Operative Technique in Plastic Surgery – Kevin C.Chung

down through the skin, subcutaneous tissue, and superficial fascia, to enter
the superficial posterior compartment of the leg.
■ During this portion of dissection, when harvesting the medial gastrocnemius
muscle, the saphenous vein should be identified and preserved. Once the
posterior compartment is entered, the gastrocnemius muscle is immediately
encountered along its posterior/superficial surface.
■ The entire muscle belly should then be free from the entire deep surface of
the posterior fascia overlying it (TECH FIG 1A).
■ This should be a relatively hemostatic dissection that can be done sharply
or bluntly, as this plane between gastrocnemius muscle and overlying fascia
is largely avascular loose areolar tissue.
■ Once this has been done, the free border of the muscle, either medial or
lateral, should then be identified along its entire length and used as the access
point to dissect the deep surface of the muscle belly (TECH FIG 1B).
■ This space is entered, and the gastrocnemius muscle is dissected free from
the underlying, deeper soleus muscle.
■ In this plane, the plantaris muscle and tendon (long and thin) will be
encountered and should also be preserved (if present).
■ This deep dissection can be performed along the entire longitudinal length
of the muscle, distally to the point of the Achilles tendon.
■ This dissection can stop at the point of confluence of the medial and lateral
gastrocnemius muscles, along their deep surface, as only the half of the
muscle being dissected will be elevated as a flap.
■ At this point, surgical dissection should have fully freed up the deep and
superficial/posterior surfaces of the gastrocnemius muscle belly (TECH FIG
1C).
■ Next, the muscle will be elevated in a distal to proximal direction, moving
up the leg.
■ First, the muscle belly to be elevated is horizontally detached above the start
of the Achilles tendon.
■ It is critical that the Achilles tendon not be disturbed and the entire fascial
contribution of the gastrocnemius muscle within the Achilles tendon
remains intact.
■ Thus, the muscle is transected one fingerbreadth above the point where the
tendons of all the muscles in this compartment join to form the Achilles.
■ At this point, the gastrocnemius muscle will contain some tendon, and this

can be used for suture anchoring on inset of the muscle flap in the defect.
■ Next, the half of the gastrocnemius muscle being elevated then is lifted in a
distal to proximal direction, by separating the medial and lateral
gastrocnemius muscles from each other (the last remaining point of
attachment).
■ This area must be carefully identified along its entire length based on
changing directionality of muscle fibers (TECH FIG 1D).
■ Often times, this point between the medial and lateral heads of the
gastrocnemius muscles is not a distinct plane, and thus, separation should
be performed with electrocautery to minimize bleeding.
■ Numerous minor perforators exist between the medial and lateral heads of
the muscle, and these must be ligated.
■ This elevation of the muscle in the proximal direction, by separating the two
halves of the gastrocnemius, should be performed just beyond the point at
which the freed muscle can rotate into the defect with no tension or stretch
(TECH FIG 1E).
■ Often times, the dissection can stop well before the point where the sural
vessels enter the deep surface of the muscle, as elevation to this point is not
necessary for adequate rotation.5
■ In such cases, the sural vessels are never directly visualized, and this will
reduce risk of vascular pedicle injury.
■ However, if necessary for adequate muscle rotation, dissection can proceed
to this point, and the sural vessels can be identified, dissected free, and
preserved.
■ In some cases, due to the need for excessive rotation, the muscle origin on
the femoral condyle can be identified and transected.
■ This will result in a significant increase in muscle rotation and length of
transposition.
■ Without the stability of the muscle insertion to prevent excess stretch on
the sural vessels, they must be carefully watched during rotation and inset,
to avoid excess tension and possible vascular traction injury or avulsion.
■ Once the muscle has been fully dissected and elevated, it can then be rotated
into the soft tissue defect (TECH FIG 1F).
■ If the muscle is tunneled underneath a planned skin bridge, it must be
ensured that the skin bridge is not excessively tight or compressive on the
underlying muscle flap.

■ The muscle is usually inset with the previous posterior/superficial surface of
the muscle belly externalized in the wound, as this portion of the muscle does
not contain aponeurosis or fascia and thus accepts a skin graft well.
■ The muscle is then inset into the soft tissue defects and secured
circumferentially to the lower extremity skin and subcutaneous tissue with
sutures (TECH FIG 1G).
■ The proximal portion of the muscle, in the area of the sural vessels, should
then be again examined after inset, to ensure no tension or stretch on this
area.
■ Finally, a skin graft can be placed on the superficial surface of the muscle
flap at this point.
■ The donor site can then be closed primarily over a drain, at the fascia and
skin level.
TECH FIG 1 • A. Patient with a medial knee soft tissue
wound, adequately debrided, and ready for soft tissue
reconstruction. Planned medial gastrocnemius muscle
flap is exposed through longitudinal incision shown.
Posterior leg skin, subcutaneous tissue, and fascia
have been elevated off the superficial surface of the

muscle flap. B. Dissection of the deep surface of the
gastrocnemius muscle flap from the underlying soleus
muscle. The aponeurosis of the soleus muscle is
visible deep to the gastrocnemius muscle. The
plantaris tendon is visible distally in the donor site and
runs along the border of the gastrocnemius muscle. C.
Both the deep and superficial surfaces of the medial
head of the gastrocnemius muscle have been fully
dissected, and the muscle has more freedom of
movement. D. The longitudinal midline border
between the medial and lateral heads of the
gastrocnemius muscle is visible, by its overlying
streak of fat. This will be the point of separation of the
two muscle bellies. E. Following transection of the
medial gastrocnemius muscle proximal to the Achilles
tendon, and separation of the medial and lateral
bellies of the muscle in the midline, the medial
gastrocnemius muscle flap has now been elevated.
The vascularized soft tissue bulk (width and thickness)
afforded by this flap is clearly visualized. F. The
muscle flap passed under the skin bridge and into the
soft tissue wound. The size and reach of the muscle
provide adequate coverage for the wound. G. The
medial gastrocnemius muscle flap, following complete
inset into the wound. The muscle is well perfused, with
no pressure or tension. At this point, the muscle belly
can be skin grafted, and the donor site can be fully
closed in primary fashion.
PEARLS AND PITFALLS

Muscle flap
elevation
■ The muscle flap only needs to be dissected proximally to the point
where it can safely be rotated and inset into the wound, without
tension; often times, complete elevation proximally to the sural
vessel level is unnecessary and to avoid risk of vascular disruption.
Tunneling
■ The tunnel or skin bridge that the muscle flap passes under must be
relaxed and without underlying tightness, to avoid muscle flap
congestion and flap loss; if necessary, the fascia on the underside of
the tunnel skin can be incised to increase the size of the tunnel.
Long muscle
transposition
length
■ In cases where the muscle flap must be advanced a long distance, it
can be detached from the femoral condyle, to allow for a significant
increase in reach; in these cases, the sural vessels must be
continuously examined for a relaxed state without stretch, as they
are no longer stabilized by the proximal muscle insertion.
Hemostasis
■ Hemostasis is critical, in both the muscle donor site, and in the
wound being reconstructed, as tension from a hematoma can
occlude the venous outflow and result in muscle flap loss.
POSTOPERATIVE CARE
■ Postoperatively, the lower extremity is placed in a stabilizing knee
immobilizer.
■ This reduces muscle stretch or tension in the acute healing phase and reduces
muscle flap edema.
■ During this period, the patient may be kept nonweight bearing if deemed
necessary or may be placed on limited foot pressure on the effected extremity
while ambulating with crutches.
■ Immobilization is usually kept on for 2 weeks, at which point the patient can
begin knee flexion and normal ambulation (FIG 1).
■ The skin graft can be covered for 5 to 7 days with either negative pressure
therapy or with a bolster dressing.
COMPLICATIONS
■ Hematoma

FIG 1 • Healed medial gastrocnemius muscle flap and
overlying split thickness skin graft, 3 months after
coverage operation in TECH FIG 1. Patient has stable
soft tissue coverage and is ambulating without difficulty.
■ Bleeding in either the donor site or the wound bed underneath the muscle flap
must be treated immediately with hematoma evacuation, to avoid pressure on
vascular pedicle and resultant muscle flap loss.
■ Infection
■ Proper wound bed debridement and removal of all nonviable tissue prior to
muscle flap coverage will reduce this risk.
■ When infection occurs, re-elevation of the muscle flap and aggressive
washout should be performed.
■ Flap loss
■ With complete flap loss, a secondary free flap often must be performed for
wound coverage.
■ Venous congestion
■ The entire flap must be elevated, and if congestion resolves, this usually
indicates pressure or kinking on vascular pedicle, which must be resolved.
■ The tunnel must be checked for excessive tightness, and if this is the case, it
can be opened with an incision and the muscle externalized in this area.
REFERENCES
1. McCraw JB, Fishman JH, Sharzer LA. The versatile gastrocnemius
myocutaneous flap. Plast Reconstr Surg. 1978;62:15-23.
2. Arnold PG, Mixter RC. Making the most of the gastrocnemius muscles. Plast

Reconstr Surg. 1983;72:38-48.
3. Hersh CK, Schenck RC, Williams RP. The versatility of the gastrocnemius
muscle flap. Am J Orthop. 1995;24:218-222.
4. Verber M, Vaz G, Braye F, et al. Anatomical study of the medial
gastrocnemius muscle flap: a quantitative assessment of the arc of rotation.
Plast Reconstr Surg. 2011;128:181-187.
5. Daigeler A, Drücke D, Tatar K, et al. The pedicled gastrocnemius muscle flap:
a review of 218 cases. Plast Reconstr Surg. 2009;123: 250-257.

33
CHAPTER
Soft Tissue Coverage of the
Knee: Free Flaps
Goo-Hyun Mun and So Young Kim
DEFINITION
■ Although most soft tissue and bony defects around the knee are usually
covered with locoregional tissues, free flaps should be considered when the
desired donor territory is damaged or unsuitable or if the defect is extensive or
complex. Free flaps offer benefits such as shortened recovery time, plentiful
availability of donor tissue, and greater flexibility in flap design.1
■ Soft tissue defects of the knee can significantly influence gait; therefore,
reconstruction should be done with proper planning and technique at an early
onset.2
■ Restoration of the thin and pliable skin for satisfactory appearance and
function of the knee is an important reconstruction goal.
ANATOMY
■ Popliteal vessels and vessels from the anterior knee can be recipients of
microvascular free flap transfer for soft tissue coverage of knee defects.
■ Recipient vessels for free flap.
■ Popliteal vessel and its branches (FIG 1A). The popliteal artery ranges from
a proximal portion starting at the opening of the adductor canal to the distal
portion lying behind the upper part of the tibia and fibula. The popliteal vessel
and branches, including the superior medial and lateral genicular vessels (FIG
1B), medial and lateral sural vessels (FIG 1C), middle genicular vessels, and
inferior genicular vessels, are considered the choice of recipient vessels for a
free flap in the knee region. However, the approach to the popliteal vessels
can be difficult when the anterior surface of the knee is reconstructed, and
sural vessels are difficult to use in a free tissue flap to the region proximal to

the knee.3 Furthermore, there is a risk of increased complications caused by
compression and twisting of the flap blood vessels, depending upon the
postsurgical position of the patient.
■ Anterior knee (FIG 2A):
• Three vessels, including the descending genicular vessel and its branches
(FIG 2B,C), and the descending branches of the lateral circumflex femoral
vessels (FIG 2D) and anterior tibial vessels are considered the choice of
recipient vessels for a free tissue transfer for the anterior knee region.
• These recipient candidates have several benefits with supine positioning and
easy accessibility to the recipient vessel. However, these branches may be
very small vessels and, if so, may be of limited value and less reliable.3
■ The perforators along the intermuscular septum of the upper leg and lower
thigh can be used as recipient vessels for free flap reconstruction of the knee,
but also note that these vessels may be small.4
FIG 1 • A. Muscular boundaries and branches of the
popliteal artery and deep neurovascular structures in
the posterior knee. B. Superior lateral genicular vessel
for recipient vessel. C. Medial sural vessel for recipient
vessel.

FIG 2 • A. Anatomy of recipient vessels of anterior knee
region. B. Descending genicular vessels–vessel for
recipient vessel. C. Descending genicular vessel–
muscular branch to the vastus medialis for recipient
vessel. D. Descending branch of the lateral circumflex
femoral vessel for recipient vessel.
PATHOGENESIS
■ Multiple prior operations and revision arthroplasties with atrophy/scarring of
soft tissues
■ Prior coverage of a total knee prosthesis and wound dehiscence due to
infection
■ Large post-traumatic defects
■ Extensive soft tissue tumor excision
■ Soft tissue necrosis and chronic infection after extremity radiation
■ Necrotizing fasciitis and septic arthritis
■ Burn scar contracture and post-traumatic stiff knee

PATIENT HISTORY AND PHYSICAL FINDINGS
■ The patient history should focus on the exact mechanism and etiology of the
defect.
■ It is important to assess the medical history including vascular disease,
systemic disease, and hypercoagulable state, which can influence the outcome
of a microsurgical procedure.
■ The preoperative evaluation for patients with a knee defect includes a detailed
assessment of function limitations. The range of motion is a widely used
measure of the knee joint, with a normal range of flexion of 45 to 105 degrees
during routine activities and full extension to 0 degree.5
IMAGING
■ The authors routinely perform preoperative computed tomography (CT)
angiography of the lower extremity unless contraindicated to evaluate the
regional vascular anatomy.
■ Magnetic resonance imaging (MRI) can also be performed for evaluation of
complex defects of soft tissue.
SURGICAL MANAGEMENT
■ The proper selection of recipient vessels is essential for the success of a free
flap and is arguably the most important factor that can affect the outcome.4,6
Major considerations regarding the choice of appropriate recipient site for
revascularizing the flap include performing the microanastomosis outside the
zone of injury and avoiding the need for vein grafts.7
■ Extending the incision from the defect is used when there is a suitable adjacent
recipient; however, a separate incision with subcutaneous tunneling can be
effective for a distant recipient vessel approach.
■ Options of free flap:
■ Commonly chosen flaps for soft tissue reconstruction of knee defects are an
anterolateral thigh (ALT) flap, rectus abdominis muscle flap, deep inferior
epigastric artery perforator (DIEP) flap, tensor fascia lata flap, superficial
circumflex iliac artery perforator (SCIP) flap, latissimus dorsi
musculocutaneous flap, and thoracodorsal artery perforator (TDAP) flap. The
TDAP flap is favored by the authors because of several advantages including
generous dimensions of the back, tissue thinness, relatively well-hidden donor
scar, a long vascular pedicle, and the versatility offered by composite tissue
transfer.

■ When complex knee trauma accompanies a patellar tendon defect, the patellar
tendon is traditionally restored using an autogenous graft, such as the
semitendinosus tendon, gracilis tendon, and fascia lata, or an allograft. Because
of the problem of delayed healing, fascia lata failure, and infection, a
composite ALT myocutaneous flap with vascularized fascia lata can be utilized
for one-stage reconstruction of complex knee defects.8
■ When there is post-traumatic loss of the quadriceps femoris muscles with
subsequent loss of knee extension, free functional transfer of the latissimus
dorsi muscle9 and contralateral rectus femoris muscle10 can be utilized to
restore knee extension.
■ For stump coverage in above or below knee amputations, the distal placement
of a flap to cover the entire weight-bearing surface of the stump is required.11
T E C H N I Q U E S
■ Wound Preparation
■ The first goal of wound preparation is to debride all contaminated soft tissue
or excise pathologic or necrotic lesions and to evaluate the extent of soft
tissue defects in terms of size and components, including the bone, tendon,
muscle, fascia, and skin (TECH FIG 1).
■ A tourniquet is usually applied on the thigh during wound preparation.
TECH FIG 1 • Wound preparation of posterior knee
defect after tumor extirpation.

■ Recipient Vessel Preparation
■ Approach to the medial sural artery
■ The procedure can be performed with the patient in prone or semilateral
decubitus position, with the recipient extremity down and the opposite leg
crossed anteriorly, with simultaneous access to the contralateral back as a
donor site (TECH FIG 2A).
■ Arising from the posterior aspect of the popliteal vessel, the medial sural
vessel enters the deep surface of the medial gastrocnemius muscle.
Between the muscular head of the medial and lateral gastrocnemius, the
medial sural vessel is easily approached12 (TECH FIG 2B). A branch of
the tibial nerve usually accompanies the dominant vascular pedicle to the
gastrocnemius muscle and should be preserved.7
■ Approach to the descending genicular artery and its branches
■ The procedure is performed with the patient in the supine position, with the
knee flexed and the thigh rotated externally.
■ The descending genicular vessel is divided into three equal branches:
■ A muscular branch to the vastus medialis muscle
■ A terminal articular branch supplying the periosteum of the medial
condyle
■ A saphenous (superficial) branch
■ After medial retraction of the sartorius muscle, the descending genicular
vessel can be identified immediately posterior to the vastus medialis
muscle4 (FIG 2B). The intramuscular portion of muscular branch to the
vastus medialis can be a candidate recipient vessel and is exposed through
retrograde intramuscular dissection of a perforator overlying the vastus
medialis4 (FIG 2C).
■ Approach to the descending branch of the lateral circumflex femoral artery
(LCFA)

TECH FIG 2 • A. Lateral decubitus position with the
recipient extremity down and the opposite leg
scissored anteriorly for the approach to the medial
sural artery. B. The medial sural vessel is prepared for
the recipient vessel.
■ The procedure can be performed in the supine position.
■ The descending branch of the LCFA with adequate size as a recipient
vessel can be found in an area 10 to 15 cm above the upper margin of the
patella; therefore, a donor flap must have a long enough pedicle.2 After
separating the rectus femoris medially from the intermuscular septum
between the vastus lateralis and the rectus femoris, the descending branch
of the LCFA is exposed. It travels with the muscular branch of the femoral
nerve along the anterior border of the vastus lateralis toward the knee joint
(FIG 2D).
■ Approach to the superior medial and lateral genicular artery
■ The superior genicular vessels arise on either side of the popliteal fossa and

wind around the femur immediately above its condyles to the front of the
knee joint.4
■ In cases of a defect in the posterior knee, the superior medial genicular
vessel is exposed after gentle retraction of the semimembranosus muscle at
the level of the upper edge of the femoral condyle when the popliteal artery
is in sight.3
■ The superior lateral genicular vessel is identified above the lateral condyle
of the femur as it courses laterally beneath the short head of the biceps
femoris and the vastus lateralis13 (FIG 1B).
■ Selection of recipient vein
■ Because the use of an accompanying concomitant vein as the recipient has
the benefit of straightforward insetting of the flap, the deep vein system is
usually considered the first choice of a recipient vein for a free flap in the
lower extremity.
■ However, in this anatomical area of the knee, a superficial vein such as the
great saphenous vein passing medial to the medial femoral condyle is
sometimes in a more convenient position and is a better size match for
anastomosis than the deep vein system.14
■ Assessment of the Defect
■ Because the knee is a large diarthrodial (synovial) joint with an extensive
range of motion, free flaps in this region should provide ample skin coverage
to allow unrestricted joint mobility in flexion and extension and to facilitate
ambulation.1,15
■ Final defect size and shape are exactly measured by making a transparent
plastic or paper template that will be used for flap design. With the
consideration both of minimizing restricted mobility of joint and avoiding
redundancy of reconstructed flap, the measurement of anterior defect is
usually conducted in slightly flexed knee status, and measurement of
posterior defect is done in position of knee extension status.
■ Dead space to be filled is also measured and accounted for in flap
design/harvest.
■ Flap Harvest

■ Outlines of the relevant muscle and other landmarks are drawn (TECH FIG
3A).
■ Perforators are located using a handheld pencil Doppler, and the flap is
designed using a template of the final defect.
■ The targeted perforator(s) are identified by suprafascial dissection through a
limited incision because the design of skin paddle could be potentially
adjusted to capture the perforator securely within the flap, and then the whole
skin paddle is elevated.
■ Meticulous intramuscular dissection of the pedicle under loupe
magnification with bipolar forceps is performed.
■ A muscle chimeric perforator flap can be harvested as needed to fill dead
space or to cover the artificial implant (TECH FIG 3B).
■ Motor nerve branches to the muscle are maximally preserved during a
perforator flap harvest, and the pedicle is divided when sufficient length is
obtained.
■ A closed suction drain is placed and the donor wound is primarily closed in
layers (TECH FIG 3C).

TECH FIG 3 • A. Outline of the relevant muscle and
landmarks are drawn on the donor site for flap design.
B. Harvested muscle chimeric TDAP flap. C. Donor
site that was primarily closed after flap harvest.
■ Microanastomosis with Temporary Inset
■ Temporary inset of the flap is performed with a skin stapler.
■ The vascular pedicle is comfortably laid to reach the recipient vessel without
kinking, twisting, or tension. This is best accomplished by prudent
preoperative planning and harvesting sufficient pedicle length.
■ Wide exposure of the operative field and creation of a comfortable milieu are
critical for successful microvascular anastomosis.
■ Either end-to-end or end-to-side microanastomoses are performed and may
depend on the size of the vessels.
■ Vascular clamps are removed after completion of anastomoses. Warm saline
is applied to the vessels and covered with moist gauzes for several minutes.
■ After checking for patent arterial inflow and venous outflow, then perform
careful hemostasis to evaluate for any bleeding points from the vascular
pedicle or recipient vessels.
■ Final Inset
■ Insetting of the flap is straightforward because it should have been harvested
based on an exact template of the defect.
■ The muscle component of a chimeric flap is placed to fill in dead space or to
cover the prosthesis (TECH FIG 4).
■ If the flap is too bulky, it may be thinned by carefully removing tissue from
the deep fat layer and part of the superficial fat layer, except for a few
centimeters of a cuff of subcutaneous tissue around the entry point of the
perforator(s). The use of loupe magnification or even the microscope may be
advised to avoid damaging small blood vessels traveling through the fat.
■ The wound is closed with placement of closed suction drains under the flap
to prevent fluid collection (TECH FIG 5).
■ A leg splint is applied for immobilization, and an elastic bandage is loosely

applied so as to avoid compression over the vascular pedicle.
■ Part of the flap is left open for postoperative monitoring of flap perfusion.
TECH FIG 4 • A. Harvested muscle chimeric
perforator flap. B. After end-to-end microanastomoses
to the corresponding vessels of the chosen free flap,
exposed artificial bone and knee joint are seen in
anterior knee. C. Muscle component of chimeric flap is
arranged to cover the artificial implant. D. Transferred
muscle chimeric TDAP flap in anterior knee after final
inset, using the medial sural vessel as recipient.
TECH FIG 5 • A. Transferred muscle chimeric TDAP
flap in posterior knee after final inset, using the medial
sural vessel as recipient. B. Transferred TDAP flap in
medial knee after final inset, using muscular branch of
the descending genicular vessel as recipient. C.

Transferred DIEP flap in anterior knee after final inset,
using muscular branch of the descending genicular
vessel as recipient. D. Transferred TDAP flap in lateral
knee after final inset, using the superolateral genicular
vessel as recipient.
PEARLS AND PITFALLS
Planning
■ Meticulous preoperative planning for recipient vessels, donor
site, flap composition, and positioning of the patient is crucial
for successful reconstruction.
■ A multidisciplinary approach with comprehensive
communication between oncologic and/or orthopedic
surgeons will enable better treatment outcomes.
Selection of
recipient vessel
■ The recipient vessel option includes the descending genicular
vessel and its branches, descending branch of lateral
circumflex femoral vessel and anterior tibial vessel in the
anterior knee, and superior medial and lateral genicular
vessel, medial and lateral sural vessel, middle genicular
vessel, and inferior genicular vessel in the popliteal area.
Surgeons may choose a recipient vessel based on the
proximity to the defect, concomitant injuries, vessel
availability, and vessel size match.
■ The deep vein system is usually considered as the first choice
of recipient vein for a free flap in the lower extremity.
However, in this anatomical area of the knee, a superficial
vein such as the great saphenous vein is sometimes in a more
convenient position and is a better size match for anastomosis
than the deep vein system.
Assessment of
the defects
■ Free flaps in this region should provide ample skin coverage
to allow unrestricted joint mobility in flexion and extension
and to facilitate ambulation.
■ Defect size and shape are exactly measured by making a
template for subsequent flap design.
Microanastomosis
and flap inset
■ It is important to avoid twisting and kinking of the pedicle.
■ Tension on the pedicle should be avoided and sufficient

acquisition of pedicle length is a safe strategy.
■ Defatting of the perforator flap at the time of inset is an
effective technique to obtain aesthetic contour but must be
performed carefully to avoid compromising blood supply.
POSTOPERATIVE CARE
■ Most surgeons who perform free flaps in the lower extremity rely upon clinical
observations including subjective visual inspection, capillary refill, turgor, and
temperature of the flap, in combination with a handheld pencil Doppler for
monitoring the flap.16 The protocol varies according to surgeon, but the authors
perform clinical assessment of flap status, combined with a handheld Doppler
examination, every 3 hours for the first 48 hours and then every 6 hours for the
next 48 hours after surgery.
■ Although preferences regarding anticoagulation regimens vary widely among
microvascular surgeons, medication for perioperative anticoagulation can be
used to minimize the risk of postoperative thrombosis. The major classes
include antiplatelet, heparin-based anticoagulant, and plasma expander drugs.
■ Postoperatively, lower extremity edema and overly aggressive mobilization
can compromise the free flap, especially causing venous congestion.17
Although the duration of immobilization time varies based on the orthopedic
injuries, generally progressive weight bearing and ambulation are achieved
when the patient is tolerating dangling at least 30 minutes, six times per day.17
■ Postoperative rehabilitation to maintain knee movement is an essential part of
treatment and should be commenced in the early postoperative period.15
OUTCOMES
■ Published success rates for free tissue transfers to the knee vary according to
the etiology of the defect, but a microvascular free flap in this region is a safe
procedure, with a success rate ranging from 97% to 100%.1,15,18
■ A microvascular free flap is a reliable reconstructive option for defects of
various sizes in various locations in the knee. The type of perforator flap,
whether cutaneous or muscle chimeric (FIG 3), is selected according to tissue
requirement.
COMPLICATIONS
■ Vascular complications such as venous and arterial thrombosis
■ Prompt emergent exploration is demanded when these conditions are

suspected.
■ Hematoma
■ Early diagnosis of a hematoma under the flap is critical so that it can be
evacuated promptly to prevent compression of the anastomotic site due to an
expanding hematoma. Any time a postoperative hematoma is noted, the
surgeon must suspect venous obstruction.
■ Infection
■ When the defect accompanies an infected prosthesis and chronic infection of
the bone or joint, a late infection or recurrence of infection after free tissue
transfer can develop.18,19 Therefore, it is critical that the wound be sufficiently
debrided of necrotic, infected, or pathologic tissue before definitive flap
reconstruction.
■ Suboptimal knee range of motion
■ Suboptimal knee range of motion may result from increased periods of
restricted knee extension followed by allowance of very limited knee range of
motion during free flap maturation.1 Therefore, early range of motion is
advised once flap viability is established.
FIG 3 • A,B. Satisfactory result of muscle-chimeric free
flap to the posterior knee defect.
REFERENCES
1. Louer CR, Garcia RM, Earle SA, et al. Free flap reconstruction of the knee: an
outcome study of 34 cases. Ann Plast Surg. 2015;74:57-63.
2. Kim JS, Lee HS, Jang PY, et al. Use of the descending branch of lateral
circumflex femoral artery as a recipient pedicle for coverage of a knee defect

with free flap: anatomical and clinical study. Microsurgery. 2010;30:32-36.
3. Park S, Eom JS. Selection of the recipient vessel in the free flap around the
knee: the superior medial genicular vessels and the descending genicular
vessels. Plast Reconstr Surg. 2001;107:1177-1182.
4. Fang T, Zhang EW, Lineaweaver WC, Zhang F. Recipient vessels in the free
flap reconstruction around the knee. Ann Plast Surg. 2013; 71:429-433.
5. Laubenthal KN, Smidt GL, Kettelkamp DB. A quantitative analysis of knee
motion during activities of daily living. Phys Ther. 1972;52:34-43.
6. Basheer MH, Wilson SM, Lewis H, Herbert K. Microvascular free tissue
transfer in reconstruction of the lower limb. J Plast Reconstr Aesthet Surg.
2008;61:525-528.
7. Hallock GG. The medial approach to the sural vessels to facilitate
microanastomosis about the knee. Ann Plast Surg. 1994;32:388-393.
8. Yagi Y, Ueda K, Shirakabe M, et al. Reconstruction of knee ligaments with a
free tensor fascia lata myocutaneous flap transfer. Br J Plast Surg.
2002;55:155-157.
9. Hallock GG. Restoration of quadriceps femoris function with a dynamic
microsurgical free latissimus dorsi muscle transfer. Ann Plast Surg.
2004;52:89-92.
10. Wechselberger G, Ninkovic M, Pulzl P, Schoeller T. Free functional rectus
femoris muscle transfer for restoration of knee extension and defect coverage
after trauma. J Plast Reconstr Aesthet Surg. 2006; 59:994-998.
11. Higgins JP. Descending geniculate artery: the ideal recipient vessel for free
tissue transfer coverage of below-the-knee amputation wounds. J Reconstr
Microsurg. 2011;27:525-529.
12. Beumer JD, Karoo R, Caplash Y, et al. The medial sural artery as recipient
vessel and the impact on the medial gastrocnemius. Ann Plast Surg.
2011;67:382-386.
13. Wiedner M, Koch H, Scharnagl E. The superior lateral genicular artery flap
for soft-tissue reconstruction around the knee: clinical experience and review
of the literature. Ann Plast Surg. 2011;66:388-392.
14. Lorenzo AR, Lin CH, Lin CH, et al. Selection of the recipient vein in
microvascular flap reconstruction of the lower extremity: analysis of 362 free-
tissue transfers. J Plast Reconstr Aesthet Surg. 2011; 64:649-655.
15. Ulusal AE, Ulusal BG, Lin YT, Lin CH. The advantages of free tissue
transfer in the treatment of posttraumatic stiff knee. Plast Reconstr Surg.
2007;119:203-210.

16. Xipoleas G, Levine E, Silver L, et al. A survey of microvascular protocols for
lower extremity free tissue transfer II: postoperative care. Ann Plast Surg.
2008;61:280-284.
17. Rohde C, Howell BW, Buncke GM, et al. A recommended protocol for the
immediate postoperative care of lower extremity free-flap reconstructions. J
Reconstr Microsurg. 2009;25:15-19.
18. Cetrulo CL Jr, Shiba T, Friel MT, et al. Management of exposed total knee
prostheses with microvascular tissue transfer. Microsurgery. 2008; 28:617-622.
19. Hierner R, Reynders-Frederix P, Bellemans J, et al. Free myocutaneous
latissimus dorsi flap transfer in total knee arthroplasty. J Plast Reconstr Aesthet
Surg. 2009;62:1692-1700.

34
CHAPTERRepair of Patella Tendon
Patrick Horrigan, Michael Bellino, and Julius Bishop
DEFINITION
■ Rupture of the patellar tendon is a disruption of the knee extensor mechanism
between the patella and the tibial tubercle.
■ Complete ruptures cause significant disability, pain, hemarthrosis, and an
inability to extend the knee.
■ Prompt treatment nearly always involves surgery and early motion during
rehabilitation.
■ Missed or delayed diagnosis and treatment can result in significant pain and
dysfunction.1
ANATOMY
■ The patellar tendon is a continuation of the quadriceps tendon, a confluence of
the vastus medialis, intermedius, and lateralis tendons and the rectus femoris
tendon. It is derived primarily from extending fibers of rectus femoris
traversing the anterior surface of the patella.
■ The tendon itself consists of 90% type I collagen. Its fibers are arranged
longitudinally relative to the axis of the lower extremity.
■ It measures approximately 32 mm in width and narrows by several
millimeters near its insertion on the tibial tubercle.
■ Its thickness in normal knees is approximately 6 mm at its proximal extent
and 6 mm distally.2,3
■ The blood supply of the patellar tendon is derived from the inferior genicular
arteries proximally and from the anterior tibial recurrent artery distally. It
shares a portion of its blood supply posteriorly with the infrapatellar fat pad.3,4

PATHOGENESIS
■ Because degenerative changes are present in most cases, tendinopathy is
increasingly given the primary pathogenic role in rupture.5
■ Rupture can also occur in the setting of direct trauma, recent corticosteroid
injections for tendonitis, and systemic disease (patients with chronic acidosis or
nephropathy requiring hemodialysis, systemic lupus erythematosus).6
■ A classic described mechanism is forceful contraction of the quadriceps
musculature with the knee in greater than 45 degrees of flexion.7
PATIENT HISTORY AND PHYSICAL FINDINGS
■ Patients will typically describe an acute popping or tearing sensation during a
brief period of forceful quadriceps contraction. This is often followed by acute-
onset knee pain, swelling, and inability to bear weight.
■ A palpable infrapatellar defect around a swollen joint can sometimes be
appreciated on the symptomatic knee.
IMAGING
■ Plain anteroposterior and lateral radiographs of the knee are usually sufficient
for diagnosis of patella tendon rupture (FIG 1).7
■ In cases of uncertain physical examination, MRI or ultrasonography may be
useful for confirmation of diagnosis.
DIFFERENTIAL DIAGNOSIS
■ Quadriceps tendon rupture
■ Patella fracture
■ Medial/lateral collateral ligament rupture
■ Anterior cruciate ligament rupture
■ Meniscus tear
■ Patellar dislocation/subluxation event
NONOPERATIVE MANAGEMENT
■ Management of patellar tendon ruptures in medically stable adults is surgical.
Nonoperative treatment predictably results in tendon retraction and loss of
active knee extension strength and extensor lag.7

FIG 1 • A,B. Anteroposterior and lateral radiographs of
a 32-year-old man with a sudden popping sensation
and left knee pain after landing from a jump while
playing basketball. Radiographs show a knee effusion,
absence of fracture and patella alta best seen on the
lateral projection.
SURGICAL MANAGEMENT
■ Surgical goals include restoration of the knee extensor mechanism with
strength to allow for early postoperative rehabilitation.
■ Secondary goals include avoidance of overcorrection resulting in patella baja
and altered knee kinematics.
■ The most commonly described technique to date consists of an augmented
primary repair using transosseous patellar tunnels and nonabsorbable suture
fixation.8
Preoperative Planning
■ AP and lateral radiographs of the affected and contralateral knee can be
reviewed for comparison and to look for other concurrent abnormalities such as
calcific tendonitis, abnormal patellar morphologies, or previous surgeries.
Positioning
■ The patient is positioned supine on a radiolucent table with arms abducted. A
bump is placed under the ipsilateral buttock and low back to facilitate internal
rotation of the operative knee to neutral.
■ A nonsterile tourniquet is applied.

■ Hair over the operative site and anticipated dressing placement is trimmed
with clippers.
■ C-arm fluoroscopy may be available for confirmation of tunnel placement or
for delineation of any occult fracture fragments not noted on initial
radiography.
Approach
■ An anterior approach to the patellar tendon provides the most direct and
extensile access to the site of injury and planned repair.
T E C H N I Q U E S
■ Transosseous Suture Technique
Anterior Approach to the Patellar Tendon and Extensor
Retinaculum
■ Landmarks: patella, tibial tubercle, and patellofemoral joint line.
■ Exsanguinate the leg and inflate a tourniquet as needed for hemostasis
■ Make a midline incision longitudinally from the superior pole of the patella
to the proximal aspect of the tibial tubercle.
■ Elevate thick skin flaps to the prepatellar bursa. Hematoma is often
encountered at this point.
■ Identify patellar paratenon for later repair if not traumatically disrupted.
■ Identify the area of patellar tendon rupture and the extent of retinacular
involvement.
■ Evacuate intra-articular hematoma.
Preparation of Tendon
■ Identify the area of the tear; most patellar tendon ruptures are from the distal
patellar pole, leaving a long distal limb for suture anchoring.
■ Debride the tendon and infrapatellar pole of any nonviable strands or areas
of degeneration and thickening. Excise any free bony fragments that
originated from the inferior patellar pole that cannot be incorporated into the
repair construct.
■ Using two separate thick nonabsorbable braided suture (no. 5 FiberWire) and

starting at the most proximal aspect of the distal segment, pass the Krackow
sutures on either side of the tendon, traversing for approximately four or five
passes before creating a second row per suture and ultimately creating four
total suture strands exiting near the suture’s entry point (TECH FIG 1).
■ Separate the four strands into three groups: one medial, two central, and one
lateral. Cut the central strands to two different lengths that can still pass
through the length of the patella and be tied down. This will differentiate
them during suture fixation.

TECH FIG 1 • A. Diagram of Krackow suture repair of
torn patellar tendon. B. Left knee patellar tendon
repair with four-strand Krackow sutures placed.

Creation of Bone Tunnels
■ Identify the medial and lateral borders of the patella. Divide this total width
into fourths, taking into account areas of thin cortical bone, particularly at the
lateral facet.
■ Using a long 2.5-mm drill, create three retrograde drill holes at the central
divisions of each of the zones described in step one (TECH FIG 2). Mark the
entry point of each drill pass with electrocautery. Consider using multiple
drill bits or saved fluoroscopic views to ensure the drill paths do not cross.
Suture Passage and Knot Tying
■ Flex the knee to approximately 20 degrees with a small bump behind the
knee. This is to ensure suture passage anterior to the quadriceps tendon to
permit knot tying as close to the patella as possible.
■ Use a 2.4-mm Beath pin with eyelet to pass each of the four suture strands
through the three drill holes using the designation created earlier. All strands
will then be superior to the patella (TECH FIG 3A–C).
■ Pass the central limbs through the quadriceps tendon to their corresponding
medial and lateral limbs using a free needle. This avoids soft tissue bridging
and possible loosening (TECH FIG 3D,E).
■ Hand tie at least five surgical knots, using a slip knot or needle driver to hold
the initial knot tight. Leave 4-mm tails of suture.
TECH FIG 2 • Drill holes placed retrograde with long
2.5-mm drill.
Completion and Assessment of Repair

■ Repair any ruptured retinaculum with large absorbable braided suture.
■ Move the knee through passive motion under direct visualization of repair.
■ Note any gapping or opening of the repair. This will be the limit of range
of motion in the early postoperative period.
■ Deflate tourniquet, irrigate, obtain hemostasis, and close in layers with
paratenon closure if possible.
■ Apply a soft dressing and a hinged knee brace locked in extension.
TECH FIG 3 • A. Beath pin passed retrograde through
each of three marked drill holes. B. Threaded Beath
pin passing through central drill hole with two suture
strands. C. Central thread strands now passed
through drill hole and quadriceps tendon with knee
slightly flexed. D. Free needle used to pass central
suture strands closer to their respective medial and
lateral strands so as to avoid soft tissue bridging. E.

All four suture strands ready for creation of two hand-
tied knots.
PEARLS AND PITFALLS
Indications
■ Confirm diagnosis with examination under anesthesia to rule out
the more proximally oriented quadriceps tendon rupture.
Tendon
preparation
■ Ensure at least three passes of each row of Krackow suture to limit
the possibility of suture pullout and subsidence of fixation.
Creation of
bone
tunnels
■ Avoid intra-articular penetration of drill, using fluoroscopic
guidance or via proprioceptive feedback with the patella held
between the thumb and index finger.
■ Oscillate when drilling tunnels so as not to bind suture in drill bit.
■ Mark bone tunnel placement in surrounding soft tissues with
electrocautery for accuracy of Beath pin passage.
■ Avoid crossing of bone tunnels, which can create suture
entanglement and prevent secure tightening of repair knots.
Suture
passage and
knot tying
■ Use a free needle to pass suture close to its accompanying strand
and avoid soft tissue bridging.
■ Avoid over- or undertensioning of suture and subsequent alteration
of patellofemoral mechanics.
POSTOPERATIVE CARE
■ In isolated tendon injuries, the patient may be discharged to home with hinged
knee brace locked in extension for 2 weeks. No active knee extension is
permitted for 6 to 8 weeks.
■ At the initial 2-week postoperative follow-up visit, the brace is unlocked for
range of motion exercises up to the limit noted at the time of operation.
■ Thirty-degree increases may be made every 2 weeks, and then knee brace is
unlocked and weaned entirely for the remainder of rehabilitative therapy.
■ Stretching and strengthening are permitted at 8 weeks, with return to full
activity as tolerated at 12 to 16 weeks.
OUTCOMES

■ Gilmore et al. analyzed the different techniques of acute and chronic patellar
tendon repair in a recent review.9
■ In searching techniques of primary repair, they noted 383 patellar tendon
ruptures repaired primarily.
• Seventy-seven percent of the primary repairs were with nonabsorbable
suture.
• Sixty-six percent of primary repairs underwent some form of augmentation.
• The most common suture method was the Krackow technique.
■ Five different outcome scoring systems were used to grade the success of
repair.
• While no comparisons in functional outcome could be made between
specific techniques, primary repairs with augmentation demonstrated the
best mean knee range of motion of 0 to 129 degrees.
■ Augmented primary repair also demonstrated the lowest failure rate at 2%.
COMPLICATIONS
■ In Gilmore et al.’s review,9 augmented primary repair demonstrated the lowest
failure rate at 2%.
■ Described complications of patellar tendon repair include1:
■ Improper tendon tensioning leading to patella alta or baja
■ Failure of repair/ rerupture
■ Infection
■ Knee stiffness
■ Prominent suture knots requiring removal
■ Deep vein thrombosis
REFERENCES
1. Volk WR, Gautam PY, Uribe JW. Complications in brief: quadriceps and
patellar tendon tears. Clin Orthop Relat Res. 2013;472(3):1050-1057.
2. Andrikoula S, Tokis A, Vasiliadis HS, Georgoulis A. The extensor mechanism
of the knee joint: an anatomical study. Knee Surg Sports Traumatol Arthrosc.
2006;14:214-220.
3. Pang J, Shen S, Pan WR, et al. The arterial supply of the patellar tendon:
anatomical study with clinical implications for knee surgery. Clin Anat.
2009;22(3):371-376.
4. Nemschak G, Pretterklieber ML. The patellar arterial supply via the
infrapatellar fat pad (of Hoffa): a combined anatomical and angiographical

analysis. Anat Res Int. 2012;(3):1-10.
5. Maffulli N, Del Buono A, Loppini M, Denaro V. Ipsilateral hamstring tendon
graft reconstruction for chronic patellar tendon ruptures. J Bone Joint Surg Am.
2013;95:e1231-e1236.
6. Rose PS, Frassica FJ. Atraumatic bilateral patellar tendon rupture: a case
report and review of the literature. J Bone Joint Surg Am. 2001;83A:1382-
1386.
7. Matava MJ. Patellar tendon ruptures. J Am Acad Orthop Surg. 1996;4:287-
296.
8. Black JC, Ricci WM, Gardner MJ, et al. Novel augmentation technique for
patellar tendon repair improves strength and decreases gap formation: a
cadaveric study. Clin Orthop Relat Res. 2016;474:2611-2618.
9. Gilmore JH, Clayton-Smith ZJ, Aguilar M, et al. Reconstruction techniques
and clinical results of patellar tendon ruptures: evidence today. Knee.
2015;22:148-155.

35
CHAPTER
Section IV: Thigh
Excision of Soft Tissue
Tumors of the Thigh
Raffi S. Avedian
DEFINITION
■ Soft tissue sarcomas are malignant tumors that arise from mesenchymal cells
and are classified according to their cell of origin such as the muscle, tendon,
or fat.
■ Peripheral nerve sheath tumors arise from neural crest cells but are typically
grouped with sarcomas because of similarities in location, natural history, and
treatment.
■ The World Health Organization groups soft tissue sarcomas into ten categories
based on the tissue of origin.
■ Most sarcomas occur in a deep location meaning below the muscle fascia,
whereas one-third of sarcomas occur in a subcutaneous location.
■ Patients with soft tissue sarcomas and patients with benign tumors often
present with the same chief complaint of having a soft tissue mass.
■ Rendering an accurate diagnosis prior to surgery is important because the
treatment plan may vary based on the nature of the diagnosis. For example, a
benign tumor may be monitored or removed with a simple excision, whereas in
the case of a sarcoma, the goal of surgery is to remove the tumor with a wide
margin.
■ With appropriate planning, radiotherapy and/or chemotherapy is often
incorporated into the treatment plan either before or after definitive surgery.1
ANATOMY

■ The critical anatomic structures that should be preserved when performing an
excision of tumor in the thigh are the femoral artery, sciatic nerve, and femoral
nerve.
■ The common femoral artery enters the thigh under the inguinal ligament. As it
travels distally, it gives several branches, the largest of which is the profundal
femoral artery (PFA). This branch travels on top of the adductor brevis until the
muscle inserts onto the linea aspera at which point the distal half of the PFA
continues just posterior to the femur.
■ Several perforator branches from the PFA pierce the lateral intermuscular
septum and go into the anterior compartment. In most patients, limb salvage
can be performed even if the PFA is ligated near its takeoff from the common
femoral artery.
■ The superficial femoral artery (SFA) is the most important blood vessel when
considering tumor excision. It must be preserved or reconstructed if excised to
maintain viable limb perfusion. As the SFA travels distally, it is located on the
anterior surface of the psoas, adductor longus, and then adductor magnus until
it courses through the adductor canal into the popliteal fossa. The sartorius
muscle acts as a cover to the superficial femoral vessels throughout the middle
of the thigh.
■ There are three muscle compartments of the thigh: anterior, medial, and
posterior.
■ The sciatic nerve travels in the posterior compartment. It branches into the
common peroneal nerve, which can reliably dissected and found just medial
and anterior to the biceps femoris in the popliteal fossa. The tibial nerve
portion of the sciatic nerve stays midline with the popliteal vessels.
■ The femoral nerve divides into several branches that spread out and innervate
the anterior compartment muscles soon after passing under the inguinal
ligament. Unlike the sciatic nerve, which can be isolated throughout the thigh,
the femoral nerve is rarely identified during tumor removal because it branches
so proximally.
PATHOGENESIS
■ The mechanism for sarcoma formation is not known.
■ Risk factors for sarcoma development include radiation exposure,
radiotherapy, pesticide exposure, and hereditary conditions including Li-
Fraumeni syndrome and neurofibromatosis.

NATURAL HISTORY
■ All sarcomas have the potential for local recurrence and metastasis.
■ Tumor variables that are associated with increased risk of metastasis include
high grade and large size (greater than 5 cm).2
■ Lungs are the most common location of metastasis.
PATIENT HISTORY AND PHYSICAL FINDINGS
■ Determining when the mass was first noticed and how rapidly it is growing
can help the clinician differentiate between benign and malignant tumors.
■ The presence of pain is often associated with a benign tumor such as a
schwannoma or vascular malformation and may not be present with sarcomas
until late in the disease course.
■ Determining the size of the tumor, manual muscle strength testing, and sensory
examination are useful to determine if there is neurological compromise. Limb
edema assessment and pulse examination can help determine if the tumor is
causing vascular or lymphatic compromise.
■ Range of motion testing and gait assessment are helpful in assessing a
patient’s mobility and functional status to guide a perioperative and
postoperative counseling.
IMAGING
■ Magnetic resonance imaging is the modality of choice for soft tissue tumor
evaluation.3
■ Fat-sensitive images such as T1-weighted sequences are best for identifying
critical anatomic structures such as nerves and vessels (FIG 1).
■ Fluid-sensitive images including T2-weighted and STIR sequences highlight
pathology very well.
■ Contrast-enhanced sequences are used to differentiated cystic from solid areas
in tumors and identify reactive peritumoral edema, which will be high signal
on fluid sequences but not enhance with contrast.
■ Some benign tumors such as lipoma and schwannoma may be diagnosed on
MRI; however, most soft tissue tumors require a biopsy for diagnosis.
DIFFERENTIAL DIAGNOSIS
■ Benign tumors
■ Sarcoma
■ Lymphoma of soft tissue

■ Infection/abscess
FIG 1 • Axial T1-weighted image demonstrating
compartments of the thigh and relevant anatomy of the
thigh. The arrow points at the sciatic nerve and the
arrowhead at the femoral vessels, and there is a
sarcoma in the vastus medialis.
SURGICAL MANAGEMENT
■ The appropriate treatment for any musculoskeletal tumor is based on its
diagnosis and natural history.
■ Performing a surgery without consideration of the diagnosis and the
appropriate margin may cause harm to patients.4
■ In cases where MR imaging is not diagnostic, a biopsy should be performed.
■ Treatment strategy including the use of preoperative radiation and specific
surgical plan should be formulated by a multidisciplinary team specializing in
sarcoma care.

FIG 2 • A. Axial MRI of the thigh demonstrating a
subcutaneous sarcoma. B. Coronal MRI of the thigh
showing a subcutaneous sarcoma.
Preoperative Planning
■ A patient is considered ready for surgery after completion of staging and
multidisciplinary review of pertinent imaging, pathology, and treatment
strategy.
■ The surgical plan is created by thorough study of the preoperative MR scan. A
plane of surgical dissection is planned to remove the tumor in its entirety while
maintaining a clean margin around it (FIG 2).
■ If the tumor encases important vascular structures, a plan for vascular
reconstruction is made with a vascular surgeon.
■ Anticipated soft tissue coverage needs are assessed such as skin graft, local
rotation flap, or free tissue transfer.
Positioning
■ The patient is placed in the supine position when the tumor is in the anterior or
medial compartment (FIG 3).
■ The patient is placed in the prone position when the tumor is in the posterior
compartment.
■ The site of a flap harvest must be completely isolated from the tumor site to
avoid contamination and tumor spread. A separate back table and clean
instruments should be used.

FIG 3 • Intraoperative photograph demonstrating patient
positioning.
Approach
■ The surgical approach varies based on the location of the tumor.
■ Previous biopsy and surgical scars are considered contaminated and must be
excised en bloc with the tumor.
T E C H N I Q U E S
■ Wide Resection of Subcutaneous Sarcoma
■ Subcutaneous sarcomas are located in the adipose tissue above the muscle
fascia. There is no anatomic barrier to longitudinal tumor spread in this
location; however, the deep fascia can act as a natural barrier to deep
penetration of the tumor. Careful review of preoperative MR imaging and
physical palpation are important when determining tumor extent and the
location of the surgical incision.
■ A surgical incision is planned 2 cm to 3 cm peripheral to the edge of the
tumor as determined by palpation and MRI. Typically, a large paddle of the
skin is removed along with the tumor (TECH FIG 1).
■ The dissection is carried through the subcutaneous fat angling away from the
tumor.
■ The deep fascia is identified and cut circumferentially around the tumor.
■ The fascia and subcutaneous tissue containing the tumor are kept in

continuity, and a small cuff of muscle is removed with the fascia to ensure a
clean deep margin.
■ The tumor and surrounding fat, fascia, and muscle are removed in their
entirety.
■ Take care not to shear off the fat from the fascia during dissection.
■ Avoid retractors on the tumor side of the dissection.
■ Most surgeries require a skin graft or muscle flap for closure. Do not
sacrifice margin to save tissue for a primary closure.
TECH FIG 1 • Operative technique for resecting a
subcutaneous sarcoma. A. Dissection of the skin and
subcutaneous tissue around the tumor, notice the
large paddle of skin that extends approximately 2 cm
beyond the palpable tumor to ensure adequate
resection margin. B. Dissection through the deep
plane leaving the fascia and small, approximately 1-
cm, cuff of underlying muscle on the tumor that serves
as the deep margin. C,D. The skin was then
reapproximated, and preparation for skin grafting was
completed. E. A split-thickness skin graft was obtained
from the contralateral thigh using completely separate
instruments, back table, and clean gowns and gloves

to avoid seeding the harvest site with tumor.
■ Wide Resection of a Deep Sarcoma
■ Because fascia acts as a natural anatomic barrier, tumors tend to grow
longest in a longitudinal dimension; as a result, larger margins in the
longitudinal plane compared to the mediolateral/anteroposterior planes are
recommended.
■ Tumors often abut major nerves and blood vessels in which case the
epineurium around the nerve and adventitia surrounding the vessel can be
used as margins5 (TECH FIG 2).
TECH FIG 2 • A. Axial T1 fat-suppressed contrast MRI
showing a high-grade sarcoma within the vastus
medialis and abutting the femoral artery and vein. B.
Coronal T1 fat-suppressed contrast MRI. C. Axial T1
fat-suppressed contrast MRI after completion of
preoperative radiation showing decreased
enhancement suggesting tumor necrosis.
■ Incision and Dissection
■ A longitudinal incision is made over the tumor by incorporating the previous
biopsy site.
■ Subcutaneous skin flaps are raised circumferentially around the tumor
making sure to the keep the deep fascia intact as a margin around the tumor.

■ Begin the deep dissection by palpating the tumor and incising the deep fascia
several centimeters further out from the tumor. If the tumor abuts the fascia,
then leave the fascia intact, trace it back to its insertion on the bone, and
remove it in its entirety as a margin around the tumor thus avoiding
inadvertent tumor penetration or exposure (TECH FIG 3).
■ It is recommended that several centimeters of muscle be removed from
cranial and caudal to the tumor. The decision on how much muscle to remove
is based on preoperative evaluation of the MRI, palpation of the tumor, and
visual inspection of the muscle to ensure the plane of dissection is outside of
the tumor and any associated abnormal tissue such as a pseudocapsule.
■ If the tumor abuts the bone but there is no evidence of bone penetration, use
a periosteal elevator to lift the periosteum off the bone with the tumor on top.
The periosteum acts as the deep margin.
■ If there is bone penetration, then depending on the extent of bone
involvement, either a hemicortical or complete resection should be performed
and reconstructed with either allograft, vascularized fibula, or endoprosthesis.
■ If the tumor encases the major blood vessels of the limb, they should be
removed en bloc with the tumor followed by vascular reconstruction.
TECH FIG 3 • Operative technique for resection of a
deep sarcoma of the thigh. A. Photograph showing
deep dissection of tumor, * indicates proximal end of
sartorius, X indicates cut distal end of adductor
magnus. The adventitia of the vessels are dissected
and left with the tumor. B. Photograph showing
complete mobilization of the vessels, the medial
intermuscular septum and vessel adventitia “*” serve
as the deep margin. C. Photograph after the
remaining muscles around the tumor are cut and the

tumor is removed with a clean margin. The wound is
closed in layers with multiple suction drains.
■ Completion
■ After tumor removal, irrigate the wound thoroughly and assess the dead
space. An attempt to myodese (muscle-to-muscle approximation with
sutures) surrounding muscles to eliminate as much dead space as possible is
recommended.
■ Other strategies to manage dead space are local or free muscle transfer,
closing over multiple drains, and rarely delayed closure using a negative
pressure dressing.
PEARLS AND PITFALLS
Hematoma
■ Dead space after tumor removal should be managed with drains,
muscle flap, free tissue transfer, or a combination of these techniques.
■ Seroma drainage in the clinic may be necessary.
Wound
breakdown
■ Incisional negative pressure dressings, aggressive dead space
management, and maximizing patients’ nutrition may reduce wound
problems.
■ Patients should be counseled about potential need for reoperation for
wound management.
Positive
margins
■ Appropriate preoperative planning is important to minimize risk of
unplanned positive margins.
■ Planned positive margins around critical structures such as nerves and
vessels may be appropriate in certain settings.
POSTOPERATIVE CARE
■ Mobilization and weight bearing depend on the extent of surgery.
■ Extremity elevation is recommended while patient is in bed.
■ Range of motion and therapy may begin after wound healing is sufficient.
■ Postoperative radiotherapy may take place 4 to 6 weeks after surgery.

OUTCOMES
■ Oncological outcomes include local recurrence and metastasis. Surveillance
for recurrence should be managed by a multidisciplinary sarcoma team.
■ Functional outcomes depend on the extent of tissue resection, patient overall
health status, and late effects of radiation. Aggressive wound care and physical
therapy may help maximize patient function.6,7
COMPLICATIONS
■ Wound healing problems that require operative intervention can occur in up to
33% of patients who undergo preoperative radiotherapy and 17% of patients
who undergo postoperative radiotherapy.1
■ Local recurrence occurs in a minority of patients and is more common in
patients with positive margins. Radiotherapy decreases the risk of local
recurrence.
REFERENCES
1. O’Sullivan B, Davis AM, Turcotte R, et al. Preoperative versus postoperative
radiotherapy in soft-tissue sarcoma of the limbs: a randomised trial. Lancet.
2002;359(9325):2235-2241.
2. van Praag VM, Rueten-Budde AJ, Jeys LM, et al. A prediction model for
treatment decisions in high-grade extremity soft-tissue sarcomas: Personalised
sarcoma care (PERSARC). Eur J Cancer. 2017;83:313-323.
3. Demas BE, Heelan RT, Lane J, et al. Soft-tissue sarcomas of the extremities:
comparison of MR and CT in determining the extent of disease. AJR Am J
Roentgenol. 1988;150(3):615.
4. Pretell-Mazzini J, Barton MD Jr, Conway SA, Temple HT. Unplanned
excision of soft-tissue sarcomas: current concepts for management and
prognosis. J Bone Joint Surg Am. 2015;97(7):597-603.
5. O’Donnell PW, Griffin AM, Eward WC, et al. The effect of the setting of a
positive surgical margin in soft tissue sarcoma. Cancer. 2014;120(18):2866-
2875.
6. Davidge KM, Wunder J, Tomlinson G, et al. Function and health status
outcomes following soft tissue reconstruction for limb preservation in
extremity soft tissue sarcoma. Ann Surg Oncol. 2010;17(4):1052-1062.
7. Davis AM, O’Sullivan B, Bell RS, et al. Function and health status outcomes
in a randomized trial comparing preoperative and postoperative radiotherapy in
extremity soft tissue sarcoma. J Clin Oncol. 2002;20(22):4472-4477.

36
CHAPTER
Excision of Bone Tumors of
the Femur
Raffi S. Avedian
DEFINITION
■ Bone tumors of the femur may be benign or malignant (bone sarcoma) and
exhibit a variable natural history ranging from latent to rapid growth.
Aggressive benign tumors and malignant tumors typically cause pain,
dysfunction, and fracture.
ANATOMY
■ The femoral artery, sciatic nerve, and femoral nerve are important structures
that need to be accounted for during surgery of the femur.
■ The common femoral artery enters the thigh under the inguinal ligament. As it
travels distally, it gives several branches, the largest of which is the profundal
femoral artery (PFA), which travels on top of the adductor brevis until the
muscle inserts onto the linea aspera at which point the distal half of the PFA
continues just posterior to the femur.
■ Several perforator branches from the PFA pierce the lateral intermuscular
septum and go into the anterior compartment. The PFA is located near the linea
aspera and is often ligated when resecting segments of the femur.
■ The superficial femoral artery (SFA) is the most important blood vessel when
considering tumor excision. It must be preserved or reconstructed if excised, to
maintain viable limb perfusion. As the SFA travels distally, it is located on the
anterior surface of the psoas, adductor longus, and then adductor magnus until
it courses through the adductor canal into the popliteal fossa. The sartorius
muscle acts as a cover to the superficial femoral vessels throughout the middle
of the thigh.
■ The sciatic nerve travels in the posterior compartment. It branches into the

common peroneal nerve, which can reliably be dissected and found just medial
and anterior to the biceps femoris in the popliteal fossa. The tibial nerve
portion of the sciatic nerve stays midline with the popliteal vessels.
PATHOGENESIS
■ The mechanism for bone tumor formation is not known.
■ Risk factors for sarcoma development include radiation exposure,
radiotherapy, pesticide exposure, and hereditary conditions including Li-
Fraumeni syndrome and retinoblastoma gene mutation.
NATURAL HISTORY
■ Active benign tumors, such as giant cell tumor of the bone, chondroblastoma,
and aneurysmal bone cyst, will progress over time and may recur after excision
but are not lethal.
■ All bone sarcomas have the potential for local recurrence and metastasis.
■ Some bone sarcomas such as low-grade chondrosarcoma exhibit a slow rate of
growth and low risk of metastasis, whereas aggressive tumors like high-grade
osteosarcoma and dedifferentiated chondrosarcoma grow rapidly and have a
relatively high risk of metastasis.
■ Tumor variables that are associated with increased risk of metastasis include
high grade and large size (greater than 8 cm).
■ Lungs and other osseous sites are the most and second most common location
of metastasis, respectively.
PATIENT HISTORY AND PHYSICAL FINDINGS
■ Pain is a common presenting symptom for aggressive bone tumors.
■ A thorough history and examination are important to assess duration of
symptoms, comorbidities, physical dysfunction, organ involvement, overall
health, and patient expectations to best tailor treatment strategy for the
individual patient.
■ Neurovascular examination is mandatory for any extremity tumor.
IMAGING
■ Plain radiographs are used to formulate a differential diagnosis and a
preoperative plan (FIG 1A).
■ Magnetic resonance imaging is routinely used to determine the extent of
intramedullary tumor involvement, presence of soft tissue extension, status of
the neurovascular structures, and preoperative planning (FIG 1B).

DIFFERENTIAL DIAGNOSIS
■ The differential diagnosis for a bone tumor includes benign tumors, sarcomas,
lymphoma of the bone, infection, and metabolic lesions (eg,
hyperparathyroidism).
■ The most common bone sarcomas are osteosarcoma, chondrosarcoma, and
Ewing sarcoma.
SURGICAL MANAGEMENT
■ The appropriate treatment for any musculoskeletal tumor is based on its
diagnosis and natural history.
■ Biopsy incisions are considered contaminated and must be resected at the time
of definitive surgery. Care should be taken to place the biopsy in a location that
does not interfere with the final surgical plan.
FIG 1 • A. Anteroposterior radiograph of a 67-year-old
man with high-grade chondrosarcoma of the proximal
femur seen as a large lucent lesion. B. Coronal T2-
weighted MRI of the same patient demonstrating
extensive soft tissue component and intramedullary
involvement by chondrosarcoma.
■ Intralesional curettage is the preferred treatment for benign tumors. Radical
resection with a clean margin is required for bone sarcomas.
■ Reconstruction depends on the extent of bone excision and may include simple
bone grafting, endoprosthetic implants, bulk allografts, osteoarticular implants,

or vascularized fibula.
■ The goal of surgery is to remove the tumor adequately to minimize recurrence
and restore the mechanical integrity of the bone and joints so that the patient
may have sufficient function to perform activities of daily living with minimal
pain.1,2
Preoperative Planning
■ A patient is considered ready for surgery after completion of staging and
multidisciplinary review of pertinent imaging, pathology, and treatment
strategy.
■ The surgical plan is created by a thorough study of the preoperative
radiographs and MR scan.
■ Bone cuts are planned by examining preoperative imaging and measuring the
distance from an intraoperatively identifiable landmark (eg, femoral condyle,
greater trochanter) to the desired osteotomy site.
■ The soft tissue margin depends on the size and location of a soft tissue
component to the tumor. For example, an anterior soft tissue mass along the
distal femur can be safely resected by incorporating a portion of the vastus
intermedius as the margin.
■ When tumor abuts but does not encase blood vessels or nerves, they can be
dissected free by leaving adventitia and epineurium on the tumor as the margin.
Positioning
■ Patient positioning is based on the surgeon’s assessment of the critical
anatomy of the surgery and how best to visualize it during surgery.
■ Distal femur resections are typically performed in the supine position.
Proximal femur tumors are often performed in the lateral position.
■ If a flap is to be used, the harvest must be performed using a separate back
table and instruments and the surgical sites completely isolated to avoid
contamination.
Approach
■ The surgical approach varies based on the location of the tumor.
■ Previous biopsy and surgical scars are considered contaminated and must be
excised en bloc with the tumor.