
riceps and sensory fibers to the knee joint, and also gives rise
to the saphenous nerve. The obturator nerve, also arising from
the L2–L4 spinal roots, enters the thigh through the obturator
foramen and splits into anterior and posterior branches. The
anterior branch of the obturator nerve provides motor inner-
vation to the adductor longus brevis and gracilis and sensory
innervation to the hip joint, and communicates with the
saphenous nerve to innervate the medial leg. The posterior
branch of the obturator nerve innervates the adductor magnus
and supplies sensory innervation to a portion of the knee joint
capsule. The sciatic nerve is the largest nerve in the body,
arising from the L4–S3 nerve roots and entering the thigh
through the sciatic foramen inferior to the piriformis (Fig.
1.20). It divides into its two major components, the tibial and
the common peroneal nerve, at a variable point within the
thigh. The tibial nerve supplies all hamstring muscles with
the exception of the short head of the biceps femoris, which
is innervated by the common peroneal nerve.
Medial circumflex femoral arterial system
The MCFA emerges from the medial and posterior aspect of
the profunda, winds around the medial side of the femur,
passes between the pectineus and the psoas major, and then
between the obturator externus and the adductor brevis to
supply the adductor compartment (Fig. 1.18). As the artery
passes between the quadratus femoris and the adductor
magnus, it splits into descending and transverse branches.
The transverse branch passes posteriorly to the femur and
joins the transverse branch of the LCFA and the IGA, known
as the cruciate connection. The descending branch of the
MCFA branches into several muscular branches to supply the
gracilis muscle. The MCFA system mirrors the LCFA system
as a nexus of branches that supply multiple different muscles
Fig. 1.18  Profunda femoris perforating branches.
Femoral artery
Deep artery of thigh
Descending branch of
lateral circumflex
femoral artery
Ascending branch
of lateral circumflex
femoral artery
Lateral circumflex
femoral artery
Superficial circumflex
iliac artery
Superficial epigastric artery
Superficial external
pudendal artery
Deep external pudendal artery
Transverse branch
of lateral circumflex
femoral artery
Descending
genicular artery
Medial circumflex
femoral artery

22
SECTION I
CHAPTER 1 • Comprehensive lower extremity anatomy
Fig. 1.19  Femoral nerve and lateral cutaneous femoral nerves. (From: Netter; © Elsevier Inc. All rights reserved.)
Lateral femoral cutaneous nerve (L2, 3)
Femoral nerve (L2, 3, 4)
Obturator nerve
Iliacus muscle
Psoas major muscle (lower part)
Articular branch
Sartorius muscle
(cut and reflected)
Pectineus muscle
Quadriceps
femoris
muscle
Rectus femoris
muscle (cut
and reflected)
Vastus
intermedius muscle
Vastus
medialis muscle
Vastus
lateralis muscle
Articularis genus muscle
Note: Only muscles
innervated by femoral
nerve shown
Lumbar plexus
T12
Lumbosacral trunk
Lateral femoral
cutaneous nerve
Anterior cutaneous
branches of
femoral nerve
Sartorius muscle
(cut and reflected)
Saphenous nerve
Infrapatellar branch
of saphenous nerve
Medial crural cutaneous
nerves (branches of
saphenous nerve)
Cutaneous
innervation
L1
L2
L3
L4
A
B

23
The thigh
Fig. 1.20  Sciatic nerve (L4, L5; S1, S2, S3) and posterior femoral cutaneous nerve (S1, S2, S3). (From: Netter; © Elsevier Inc. All rights
reserved.)
Posterior femoral
cutaneous nerve
(S1, 2, 3)
Inferior clunial nerves
Perineal branches
Tibial division
of sciatic nerve
Long head (cut) of
biceps femoris muscle
Adductor magnus muscle
(also partially supplied
by obturator nerve)
Semitendinosus muscle
Semimembranosus muscle
Tibial nerve
Articular branch
Plantaris muscle
Medial sural
cutaneous nerve
Gastrocnemius muscle
Sural nerve
Soleus muscle
Tibial nerve
Medial
calcaneal branches
Medial and lateral
plantar nerves
Greater sciatic foramen
Sciatic nerve (L4, 5, S1, 2, 3)
Common fibular (peroneal)
division of sciatic nerve
Short head of
biceps femoris muscle
Cutaneous innervation
Long head (cut)
of biceps femoris
muscle
Common fibular
(peroneal) nerve
Articular
branch
Lateral sural
cutaneous nerve
Sural
communicating
branch
Posterior femoral
cutaneous nerve
From sciatic
nerve
Lateral calcaneal
branches
Lateral dorsal
cutaneous nerve
Common fibular
(peroneal) nerve
via lateral sural
cutaneous nerve
Medial sural
cutaneous nerve
Superficial fibular
(peroneal) nerve
Sural nerve
Tibial nerve
via medial
calcaneal
branches
A
B

24
SECTION I
CHAPTER 1 • Comprehensive lower extremity anatomy
tibial tuberosity is a small, raised triangular area where the
anterior condylar surfaces merge. The primary functional role
of the patella is to assist in knee extension, amplifying the
extensor force by 30%.27
The knee comprises two joints, the patellofemoral and the
tibiofemoral joint. The patellofemoral joint assists in produc-
ing leg flexion and extension at the tibiofemoral joint. The
tibiofemoral joint is a bicompartmental synovial joint whose
stability and range of motion are governed by a complex
interplay between the bony anatomy and its soft-tissue con-
straints. The femoral condyles, their articular surfaces on the
tibia, and the intercondylar regions are all uniquely and asym-
metrically shaped. This gives the knee lateral translocation
and rotational movement beyond any hinge joint. The medial
collateral ligament, lateral collateral ligament, posterior cruci-
ate, anterior cruciate, popliteofibular, transverse, coronary,
and tibiofibular ligaments all work in cooperation with the
muscular attachments to provide knee joint stability. The
medial and lateral menisci are semilunar cartilaginous struc-
tures connected to the surrounding peripheral ligaments that
deepen the articulation surface between the tibia and the
femoral condyles.
Leg skeletal structure
The shafts of both the tibia and the fibula form triangular
cross-sectional shapes. The apex of the tibia is oriented ante-
riorly with a smooth curvilinear medial surface and a shelf-
like lateral surface that brackets the lateral compartment
musculature. The triangular apex of the fibula is oriented
laterally and 90° to that of the tibia. The interosseous mem-
brane crosses the leg in the anterior one-third area and is
attached between the interosseous crests of the tibia and the
fibula (Fig. 1.23). The vascular supply to the tibia and fibula
is provided from multiple sources. The tibia receives major
endosteal vascularity through the proximal nutrient foramen
that lies near the soleal line, a bony ridge on the posterior
superior aspect of the tibia that serves as the origin of the
soleus, flexor digitorum longus, and tibialis posterior muscles
(Fig. 1.23).28 The endosteal blood supply to the tibia enters this
area after branching off the posterior tibial artery as it exits
the popliteal fossa. This branch may also stem from the pop-
liteal bifurcation of the anterior tibial artery and the tibiope-
roneal trunk. The periosteal supply to the tibial shaft arises
from multiple segmental branches directly from the anterior
tibial artery and from perforating branches from the sur-
rounding musculature. The distal tibia is supplied by branches
from the connection around the ankle between the peroneal
and posterior tibial vessels.
The fibular shaft receives its endosteal blood supply from
a branch of the peroneal artery that enters the bone through
a nutrient foramen in the middle one-third of the shaft. The
nutritive branch enters the fibula on the posteromedial surface,
posterior to the interosseous membrane.29 The fibula also
receives a periosteal blood supply from multiple branches
from the peroneal artery. The fibular head receives a separate
blood supply. The anterior tibial artery gives off recurrent
branches and both the inferior lateral genicular arteries may
supply the fibular head and neck. The distal metaphyseal
region of the fibula is supplied by the ankle connection
between the peroneal and the posterior tibial vessels similar
to the distal tibia.
Cutaneous innervation
The cutaneous innervation of the thigh is shared by two pure
cutaneous nerves directly branching from the lumbosacral
plexus (lateral and posterior femoral cutaneous nerves) and
cutaneous branches from two mixed nerves (femoral and
obturator) (Figs. 1.19–1.21).
The lateral femoral cutaneous nerve arises from the dorsal
branches of the second and third lumbar rami. It travels from
intra-abdominal and behind the descending colon to exit to
the thigh underneath or through the inguinal ligament. The
nerve may become entrapped or compressed at this point in
a condition known as meralgia paresthetica. The lateral
femoral cutaneous nerve divides into an anterior and poste-
rior branch. The anterior branch pierces the fascia lata and
becomes superficial ≈10 cm below the ASIS. The posterior
branch pierces the fascia lata more superiorly than the anterior
branch. The posterior branch supplies the cutaneous region
around the greater trochanter and midthigh. The anterior
branch supplies the anterolateral skin of the thigh down to
the knee.
The posterior femoral cutaneous nerve arises from the first
and second sacral rami. It leaves the pelvis via the greater
sciatic foramen and descends distally under the gluteus
maximus with the inferior gluteal vessels. It travels down the
thigh superficial to the long head of the biceps femoris but
still under the fascia lata. It pierces the deep fascia behind the
knee, and its terminal branches continue down to the midcalf.
The posterior femoral cutaneous nerve supplies the majority
of the posterior thigh skin via branches that pierce the fascia
lata to travel superficially. The skin over the popliteal fossa is
also supplied by the posterior femoral cutaneous nerve.
The femoral nerve course has been described previously.
Its anterior division supplies the medial superior and inferior
thigh skin by way of the intermediate cutaneous and medial
cutaneous nerve of the thigh. The obturator nerve arises from
the second to the fourth lumbar rami. It exits the pelvis, ini-
tially descending within the psoas major then finally through
the obturator foramen, anterosuperior to the obturator vessels.
It branches into an anterior and posterior division. The
branches off the anterior division give cutaneous innervation
to the inferomedial thigh (Fig. 1.21).
The leg
As the lower extremity extends distally, the anatomic struc-
tures narrow significantly and the tissues become more
compact. The amount of redundant soft tissue present in the
thigh is not available in the leg, and there is less redundancy
of similar functioning muscles. These issues make the leg
more of a target for tissue reconstruction, rather than a source
of donor tissue.
Knee skeletal structure
The knee is the largest synovial joint in the body. It comprises
the two largest long bones of the body (femur and tibia)
and the largest sesamoid bone (patella). The tendons of the
vastus lateralis, vastus medialis, vastus intermedialis, and
rectus femoris all come to a confluence at the superior surface
of the patella and then insert on the smooth proximal region
of the tibial tuberosity as the patellar tendon (Fig. 1.22). The

25
The leg
Fig. 1.21  Obturator nerve. (From: Netter; © Elsevier Inc. All rights reserved.)
Iliohypogastric nerve
Ilioinguinal nerve
Genitofemoral nerve
Lateral femoral
cutaneous nerve
Femoral nerve
Obturator nerve
(L2, 3, 4)
Posterior branch
Articular branch
Anterior branch
Posterior branch
Cutaneous branch
Articular branch
to knee joint
Adductor hiatus
Note: Only muscles
innervated by obturator
nerve shown
Cutaneous
innervation
Lumbar plexus
Lumbosacral trunk
L1
Obturator externus muscle
Adductor brevis muscle
Adductor longus muscle (cut)
Adductor magnus muscle
(ischiocondylar, or
“hamstrings”, part supplied
by sciatic [tibial] nerve)
Gracilis muscle
L2
L3
L4
A
B

26
SECTION I
CHAPTER 1 • Comprehensive lower extremity anatomy
the fibular head to the lateral malleolus.30 Therefore to reliably
capture these perforators, the cutaneous paddle should be
designed over the third quarter of the fibula, or centered
between 20 and 25 cm from the fibula head in adult patients.31
Leg fascial composition
The fascial structure of the leg is in continuation with the
fascial system of the thigh. The superficial fascia of the leg lies
within the subcutaneous tissue. It is often present in two or
more layers of areolar tissue, but the layers can also be densely
adherent and appear as one. In the leg, the greater and lesser
saphenous veins and the sural and saphenous nerve travel
along the superficial fascia (Fig. 1.24).
Clinical correlation – fibula osteocutaneous flap
The fibula flap, initially described as an osseous free flap and
later modified to include a cutaneous paddle, is a workhorse
flap in microvascular reconstruction of bony defects. The
proximal 6 cm of the fibula should be maintained to protect
the peroneal nerve and the attachments of the peroneus
muscles, and the distal 6 cm should be preserved to maintain
ankle stability. To reliably harvest this as an osteocutaneous
flap, incorporation of peroneal artery perforators is essential.
Peroneal artery perforators to the skin can be identified using
common anatomic landmarks: the proximal fibular head is
the proximal landmark, and the lateral malleolus is the distal
landmark, creating the fibula axis. The highest concentration
of septocutaneous perforators is found at the 60% mark from
Fig. 1.22  Knee joint (lateral, medial, and anterior views). (From: Netter; © Elsevier Inc. All rights reserved.)
Semitendinosus m.
Semimembranosus m.
Gracilis m.
Tibial collateral ligament,
parallel fibers,
oblique fibers
Adductor magnus tendon
Anserine bursa
under semi-
tendinosus,
gracilis, and
sartorius tendons
Bursa under
semimembranosus
tendon
Gastrocnemius m.
Popliteus m.
IIiotibial tract
Biceps femoris m.,
long head,
short head
Bursa under
iliotibial tract
Plantaris m.
Peroneus
longus m.
Tibialis
anterior m.
Head of fibula
Biceps femoris tendon
and bursa
Common
peroneal n.
Soleus m.
Gastrocnemius m.
Fibular collateral
ligament and bursa
Sartorius m.
Vastus medialis m.
Patella
Rectus femoris
tendon
Lateral patellar
retinaculum
Joint capsule
Medial patellar
retinaculum
Tuberosity of tibia
Patellar ligament
Vastus
lateralis m.
IIiotibial tract
Fibular collateral ligament and bursa
Lateral patellar retinaculum
Lateral condyle of femur
Biceps femoris tendon and bursa
Insertion of iliotibial tract
to oblique line of tibia
Bursa under iliotibial tract
Head of fibula
Peroneus longus m.
Common peroneal n.
Extensor digitorum longus m.
Tibialis anterior m.
Vastus lateralis m.
Articularis genus m.
Rectus femoris tendon
Vastus medialis m.
Patella
Medial patellar retinaculum
Medial condyle of femur
Semitendinosus,
gracilis, and
sartorius tendons
Tibial collateral ligament
Anserine bursa
Patellar ligament
Gastrocnemius m.
Tuberosity of tibia
Medial condyle of tibia
Femur
Knee Joint
Medial view
Lateral view
Anterior view
A
B
C

27
The leg
Fig. 1.23  Bony attachments of muscles of leg. (From: Netter; © Elsevier Inc. All rights reserved.)
A
B
Anterior view
Iliotibial tract
Biceps femoris muscle
Fibularis
(peroneus)
brevis muscle
Fibularis
(peroneus)
longus muscle
Extensor
digitorum
longus muscle
Fibularis
(peroneus)
tertius muscle
Extensor hallucis
longus muscle
Fibularis
(peroneus)
brevis muscle
Fibularis
(peroneus)
tertius muscle
Gastrocnemius muscle
(medial head)
Semimembranosus
muscle
Sartorius muscle
Gracilis muscle
Semitendinosus
muscle
Quadriceps femoris
muscle via
patellar ligament
Tibialis anterior
muscle
Origins
Insertions
Note: Attachments
of intrinsic muscles
of foot not shown
Extensor
digitorum
longus muscle
Popliteus
muscle
Soleus
muscle
Flexor
digitorum
longus muscle
Tibialis
posterior muscle
Tibialis
anterior muscle
Flexor hallucis
longus muscle
Plantaris muscle
Gastrocnemius muscle
(lateral head)
Popliteus muscle
Tibialis posterior
muscle
Flexor hallucis
longus muscle
Fibularis (peroneus)
brevis muscle
Plantaris muscle
Soleus and
gastrocnemius
muscles via
calcaneal (Achilles)
tendon
Fibularis
(peroneus)
longus
muscle
Flexor
digitorum
longus
muscle
Pes anserinus
Posterior view
Extensor
hallucis
longus muscle

28
SECTION I
CHAPTER 1 • Comprehensive lower extremity anatomy
Fig. 1.24  Leg: cross-sections and fascial compartments. (From: Netter; © Elsevier Inc. All rights reserved.)
Interosseous membrane
Tibia
Deep posterior compartment
Deep flexor muscles
Flexor digitorum longus
Tibialis posterior
Flexor hallucis longus
Popliteus
Posterior tibial artery and veins
Tibial nerve
Fibular (peroneal) artery and veins
Transverse intermuscular septum
Superficial posterior compartment
Superficial flexor muscles
Soleus
Gastrocnemius
Plantaris (tendon)
Deep fascia of leg
(crural fascia)
Anterior compartment
Extensor muscles
Tibialis anterior
Extensor digitorum longus
Extensor hallucis longus
Fibularis (peroneus) tertius
Anterior tibial artery and veins
Deep fibular (peroneal) nerve
Anterior intermuscular septum
Lateral compartment
Fibularis (peroneus) longus muscle
Fibularis (peroneus) brevis muscle
Superficial fibular (peroneal) nerve
Posterior intermuscular septum
Fibula
Deep fascia of leg (crural fascia)
Cross-section just above middle of leg
Anterior tibial artery and veins and
deep fibular (peroneal) nerve
Tibia
Interosseous membrane
Great saphenous vein
and saphenous nerve
Tibialis posterior muscle
Flexor digitorum longus
muscle
Fibular (peroneal) artery
and veins
Posterior tibial artery
and veins and tibial nerve
Flexor hallucis longus
muscle
Deep fascia of leg (crural fascia)
Plantaris tendon
Gastrocnemius muscle (medial head)
Medial sural cutaneous nerve
Small saphenous vein
Tibialis anterior muscle
Extensor hallucis longus muscle
Extensor digitorum longus muscle
Superficial fibular (peroneal) nerve
Anterior intermuscular septum
Deep fascia of leg
(crural fascia)
Fibularis (peroneus)
longus muscle
Fibularis (peroneus)
brevis muscle
Posterior intermuscular septum
Fibula
Lateral sural cutaneous nerve
Transverse intermuscular septum
Soleus muscle
Gastrocnemius muscle (lateral head)
Sural communicating branch
of lateral sural cutaneous nerve
A
B

29
The leg
therefore, the superficial posterior compartment is much more
expansile and slightly less at risk for compartment syndrome.
Leg musculature
Anterior compartment
The composition of the compartments of the leg follows a
congruent order, with the muscular components of each
compartment sharing similar functions. The anterior compart-
ment comprises four muscles (tibialis anterior, extensor digi-
torum longus, extensor hallucis longus, and peroneus tertius),
one major artery (anterior tibial), and one major mixed nerve
(deep peroneal) (Figs. 1.25 & 1.26). These muscles are respon-
sible for dorsiflexion of the ankle, foot, and toes. The tibialis
anterior is the most superficial muscle in the compartment,
overlying the anterior tibial vessels and the deep peroneal
nerve in the proximal leg. Its tendon passes through the
medial compartments of the superior and inferior extensor
retinacula to insert on the medial cuneiform and first meta-
tarsal base. Its specific mechanism of action is foot dorsiflexion
and inversion. The tibialis receives its blood supply from the
anterior tibial artery, usually in branches organized in two
columns. These columns give off 8–12 branches that segmen-
tally supply the muscle. The extensor digitorum longus lies
lateral to the tibialis anterior in the anterior compartment,
travels distally in the lateral aspect of the ankle and transitions
to tendon around the same point as the tibialis anterior. It
divides into four slips that proceed to the second through fifth
toes. The extensor digitorum longus extends the toes, dorsi-
flexes synergistically with the tibialis anterior and extensor
hallucis, as well as everts the foot. It has a segmental blood
supply from the anterior tibial artery similar to that of the
tibialis anterior. The extensor hallucis longus shares the origin
of the extensor digitorum longus but inserts on the base of the
distal phalanx of the first toe. Its mechanism of action is
dorsiflexion of the first toe and foot. Like all muscles in the
anterior compartment, its blood supply is segmental from
the anterior tibial artery. This segmental vascularity limits the
mobility and arc of rotation of anterior-compartment muscle
flaps. The peroneus tertius is a muscle unique to the human
species. Along with the popliteus, it is the shortest muscle in
the leg. Its mechanism of action is to work in collaboration
with the other muscles of the anterior compartment to dorsi-
flex and evert the foot. All the muscles of the anterior com-
partment are innervated by the deep peroneal nerve.
Lateral compartment
The lateral compartment comprises only two muscles – the
peroneus longus and brevis, which originate from, and are
anatomically related to, the fibula (Figs. 1.23 & 1.25). The
peroneus longus is the more superficial of the two and has a
more superior origin on the fibula than the brevis (Table 1.3).
Both muscles transition to tendons at the ankle, course in a
groove behind the lateral malleolus, and ultimately travel on
the plantar surface of the foot to their insertions. The peroneus
brevis inserts on the plantar surface of the base of the fifth
metatarsal. The peroneus longus crosses the foot traveling
beneath the midsole musculature to insert on the plantar
surface of the base of the first metatarsal. Both muscles work
The deep fascia of the leg (also called the investing fascia
or fascia cruris) constrains the leg musculature. The deep
fascia is actually a continuation of the deep fascia of the thigh
and receives fascial expansions from the tendons of the knee
extensors and flexors. The deep fascia varies in thickness in
different regions and is closely attached to the tissue structures
beneath it.
The interosseous membrane of the leg is a band of dense
fibrous fibers oriented obliquely that extends between the
interosseous crests of the tibia and the fibula (Fig. 1.24). It
separates the anterior and posterior compartments of the leg.
The muscles that lie directly on the membrane (tibialis ante-
rior, extensor hallucis longus; tibialis posterior, flexor hallucis
longus) use the membrane as a muscular origin. At the supe-
rior aspect of the interosseous membrane is an oval aperture
that allows for passage of the anterior tibial vessels traveling
from the popliteal bifurcation in the popliteal fossa to the
anterior leg. At the inferior edge of the interosseous membrane
there is another opening that allows for the passage of perfo-
rating branches from the distal peroneal artery.
Lower leg compartments
Intermuscular septa radiate from the tibia and fibula to the
investing deep fascia and divide the leg musculature into
compartments (Fig. 1.24). These compartments organize the
musculature into groups of similar function. These intermus-
cular septa divide the leg into anterior, lateral, and posterior
compartments. The boundaries of the anterior muscle com-
partment are the tibial surface medially, the interosseous
membrane as the floor, the deep fascia as the roof, and the
intermuscular septum, which divides the anterior compart-
ment from the lateral compartment, as the lateral wall. The
lateral compartment boundaries are as follows: the floor is the
anterior surface of the fibula, the roof is the investing fascia
of the leg, and the other wall is the intermuscular septum
dividing the lateral from the posterior compartment. The
posterior compartment is the largest of the three major com-
partments and lies posterior to the interosseous membrane.
The transverse intermuscular septum creates a division line
from the lateral deep fascia wall to the medial deep fascia
wall, separating the posterior compartment into the deep and
superficial layers. The superficial layer is the only compart-
ment that does not have a bony component. The medial
surface of the tibia is bare, with no muscular peripheral cover-
age, and therefore there is no medial compartment.
Clinical correlation – compartment syndrome
The functional advantage of osteofascial compartment organi-
zation can turn problematic when the compartment volume is
pathologically expanded against its fascial constraints. Trauma,
infection, and intravenous extravasation of liquids can increase
compartmental volume through edema, inflammation, and/or
direct volume addition.32 As the volume of a compartment
increases, so does the intracompartmental pressure due to the
rigid nature of the fascial boundaries. As intracompartmental
pressure rises above capillary and arterial filling pressure,
perfusion and vascular inflow decreases, leading to tissue
ischemia. Because the investing fascia of the leg is thickest on
the anterior surface, the anterior compartment is the least
expansile of the four major compartments of the leg. The pos-
terior aspect of the investing fascia of the leg is more pliable;
Text continued on p. 34

30
SECTION I
CHAPTER 1 • Comprehensive lower extremity anatomy
Fig. 1.25  Muscles of leg (superficial dissection): anterior view. (From: Netter; © Elsevier Inc. All rights reserved.)
Vastus lateralis muscle
Iliotibial tract
Superior lateral genicular artery
Lateral patellar retinaculum
Biceps femoris tendon
Inferior lateral genicular artery
Common fibular (peroneal) nerve
Head of fibula
Fibularis (peroneus) longus muscle
Tibialis anterior muscle
Fibula
Superior extensor retinaculum
Lateral malleolus
Inferior extensor retinaculum
Extensor digitorum longus tendons
Fibularis (peroneus) tertius tendon
Extensor digitorum brevis tendons
Dorsal digital nerves
Vastus medialis muscle
Patella
Superior medial genicular artery
Tibial collateral ligament
Medial patellar retinaculum
Inferior medial genicular artery
Infrapatellar branch (cut) of
Saphenous nerve (cut)
Joint capsule
Patellar ligament
Insertion of sartorius muscle
Tibial tuberosity
Tibia
Gastrocnemius muscle
Soleus muscle
Medial malleolus
Rectus femoris tendon (becoming
quadriceps femoris tendon)
Superficial fibular
(peroneal) nerve (cut)
Fibularis (peroneus)
brevis muscle
Extensor digitorum longus muscle
Dorsal digital branches
of deep fibular (peroneal) nerve
Extensor hallucis brevis tendon
Extensor hallucis longus tendon
Medial branch of deep fibular (peroneal) nerve
Tibialis anterior tendon
Extensor hallucis longus muscle
Muscles of Leg (Superficial Dissection): Anterior View
Vastus lateralis muscle
Lateral patellar retinaculum
Superior lateral genicular artery
Quadriceps femoris tendon
Iliotibial tract
Patella
Tibialis anterior muscle
Tibial tuberosity
Patellar ligament
Lateral condyle of tibia
Superior extensor retinaculum
Inferior extensor retinaculum
5th metatarsal
bone
Fibularis (peroneus) tertius tendon
Fibularis (peroneus) brevis tendon
Extensor digitorum longus tendons
Extensor hallucis longus tendon
Extensor digitorum brevis muscle
Extensor hallucis longus muscle and tendon
Extensor digitorum longus tendon
Superficial fibular
(peroneal) nerve (cut)
Extensor digitorum longus muscle
Lateral malleolus
Calcaneal (Achilles) tendon
(Subtendinous) bursa
of tendocalcaneus
Superior fibular
(peroneal) retinaculum
Inferior fibular
(peroneal) retinaculum
Fibularis (peroneus) longus
tendon passing to sole of foot
Fibula
Soleus muscle
Fibularis (peroneus) longus
muscle and tendon
Fibularis (peroneus) brevis
muscle and tendon
Fibular collateral ligament
Common fibular
(peroneal) nerve
Inferior lateral
genicular artery
Head of fibula
Gastrocnemius muscle
Long head
Short head
Tendon
Biceps
femoris
muscle
A
B

31
The leg
Fig. 1.26  Muscles of leg (deep dissection): anterior view. (From: Netter; © Elsevier Inc. All rights reserved.)
Superior lateral genicular artery
Fibular collateral ligament
Lateral patellar retinaculum
Iliotibial tract (cut)
Biceps femoris tendon (cut)
Inferior lateral genicular artery
Common fibular (peroneal) nerve
Head of fibula
Fibularis (peroneus) longus muscle (cut)
Anterior tibial artery
Extensor digitorum longus muscle (cut)
Superficial fibular (peroneal) nerve
Deep fibular (peroneal) nerve
Fibularis (peroneus) longus muscle
Extensor digitorum longus muscle
Fibularis (peroneus)
brevis muscle and tendon
Superior medial genicular artery
Quadriceps femoris tendon
Tibial collateral ligament
Medial patellar retinaculum
Infrapatellar branch of saphenous nerve (cut)
Inferior medial genicular artery
Saphenous nerve (cut)
Patellar ligament
Insertion of sartorius tendon
Anterior tibial recurrent artery and
recurrent branch of deep peroneal nerve
Interosseous membrane
Tibialis anterior muscle (cut)
Gastrocnemius muscle
Soleus muscle
Tibia
Superficial fibular (peroneal) nerve (cut)
Extensor hallucis longus muscle and tendon (cut)
Interosseous membrane
Anterior medial malleolar artery
Medial malleolus and arterial network
Dorsalis pedis artery
Tibialis anterior tendon
Medial tarsal artery
Medial branch of deep fibular (peroneal) nerve
Arcuate artery
Deep plantar artery
Dorsal metatarsal arteries
Extensor hallucis longus tendon (cut)
Extensor hallucis brevis tendon (cut)
Dorsal digital branches of
deep fibular (peroneal) nerve
Fibularis (peroneus) longus tendon
Perforating branch of
fibular (peroneal) artery
Anterior lateral malleolar artery
Lateral malleolus and arterial network
Lateral tarsal artery and lateral
branch of deep fibular (peroneal) nerve
Extensor digitorum brevis and
extensor hallucis brevis muscles (cut)
Fibularis (peroneus) brevis tendon
Posterior perforating branches
from deep plantar arch
Extensor digitorum longus tendons (cut)
Extensor digitorum brevis tendons (cut)
Dorsal digital arteries
Branches of proper plantar
digital arteries and nerves

32
SECTION I
CHAPTER 1 • Comprehensive lower extremity anatomy
Table 1.3  Leg musculature
Muscle
Origin
Insertion
Function
Muscle
Blood
supply
Flap blood
supply type
Innervation
Anterior
compartment
1
Tibialis anterior
Shaft of tibia and
interosseous
membrane
Medial
cuneiform
and base of
first
metatarsal
Foot dorsiflexion and
inversion
Tibialis anterior
Anterior tibial
Segmental
(IV)
Deep
peroneal
nerve
2
Extensor
digitorum
longus
Shaft of fibula
and
interosseous
membrane
Extensor
expansion of
lateral four
toes
Foot and II–V toe
dorsiflexion and foot
eversion
Extensor
digitorum
longus
Anterior tibial
Segmental
(IV)
Deep
peroneal
nerve
3
Extensor hallucis
longus
Shaft of fibula
and
interosseous
membrane
Base of distal
phalanx of
big toe
First-toe dorsiflexion
Extensor hallucis
longus
Anterior tibial
Segmental
(IV)
Deep
peroneal
nerve
4
Peroneus tertius
Shaft of fibula
and
interosseous
membrane
Base of fifth
metatarsal
bone
Dorsiflexes (extends) foot;
everts foot at subtalar
and transverse tarsal
joints
Peroneus tertius
Anterior tibial
Segmental
(IV)
Deep
peroneal
nerve
Lateral
compartment
5
Peroneus longus
Shaft of fibula
Base of first
metatarsal
and medial
cuneiform
Plantarflexes foot; everts
foot at subtalar and
transverse tarsal joints;
supports lateral
longitudinal and
transverse arches of
foot
Peroneus longus
Peroneal
Dominant
pedicle
and minor
pedicle(s)
(II)
Superficial
peroneal
nerve
6
Peroneus brevis
Shaft of fibula
Base of fifth
metatarsal
bone
Plantarflexes foot; everts
foot at subtalar and
transverse tarsal joints;
supports lateral
longitudinal arch
Peroneus brevis
Peroneal
Dominant
pedicle
and minor
pedicle(s)
(II)
Superficial
peroneal
nerve

33
The leg
Superficial
posterior
compartment
7
Medial
gastrocnemius
Medial femoral
condyle
Calcaneum via
Achilles
tendon
Plantarflexes foot; flexes
leg
Medial
gastrocnemius
Posterior
tibial
One vascular
pedicle (I)
Tibial nerve
8
Lateral
gastrocnemius
Lateral femoral
condyle
Calcaneum via
Achilles
tendon
Plantarflexes foot; flexes
leg
Lateral
gastrocnemius
Posterior
tibial
One vascular
pedicle (I)
Tibial nerve
9
Plantaris
Lateral
supracondylar
ridge of femur
Calcaneum
Plantarflexes foot; flexes
leg
Plantaris
Posterior
tibial
Segmental
(IV)
Tibial nerve
10
Soleus
Shafts of tibia
and fibula
Calcaneum via
Achilles
tendon
Foot plantarflexion
Soleus
Posterior
tibial
Dominant
pedicles
and minor
pedicle (II)
Tibial nerve
Deep posterior
compartment
11
Popliteus
Lateral condyle of
femur
Shaft of medial
tibia
Flexes leg; unlocks full
extension of knee by
laterally rotating femur
on tibia
Popliteus
Medial and
lateral
genicular
arteries
Segmental
(IV)
Tibial nerve
12
Flexor digitorum
longus
Shaft of tibia
Distal
phalanges of
lateral four
toes
Flexes distal phalanges of
lateral four toes;
plantarflexes foot;
supports medial and
lateral longitudinal
arches of foot
Flexor digitorum
longus
Posterior
tibial
branches
Segmental
(IV)
Tibial nerve
13
Flexor hallucis
longus
Shaft of fibula
Base of distal
phalanx of
big toe
Flexes distal phalanx of
big toe; plantarflexes
foot; supports medial
longitudinal arch
Flexor hallucis
longus
Peroneal
branches
Segmental
(IV)
Tibial nerve
14
Tibialis posterior
Shafts of tibia
and fibula and
interosseous
membrane
Tuberosity of
navicular
bone and the
medial
cuneiform
Plantarflexes foot; inverts
foot at subtalar and
transverse tarsal joints;
supports medial
longitudinal arch of foot
Tibialis posterior
Posterior
tibial and
peroneal
Segmental
(IV)
Tibial nerve

34
SECTION I
CHAPTER 1 • Comprehensive lower extremity anatomy
together to evert and plantarflex the foot. The blood supply
for both muscles is the same, type II, with the major pedicle
branching from the peroneal artery in the proximal one-third
and a distal minor branch coming off the anterior tibial artery
in the distal two-thirds of the muscles. There is no major
vessel within the lateral compartment, so both pedicles must
traverse the intermuscular septa to reach their target muscles.
Both muscles are innervated by the superficial branch of the
peroneal nerve.
Posterior compartment – superficial layer
The posterior compartment is the largest compartment of the
leg and is divided into deep and superficial layers by the deep
transverse fascia. The superficial group contains four muscles
– medial and lateral gastrocnemius, soleus, and plantaris (Fig.
1.24). The gastrocnemius and plantaris muscles originate on
the femur and insert on the calcaneus (Table 1.3). Therefore
these muscles cause activity on both the knee (flexion) and
ankle joints (plantar flexion). The medial head of the gastroc-
nemius is larger and longer than the lateral head. The proximal
aspect of the gastrocnemius defines the inferior border of the
popliteal fossa (the superior border is marked by the terminus
of the biceps femoris, semitendinosus, and semimembrano-
sus). The lateral head overlies the biceps femoris, and the
medial head overlies the semimembranosus. The muscle mass
of the gastrocnemius extends to midcalf and transitions to
its tendinous component more proximally than the soleus
muscle. Of note, in 10–30% of individuals, a sesamoid bone
can be present in the proximal tendon of the lateral head of
the gastrocnemius. Located behind the femoral condyle, this
sesamoid body is called the fabella and can be either fibrocar-
tilaginous or bony. Radiographically, the fabella can mistak-
enly be identified as a foreign body or an osteophyte.33
Each head of the gastrocnemius is supplied by a sural
branch off the popliteal artery. The medial sural artery always
arises more proximally from the popliteal artery than the
lateral, usually at the level of the tibiofemoral joint line. Each
sural artery enters the deep surface of the gastrocnemius at
about the midpoint of the popliteal fossa, paired with a motor
branch from the tibial nerve. These muscles follow a single
major pedicle vascular supply pattern (type I), but also have
some small connecting vessels between the muscle heads. The
plantaris muscle is a small, expendable muscle that lies
between the gastrocnemius muscles and the soleus. It is absent
in approximately 10% of the population, and its tendon, often
used as a source for tendon grafting, is located medial and
anterior to the Achilles tendon.34 The soleus is a broad, flat
muscle that works synergistically with the other muscles of
the compartment to plantarflex the foot. In the proximal calf,
the gastrocnemius overlies the soleus. However, the muscle
belly of the soleus continues much more distally than the
gastrocnemius until its musculotendinous transition into the
Achilles. The tendons of the gastrocnemius, soleus, and plan-
taris coalesce to create the broad, thick Achilles tendon that
inserts into the posterior calcaneus. The soleus has a type II
blood supply with three major dominant pedicles feeding it
from the popliteal, peroneal, and posterior tibial arteries.
Proximally, near the soleal origin, the popliteal artery sends
two branches to the soleus; just below the tibioperoneal
bifurcation, the peroneal artery contributes two branches; and
the posterior tibial artery delivers two major pedicle branches
in the proximal one-third of the soleus. Additionally, there are
minor pedicles that flow as segmental branches from the
posterior tibial artery in the distal one-third of the leg. Because
of the multiple different vascular supplies, basing an entire
soleus muscle flap off one or two closely related pedicles
usually results in some ischemia of the muscle area most
distant from the arterial inflow. Of note, the muscles of the
superficial posterior compartment create a “muscle pump”
effect which helps facilitate venous return. There is an intra-
muscular venous plexus within the soleus that is important
for adequate lower extremity venous return, especially when
an upright position is maintained. Consequently, most distal
deep venous thromboses are seen in either the soleus or
gastrocnemius.
Posterior compartment – deep layer
The deep posterior compartment comprises four muscles –
popliteus, flexor digitorum longus, flexor hallucis longus, and
tibialis posterior (Table 1.3). These muscles function to flex the
toes and plantarflex the ankle. All muscles in this compart-
ment are innervated by the tibial nerve (Fig. 1.27). The pop-
liteus is a flat muscle that travels obliquely across the popliteal
fossa from its origin on the posterior aspect of the lateral
femoral condyle to the posterior aspect of the proximal tibial
shaft. The popliteus is characterized as the muscle that
“unlocks” the knee joint from full extension. It rotates the tibia
medially on the femur to allow the beginning of knee flexion.
The flexor digitorum longus descends down the leg, and its
tendon courses posterior to the medial malleolus and across
the sole of the foot to insert to the plantar surfaces of the base
of the distal phalanges. The flexor hallucis longus travels from
the fibular origin down to the ankle with most of the muscle
belly uniquely still present at the calcaneal level. It crosses the
sole of the foot under the flexor digitorum longus to insert
into the base of the plantar surface of the first-toe distal
phalanx. Slips of tendons connect the flexor digitorum longus
and the flexor hallucis longus. This allows coordinated flexion
between the great toe and the other toes to maintain balance.
The blood supply for the flexor digitorum longus comes from
multiple segmental branches of the posterior tibial artery. The
flexor hallucis longus, originating from the fibula, is supplied
by the peroneal artery via multiple segmental branches. The
tibialis posterior is the deepest muscle of the posterior com-
partment. As the tibialis posterior progresses to the musculo-
tendinous junction, it courses behind the medial malleolus
with the flexor digitorum longus and crosses the plantar
surface of the foot beneath the flexor retinaculum, inserting
onto the navicular and the medial cuneiform. It receives a
segmental blood supply from multiple branches of the poste-
rior tibial artery (Fig. 1.28).
Leg vasculature
The lower leg is entirely supplied by branches from the pop-
liteal artery (Fig. 1.29). The popliteal artery is an extension of
the femoral artery after it exits the adductor canal and crosses
the popliteal fossa. Prior to entering the fossa, it gives off
multiple genicular branches that form a rich vascular plexus
that wraps anteriorly around the knee. The superior genicular
arteries connect with descending branches from the LCFA and
superficial femoral artery (Fig. 1.18). As the popliteal artery

35
The leg
Fig. 1.27  Tibial nerve. (From: Netter; © Elsevier Inc. All rights reserved.)
Tibial nerve
(L4, 5; S1, 2, 3)
Medial sural
cutaneous nerve (cut)
Articular branches
Plantaris muscle
Gastrocnemius
muscle (cut)
Nerve to popliteus muscle
Popliteus muscle
Interosseous nerve of leg
Soleus muscle (cut and
partly retracted)
Flexor digitorum
longus muscle
Tibialis posterior muscle
Flexor hallucis
longus muscle
Sural nerve (cut)
Lateral calcaneal branch
Medial
calcaneal branch
Flexor retinaculum (cut)
Lateral dorsal
cutaneous nerve
Common fibular (peroneal) nerve
Lateral sural cutaneous nerve (cut)
Medial calcaneal
branches
(S1, 2)
Medial
plantar nerve
(L4, 5)
Lateral
plantar nerve
(S1, 2)
From
tibial nerve
Saphenous nerve
(L3, 4)
Sural nerve
(S1, 2) via
lateral calcaneal
and lateral dorsal
cutaneous
branches
Cutaneous innervation of sole
Flexor
retinaculum
(cut)
Tibial
nerve
Medial
calcaneal
branch
Medial plantar
nerve
Flexor digitorum
brevis muscle
and nerve
Abductor hallucis
muscle and nerve
Flexor hallucis
brevis muscle
and nerve
1st lumbrical
muscle and
nerve
Common
plantar
digital
nerves
Proper
plantar
digital
nerves
Lateral calcaneal
branch of sural nerve
Lateral plantar
nerve
Quadratus plantae
muscle and nerve
Nerve to abductor
digiti minimi muscle
Abductor digiti
minimi muscle
Deep branch
to interosseous
muscles,
2nd, 3rd, and 4th
lumbrical muscles
and
Adductor hallucis
muscle
Superficial
branch to
4th interosseous
muscle
and
Flexor digiti minimi
brevis muscle
Common and
Proper plantar
digital nerves
Note: Articular branches not shown
Articular branch
A
B
C

36
SECTION I
CHAPTER 1 • Comprehensive lower extremity anatomy
Fig. 1.28  Muscles, arteries, and nerves of the leg: deep dissection (posterior view). (From: Netter; © Elsevier Inc. All rights reserved.)
Superior lateral genicular artery
Plantaris muscle (cut)
Gastrocnemius muscle (lateral head) (cut)
Fibular collateral ligament
Biceps femoris tendon (cut)
Inferior lateral genicular artery
Head of fibula
Fibular (peroneal) artery
Interosseous membrane
Perforating branch
Communicating branch
of fibular
(peroneal) artery
Superior medial genicular artery
Gastrocnemius muscle (medial head) (cut)
Sural (muscular) branches
Popliteal artery and tibial nerve
Tibial collateral ligament
Semimembranosus tendon (cut)
Inferior medial genicular artery
Popliteus muscle
Posterior tibial recurrent artery
Tendinous arch of soleus muscle
Posterior tibial artery
Flexor digitorum longus muscle
Tibial nerve
Tibialis posterior muscle
Calcaneal (Achilles) tendon (cut)
Flexor digitorum longus tendon
Tibialis posterior tendon
Medial malleolus and posterior medial
malleolar branch of posterior tibial artery
Flexor retinaculum
Medial calcaneal branches of
posterior tibial artery and tibial nerve
Tibialis posterior tendon
Medial plantar artery and nerve
Lateral plantar artery and nerve
Flexor hallucis longus tendon
1st metatarsal bone
5th metatarsal bone
Flexor digitorum longus tendon
Fibularis (peroneus) longus tendon
Fibularis (peroneus) brevis tendon
Inferior fibular (peroneal) retinaculum
Lateral calcaneal branch of sural nerve
Lateral calcaneal branch
of fibular (peroneal) artery
Superior fibular (peroneal) retinaculum
Lateral malleolus and posterior lateral
malleolar branch of fibular (peroneal) artery
Fibularis (peroneus) brevis tendon
Fibularis (peroneus) longus tendon
Flexor hallucis longus muscle (retracted)
Fibular (peroneal) artery
Anterior tibial artery
Soleus muscle (cut and reflected)
Common fibular (peroneal) nerve

37
The leg
exits the popliteal fossa, at the distal edge of the popliteus, it
produces its first terminal branch, the anterior tibial artery.
The anterior tibial artery passes between the heads of the
tibialis posterior and penetrates through the oval aperture in
the superior aspect of the interosseous membrane. It then
enters the anterior compartment and descends along the
anterior surface of the interosseous membrane until it reaches
the ankle. At the ankle, the anterior tibial artery is positioned
midway between the lateral and the medial malleoli on the
anterior surface of the ankle and enters the foot as the dorsalis
pedis artery.
After the anterior tibial artery branches from the popliteal
artery, there is usually a short segment of vessel known as
the tibioperoneal trunk, which divides into the peroneal and
posterior tibial vessels (Fig. 1.30). Both arteries remain in the
deep layer of the posterior compartment with the peroneal
artery traveling deeper and laterally, closely related to the
fibula. The posterior tibial artery descends down the leg,
initially slightly more superficially than the peroneal artery,
and then courses deeper to just under the deep transverse
fascia. As it progresses distally, it becomes more superficially
located until it is only covered by skin and subcutaneous fat
as it traverses the ankle posterior to the medial malleolus.
The tibial nerve runs with the posterior tibial artery in the
calf. Approximately five fasciocutaneous perforators emerge
between the flexor digitorum longus and the soleus to pass
through the deep fascia to the skin (Fig. 1.31). As the poste-
rior tibial artery rounds the medial malleolus, it divides
into its terminal branches – the medial and lateral plantar
arteries.
Leg nerve anatomy
Leg innervation is derived from the tibial and peroneal
branches of the sciatic nerve. The sciatic nerve bifurcates into
the tibial and common peroneal nerves in the popliteal fossa.
The tibial nerve continues down the deep posterior compart-
ment running alongside the posterior tibial artery (Fig. 1.28).
It innervates all the musculature of both the deep and the
superficial posterior compartments. The tibial nerve accom-
panies the posterior tibial artery to the ankle, and they course
together behind the medial malleolus under the flexor reti-
naculum. As the tibial nerve leaves the ankle and enters the
plantar surface of the foot, it bifurcates into the medial and
lateral plantar nerves.
In the popliteal fossa, the common peroneal nerve branches
off laterally from the sciatic nerve and then passes from the
posterior to the lateral aspect of the leg. It curves laterally
around the fibular neck, passing beneath the posterior crural
intermuscular septum that acts as an anatomic compression
point. The peroneal nerve continues deep to the peroneus
longus, the extensor digitorum longus, and the tibialis ante-
rior. The nerve divides into superficial and deep peroneal
nerves beneath the peroneus longus (Fig. 1.32). The superficial
peroneal nerve travels distally down the leg between the
peroneus and the extensor digitorum longus. In the proximal
two-thirds of the leg, it gives off its motor innervation to the
muscles of the lateral compartment. As the superficial pero-
neal nerve continues to the lateral compartment, it pierces the
fascia between the distal and the middle thirds. Here it bifur-
cates into medial and lateral branches that provide innerva-
tion to the skin of the lower leg and foot.
Fig. 1.29  The popliteal artery.

38
SECTION I
CHAPTER 1 • Comprehensive lower extremity anatomy
The deep peroneal nerve begins its course splitting from
the common peroneal nerve between the fibula and the proxi-
mal part of the peroneus longus. It crosses medially from the
lateral leg compartment to the deep aspect of the anterior
compartment. There, it travels down the leg in front of
the interosseous membrane, behind the extensor digitorum
longus. It descends to the ankle alongside the anterior tibial
artery and sends terminal branches into the foot joints and
first webspace.
Lower leg motor innervation
The motor innervation of the leg muscles follows a “one
compartment, one nerve” principle. The muscles of the ante-
rior compartment are innervated by the deep peroneal nerve;
the muscles of the lateral compartment are innervated by the
superficial peroneal nerve; and, the muscles of the posterior
compartment (both superficial and deep layers) are innervated
by the tibial nerve.
Lower leg cutaneous innervation
Cutaneous innervation of the leg is shared by branches of
the major mixed nerves of the lower extremity (femoral and
sciatic nerves) and the posterior cutaneous nerve of the thigh
(Figs. 1.19 & 1.20). The nerves that innervate the skin sur-
faces of the knee and leg are saphenous, posterior femoral
cutaneous, common peroneal, superficial peroneal, and sural
nerves.
The saphenous nerve branches from the femoral nerve in
the middle one-third of the thigh. It travels within the adduc-
tor canal, passing medially and underneath the sartorius, and
then heads superficially between the sartorius and the gracilis.
Here, the saphenous nerve pierces the fascia and enters the
subcutaneous space. As it descends inferiorly, it gives off an
infrapatellar branch that innervates the medial knee and
medial crural branches that supply the entire medial leg.
The posterior femoral cutaneous nerve, described in detail
earlier in the chapter, sends off multiple branches to the
posterior thigh and continues distally to innervate the poste-
rior knee where it also forms communicating branches with
the sural nerve.
The course of the common peroneal nerve in the proximal
leg has previously been discussed. As it curves lateral to the
fibula neck the common peroneal nerve gives off cutaneous
branches that innervate the lateral knee skin. Beneath the
peroneus longus muscle, the common peroneal nerve divides
into superficial and deep peroneal nerves (Fig. 1.32).
The superficial peroneal nerve is responsible for the cutane-
ous nerve supply for the middle one-third area of the antero-
lateral leg (Fig. 1.32). The superficial peroneal nerve cutaneous
innervation continues distally to the anterior ankle. Both the
superficial and the deep peroneal branches exit the ankle into
the foot to give dorsal cutaneous innervation. In the dorsal
foot, the deep peroneal nerve courses below the superior
extensor retinaculum, whereas the superficial peroneal nerve
passes above the retinaculum in the subcutaneous space. The
majority of the dorsal foot is innervated by the peroneal nerve,
and only the first webspace is innervated by the deep peroneal
nerve. The cutaneous innervation of the lateral side of the
dorsum of the foot is also provided by the sural nerve via the
lateral dorsal cutaneous branch.
Fig. 1.30  Posterior tibial and peroneal artery and tibial nerve.
Femoral artery
Tibial nerve
Soleus
Popliteus
Gastrocnemius
lateral head
Gastrocnemius
medial head
Adductor magnus tendon
Posterior tibial artery
Popliteal artery
Flexor digitorum longus
Tibialis posterior
Flexor hallucis longus
Calcaneal tendon
Flexor hallucis longus
Peroneus longus
Peroneus brevis
Peroneal artery
Peroneal artery
Communicating branch
Perforating branch

39
The leg
Fig. 1.31  Leg vasculature.
A
B
Femoral artery
Vastus medialis
Soleus
Gastrocnemius
Gastrocnemius
Gastrocnemius
perforators
Perforators from
peroneal artery
Perforators from
anterior tibial artery
Fasciocutaneous perforators
Anterior tibial/dorsal pedis perforators
Calcaneal branch of
peroneal artery
Calcaneal branch of
posterior tibial artery
Bifurcation of lateral
and medial
plantar artery
Anterior perforating branch of
peroneal artery
Adductor magnus tendon
Posterior tibial artery
Popliteal artery
Flexor digitorum longus
Extensor digitorum longus
Tibialis anterior
Tibialis posterior
Calcaneal tendon
Peroneus longus
Peroneus brevis
Peroneal artery
Saphenous artery
Descending genicular artery

40
SECTION I
CHAPTER 1 • Comprehensive lower extremity anatomy
Fig. 1.32  Common fibular (peroneal) nerve. (From: Netter; © Elsevier Inc. All rights reserved.)
Common fibular
(peroneal) nerve
(phantom)
Biceps femoris tendon
Common fibular (peroneal)
nerve (L4, 5; S1, 2)
Head of fibula
Fibularis (peroneus)
longus muscle (cut)
Superficial fibular
(peroneal) nerve
Branches of lateral
sural cutaneous nerve
Fibularis (peroneus)
longus muscle
Fibularis (peroneus)
brevis muscle
Medial dorsal cutaneous nerve
Intermediate dorsal
cutaneous nerve
Inferior extensor
retinaculum (partially cut)
Lateral dorsal cutaneous nerve
(branch of sural nerve)
Dorsal digital nerves
Lateral sural cutaneous nerve (phantom)
Articular branches
Recurrent articular nerve
Extensor digitorum longus muscle (cut)
Deep fibular (peroneal) nerve
Tibialis anterior muscle
Cutaneous innervation
Extensor digitorum
longus muscle
Extensor hallucis
longus muscle
Lateral sural
cutaneous nerve
Superficial fibular
(peroneal) nerve
Lateral branch of
deep fibular
(peroneal) nerve to
Extensor hallucis brevis
and
Extensor digitorum brevis
muscles
Medial branch of
deep fibular
(peroneal) nerve
Deep
fibular
(peroneal)
nerve
Sural nerve
via lateral dorsal
cutaneous branch
A
B

41
The ankle and foot
range of motion, including rotational and inversion–eversion
movements.
Foot
The tarsal bones are arranged in a proximal and distal row,
analogous to the carpal bones in the wrist. The talus and
calcaneus make up the proximal row in the foot, while the
medial, intermediate, and lateral cuneiforms and the cuboid
comprise the distal row. The navicular bone is interspersed
between the talus and the cuneiform. The bones of the toes
are very similar to the hand with the second through fifth toes
consisting of metatarsal, proximal, middle, and distal phalan-
ges. The first toe – similar to the thumb – does not contain a
middle phalanx (Fig. 1.33).
Ankle and foot fascial composition
The retinacula of the ankle are important structural elements
for maintaining normal function of the foot. They restrain
the tendons crossing the ankle, preventing bowstringing
and subluxation. Additionally, they keep the tendons closely
adapted to the bony structure of the ankle for maximum
stability. Three retinacula separate the musculotendinous
units crossing the ankle into groups: the extensor retinacula
on the dorsum of the foot, the flexor retinaculum on the
medial ankle, and the peroneal retinaculum on the lateral
ankle.
Extensor retinacula
Two retinacular bands restrain the dorsal tendons of the foot
and ankle – the superior and inferior extensor retinacula. This
retinacular system contains the tibialis anterior, extensor hal-
lucis longus, extensor digitorum longus, and peroneus tertius
(Table 1.4). The superior extensor retinaculum attaches to the
distal tibia and fibula just superior to the malleoli. The inferior
extensor retinaculum is a Y-shaped band inserting laterally on
the superior calcaneus and medially on the medial malleolus
and the plantar aponeurosis (Fig. 1.34).
The sural nerve system is an intercommunicating complex
of nerve branches that travel between the common peroneal
and the tibial nerves. There is a medial sural branch from the
tibial nerve that supplies the medial posterior portion of the
leg and a lateral sural nerve from the common peroneal nerve
that supplies the lateral posterior portion of the leg. The true
sural nerve is composed of several different possible inter-
communicating cutaneous branches of the leg. The branches
coalesce in the proximal leg and form the sural nerve. The
sural nerve pierces the deep fascia of the leg at the inferior
edge of the gastrocnemius head median raphe. It travels
down the leg in the subcutaneous space with the lesser saphe-
nous vein. It innervates the distal one-third of the posterolat-
eral leg.
The sural nerve is of specific clinical importance as it is
commonly harvested for use as a nerve graft. The distal sural
nerve is located approximately 1 cm posterior to the lateral
malleolus and has an intimate relationship with the short
saphenous vein.35 This superficial location, the relatively small
number of branches present, and the tolerable anesthetic
defect in the lateral lower leg and foot left after harvest make
the use of the sural nerve graft very appealing for nerve
reconstruction.
The ankle and foot
The ankle and foot region has significant functional responsi-
bility for ambulation and upright positioning. It is an area
of frequent concern in reconstructive surgery, as there is
only thin soft-tissue coverage over highly complex and
compact osteoligamentous structures. Adequate ambulation
and balance rely on a proper interplay between propriocep-
tion and sensation, musculotendinous performance, and bony
alignment. Proficient reconstruction of the ankle and foot
requires a focus on maintaining these essential anatomic
interactions.
Ankle and foot skeletal structure
There are 28 major bones in the human foot. The bony
arrangement produces an intricate system, reinforced by the
surrounding ligament system that supports the entire weight
of the body. The ankle is the region of transition from the leg
to the foot and orientation of bones and muscles from vertical
to horizontal.
Ankle
The ankle comprises two joints: (1) the ankle joint – the articu-
lation between the distal surfaces of the fibula (lateral malleo-
lus) and tibia (medial malleolus) to the superior aspect of the
talus; and (2) the subtalar joint – the articulation of the inferior
aspect of the talus to the superior aspect of the calcaneus and
four bones (lateral malleolus, medial malleolus, talus, and
calcaneus). Strong ligaments support this structure through-
out its multiplanar movement. The anterior and posterior
inferior tibiofibular ligaments, the interosseous ligament, and
the interosseous membrane act synergistically to stabilize the
joint. The ankle joint is a hinged synovial joint with plan-
tarflexion and dorsiflexion movements, but the addition of
the subtalar joint allows the ankle to have comprehensive
Table 1.4  Retinacular contents at the ankle
Extensor retinaculum
Anterior tibial vessels
Deep peroneal nerve
Tibialis anterior
Extensor hallucis longus
Extensor digitorum longus
Peroneus tertius
Flexor retinaculum
Tibialis posterior
Flexor digitorum longus
Posterior tibial vessels
Tibial nerve
Flexor hallucis longus
Peroneal retinaculum
Peroneus longus tendon
Peroneus brevis tendon

42
SECTION I
CHAPTER 1 • Comprehensive lower extremity anatomy
Fig. 1.33  Bones of the foot. (From: Netter; © Elsevier Inc. All rights reserved.)
Dorsal view
Calcaneus
Body
Fibular
(peroneal)
trochlea
Tarsal sinus
Transverse
tarsal joint
Cuboid
Metatarsal
bones
Phalanges
Proximal
Middle
Distal
Lateral tubercle
Medial tubercle
Trochlea
Neck
Head
Navicular
Tuberosity
Lateral
Intermediate
Medial
Tarsometatarsal joint
Base
Shaft (body)
Head
Base
Shaft (body)
Head
Base
Tuberosity
Plantar view
Talus
Calcaneus
Tuberosity
Medial process
Lateral process
Sustentaculum tali
Fibular (peroneal)
trochlea
Tuberosity
l
Tuberosity
of 5th
metatarsal
bone
Base
Shaft (body)
Head
Base
Shaft (body)
Head
Base
Head
Base
Tuberosity
Cuneiform bones
Transverse
tarsal joint
Navicular
Tuberosity
Lateral
Intermediate
Medial
Tarsometatarsal joint
Metatarsal bones
Sesamoid bones
Medial
Lateral
Phalanges
Proximal
Middle
Distal
Lateral
tubercle
Medial
tubercle
Posterior
process
Head
Talus
5
1
Cuneiform bones
2
3
4
5
4
3
2
1
Posterior
process
Cuboid
Tuberosity
of 5th
metatarsal
bone
Groove for
tendon of flexor
hallucis longus
Groove for
fibularis
(peroneus)
longus tendon
Groove for
tendon of
flexor hallucis
longus
Lateral view
Talus
Transverse tarsal joint
Navicular
Head
Neck
Trochlea
Lateral process
Posterior process
Intermediate
Lateral
Cuneiform bones
Tarsometatarsal joint
Metatarsal bones
Phalanges
Tarsal sinus
Calcaneus
Body
Tuberosity
Fibular
(peroneal)
trochlea
Cuboid
Tuberosity
Medial view
Transverse tarsal joint
Navicular
Tuberosity
Cuneiform bones
Intermediate
Tarsometatarsal joint
Metatarsal bones
Phalanges
Talus
Neck
Head
Trochlea
Sesamoid bone
Posterior
process
Tuberosity
Sustentaculum tali
Calcaneus
5
Medial
4
3
2
2
1
Groove for
fibularis
(peroneus)
longus tendon
Groove for fibularis
(peroneus) longus tendon
Tuberosity of
5th metatarsal bone
Tuberosity of
1st metatarsal bone
Groove for tendon of
flexor hallucis longus
A
B
C
D
Bones of Foot

43
The ankle and foot
Fig. 1.34  Muscles of the dorsum of the foot: superficial dissection. (From: Netter; © Elsevier Inc. All rights reserved.)
Superficial fibular (peroneal) nerve (cut)
Fibularis (peroneus) brevis muscle
Fibularis (peroneus) longus tendon
Extensor digitorum
longus muscle and tendon
Superior extensor retinaculum
Fibula
Perforating branch of
fibular (peroneal) artery
Lateral malleolus and anterior
lateral malleolar artery
Inferior extensor retinaculum
Lateral tarsal artery and lateral
branch of deep peroneal nerve
(to muscles of dorsum of foot)
Fibularis (peroneus) brevis tendon
Fibularis (peroneus) tertius tendon
Tuberosity of 5th metatarsal bone
Extensor digitorum brevis and
extensor hallucis brevis muscles
Extensor digitorum
longus tendons
Lateral dorsal cutaneous
nerve (continuation of
sural nerve) (cut)
Dorsal metatarsal arteries
Dorsal digital arteries
Dorsal branches of
proper plantar digital
arteries and nerves
Tibialis anterior tendon
Anterior tibial artery and
deep fibular (peroneal) nerve
Tibia
Extensor hallucis longus tendon
Tendinous sheath of
extensor digitorum longus
Medial malleolus
Tendinous sheath of
tibialis anterior
Tendinous sheath of
extensor hallucis longus
Anterior medial malleolar artery
Dorsalis pedis artery and medial branch
of deep fibular (peroneal) nerve
Medial tarsal artery
Arcuate artery
Deep plantar artery passing between
heads of 1st dorsal interosseous
muscle to join deep plantar arch
Extensor hallucis longus tendon
Extensor expansions
Dorsal digital branches of
deep fibular (peroneal) nerve
Dorsal digital branches
of superficial fibular
(peroneal) nerve

44
SECTION I
CHAPTER 1 • Comprehensive lower extremity anatomy
(Table 1.4). As the peroneal artery passes distally from the leg
to the foot, it exits from the deep region of the ankle to pass
superficially to the peroneal retinaculum and provides vascu-
lar supply to the calcaneal and lateral malleolar regions of the
ankle.
Plantar fascia
The plantar fascia (also called the plantar aponeurosis) is a
thick fibrous band that constrains the intrinsic structures of
the foot deeper to it and serves as the fixed base for the
densely adherent glabrous skin superficial to it. It is analogous
to the palmar fascia of the hand in providing a stable base for
overlying skin to resist shear forces and to facilitate ambula-
tion. In the multilayered sole of the foot, the plantar fascia is
the first defined structure beneath the subcutaneous fat.
Proximally, the plantar fascia is attached to the calcaneus and,
distally, it divides into five slips that are joined by transverse
fibers and then insert to the dermis beyond the metatarsal
heads via retinacula cutis skin ligaments (Fig. 1.36). It is joined
at a right angle, just distal to the metatarsal heads, by the
transverse metatarsal ligament. The plantar fascia is not
uniform in its consistency: it is strongest and thickest centrally
and thins laterally and distally.
Fascial compartments of the foot
The foot can be divided into several distinct fascial compart-
ments (Table 1.5). These divide the foot musculature into
distinct functional units. The plantar compartments include
the medial, central, lateral, and interosseous compartments.
The central compartment is further subdivided into adductor,
deep, and superficial compartments (Fig. 1.37). The interosse-
ous compartment is actually four separate spaces divided by
the metatarsals. There are several distinct fascial layers in the
dorsum of the foot, but this can effectively be thought of as a
single functional compartment.
Flexor retinaculum
The flexor retinaculum (also called the laciniate ligament) is
a medial ankle-located fascial band that restricts bowstringing
of the plantar-flexing tendons traveling from the leg to the
foot behind the medial malleolus (Fig. 1.35). The retinaculum
is attached to the medial malleolus and fans out to the
calcaneus and plantar aponeurosis. The flexor retinaculum
retains the tendons of the flexor digitorum longus, flexor hal-
lucis longus, and the tibialis posterior, the posterior tibial
vessels, and the tibial nerve (Table 1.4). The tendons are
usually located anteriorly and the neurovascular structures
posteriorly.
An osteoligamentous passageway is created superficially
by the flexor retinaculum and deeply by the talus and calca-
neus. This structure is also called the tarsal tunnel and is
analogous in many ways to the carpal tunnel of the hand.
Both tunnels contain flexor tendons and a mixed motor and
sensory nerve that gives supply to intrinsic muscles and the
glabrous skin of the distal extremity. There is very little elastic-
ity in the ligament roofs of both tunnels and none in the bony
floor. As the tarsal tunnel courses distally, it becomes septated
into medial and lateral tarsal tunnels, which contain the
medial and lateral plantar neurovascular structures.
Peroneal retinaculum
On the lateral aspect of the ankle, the tendons of the peroneus
longus and brevis are held in position by a dual-positioned
fascial band – the peroneal retinaculum. The superior peroneal
retinaculum extends from the posterior surface of the lateral
malleolus to the calcaneus. The inferior peroneal retinaculum
retains the tendons by attaching from the inferolateral surface
of the calcaneus and inserting on the superior surface of the
calcaneus
The peroneal retinaculum retains only two structures: the
peroneus longus tendon and the peroneus brevis tendon
Fig. 1.35  Fascial components of foot.
Synovial sheath of extensor hallucis longus
Extensor hoods
Superior extensor retinaculum
Inferior extensor retinaculum
Soleus
Posterior
tibial
artery
Tibial
nerve
Tibialis anterior tendon and sheath
Medial malleolus
Flexor digitorum longus
Calcaneal tendon
Flexor retinaculum
Abductor hallucis
Lateral plantar artery
Medial plantar artery

45
The ankle and foot
Fig. 1.36  Sole of the foot: superficial dissection. (From: Netter; © Elsevier Inc. All rights reserved.)
Superficial transverse
metatarsal ligaments
Proper plantar digital
arteries and nerves
Transverse fasciculi
Digital slips of
plantar aponeurosis
Medial plantar fascia
Cutaneous branches of medial
plantar artery and nerve
Plantar aponeurosis
Medial calcaneal branches of tibial
nerve and posterior tibial artery
Lateral plantar fascia
Cutaneous branches
of lateral plantar
artery and nerve
Lateral band of plantar aponeurosis
(calcaneometatarsal ligament)
Tuberosity of calcaneus
with overlying fat
pad (partially cut away)
Superficial branch of
medial plantar artery

46
SECTION I
CHAPTER 1 • Comprehensive lower extremity anatomy
Table 1.5  Fascial compartments of the foot
Plantar
  Medial compartment
Contains abductor hallucis and flexor
hallucis brevis
  Central compartment
Contains flexor digitorum brevis,
lumbricals, flexor accessorius, and
adductor hallucis
  Lateral compartment
Contains abductor digiti minimi and
flexor digit minimi brevis
  Interosseous
compartment
Contains the seven interossei
Dorsal compartment
Although several fascial layers in
dorsum, effectively there is one
dorsal compartment
Fig. 1.37  Muscles of the foot and ankle. (From:
Netter; © Elsevier Inc. All
rights reserved.)
Medial compartment
Superficial central compartment
(flexor digitorum brevis)
Deep central compartment (quadratus plantae)
Adductor compartment (adductor hallucis)
Lateral compartment
Four interosseus
compartments
(dorsal 4 plantar
interosseus muscles)
Flexor digiti
minimi brevis
Abductor digiti
minimi muscle
Flexor hallucis
brevis muscle
Abductor hallucis
muscle
Dorsal fasciotomy incisions
Medial fasciotomy
incisions
A
B
Similar to the leg, conditions that cause increased intra­
compartmental pressure can lead quickly to compartment
syndrome of the foot. Release of the surrounding fascial
attachments is essential to avoid tissue ischemia and necrosis.
Crush injuries, calcaneal fractures, and tarsometatarsal joint
dislocations are the most common causes for foot compart-
ment syndrome.
Foot musculature
The foot and ankle are acted upon by both extrinsic and
intrinsic musculature. The extrinsic muscles all originate from
proximal to the foot and have been described in the leg section.
The intrinsic muscles of the foot originate and insert within
the foot and act primarily on the toes. Their secondary func-
tion is to maintain postural balance through stabilization of
the osteocartilaginous architecture of the foot.
The plantar muscles of the foot can be thought of as orga-
nized by layers from sole of the foot progressing deep to the
bony structures (Table 1.6). The first layer consists of muscles
found just beneath the plantar aponeurosis – the flexor digi-
torum brevis, the abductor hallucis, and the abductor digiti
minimi (Fig. 1.38). These muscles extend from calcaneus to
toes and create a functional group that assists in maintaining
foot concavity. All three have been described as local pedicled
muscle flaps, and all have type I vascular supply. The flexor
digitorum brevis is supplied by branches of the posterior
tibial artery via the medial and lateral plantar arteries on its
proximal deep surface. The abductor hallucis is supplied by
a dominant pedicle on its deep surface and by a branch of the
medial plantar artery in the proximal foot. The abductor digiti
minimi muscle receives its dominant pedicle from a lateral
branch of the proximal lateral plantar artery.
The first layer for the plantar foot is separated from the
second layer by the tendons of the extrinsic muscles of the
flexor digitorum longus and the flexor hallucis longus. Also,
the medial and lateral plantar artery and nerve course in this
intermediary plane (Fig. 1.39). The second layer consists of
the quadratus plantae muscle and the lumbrical muscles
of the foot. The quadratus plantae is one of the few muscles
of the foot that does not have an analogous structure in the
hand. It has two heads extending from the medial and lateral
border of the calcaneus, inserts into the tendon of the flexor
digitorum longus, and aids in plantarflexion of the second to
fifth toes. The lumbricals of the foot mirror those of the hand
in their unique attribute of both originating and inserting on
tendons. These four muscles arise from the medial side of the
flexor digitorum longus and insert on the extensor system of
the second through fifth phalanges (Fig. 1.39). The foot lum-
bricals follow the same course as those of the hand and flex

47
The ankle and foot
posterior tibial artery, and the terminal branches of the pero-
neal artery.
Dorsalis pedis artery
The dorsalis pedis is a direct extension from the anterior tibial
artery and is the major vascular supply for the dorsum of the
foot. It passes from underneath the extensor retinaculum and
travels underneath the extensor digitorum brevis, passing
between the tendons of the extensor hallucis longus medially
and the extensor digitorum longus laterally. As it crosses over
the tarsus and continues over the space between the first and
the second metatarsal, it gives off a major terminal branch that
dives deep between the first intermetatarsal space and joins
the lateral plantar artery to complete the plantar arterial arch
(Fig. 1.40). This branching is significant because it provides
communication between the dorsal foot circulation, primarily
supplied by the dorsalis pedis, and the plantar circulation,
supplied by the posterior tibial artery (via the lateral and
medial plantar arteries). Another major terminal branch from
the dorsalis pedis is the first dorsal metatarsal artery that
courses distally and supplies the dorsal skin of the first
and second toes. In the mid-forefoot the dorsalis pedis
(and variably the first dorsal metatarsal artery) gives off
septocutaneous branches that supply the dorsal skin of the
medial two-thirds of the foot. This area of skin can be har-
vested with the dorsalis pedis artery as a fasciocutaneous
dorsalis pedis flap.
Posterior tibial artery – medial and lateral
plantar arteries
The posterior tibial artery runs beneath the flexor retinaculum
and splits into the medial and lateral plantar arteries as it
enters the sole of the foot in between the first and second
the metatarsophalangeal joints and extend the interphalangeal
joints.
The third layer consists of the flexor hallucis brevis, the
adductor hallucis, and flexor digiti minimi brevis (Fig. 1.39).
These form a small, deep intrinsic musculature that contrib-
utes in the maintenance of the longitudinal plantar arch and
participates in the stabilization of intrinsic foot osteoligamen-
tous intercalation and balance.
The fourth layer is the interosseous compartment that
contains both the plantar and the dorsal interossei. The three
plantar interosseous muscles adduct the toes. The four dorsal
interosseous muscles abduct the toes. The adduction–
abduction activity of the interossei is based through the axis
of the second toe, making this toe the least mobile at the
metatarsophalangeal joints. Tendons of the tibialis posterior
and the peroneus longus are considered part of the fourth
layer.
The dorsum of the foot contains two muscles – the extensor
digitorum brevis and extensor hallucis brevis (Fig. 1.34).
These muscles perform accessory toe extension function to the
extrinsic toe extensors. The loss of these muscles does not
significantly affect toe extension or impede ambulation. The
extensor digitorum brevis extends the second through fifth
toes while the extensor hallucis brevis extends the great toe.
The extensor digitorum brevis receives its blood supply from
the lateral tarsal artery, a branch off the dorsalis pedis. The
extensor digitorum brevis is a useful muscle flap for small
skin defects of the proximal foot and ankle. It can also be used
as joint interposition to prevent fusion in nearby tarsal joints
(e.g., calcaneonavicular bar).
Foot and ankle vasculature
The foot and ankle receive blood supply from three proximal
sources: the dorsalis pedis artery, the terminal branches of the
Table 1.6  Muscles of the foot
Plantar musculature
First layer
Abductor hallucis
Flexor digitorum brevis
Abductor digiti minimi
All three extend from calcaneus to toes and create a functional group that
assists in maintaining foot concavity
Second layer
Flexor digitorum accessorius
Lumbrical muscles
Injury to the motor supply branch for the tibial nerve to the lumbricals can cause
clawing of the toes
Third layer
Flexor hallucis brevis
Adductor hallucis
Flexor digiti minimi brevis
Highly interrelated musculature that contributes in the maintenance of the
longitudinal plantar arch
Fourth layer
(interosseous
compartment)
Dorsal interossei
Plantar interossei
The adduction–abduction activity of the interossei is based through the axis of
the second toe (dissimilar from the third finger in the hand). Therefore the
second toe is the least mobile of the metatarsophalangeal joints. Tendons of
the tibialis posterior and the peroneus longus are considered part of the
fourth layer
Dorsal musculature
Extensor digitorum brevis
Additional extensor of toes; if it or the extensor digitorum longus are cut, then
the toes still extend and do not impede ambulation. Useful muscle flap for
small skin defects and as joint interposition to prevent fusion (e.g.,
calcaneonavicular bar). Major vascular pedicle from dorsalis pedis perforator
and minor pedicle from peroneal artery perforator
Extensor hallucis brevis
Closely associated with the extensor digitorum brevis and sometimes
considered as variant slip of the extensor digitorum brevis

48
SECTION I
CHAPTER 1 • Comprehensive lower extremity anatomy
Fig. 1.38  Muscles of the sole of the foot: first layer. (From: Netter; © Elsevier Inc. All rights reserved.)
Proper plantar digital branches
of medial plantar nerve
Proper plantar digital branches
of lateral plantar nerve
Fibrous sheaths
of flexor tendons
Flexor digitorum brevis tendons
overlying
Flexor digitorum longus tendons
Plantar metatarsal branch of
lateral plantar artery
Flexor digiti minimi brevis muscle
Abductor digiti minimi muscle
(deep to lateral plantar fascia)
Proper plantar digital arteries
Common plantar digital arteries
from plantar metatarsal arteries
Lumbrical muscles
Superficial branch of
medial plantar artery
Lateral head
and
Medial head
of flexor hallucis
brevis muscle
Flexor hallucis longus tendon
Abductor hallucis muscle
and tendon
Flexor digitorum brevis muscle
Plantar aponeurosis (cut)
Medial calcaneal branches of tibial
nerve and posterior tibial artery
Medial process
and
Lateral process
of
Tuberosity
of calcaneus

49
The ankle and foot
Fig. 1.39  Muscles of the sole of the foot: second and third layers. (From: Netter; © Elsevier Inc. All rights reserved.)
Muscles of the Sole of the Foot: Second Layer
Proper plantar digital branches
of medial plantar nerve
Proper plantar digital branches
of lateral plantar nerve
Flexor digiti minimi
brevis muscle
Superficial branch
and
Deep branch
of lateral
plantar nerve
Lateral plantar nerve and artery
Quadratus plantae muscle
Abductor digiti minimi muscle (cut)
Nerve to abductor digiti minimi muscle
(from lateral plantar nerve)
Flexor digitorum brevis muscle
and plantar aponeurosis (cut)
Lateral calcaneal nerve and artery (from
sural nerve and fibular [peroneal] artery)
Flexor digitorum longus tendons
Flexor digitorum brevis tendons
Fibrous sheaths (opened)
Sesamoid bones
Common plantar digital
nerves and arteries
Lumbrical muscles
Lateral head
and
Medial head of
flexor hallucis brevis muscle
Flexor hallucis longus tendon
Abductor hallucis tendon
and muscle (cut)
Flexor digitorum longus tendon
Superficial and deep branches
of medial plantar artery
Medial plantar artery and nerve
Tibialis posterior tendon
Flexor hallucis longus tendon
Posterior tibial artery and
tibial nerve (dividing)
Flexor retinaculum
Abductor hallucis muscle (cut)
Tuberosity of calcaneus
Medial calcaneal artery and nerve
Muscles of the Sole of the Foot: Third Layer
Proper plantar digital branches of medial plantar nerve
Proper plantar digital branch
of superficial branch
of medial plantar artery
Anterior perforating arteries
to dorsal metatarsal arteries
Tendons of lumbrical muscles (cut)
Sesamoid bones
Transverse head
and
Oblique head of
adductor hallucis muscl e
Medial head
and
Lateral head of
flexor hallucis brevis muscle
Superficial branches of medial
plantar artery and nerve
Flexor hallucis longus tendon (cut)
Abductor hallucis muscle (cut)
Deep branches of medial
plantar artery and nerve
Flexor digitorum longus tendon (cut)
Tibialis posterior tendon
Medial plantar artery and nerve
Flexor hallucis longus tendon
Flexor retinaculum
Abductor hallucis muscle (cut)
Flexor digitorum brevis muscle
and plantar aponeurosis (cut)
Medial calcaneal artery and nerve
Flexor digitorum
longus tendons
Flexor digitorum
brevis tendons (cut)
Flexor digiti minimi
brevis muscle
Plantar metatarsal arteries
Plantar interosseous muscles
Superficial branch of
lateral plantar nerve
Deep plantar arterial arch and
deep branches of lateral plantar nerve
Tuberosity of 5th metatarsal bone
Peroneus brevis tendon
Peroneus longus tendon
and fibrous sheath
Quadratus plantae muscle
(cut and slightly retracted)
Lateral plantar artery and nerve
Abductor digiti minimi muscle (cut)
Lateral calcaneal artery and nerve
Tuberosity of calcaneus
Proper plantar digital branches
of lateral plantar nerve
A
B

50
SECTION I
CHAPTER 1 • Comprehensive lower extremity anatomy
Fig. 1.40  Anatomy of the foot: nerves. (From: Netter; © Elsevier Inc. All rights reserved.)
Dorsal view
Medial dorsal
cutaneous nerve
Supplies skin on
medial sides and
dorsum of foot and
adjacent sides of
2nd and 3rd toes
Anterior
tibial
artery
Posterior
tibial
artery
Posterior
tibial
artery
Anterior
and
posterior
medial
malleolar
arteries
Anterior
lateral
malleolar
arteries
Anterior
tibial
artery
Anterior and
posterior
medial
malleolar
arteries
Dorsalis
pedis
artery
Medial
tarsal
arteries
Arcuate
artery
Dorsal
metatarsal
arteries
Dorsal
digital
arteries
Proper
plantar
digital
arteries
Common plantar
digital arteries
Plantar
metatarsal
arteries
Plantar
arch
Lateral tarsal
arteries
Intermediate dorsal
cutaneous nerve
Supplies skin on lateral
side of dorsum of foot,
ankle, and adjacent
sides of 3rd, 4th and
5th toes
Deep peroneal
nerve Supplies
the muscles: tibialis
anterior, extensor
hallucis longus,
extensor digitorum
longus, and peroneus
tertius of the ankle joint
Sural nerve
Supplies
dorsal and
calcaneal
areas of
the skin of
the foot
Saphenous nerve
Supplies the skin on the
medial side of the foot,
and often the allucial
metatarsophalangeal
joint
Lateral plantar nerve
Sensitivity of skin of 5th
toe and lateral aspect
of the 4th one. Supplies
deep muscles of foot
Lateral dorsal
cutaneous nerve
(branch of the
sural nerve)
Superficial
peroneal
nerve
Tibial
nerve
Tibial
nerve
Saphenous
nerve
Superficial
and deep
peroneal
nerve
Sural
nerve
Lateral
dorsal
cutaneous
nerve
Plantar view
Medial plantar nerve
Sensitivity of skin of sole
of foot, both sides of 1st,
2nd, 3rd and medial toes,
and medial aspect of the
4th toe, as well as joints
of tarsus and metatarsus
of the related toes
A
B

51
Conclusion
may have an expanded contribution to the foot and ankle
vascular supply. A dominant peroneal artery is seen in
7–12% of the population. In up to 5%, the peroneal artery
may be the only blood supply to the foot, known as peronea
arteria magna.36,37 These variants stress the importance of
preoperative evaluation of the leg vasculature prior to fibula
harvest.
Ankle and foot nerve anatomy
Foot cutaneous innervation
The cutaneous innervation of the foot is shared by the super-
ficial peroneal, deep peroneal, saphenous, sural, and tibial
terminal branches (medial calcaneal, medial plantar, and
lateral plantar) (Fig. 1.40). As discussed above, the dorsum of
the foot is innervated mostly by the superficial peroneal nerve.
The first webspace is supplied by the deep peroneal nerve and
the lateral foot by the sural nerve. The saphenous nerve inner-
vates the proximal anteromedial foot and ankle. The cutaneous
sensation of the sole of the foot is primarily innervated by the
tibial nerve and its branches – medial calcaneal, medial plantar,
and lateral plantar (Fig. 1.27).
Foot motor innervation
The motor supply to the intrinsic muscle of the foot comes
from the same nerves as the cutaneous innervation and is
organized similarly. The dorsal muscles of the extensor hal-
lucis brevis and the extensor digitorum brevis are innervated
by the deep peroneal nerve. All the intrinsic muscles of the
plantar surface are innervated by the tibial nerve via the
medial and lateral plantar nerves.
The medial and lateral plantar nerves follow the course of
the corresponding medial and lateral plantar arteries. The
medial plantar nerve follows an innervation pattern similar
to the median nerve. The muscles to the great toe (abductor
hallucis, flexor digitorum brevis, flexor hallucis brevis, and
first lumbrical) and the medial plantar cutaneous region,
including the first through to the third toes, are supplied by
the medial plantar nerve. The lateral plantar nerve mirrors the
ulnar nerve as it innervates the deep muscles (interossei,
second through fourth lumbricals, adductor hallucis, flexor
digitorum brevis and flexor digitorum accessorius, and
abductor digiti minimi) and the lateral side of the plantar skin,
including the fourth and fifth toes.
Conclusion
The reconstructive surgeon may be called upon to treat spe-
cific tissue defects of the lower extremity, or to harvest tissue
for transfer from the many potential donor sites in the lower
extremity. Therefore an intricate understanding of the struc-
tural and functional anatomy of the lower extremity is essen-
tial. This chapter provides the reader with a comprehensive
review of the 3D anatomy of the lower extremity. With a
thorough anatomical foundation, the reconstructive options
discussed in the following chapters will be better appreciated.
It is our goal that this chapter serves as a valuable resource
for readers, of all experience levels, to facilitate operative
planning and clinical decision-making in reconstructive
surgery.
layers (Fig. 1.39). The bifurcation occurs under the abductor
hallucis muscle, and both the lateral and medial plantar arter-
ies arborize to give branches to the toes. The medial plantar
artery has a smaller caliber than the lateral plantar artery, runs
along the medial side of the foot, and contributes to the
plantar digital arteries of the first through third toes. The
lateral plantar artery is analogous to the ulnar artery in
the hand and similarly is the dominant blood supply for the
plantar arterial arch (Fig. 1.40). At the first intermetatarsal
space, a perforating branch from the dorsalis pedis traverses
the foot to the plantar surface and connects with the plantar
arterial arch via the lateral plantar artery. Together, the dorsalis
pedis branch and the lateral plantar arch feed the toes through
metatarsal branches. These branches join with branches from
the medial plantar artery to complete the connecting blood
supply to the toes.
Peroneal arterial branches
In the distal leg, the peroneal artery primarily contributes to
the ankle blood supply (Fig. 1.41). The terminal branches of
the peroneal artery join with the lateral malleolar and calca-
neal branches of the posterior tibial artery system at the
posterior ankle and heel. The peroneal artery usually termi-
nates at the level of the calcaneus. However, the size and
contribution of the peroneal arterial system is inversely pro-
portional to the other arteries of the ankle and foot. Depend-
ing on the size and perfusion from the posterior tibial and
anterior tibial arterial systems, the peroneal artery system
Fig. 1.41  The peroneal artery.

52
SECTION I
CHAPTER 1 • Comprehensive lower extremity anatomy
4. Ebraheim NA, Elgafy H, Xu R. Bone-graft harvesting from iliac and
fibular donor sites: techniques and complications. J Am Acad Orthop
Surg. 2001;9(3):210–218.
6. Mathes SJ, Nahai F. Classification of the vascular anatomy of
muscles: experimental and clinical correlation. Plast Reconstr Surg.
1981;67(2):177–187. This landmark article, one of the most cited in the
reconstructive surgery literature, first proposed a classification system for
flaps based on the vascular anatomy of muscles. This classification system
is used ubiquitously in reconstructive surgery and knowledge of the
vascular pattern of each muscle facilitates the choice and design of flaps
throughout the body.
8. Rozen WM, Ting JW, Grinsell D, Ashton MW. Superior and inferior
gluteal artery perforators: in-vivo anatomical study and planning
for breast reconstruction. J Plast Reconstr Aesthet Surg.
2011;64(2):217–225.
13. Yamamoto H, Jones DB Jr, Moran SL, et al. The arterial anatomy of
the medial femoral condyle and its clinical implications. J Hand
Surg [Eur]. 2010;35(7):569–574. An excellent overview of the arterial
anatomy of the medial femoral condyle region, including intraosseous and
extraosseous vascular anatomy, is provided in this article. This study
demonstrates the reliability and usefulness of the medial femoral condyle
as a source for vascularized periosteal and bone grafts.
15. Buckland A, Pan WR, Dhar S, et al. Neurovascular anatomy of
sartorius muscle flaps: implications for local transposition and facial
reanimation. Plast Reconstr Surg. 2009;123(1):44–54. This article, from
Dr. G. Ian Taylor’s lab, describes the neural and vascular anatomy of the
sartorius muscle, with particular emphasis on the supply for local,
regional and free tissue transfer. It provides exquisite illustrations and
objective data, from cadaveric dissections, regarding the neurovascular
anatomy of the sartorius muscle and is an essential article for any
reconstructive surgeon operating in the lower extremity.
16. Mojallal A, Wong C, Shipkov C, et al. Redefining the vascular
anatomy and clinical applications of the sartorius muscle and
myocutaneous flap. Plast Reconstr Surg. 2011;127(5):1946–1957.
20. Lakhiani C, Lee MR, Saint-Cyr M. Vascular anatomy of the
anterolateral thigh flap: a systematic review. Plast Reconstr Surg.
2012;130(6):1254–1268.
21. Wong CH, Wei FC, Fu B, et al. Alternative vascular pedicle of the
anterolateral thigh flap: the oblique branch of the lateral circumflex
femoral artery. Plast Reconstr Surg. 2009;123(2):571–577. This article,
derived from the extensive experience at Chang Gung Memorial Hospital
with anterolateral thigh flap harvest and transfer, further clarifies the
vascular anatomy of the anterolateral thigh region and proposes the
existence, in a proportion of patients, of an oblique branch of the lateral
circumflex femoral artery. The reliability of harvesting an anterolateral
thigh flap using the oblique branch as the vascular pedicle and the clinical
implications of the presence of this oblique branch are detailed in this
study.
30. Iorio ML, Cheerharan M, Olding M. A systematic review and
pooled analysis of peroneal artery perforators for fibula
osteocutaneous and perforator flaps. Plast Reconstr Surg.
2012;130(3):600–607. This article represents a significant contribution to
the literature by conclusively demonstrating the optimal design for fibular
osteocutaneous and perforator flaps based on the distribution of the
peroneal artery perforators. This systematic review and pooled analysis
comprehensively analyzes the existing literature, including clinical and
cadaveric reports, to provide the most up-to-date data to guide
reconstructive surgeons in the design and harvest of osteocutaneous and
perforator flaps along the lateral lower leg.
36. Rosson GD, Singh NK. Devascularizing complications of free fibula
harvest: peronea arteria magna. J Reconstr Microsurg.
2005;21(8):533–538.
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reconstructive surgery literature, first proposed a classification system for
flaps based on the vascular anatomy of muscles. This classification system
is used ubiquitously in reconstructive surgery, and knowledge of the
vascular pattern of each muscle facilitates the choice and design of flaps
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2011;64(2):217–225.
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vascular anatomy and clinical implications. Plast Reconstr Surg.
2009;124(5):1529–1544.
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13. Yamamoto H, Jones DB Jr, Moran SL, et al. The arterial anatomy of
the medial femoral condyle and its clinical implications. J Hand
Surg [Eur]. 2010;35(7):569–574. An excellent overview of the arterial
anatomy of the medial femoral condyle region, including intraosseous and
extraosseous vascular anatomy, is provided in this article. This study
demonstrates the reliability and usefulness of the medial femoral condyle
as a source for vascularized periosteal and bone grafts.
14. Iorio ML, Masden DL, Higgins JP. The limits of medial femoral
condyle corticoperiosteal flaps. J Hand Surg Am.
2011;36(10):1592–1596.
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sartorius muscle flaps: implications for local transposition and facial
reanimation. Plast Reconstr Surg. 2009;123(1):44–54. This article, from
Dr. G. Ian Taylor’s lab, describes the neural and vascular anatomy of the
sartorius muscle, with particular emphasis on the supply for local,
regional and free tissue transfer. It provides exquisite illustrations and
objective data, from cadaveric dissections, regarding the neurovascular
anatomy of the sartorius muscle and is an essential article for any
reconstructive surgeon operating in the lower extremity.
16. Mojallal A, Wong C, Shipkov C, et al. Redefining the vascular
anatomy and clinical applications of the sartorius muscle and
myocutaneous flap. Plast Reconstr Surg. 2011;127(5):1946–1957.
17. Daigeler A, Dodic T, Awiszus F, et al. Donor-site morbidity of the
pedicled rectus femoris muscle flap. Plast Reconstr Surg.
2005;115(3):786–792.
18. Fattah AY, Ravichandiran K, Zuker RM, Agur AM. A three-
dimensional study of the musculotendinous and neurovascular
architecture of the gracilis muscle: application to functional
muscle transfer. J Plast Reconstr Aesthet Surg. 2013;66(9):
1230–1237.
19. Morris SF, Yang D. Gracilis muscle: arterial and neural basis for
subdivision. Ann Plast Surg. 1999;42(6):630–633.
20. Lakhiani C, Lee MR, Saint-Cyr M. Vascular anatomy of the
anterolateral thigh flap: a systematic review. Plast Reconstr Surg.
2012;130(6):1254–1268.
21. Wong CH, Wei FC, Fu B, et al. Alternative vascular pedicle of the
anterolateral thigh flap: the oblique branch of the lateral circumflex
femoral artery. Plast Reconstr Surg. 2009;123(2):571–577. This article,
derived from the extensive experience at Chang Gung Memorial Hospital
with anterolateral thigh flap harvest and transfer, further clarifies the
vascular anatomy of the anterolateral thigh region and proposes the
existence, in a proportion of patients, of an oblique branch of the lateral
circumflex femoral artery. The reliability of harvesting an anterolateral
thigh flap using the oblique branch as the vascular pedicle and the clinical
implications of the presence of this oblique branch are detailed in this
study.
22. Wong CH, Ong YS, Wei FC. Revisiting vascular supply of the rectus
femoris and its relevance in the harvest of the anterolateral thigh
flap. Ann Plast Surg. 2013;71(5):586–590.
23. Adler N, Dorafshar AH, Agarwal JP, Gottlieb LJ. Harvesting the
lateral femoral circumflex chimera free flap: guidelines for
elevation. Plast Reconstr Surg. 2009;123(3):918–925.
24. Zhou G, Qiao Q, Chen GY, et al. Clinical experience and surgical
anatomy of 32 free anterolateral thigh flap transplantations. Br J
Plast Surg. 1991;44(2):91–96.
25. Pribaz JJ, Orgill DP, Epstein MD, et al. Anterolateral thigh free flap.
Ann Plast Surg. 1995;34(6):585–592.
26. Yu P, Selber J, Liu J. Reciprocal dominance of the anterolateral and
anteromedial thigh flap perforator anatomy. Ann Plast Surg.
2013;70(6):714–716.
27. Kaufer H. Mechanical function of the patella. J Bone Joint Surg Am.
1971;53(8):1551–1560.
28. Hallock GG, Anous MM, Sheridan BC. The surgical anatomy of the
principal nutrient vessel of the tibia. Plast Reconstr Surg.
1993;92(1):49–54.
29. Guo F. Observations of the blood supply to the fibula. Arch Orthop
Trauma Surg. 1981;98(2):147–151.
30. Iorio ML, Cheerharan M, Olding M. A systematic review and
pooled analysis of peroneal artery perforators for fibula
osteocutaneous and perforator flaps. Plast Reconstr Surg.
2012;130(3):600–607. This article represents a significant contribution to
the literature by conclusively demonstrating the optimal design for fibular
osteocutaneous and perforator flaps based on the distribution of the
peroneal artery perforators. This systematic review and pooled analysis
comprehensively analyzes the existing literature, including clinical and
cadaveric reports, to provide the most up-to-date data to guide
reconstructive surgeons in the design and harvest of osteocutaneous and
perforator flaps along the lateral lower leg.
31. Yu P, Chang EI, Hanasono MM. Design of a reliable skin paddle for
the fibula osteocutaneous flap: perforator anatomy revisited. Plast
Reconstr Surg. 2011;128(2):440–446.
32. Mauser N, Gissel H, Henderson C, et al. Acute lower-leg
compartment syndrome. Orthopedics. 2013;36(8):619–624.
33. Driessen A, Balke M, Offerhaus C, et al. The fabella syndrome – a
rare cause of posterolateral knee pain: a review of the literature and
two case reports. BMC Musculoskelet Disord. 2014;15:100.
34. Simpson SL, Hertzog MS, Barja RH. The plantaris tendon graft: an
ultrasound study. J Hand Surg Am. 1991;16(4):708–711.
35. Riedl O, Frey M. Anatomy of the sural nerve: cadaver study and
literature review. Plast Reconstr Surg. 2013;131(4):802–810.
36. Rosson GD, Singh NK. Devascularizing complications of free fibula
harvest: peronea arteria magna. J Reconstr Microsurg.
2005;21(8):533–538.
37. Lohan DG, Tomasian A, Krishnam M, et al. MR angiography of
lower extremities at 3 T: presurgical planning of fibular free flap
transfer for facial reconstruction. AJR Am J Roentgenol.
2008;190(3):770–776.

SECTION I • Lower Extremity Surgery
2 
Management of lower extremity trauma
Yoo Joon Sur, Shannon M. Colohan, and Michel Saint-Cyr
SYNOPSIS
■ Lower extremity trauma is common and often associated with other
injuries.
■ An Advanced Trauma Life Support (ATLS) approach is required in
order to evaluate properly a patient with lower extremity injuries.
■ Initial management includes fracture reduction to reduce bleeding, and
appropriate radiologic investigations.
■ External fixation is useful in the temporization of complex fractures
until definitive fixation can be achieved.
■ Evidence-based practice with regard to antibiotics, anticoagulation, and
timing of reconstruction is recommended.
■ A multidisciplinary approach is required in the acute and rehabilitative
phases of a patient with lower extremity trauma.
Access the Historical Perspective section online at

Introduction
Major injuries are a significant cause of death and disability
worldwide. Injuries are among the leading causes of death in
the USA, with unintentional injuries as the fourth leading
cause of death in all ages.1 During the years 1999–2013 unin-
tentional injuries were the leading cause of death for those
aged 1–44 years, and the third leading cause of death in those
aged 45–54 years.2 In the most recent National Vital Statistics
Report (2010), motor vehicle collisions (MVCs) were respon-
sible for 18.6% of injury-related deaths.3 The World Health
Organization ranked MVCs as the ninth leading cause of
disability-adjusted life years and predicted an increase in
ranking to seventh by 2030.4 According to the National Trauma
Bank’s Annual Report (2014),5 the greatest number of incidents
occur between the ages of 25 and 34 years, with a case-fatality
rate of 3.76. The highest case-fatality rate occurred in those
>85 years of age (8.69). Males have a higher case fatality rate
beyond age 15.
The majority of our trauma systems were designed follow-
ing experience gained in military combats. These have been
further modified and improved with the development of
standardized trauma protocols, such as those published by
ATLS, and the establishment of scoring systems such as the
Glasgow Coma Scale (GCS), Injury Severity Scale (ISS), and
Trauma and Injury Severity Score (TRISS). Furthermore,
scoring systems specific to lower extremity trauma have been
developed and include the Mangled Extremity Severity Score
(MESS), Limb Salvage Index (LSI), Predictive Salvage Index
(PSI), the Hanover Fracture Scale-97 (HFS-97), and the Nerve
Injury, Ischemia, Soft-tissue Injury, Skeletal Injury, Shock, and
Age of patient score (NISSSA).
The management of a patient with lower extremity trauma
involves a multidisciplinary approach. Following the initial
provision of emergent trauma care and evaluation by general,
vascular, and orthopedic surgery colleagues, the plastic
surgeon is often involved in the management of extremity
coverage and reconstruction of both salvaged and amputated
limbs. This is often done in conjunction with orthopedics, thus
emphasizing Levin’s concept of the “orthoplastic approach”.6
The current literature is constantly evolving to reflect changes
in practice regarding the criteria for limb salvage, timing of
reconstruction, and appropriate supportive and adjunctive
patient care.
Basic science and disease process
The body’s response to trauma is a complex orchestration
of inflammatory and immune responses. There is interplay
between those mediators produced at the site of injury (e.g.,
cytokines, growth factors, nitric oxide, and platelet-activating
factors) and the activation of local and systemic polymor-
phonuclear neutrophils, lymphocytes, and macrophages.16
The changes in hemodynamics and immune and metabolic
  Access video and video lecture content for this chapter online at expertconsult.com

53.e1
Historical perspective
Historical perspective
The evolution of surgical management of the lower extremity
trauma spans centuries, and during the past century has been
significantly influenced by military combat.
In the ancient era, compound fractures were considered a
fatal injury and not treated.7 This was prior to the advent of
amputation. It was not until the time of Hippocrates (460–370
BC) that amputation was first mentioned; Hippocrates sug-
gested the use of amputation as a “last resort” in the treatment
of ischemic gangrene.8 In this circumstance, he recommended
that one could “complete” the amputation already underway
by cutting through the necrotic region to minimize the risk of
hemorrhage and patient discomfort.8
Aurelius Cornelius Celsus (25 BC–50 AD) was the first to
address important principles in wound care, including clean-
ing wounds of extraneous material and properly placing
sutures to relieve tension.7 He recommended amputation
through viable tissue, and proper shaping of the stump, as
well as the use of the “hemostasis ligature”. In the early first
century AD, hemostasis was achieved through ligation as well
as through cauterization using hot irons or boiling oil.
The advent of war brought with it significant advances in
the management of wounds and traumatic injuries. Warfare
incorporated the use of gunpowder in 1338, and this changed
the nature and severity of wounds requiring medical atten-
tion.7 Gunpowder was thought to be poisonous, and many
attempts to extract it were made, including the use of setons,
oil-moistened lint plugs, and manual extraction of shot or
bone splinters.9
It was perhaps the work of Ambroise Paré (1509–90) that
modernized trauma surgery and wound care. His initial
enthusiasm for cauterization was abandoned when his remedy
“olye of Elders scalding hot” became unavailable, and he was
forced to use an alternative dressing, consisting of egg yolk,
rose oil, and turpentine, with better results.10 He reserved
amputation for gangrenous extremities, but, when required,
he paid careful attention to the ligation of large blood vessels
(following a brief period of permissive bleeding to reduce
inflammation), cutting the bone shorter to allow good mus-
cular coverage of the stump, and the use of large sutures.10 He
was the first to take care to create a stump amenable to pros-
thetic fitting (e.g., cutting the tibia five finger-breadths below
the knee). He was also involved in the production of several
extremity prostheses, as well as the design of a ligation clamp
named the crow’s beak (bec de corbin).
It was during the 17th and 18th centuries that the concept
of primary and secondary amputation of a traumatic limb
came to fruition. This coincided with published work by John
Hunter that demonstrated a better understanding of physiol-
ogy and disease processes such as shock, phlebitis, and
pyemia.11 Hunter documented conditions for primary ampu-
tation that included massive crush injury, partial amputation,
and uncontrolled bleeding. The relevance of wound necrosis
and the importance of debridement were established by
Pierre-Joseph Desault in the late 18th century.7 One of his
trainees, Dominique-Jean Larrey (1766–1842), went on to
become Napoleon’s chief surgeon, and further contributed to
the development of trauma surgery. It was Larrey who pushed
for early (primary) amputation as he observed that the first
24 h were the only “hours of calm that nature would allow”.12
With this in mind, it was Larrey who formed the “flying
ambulance” corps of the French army, promoting the prompt
evacuation of wounded soldiers.
Over the next few centuries, several medical advances
improved the care of the traumatized lower extremity. Firstly,
the advent of anesthesia (ether (1846) and chloroform (1847))
allowed the surgeon to focus more on technique rather than
on speed. This also allowed for fewer surgical assistants, who
had previously been required to hold the patient and stabilize
the limb during surgery. Secondly, with the advent of antisep-
sis and microbiology, surgeons became aware of the concept
of infection. Joseph Lister (1827–1912) proposed the treatment
of compound fractures using occlusive dressings soaked in
carbolic acid.13,14 Initially, many surgeons failed to adopt
Lister’s principles in their approach. However, the Germans
were the exception and later went on to develop steam ster-
ilization, facemasks, and sterile operating gowns.7
With the onset of the 20th century, warfare gradually
became modernized as experience was gained in the Civil
War, followed by WWI and II. With advances in ballistics,
once again the nature of injury evolved and produced mutila-
tion that had not previously been encountered. The medical
field responded with advances in bacteriology (i.e., the dis-
covery of sulfa antibiotics and, later on, penicillin), radiology,
and the establishment of acute surgical management and
resuscitation protocols that included early debridement and
volume repletion with saline and blood. The role of amputa-
tion was also further debated, with the abandonment of
prophylactic limb amputation in cases of compound fractures.7
It was through wars that the specialty of plastic surgery
gained greater acceptance, as there was a need for the recon-
struction of combat injuries.15 Prior to the world wars, recon-
struction was primarily aimed at the reconstruction of facial
defects. Work by surgical pioneers Sir Harold Gillies and
Vilray Blair during WWI popularized the use of tube flaps and
delayed flap transfer.15 Similarly, advances in orthopedic
surgery made by Sir Robert Jones and Hugh Thomas popular-
ized their now commonly used splints in the stabilization of
lower extremity fractures. In addition, Jones was instrumental
in the training of over 400 orthopedic surgeons and the estab-
lishment of rehabilitation medicine.7

54
SECTION I
CHAPTER 2 • Management of lower extremity trauma
Table 2.1  Glasgow coma scale
Eye
opening
Spontaneously
4
To speech
3
To pain
2
None
1
Verbal
response
Oriented
5
Confused
4
Inappropriate
3
Incomprehensible
2
None
1
None – intubated
1T
Motor
response
Obeys commands
6
Localizes to pain
5
Withdraws from pain
4
Flexion to pain (decorticate)
3
Extension to pain (decerebrate)
2
None
1
Maximum
score
15
Minimum
score
3
(3T if intubated)
responses following trauma are largely due to the effects of
cytokines. Cytokines act through specific cellular receptors
and activate intracellular signaling pathways that regulate
gene transcription.
The amplitude of the inflammatory response is often
related to the severity of the injury. In addition to the initial
response to the trauma, a secondary response, or secondary
hit phenomenon, occurs with further interventions, including
surgical management of fractures and reconstruction.17–19
There has been increasing focus on methods of avoiding or
decreasing the effect of this second hit.
Those patients who succumb to their injury in the third
peak of the trimodal distribution (days to weeks postinjury)
may be victims of a hyperactive inflammatory response that
leads to systemic inflammatory response syndrome, acute
respiratory distress syndrome, and, ultimately, multiple-organ
failure syndrome.20
Diagnosis and patient presentation
Lower extremity trauma is often seen in the setting of poly-
trauma, emphasizing the need to follow protocols during
the assessment and management of these patients. Vigilance
to rule out other injuries is important, as complex lower-
extremity injuries can be a significant form of distracting
injury. Death due to trauma is often described as having a
trimodal distribution.20 Immediate death is attributed to
central nervous system etiologies, including severe brain
injury and high spinal cord injury, or major vessel/cardiac
injury. Salvage of these patients is rare, emphasizing the need
for prevention of such injuries. The second peak occurs within
minutes to hours, and deaths are comprised of subdural/
epidural hematomas, hemopneumothorax, intra-abdominal
major-organ lacerations, pelvic fracture, and hemorrhage
from multiple combined injuries. Finally, the third peak occurs
within days to weeks and is due to sepsis or multiple-organ
failure, pulmonary embolism, and unrecoverable head injury.
The assessment of the patient with lower extremity trauma
starts with triage, to insure that the patient is treated in the
appropriate facility capable of managing the injuries. The
ultimate goal is to provide timely care (in the “golden hour”)
to minimize secondary injury. In patients presenting with
lower extremity injuries, associated life-threatening injuries
may be present in 10–17%.21 It is therefore paramount to use
a protocol-based assessment of the patient such as the ATLS
algorithm. Beginning with the primary survey, the airway is
maintained or secured while providing cervical spine control,
followed by assessment of breathing. Once this is complete, a
circulatory exam is carried out, ensuring proper end-organ
perfusion and peripheral circulation, as well as control of
bleeding. The appropriate monitors are placed, two large-bore
intravenous lines are inserted for fluid resuscitation, and a
Foley catheter is inserted once a proper rectal/genitourinary
screening exam is complete. Any areas of obvious hemor-
rhage are compressed, and splints or pelvic binders are placed
to stabilize orthopedic injuries. Following this, a screening
neurological exam is performed to assess the patient’s level
of consciousness (Table 2.1), cranial nerve function, lateraliz-
ing signs, and peripheral nerve function including documen-
tation of motor/sensory levels. If it can be safely done, the
neurological exam is especially important to perform prior to
analgesia, sedating medications, or intubation. Finally, head-
to-toe examination of the patient is done in a manner that
exposes the patient while preventing hypothermia. Once the
primary survey is complete, a secondary survey is carried out,
and appropriate radiologic and laboratory investigations are
ordered. These may include, but are not limited to, cervical
spine, chest, and pelvic X-rays; diagnostic peritoneal lavage,
or Focused Assessment with Sonography for Trauma (FAST);
computed tomography (CT) scan or angiography; specific
extremity X-rays; and laboratory tests including hematologic
and chemistry profiles, arterial blood gas, cross-match, and
toxicology screen.
Concerning lower extremity injuries, it is not only impor-
tant to assess the injury itself, but also to be aware of its
possible complications, such as significant bleeding or fat
embolism from long bone injuries, rhabdomyolysis from
crush injury, and acute compartment syndrome. In the initial
management of these injuries, splinting helps to control blood
loss and reduce pain. During the secondary survey, an appro-
priate history-taking helps determine the mechanism of injury
and anticipated degree of injury. The physical examination of
the lower extremity includes examination of the skin, neuro-
logical status, circulatory status, and skeletal or ligamentous
injury. The degree of soft-tissue damage and contamination is
important, as these patients will often require prophylactic
broad-spectrum antibiotic coverage and tetanus immuniza-
tion if not up to date (Table 2.2). Neurological examination

55
Patient selection
Table 2.2  Tetanus prophylaxis immunization schedule
History of tetanus immunization
Tetanus-prone wound
Non-tetanus-prone wound
TD
TIG
TD
TIG
Unknown or <3 doses
Yes
Yes
Yes
No
≥3 doses
No*
No
No†
No
TD, tetanus/diphtheria vaccine; TIG, tetanus immune globulin.
*Yes, if >5 years since last booster. †Yes, if >10 years since last booster.
Table 2.3  Classification of lower extremity injury
System
Grade
Details
Gustilo
I
Wound <1 cm
Simple fracture, no comminution
II
Wound >1 cm
Minimal soft-tissue damage
Moderate comminution/contamination
III
Extensive soft-tissue damage, comminuted fracture, unstable
IIIA
Adequate soft-tissue coverage
IIIB
Extensive soft-tissue loss with periosteal stripping and exposed bone
IIIC
Arterial injury requiring repair
System
Type
Byrd
I
Wound <2 cm
Low-energy causing spiral or oblique fracture pattern
II
Wound >2 cm, contusion of skin/muscle
Moderate-energy force causing comminuted or displaced fracture
III
Extensive skin loss and devitalized muscle
High-energy force causing significantly displaced fracture with severe comminution, segmental fracture,
or bone defect
IV
Degloving or associated vascular injury requiring repair
Extensive energy forces with type III fracture pattern
should include motor/sensory function and deep tendon
reflexes. Assessment of posterior tibial nerve function can
be particularly important in guiding decisions regarding
limb salvage. Any circulatory compromise suggests possible
arterial injury. Initial management should include fracture
reduction, and, if pulses are still not restored, appropriate
angiographic studies should be sought along with consulta-
tion of an orthopedic or vascular surgery colleague. Vascular
injury should be suspected in cases of active hemorrhage,
expanding or pulsatile hematoma, thrill/bruit over wound,
absent distal pulses, or distal ischemic manifestations (the five
“Ps”: pain, pallor, paralysis, paresthesia, and poikilothermy).22
Ischemic time should be estimated for any amputated or
vascular-compromised segments. X-rays should be obtained
of all areas of suspected injury, including the joint above and
below the injury site.
Several grading systems exist to classify lower extremity
trauma. The systems most commonly used are the Gustilo
and the Byrd systems, in which tibial fractures are classi-
fied based on the size of the wound, amount of soft-tissue
injury, degree of bony injury, and presence of vascular injury
(Table 2.3).23,24
Patient selection
When managing the patient with complex lower extremity
trauma, it is important to recognize that futile attempts at limb
salvage may be associated with physical, mental, social, and
financial implications.25 Despite advances in microsurgical
reconstruction, bony regeneration, and infection control,
many patients undergo a number of surgeries only to have
eventual amputation. It is important to identify such patients
at the outset and provide them with the best option that
maximizes function and recovery.
Amputation versus salvage
The establishment of the MESS by Johansen et al. in 1990 was
the first effort to produce a set of guidelines that would help
a physician to decide between salvage and amputation.26 This
score relied on four criteria: (1) skeletal/soft-tissue injury; (2)
limb ischemia; (3) shock; and (4) patient age (Table 2.4). A
score of 7 or greater was used as the cutoff point in favor of
amputation. Unfortunately, even with this tool there was still

56
SECTION I
CHAPTER 2 • Management of lower extremity trauma
debate over definitive criteria for amputation, and this led to
the recent multicenter study entitled the Lower Extremity
Assessment Project (LEAP), carried out at eight level I trauma
centers in the USA.27 This study looked prospectively at
patients with traumatic amputations below the distal femur,
Gustilo grade III (A–C) open tibia fractures, devascular inju-
ries below the distal femur, major soft-tissue injuries below
the distal femur excluding the foot, open pilon fractures
(grade III), open ankle fractures (grade IIIB), and severe open
hindfoot and midfoot injuries with degloving and nerve
injury. The goal of the study was to define the characteristics
of the individuals sustaining lower extremity trauma. A total
of 601 patients were enrolled, and the patient demographics
were primarily male (77%), Caucasian (72%), and young
(71% between 20 and 45 years old). The results demonstrated
that the patients who sustained a high degree of extremity
trauma had several disadvantages prior to their injury (social,
economic, and personality), and that quality of life and func-
tional outcome data seemed more related to these than to the
injury.
A subset of the LEAP studies assessed several available
clinical decision-making scores relating to injury severity,28
which included MESS, LSI, PSI, NISSSA, and HFS-97. When
applying these scores to the open tibial fracture group, MESS,
PSI, and LSI demonstrated high specificity (91%, 87%, and
97%, respectively) but low sensitivity (46%, each). Specificity
is important to insure that a minimal number of salvageable
limbs are incorrectly assigned to amputation, and sensitivity
Table 2.4  Mangled extremity severity score (MESS) criteria
Variable
Points
A
Skeletal/soft-tissue injury
Low-energy (stab, simple fracture, civilian
gunshot wound)
1
Medium-energy (open/multiple fractures,
dislocation)
2
High-energy (close-range shotgun, military
gunshot wound, crush)
3
Very-high-energy (above + gross contamination)
4
B
Limb ischemia*
Pulse reduced or absent; perfusion normal
1
Pulseless, paresthesias, diminished capillary refill
2
Cool, paralyzed, insensate, numb
3
C
Shock
Systolic blood pressure always >90 mmHg
1
Transient hypotension
2
Persistent hypotension
3
D
Age
<30 years
1
30–50 years
2
>50 years
3
Maximum score possible
16
Threshold score for amputation
7
*Score doubled for ischemia time >6 h.
is important to guard against delay in amputation for limbs
that are not salvageable. Discrimination was moderately good
in assessing salvage versus amputation of the limb. Overall,
the analysis did not validate the clinical utility of any of the
lower extremity injury severity scores, and advised for their
cautious application when making decisions regarding limb
salvage. Additionally, these scores are not predictive of func-
tional recovery in patients who undergo successful limb
reconstruction, as shown by Ly et al.29
Unfortunately, despite a number of studies, there are still
no definite criteria for amputation. Several proposed criteria
have since been refuted following proper outcome studies.
For example, it is a widely held belief that tibial nerve injury
or absence of plantar foot sensation is an indication for ampu-
tation. However, a study by Bosse et al.,30 examining functional
outcomes of patients with severe lower extremity injuries,
found that more than half of the patients who initially pre-
sented with an insensate foot that underwent salvage regained
sensation by 2 years. The authors concluded that initial plantar
sensation was not prognostic of long-term plantar sensation
status or functional outcome, and that this should therefore
not be a criterion in limb salvage algorithms.
Risk factors that may contribute to or predict the need for
amputation include:22
■ Gustilo grade IIIC tibial injuries
■ Sciatic or tibial nerve injury
■ Prolonged ischemia (>4–6 h)/muscle necrosis
■ Crush or destructive soft-tissue injury
■ Significant wound contamination
■ Multiple/severely comminuted fractures; segmental bone
loss
■ Old age or severe comorbidity
■ Apparent futility of revascularization or failed
revascularization.
In addition to these risk factors, several prognostic factors for
limb salvage have been identified.22 These include mechanism
of injury, anatomy of injury (e.g., popliteal artery injury has
worst prognosis), presence of associated injuries, age and
physiologic health of the patient, and clinical presentation
(e.g., shock and obvious limb ischemia). The environmental
circumstances may also play a role in determining salvage,
with higher amputation rates in combat zones, austere envi-
ronments, and multicasualty events.
Treatment and surgical techniques
Timing of treatment
There is no debate that a patient with complex trauma should
undergo thorough irrigation of open fractures and debride-
ment of devitalized tissue. This is considered to be of para-
mount importance for the prevention of infection. It is
commonly taught that the standard of care is to take patients
to the operating room within 6 h of injury.31,32 However, this
timeframe is not supported by evidence and was recently
addressed in a subgroup analysis of the LEAP study.33 Among
those patients who developed major infections, significant
factors included bone loss >2 cm and Gustilo grade IIIC
fractures. Factors such as degree of nerve/muscle damage,
size of skin defect, injury severity score, and surgeon’s

57
Treatment and surgical techniques
It is important to recognize that immediate reconstruction
is not the answer for all patients under all circumstances.
The surgeon has to be highly skilled to perform single-
stage debridement and immediate reconstruction. The
patient must also not have other life-threatening injuries or
multiple comorbidities.40 In some cases, serial debridement,
vacuum-assisted closure, and delayed reconstruction may be
preferred.
Fracture management
The initial orthopedic management of an open lower extrem-
ity fracture has traditionally involved external fixation, in an
effort to avoid implantation of metal in a contaminated field.
Recently, more orthopedic surgeons perform internal fixation
using IM nail or minimally invasive plate osteosynthesis
(MIPO) technique.40 The safety of an unreamed IM nail is
thought to be equivalent to external fixation with respect to
union, delayed union, deep infection, and chronic osteomy-
elitis.41 Use of external fixators may be associated with pin
tract infection, and may interfere with access for microvascu-
lar reconstruction.
Vascular injury
True vascular injury in the setting of lower extremity trauma
is rare. Most definitive signs of vascular compromise can be
attributed to soft-tissue and bone bleeding, traction of intact
arteries with pulse loss (i.e., due to displaced fractures), or
compartment syndrome. However, it is prudent to rule out
vascular injury, and therefore liberal use of imaging should
be carried out in the presence of hard signs. Traditionally, the
arteriogram was the gold standard in the diagnosis of vascular
injuries. Although it is accurate in diagnosing vascular injury,
it has several disadvantages, including cost, duration of pro-
cedure, potential delay to repair, and need for a specialized
team to perform it.42 There is also an associated risk of morbid-
ity in the form of contrast allergy and percutaneous vascular
access-related complications. The advent of CT angiography
(CTA) has helped provide rapid diagnosis of vascular injury
with lower morbidity. It also enables multiple parts of the
body to be assessed. CT angiographic signs of arterial injury
include active extravasation of contrast material, pseudoan-
eurysm formation, abrupt narrowing of an artery, loss of
opacification of an arterial segment, and arteriovenous fistula
formation.42 Studies comparing CTA and conventional angi-
ography have demonstrated a high sensitivity and specificity
of CTA for arterial injury that was confirmed with conven-
tional angiography. There is also a significant cost saving – in
one institution savings exceeded $13 000 per patient when
performing CTA alone.43
There is no doubt that “time is muscle”, and prompt repair
of any vascular injury should be carried out. Permanent
ischemic injury may occur anywhere from 2 to 12 h postinjury
according to the literature. This wide range may be due to
variation in injury mechanism, presence of collateral flow, and
level of injury.44 The decision to perform a definitive vascular
repair in the setting of lower extremity trauma depends on
the clinical circumstances. There are some situations in which
the patient is best served with temporary intraluminal shunt-
ing following distal thrombectomy and heparinization. These
include unstable fractures, gross contamination of the wound
assessment of the degree of contamination were non-predictive
of infection. Regarding their treatment, patients who were
managed with intramedullary (IM) nail had a lower incidence
of infection compared with those who were externally fixated
or treated with plate/screw fixation. There was no significant
difference in terms of mean time to debridement between
patients who developed infection and those who did not.
Time from initial debridement to eventual soft-tissue cover-
age was also not a risk factor for infection. Multivariate
regression showed that delayed admission of patients to a
primary trauma center (>2 h postinjury) or delayed transfer
from an outside institution to primary trauma center resulted
in higher rates of infection. It is unclear whether delay in
admission to a trauma center was in fact a surrogate marker
indicative of a higher degree of injury.
With regard to the timing of reconstruction of lower
extremity trauma, most believe that early reconstruction leads
to better outcome. This follows the study by Godina34 in
which the timing of microsurgical reconstruction was ana-
lyzed with respect to flap failure, infection, bone-healing time,
length of hospital stay, and number of operative procedures.
This study stratified patients into three groups of repair: (1)
within 72 h; (2) between 72 h and 3 months; and (3) beyond
3 months postinjury. The study concluded that reconstruction
within 72 h showed the best outcomes for all analyzed factors.
Those reconstructed between 72 h and 3 months postinjury
had the highest flap failure rates and highest rates of infection.
Those reconstructed beyond 3 months had the longest time
to bone healing and the greatest number of operations
(Table 2.5). Criticisms of Godina’s study include the fact that
the initial 100 patients in the series were treated in a delayed
fashion with average operative times of 6–8 h, whereas those
subsequently treated in an immediate fashion (when micro-
surgical experience was improved) had shorter operative
times.35 Patients were also not randomized to their treatment
regimens, had variable reconstruction (i.e., different flap
choices), and upper/lower extremity reconstruction outcomes
were pooled. There have been several subsequent studies
on this topic – and the results have varied from indifference
to favoritism of immediate reconstruction.23,35–39 Again, the
majority of these have been retrospective reviews, where
patients were not randomized to treatment, with non-
standardized reconstructive options.
Table 2.5  Godina’s results on the timing of microsurgical repair
Early
(<72 h)
Delayed
(72 h–3
months)
Late (>3
months)
Number of patients
134
167
231
Free flap failures
0.75%
12%
22%
Postoperative
infection
1.5%
17.5%
6%
Bone healing time
(average)
6.8 months
12.3 months
29 months
Time in hospital
(average)
27 days
130 days
256 days
Number of surgeries
(average)
1.3
4.1
7.8

58
SECTION I
CHAPTER 2 • Management of lower extremity trauma
bed, soft-tissue deficits that would lead to an exposed
reconstruction/repair, unstable patient, unavailable resources/
surgical expertise in vascular repair, and coincident life-
threatening injury.22
In combined injuries involving bone and vascular disrup-
tion, the operative sequence of repair has been debated. In one
systematic review,45 survival of the extremity was directly
related to ischemic time, with a steep increase in incidence
beyond 3–4 h of ischemic time. Those favoring immediate
vascular repair believe that the reversal of ischemia is most
important, whereas those favoring skeletal fixation prior to
vascular repair argue that stabilization of the bony fragments
first will avoid disruption of a vascular repair during bony
manipulation. There have been several reports of fracture
fixation following vascular repair, with no disruption of the
repair.46–48 A meta-analysis comparing the outcomes of surgi-
cal sequence in 14 published studies did not demonstrate a
clear difference among groups regarding incidence of subse-
quent amputation.49
Reconstructive options
In patients with lower extremity trauma, it is important to
consider all options for reconstruction and choose one that is
most reliable or will provide the best functional outcome. The
reconstructive ladder is often considered but, in major lower
extremity trauma where soft-tissue damage is extensive and
the zone of injury is wide, local options are often eliminated,
emphasizing the need for free flap coverage. When choosing
a reconstructive option, consideration is given to the size and
location of the defect, functional needs (i.e., innervated flap),
zone of injury, anticipated location of vascular anastomosis
for free flap reconstruction, and, accordingly, length of vascu-
lar pedicle required for vascular anastomosis. Consideration
should also be given to the need for future operative interven-
tions (e.g., tendon or bone reconstruction). Regardless of flap
options chosen for reconstruction, adequate debridement of
all non-viable tissue is imperative. High-energy trauma can
result in significant soft-tissue destruction with a need for
extensive debridement of non-viable tissue (Fig. 2.1).
The following is a brief overview of flap options that will
be described in more detail in subsequent chapters on lower-
extremity reconstruction.
Local flaps
There are a variety of local flap options available in lower
extremity reconstruction. Based on anatomic and angiographic
studies, local flaps may be safely performed when based on
known perforators. Local flaps are advantageous as they offer
a viable reconstructive option with shorter operative times
and less complexity;50 they also provide tissue that is similar
in composition to the area of the defect. Patients should be
screened for comorbidities that would compromise vascular
supply of the lower extremity, and have an appropriate vas-
cular examination. A number of local flap options are dis-
cussed in the following sections.
Perforator flaps
The lower extremity is an anatomic region where perforators
available as a flap pedicle are plentiful (Figs. 2.2 & 2.3). They
have been mapped out in extensive detail through cadaveric
Fig. 2.1  Complex lower extremity wound with significant soft-tissue trauma and
devitalization. This wound will require extensive debridement of non-viable skin,
muscle, and bone prior to flap coverage in order to prevent infection.
Fig. 2.2  Computed tomography angiography of perforators of the thigh
demonstrating a rich density of available cutaneous perforators for flap design and
harvest.
injection studies and angiographic investigations. In the
gluteal region, most of perforators are musculocutaneous and
arise from the superior and inferior gluteal arteries, with
minor contributions from the iliolumbar and internal puden-
dal arteries. They are the basis for commonly used gluteal
perforator flaps including the superior and inferior gluteal
artery perforator flaps.
In the hip and thigh region, there are a combination of
musculocutaneous and septocutaneous perforators from six
source arteries originating from the common femoral artery.51
The anteromedial thigh (AMT) is supplied by perforators of
the lateral circumflex femoral artery (LCFA) and superficial

59
Treatment and surgical techniques
Fig. 2.3  Computed tomography angiography of perforators of the leg,
demonstrating a rich density of available cutaneous perforators for flap design and
harvest.
Fig. 2.4  A 66-year-old female with a recurrent squamous cell carcinoma on the
left groin following wide excision. Ample laxity was found in the anterior thigh
region.
Fig. 2.5  Pedicled anterolateral thigh flap tunneled and inset with primary closure of
the donor site.
femoral artery. The anterolateral thigh (ALT) is primarily sup-
plied by the three terminal branches (ascending, transverse,
and descending branches) of the LCFA. Perforators of these
branches supply the tensor fasciae latae perforator flap and
the ALT flap (Figs. 2.4 & 2.5). Just superior to these areas is
the superficial circumflex iliac artery, which provides perfora-
tors to the free superficial circumflex iliac artery perforator
flap and contributes to the groin flap. Perforators from the
medial circumflex femoral, profunda femoris, and popliteal
arteries supply the posteromedial thigh. The posterolateral
thigh is supplied by the profunda femoris and inferior
gluteal arteries. Inferiorly, the medial and lateral superior
genicular arteries supply the region around the knee and
are sources of local perforator flaps in knee reconstruction
(Figs. 2.6 & 2.7).
Surrounding the knee are musculocutaneous perforators
from the superficial femoral artery, as well as several
septocutaneous perforators from the descending genicular,
medial/lateral superior and inferior genicular, anterior tibial
recurrent, and popliteal arteries51 (Figs. 2.8–2.10). The saphe-
nous artery is a superficial branch of the descending genicular
artery, arising medially with the saphenous nerve and vein,
and is the basis of the descending genicular artery perforator
flap, which may incorporate the nerve to create an innervated
flap. Posteriorly, the sural arteries (medial/lateral) arise from
the popliteal trunk and may be sources of local perforator
flaps, including the more reliable medial sural artery perfora-
tor flap.
Within the leg, perforators arise from the posterior tibial,
anterior tibial, and peroneal arteries. The posterior tibial
artery perforator flap incorporates perforators emerging from
the intermuscular septum between the soleus and the flexor
digitorum longus. The anterior tibial artery perforator flap is
based on perforators that occur in two rows – one between
the tibia and the tibialis anterior muscle, and the other from
the anterior crural septum between the extensor digitorum
longus and peroneus longus. The peroneal artery perforator
flap is nourished by perforators that emerge from the posterior
crural septum between the peroneus longus and the soleus
(Figs. 2.11–2.15).
In the foot, the terminal branches of the anterior tibial,
posterior tibial, and peroneal arteries are sources of perforator
flaps. These include the lateral calcaneal artery perforator flap
and medial plantar artery perforator-based flaps (medialis
pedis flap, instep flap, and abductor hallucis muscle flap) (Fig.
2.16).
Muscle-based flaps
In the thigh, a number of local muscles may be used to recon-
struct defects. These include the gracilis flap, which is based
on the ascending branch of the medial circumflex femoral
artery. As a local flap, this is commonly used to reconstruct
the groin, perineum, and ischium. The sartorius flap, which
is based on the superficial femoral artery (type IV vascular
supply), may be used to cover groin defects and exposed
femoral vessels, and is rarely used as a distally based flap to
cover small knee defects. The anterior thigh musculature may
provide coverage of the inferior abdomen, groin, perineum,

60
SECTION I
CHAPTER 2 • Management of lower extremity trauma
A
B
Fig. 2.6  Exposed popliteal arterial vein graft used to revascularize the lower extremity following a gunshot wound to the proximal leg. (A) The design of a lateral superior
genicular artery pedicle perforator flap with the long axis of the flap designed parallel to the long axis of the thigh. (B) The pedicle perforator flap harvested based on a single
lateral superior genicular artery perforator. (C) The perforator following subfascial harvest of the flap. (D) Flap inset with no tension and primary closure of the donor site.
C
D
Fig. 2.7  Computed tomography angiography following lead oxide injection of a
single lateral superior genicular artery perforator. Perfusion is seen to extend
proximally up to the midthigh region and to the anterior and posterior midaxial lines
bilaterally.

61
Treatment and surgical techniques
Fig. 2.8  A 64-year-old male with post-traumatic deformity and subsequent arthritis of right knee. Soft-tissue augmentation of medial side of the knee is needed for total
knee replacement arthroplasty.
A
B
C
Fig. 2.9  Pedicled superficial femoral artery perforator flap was performed to
augment medial side of the knee.
A
B
C

62
SECTION I
CHAPTER 2 • Management of lower extremity trauma
A
Fig. 2.10  Three months postoperatively with
well-perfused flap and sufficient soft tissue on medial
side of the knee.
B
A
B
Fig. 2.11  Lateral malleolus wound covered with an anterior tibial artery pedicle perforator flap, which was rotated 180° (“propeller” flap) to reach the defect.
C
D
and ischium, and includes the rectus femoris (based on pro-
funda femoris artery), vastus lateralis (descending branch of
LCFA), and vastus medialis (superficial femoral artery) flaps.
Laterally, the tensor fasciae latae flap (ascending branch
of LCFA) may be used for similar applications, and may
additionally reach the trochanteric region and sacrum for
pressure sore reconstruction. Posteriorly, the biceps femoris
flap (profunda femoris) is used primarily for pressure sore
reconstruction.
In the lower leg, the most commonly used muscle flaps
include the gastrocnemius and soleus flaps. The gastrocne-
mius has medial and lateral heads, based on the medial and
lateral sural arteries, respectively. The medial head is most
commonly used as it is longer and has better reach. This is

63
Treatment and surgical techniques
Fascial-based flaps (Video 2.1 )
In the thigh, the ALT flap has become a workhorse flap and
is used primarily as a free flap. This flap is based on the
descending branch of the LCFA, which arises from the pro-
funda femoris artery. This flap is described as having three
cutaneous perforators – A, B, and C – that lie along a line
marked from the anterior superior iliac spine to the supero-
lateral corner of the patella.52 These perforators may have a
septocutaneous course between the vastus lateralis and the
rectus femoris, or a musculocutaneous course through the
vastus lateralis. Dissection can be performed suprafascially or
subfascially. An extended ALT flap has been described that
used primarily in knee and upper-third leg coverage (Figs.
2.17 & 2.18). The soleus flap is based on perforators from
the popliteal, posterior tibial, and peroneal arteries. Distally,
segmental perforators from the posterior tibial artery allow
for a reverse soleus flap. A number of other smaller muscle-
based flaps have been described (extensor hallucis longus,
flexor hallucis longus, extensor digitorum longus, flexor
digitorum longus, and peroneus brevis/longus flaps), but
these flaps provide minimal bulk, and often suboptimal,
coverage in larger defects.
The foot is a source of several small local muscular flaps,
including the abductor digiti minimi, abductor hallucis, and
flexor digitorum brevis flaps.
Fig. 2.12  Location of all major clusters of perforators from (A) the posterior tibial, (B) anterior tibial, and (C) peroneal arteries. These perforator cluster locations can help
in the design and planning of local pedicle perforator flaps in the lower extremity.
A
Posterior tibial artery
35 cm
4–9 cm
21–26 cm
13–18 cm
Anterior tibial artery
35 cm
4–9 cm
21–26 cm
B
C
Peroneal artery
35 cm
13–18 cm