Operative Technique in Plastic Surgery – Kevin C.Chung

violating the nail matrix.
■ Make a longitudinal midaxial incision dorsal to the digital neurovascular
bundle and volar to the lateral nail germinal matrix on the side of the digit
closest to the lesion (TECH FIG 2A).
■ Dissect sharply to the level of the distal phalanx.
■ Create a composite dorsal subperiosteal flap with a sharp elevator. The flap
consists of skin, nail, germinal tissue, and the nail plate as a unit7 (TECH
FIG 2B).
■ Identify the lesion and excise it or remove it with a curette. Inspect for any
additional lesions to excise.
■ Replace the flap and close the incision primarily with an interrupted
permanent suture.
■ Place a bulky dressing.
TECH FIG 2 • A. Incision for the lateral approach. B.

Exposure is obtained by raising a dorsal subperiosteal
flap exposing the glomus tumor (arrow).
PEARLS AND PITFALLS
Approach
■ Transungual approach will give the widest view of the tumor.
■ The lateral approach has less incidence of nail deformity.
Outcomes
■ Early postoperative recurrence of symptoms is typically from an
incomplete resection.
■ A delayed recurrence is likely the development of a new tumor.
POSTOPERATIVE CARE
■ The patient remains in the bulky dressing for 1 to 2 weeks.
■ Sutures are removed at 10 to 14 postoperative days.
■ Early range of motion and return to normal activity is encouraged.
OUTCOMES
■ Recurrence rates range from 15% to 24%.7
■ Early recurrence is typically from an incomplete excision, whereas late
recurrence is likely from the formation of a new tumor.
COMPLICATIONS
■ A nail bed deformity is described in 3.3% to 10% of cases with transungual
excision.7
■ There is always a risk of digital nerve injury with the lateral subperiosteal
approach.
REFERENCES
1. Lee W, Kwon SB, Cho SH, et al. Glomus tumor of the hand. Arch Plast Surg.
2015;42(3):295-301.
2. Walsh JJ, Eady JL. Vascular tumors. Hand Clin. 2004;20(3):
261-268.
3. McDermott EM, Weiss APC. Glomus tumors. J Hand Surg [Am].
2006;31(8):1397-1400.

4. Van Geertruyden J, Lorea P, Goldschmidt D, et al. Glomus tumours of the
hand: a retrospective study of 51 cases. J Hand Surg Br. 1996;2(21):
257-260.
5. Rohrich R, Hochstein L, Millwee R. Subungual glomus tumors: an
algorithmic approach. Ann Plast Surg. 1994;33(3):300-304.
6. Netscher DT, Aburto J, Koepplinger M. Subungual glomus tumor. J Hand
Surg [Am]. 2012;37(4):821-823.
7. Vasisht B, Watson HK, Joseph E, Lionelli GT. Digital glomus tumors: a 29-
year experience with a lateral subperiosteal approach. Plast Reconstr Surg.
2004;114(6):1486-1489.

73
CHAPTER
Excision of Hemangioma of
the Hand
Paymon Rahgozar and Kevin C. Chung
DEFINITION
■ Hemangiomas are the most common benign tumor of infancy, with
approximately 15% found on the upper extremities.1,2
■ The lesion is a vascular tumor consisting of plump endothelial cells with a
rapid turnover and a three-phase growth cycle3:
■ Rapid cell proliferation and growth
■ Slow growth and maturation
■ Involution
ANATOMY
■ Histologically, there are two types of infantile hemangiomas.
■ The capillary type is nonvascular with a spongy appearance.
■ The cavernous type has plump endothelial cells and many mast cells lining
large vessels with small lumina.1,2
■ During the proliferative phase, the lumina widen and the endothelium flattens.
As the hemangioma enters the involution phase, there is increased mast cell
infiltration and progressive fibrosis of the mass.1
■ Infantile hemangiomas will stain positive for GLUT-1 in all phases,
differentiating them from other hemangiomas.2
PATHOGENESIS
■ Hemangiomas occur as a result of endothelial cell proliferation.
■ Congenital hemangiomas are caused by a failure of proper differentiation of
vascular channels during embryonic development.
■ Studies have shown that children with hemangiomas have increased estrogen

levels that resolve after treatment. That, along with a female predominance,
suggests a hormonal association.1,3
NATURAL HISTORY
■ Although only 30% of hemangiomas are visible at birth, 70% to 90% are
apparent by 4 weeks of age.
■ The rapid cell proliferation phase outpaces the growth of the child, whereas
the slow growth phase is more proportional to the child’s growth.1
■ About 50% will involute by age 5 and 90% involute by age 9 years.2
■ Thirty percent of hemangiomas ulcerate with superficial bleeding.3
PATIENT HISTORY AND PHYSICAL FINDINGS
■ Hemangiomas of the hand are found most commonly on the palm because it is
the richest vascular area of the hand.4
■ Superficial hemangiomas appear as a raised red papule, nodule, or plaque
(FIG 1A,B). Deeper hemangiomas have a bluish hue (FIG 1C).
■ An area of pallor with telangiectasias may be a precursor lesion identifiable at
birth.2
■ Children with a propensity to suck their fingers may present with ulcerations
and paronychia.
■ Other clinical findings may include pain, infection, bleeding, or congestive
heart failure in very large lesions. Pain is most notable when the extremity is
held in a dependent position secondary to venous engorgement.
■ Platelet trapping within the hemangioma can lead to gross thrombocytopenia
and consumptive coagulopathy, known as Kasabach-Merritt syndrome.
■ Upper extremity growth and function is typically unaffected with
hemangiomas.

FIG 1 • A,B. Superficial hemangiomas typically appear
as a raised red-colored papule. C. Deeper
hemangiomas typically have a bluish hue.
IMAGING
■ Plain radiographs rarely show small, smooth, round calcifications, termed
phleboliths, but otherwise are of limited value.4,5
■ Hemangiomas appear as a well-circumscribed mass on MRI with gadolinium
enhancement.
■ The T1 signal is low and the T2 signal is high with an appearance of
heterogeneity due to the variable feeding and draining vessels.1
■ Ultrasound is also a valuable preoperative tool to determine the depth of the
lesion.
■ Angiograms will show a well-circumscribed lesion with a blush, as well as
tributary feeding and draining vessels. It can be used for diagnosis and
treatment if embolization is planned.
DIFFERENTIAL DIAGNOSIS
■ Arteriovenous or lymphatic malformation
■ Glomus tumor
■ Angiosarcoma
■ Hemangioendothelioma
■ Pyogenic granuloma
NONOPERATIVE MANAGEMENT
■ In the absence of systemic hematologic symptoms (thrombocytopenia), the
initial treatment for hemangiomas is observation.
■ Other modalities including steroids, propranolol, vincristine, laser ablation,
and treatment with interferon alpha have been described.
■ Propanolol is thought to increase apoptosis of endothelial cells and induce
adipogenesis of hemangioma stem cells.2
SURGICAL MANAGEMENT
■ Surgery is rarely indicated except for cases of mass effect, uncontrollable
bleeding, or lesions refractory to conservative measures.
■ Presence of a pseudocapsule during the proliferative phase simplifies excision

as compared to surgery during the maturation or involution phases when the
margins are more difficult to define.3
Preoperative Planning
■ Appropriate radiographic studies should be performed to identify the extent of
the lesion and involvement of any vital structures.
■ Complete knowledge of the vascular anatomy is crucial, including assessment
of the superficial palmar arch with an Allen test.
Positioning
■ The patient is positioned supine on the operating table, and the extremity is
positioned on a hand table.
■ The extremity is prepped and draped circumferentially.
■ Anesthesia is administered and a tourniquet is applied.
Approach
■ The location of the lesion dictates the approach to provide adequate
visualization for excision.
■ Digital lesions are best approached with mid-axial or zigzag incisions, taking
care to avoid crossing the flexion creases.
■ Similarly, palmar lesions are best excised with zigzag incisions by avoiding
placement of the incision at 90-degree angles to flexion creases.
T E C H N I Q U E S
■ Incision and Dissection
■ Apply a tourniquet without exsanguinating the extremity so that the entire
tumor mass can be better identified for excision.4
■ Make an incision to provide adequate access for excision of the hemangioma
(TECH FIG 1A,B).
■ If ulceration is present, use an elliptical incision to excise the affected skin.
■ Take care to incise only to the depth of the dermis, avoiding the subdermal
layer with any potential dilated plexuses.
■ Identify the dilated subdermal vessels and ligate with suture or, if small

enough, with electrocoagulation.
■ Circumferentially dissect the tumor (TECH FIG 1C,D).
■ Between the surrounding fat will be septal structures with capillary
networks that must be identified and coagulated with bipolar cautery.
■ Any reddish or purple fat particles within the tumor should not be
disturbed to avoid significant bleeding.6
■ Carefully dissect through the subcutaneous tissue to identify and ligate the
proximal and distal tributary vessels (TECH FIG 1E).
TECH FIG 1 • A. Hemangioma of the palm of the
hand. Note the zigzag incision for exposure. B.
Hemangioma of the volar thumb. The incision
provides adequate exposure and does not cross the

flexion creases avoiding the risk of scar contracture.
C,D. Identification and circumferential dissection of the
tumor. Take care to avoid injury to the tributary vessels
prior to ligation. E. The tributary vessels feeding and
draining the hemangioma should be ligated as far
from the tumor as possible.
■ Excision
■ Identify all local neurovascular structures to confirm that the tumor is not
wrapped around a nerve or vessel.
■ Occasionally, the tumor may arise from vessels within striated muscle.
Perform careful dissection and take a small cuff of muscle if necessary.4
■ Excise the hemangioma and confirm that the resection is complete with
margins (TECH FIG 2A,B).
■ Inspect to confirm there is no injury to surrounding neurovascular structures
(TECH FIG 2C).
■ Release the tourniquet and obtain hemostasis.
■ Perform primary closure if possible (TECH FIG 2D). If skin is excised due
to dermal involvement and primary skin closure is not possible, the resultant
defect may be closed with a skin graft or local flap.

TECH FIG 2 • A. Excision of the specimen. B.
Resected specimen. Hemangiomas can vary in size
from millimeters to multiple centimeters in size. C.
Inspection reveals that the digital neurovascular
bundle remains intact. D. Primary closure following
excision of a thumb hemangioma.
PEARLS AND PITFALLS
Management
■ Most lesions can be managed with observation.
Operative
■ Surgical excision is easiest in the proliferative phase because of the
presence of a pseudocapsule making it easier to identify tumor
margins.
■ Apply the tourniquet without exsanguination.
■ Ligate the tributary vessels as far as possible from the lesion.
■ The lesion may be encasing a neurovascular structure. Meticulous
dissection is crucial.
POSTOPERATIVE CARE
■ A bulky dressing is applied for approximately 1 week and sutures are removed
at 10 to 14 days after surgery.
■ If a skin graft or flap is required, the appropriate dressing and wound care
should be performed.
OUTCOMES
■ Diffuse lesions have higher recurrence rates.
■ Amputation may be necessary if there are multiple recurrences despite
repeated excisions.
■ Deep cavernous hemangiomas are the only type found to recur due to its
intramuscular location, high vascularity, and proximity to neurovascular
structures.5
■ Most recurrences manifest by 2 years but can appear as long as 6 years after
the primary excision.7

COMPLICATIONS
■ Although rare, the most common complications are wound related (infection,
dehiscence, contracture).
■ Postoperative hematoma or bleed can best be avoided with meticulous
hemostasis.
REFERENCES
1. Jacobs BJ, Anzarut A, Guerra S, et al. Vascular anomalies of the upper
extremity. J Hand Surg [Am]. 2010;35(10):1703-1709; quiz 1709.
2. Willard KJ, Cappel MA, Kozin SH, Abzug JM. Congenital and infantile skin
lesions affecting the hand and upper extremity, part 1: vascular neoplasms and
malformations. J Hand Surg [Am]. 2013;38(11):
2271-2283.
3. Walsh JJ, Eady JL. Vascular tumors. Hand Clin. 2004;20(3):261-268.
4. Palmieri TJ. Subcutaneous hemangiomas of the hand. J Hand Surg [Am].
1983;8(2):201-204.
5. Canavese FS, Soo BC, Chia SK, Krajbich JI. Surgical outcome in patients
treated for hemangioma during infancy, childhood, and adolescence: a
retrospective review of 44 consecutive patients. J Pediatr Orthop.
2008;28(3):381-386.
6. Fujino T, Yamamoto K, Kuboto J, et al. Microsurgical technique in resection
of hemangioma in infants. Ann Plast Surg. 1985;14(3):
190-204.
7. Tang P, Hornicek FJ, Gebhardt MC, et al. Surgical treatment of hemangiomas
of soft tissue. Clin Orthop. 2002;86(399):205-210.

74
CHAPTER
Excision of Metacarpal
Enchondroma
Paymon Rahgozar and Kevin C. Chung
DEFINITION
■ Enchondromas are benign, intramedullary, cartilaginous lesions that are the
most common primary bone tumors of the hand.
ANATOMY
■ Enchondromas are typically white to blue-gray solitary lesions found in the
diaphysis of tubular hand bones with varying degrees of calcification.
■ The lesions are most often found in medullary cavities of the metacarpals and
the phalanges.
PATHOGENESIS AND NATURAL HISTORY
■ Enchondromas are thought to arise from displaced chondrocytes left behind in
the metaphysis and diaphysis as the epiphysis moves through the process of
enchondral growth.1
■ Typically, they are found incidentally, but they can occasionally present with
pathologic fractures.
■ Although incidental enchondromas can be observed, those presenting with a
fracture or radiographically at risk for a fracture can be treated surgically with
a low likelihood for recurrence.2
■ Rarely, an enchondroma may transform to chondrosarcoma.
■ Malignant transformation is more likely in patients with enchondromatosis.
However, malignancy occurs more often in the long bones rather than in the
hand.3
PATIENT HISTORY AND PHYSICAL FINDINGS

■ Enchondromas are typically asymptomatic and found incidentally.
■ Bony deformities can be present with pathologic fractures.
■ Patients may complain of painful swelling if bone distension is present.
■ Multiple enchondromas are found in patients with Ollier disease (multiple
enchondromatosis) and Maffuci syndrome (multiple enchondromatosis with
multiple soft tissue hemangiomas).
IMAGING
■ An appearance of a well-defined lobulated lytic lesion in the diaphysis or
metadiaphysis on plains films is characteristic (FIG 1).
■ There may be calcifications or endosteal scalloping.2
■ Findings concerning for malignant degeneration include progressive cortical
bone destruction, replacement of the mineralized portion by a nonmineralized
component, bone proliferation, or a soft tissue mass.2
FIG 1 • Radiograph of fifth metacarpal enchondroma
presenting with pathologic fracture (arrow).

DIFFERENTIAL DIAGNOSIS
■ Chondrosarcoma
■ Chondroblastoma
■ Unicameral bone cyst
■ Giant cell tumor of bone
■ Chondromyxoid fibroma
■ Fibrous dysplasia
■ Bone infarct
NONOPERATIVE MANAGEMENT
■ Incidental enchondromas can be observed if radiographic assessment suggests
a benign, nonaggressive lesion.
■ It is imperative to determine the risk of pathologic fracture, given the patient’s
activity level. Any concern for the possibility of pathologic fracture should
prompt excision.
■ The patient must be made aware of the rare but present risk of malignant
degeneration with observation.
■ Routine follow-up radiographs should be performed for at least a 2-year period
to confirm stability of the lesion.2
■ There should be a low threshold to re-evaluate a patient should symptoms
develop.
SURGICAL MANAGEMENT
■ Enchondromas that present with a pathologic fracture should be treated after a
period of immobilization to allow fracture healing.
■ If the fracture requires acute treatment with an open approach, immediate
treatment of the enchondroma should be considered.4
■ The first step in surgical management is an open biopsy with frozen section
analysis to confirm the presence of cartilage tissue and rule out
chondrosarcoma. If there is a concern for malignancy, the wound should be
closed and further treatment deferred until permanent section analysis is
performed.2
■ The bony defect can be filled with bone autograft, bone allograft, a bone
substitute such as calcium-based cement, or left unfilled with relatively
comparable results.4–7

Preoperative Planning
■ Radiographic imaging will reveal the location and extent of the lesion.
Positioning
■ The patient is positioned supine on the operating table, and the extremity is
positioned on a hand table.
■ The extremity is prepped and draped circumferentially.
■ The appropriate anesthesia is administered (general, regional block, digital
block), and a tourniquet is applied.
Approach
■ Metacarpal lesions are best approached through a dorsal incision.
■ A longitudinal incision is preferable to facilitate future limb-sparing surgery if
malignancy is identified on pathology.
T E C H N I Q U E S
■ Enchondroma Excision and Bone Grafting
■ Make a dorsal longitudinal incision overlying the involved metacarpal
(TECH FIG 1A).
■ Reflect the periosteum and identify the metacarpal bone (TECH FIG 1B).
■ Create a cortical bone window with the use of a blade, rongeur, curette, or
drill.
■ Send a sample to pathology for frozen section to confirm the diagnosis of a
benign enchondroma.
■ If there is any question of a malignancy, definitive treatment must be
deferred until a final diagnosis is made on permanent pathologic analysis.
■ Once diagnosis of enchondroma is confirmed, enlarge the bone window and
curette the lesion (TECH FIG 1C).
■ It is imperative that there is adequate exposure to confirm complete
excision.
■ Pack the resultant cavity with preferred bone grafting material (autograft,
allograft, or synthetic bone substitute; TECH FIG 1D).
■ Confirm complete excision and adequate grafting with intraoperative

radiographs.
■ Close the incision primarily (TECH FIG 1E).
■ Apply a bulky dressing and a protective splint.
TECH FIG 1 • A. Dorsal longitudinal incision for a fifth
metacarpal enchondroma. B. Soft tissue dissection
reveals the periosteum of the metacarpal. C. An
appropriately sized bone window will give access to

curettage the enchondroma specimen, which has
been removed in this photo. D. Placement of allograft
in the bone defect. E. Primary closure of incision.
PEARLS AND PITFALLS
Presentation
■ In cases of pathologic fracture, allow healing of the fracture site
before definitive treatment because fixation of the fracture can be
difficult in the thin bone surrounding the tumor.
■ If found incidentally, the lesion can be observed if no malignant
features are present.
Diagnosis
■ Plain films will show characteristic features.
■ Malignancy must be ruled out before proceeding with definitive
excision. Consult a pathologist in advance.
Operative
■ Make the “bone window” approximately 2/3 the size of the lesion
for adequate visualization of the lesion and the cavity.
■ Confirm complete excision with imaging before leaving the
operating theater.
POSTOPERATIVE CARE
■ Continue protective splinting for 6 weeks after surgery but begin range-of-
motion exercise at 7 to 10 days after surgery with supervised therapy.
■ Obtain surveillance radiographs at 6 months, 1 year, 2 year, and subsequently
if symptoms develop.
OUTCOMES
■ Recurrence after curettage is between 2% and 15%.2,7
■ A malignant process must be considered and ruled out in all cases of
recurrences, prompting a thorough review of the radiographs and histology.
COMPLICATIONS
■ Enchondromas may lead to extensor tendon adhesions, nonunions, metacarpal
shortening, decreased range of motion, or postoperative fracture.
■ Complication rates are higher with excision of recurrent lesions.7

REFERENCES
1. Milgram JW. The origins of osteochondromas and enchondromas: a
histopathologic study. Clin Orthop Relat Res. 1983;(174):264-284.
2. O’Connor MI, Bancroft LW. Benign and malignant cartilage tumors of the
hand. Hand Clin. 2004;20(3):317-323.
3. Liu J, Hudkins PG, Swee RG, Unni KK. Bone sarcomas associated with
Ollier’s disease. Cancer. 1987;59(7):1376-1385.
4. Haase SC. Treatment of pathologic fractures. Hand Clin. 2013;29(4):
579-584.
5. Bachoura A, Rice IS, Lubahn AR, Lubahn JD. The surgical management of
hand enchondroma without postcurettage void augmentation: authors’
experience and a systematic review. Hand. 2015;10(3):461-471.
6. Lin SY, Huang PJ, Huang HT, et al. An alternative technique for the
management of phalangeal enchondromas with pathologic fractures. J Hand
Surg [Am]. 2013;38(1):104-109.
7. Sassoon AA, Fitz-Gibbon PD, Harmsen WS, Moran SL. Enchondromas of the
hand: factors affecting recurrence, healing, motion, and malignant
transformation. J Hand Surg [Am]. 2012;37(6):
1229-1234.

75
CHAPTER
Excision of Peripheral Nerve
Schwannoma
Paymon Rahgozar and Kevin C. Chung
DEFINITION
■ Schwannomas, also termed neurilemmomas are the most common benign
nerve tumors of the hand.
■ The lesions are peripheral nerve sheath tumors arising from Schwann cells
within the endoneurial layer.
■ Schwannomas do not result in neural dysfunction. As a result, if it is not
considered in the differential for an upper extremity mass, inadvertent nerve
injury may result during excision.
ANATOMY
■ Schwannomas grow eccentrically from the nerve sheath and are well
encapsulated. As a result, nerve fasciculi cannot enter the lesions.
■ The tumors are typically found on the volar surface of the forearm or the hand
and are usually less than 2.5 cm in diameter.1
■ On histology, there are interlacing fascicles of spindle cells with large oval
nuclei in a palisade appearance, referred to as Antoni type A. Areas that are
less well defined with fewer cells and less extracellular ground substance are
termed Antoni type B.1,2
PATHOGENESIS
■ Schwannomas are a result of a benign proliferation of differentiated Schwann
cells of a single nerve funiculus that surround the nerve.3
■ Malignant transformation is rare.4
■ Neurofibromas also arise from Schwann cells but can easily be differentiated
from schwannomas due to growth within the substance of the nerve, making

enucleation impossible.
NATURAL HISTORY
■ Schwannomas are quite rare and have a variable presentation, frequently
leading to an incorrect clinical diagnosis.
■ Multiple schwannomas of the large peripheral nerve trunks may be found in
patients with neurofibromatosis type 1 (von Recklinghausen disease).
■ Patients with neurofibromatosis type 2 develop bilateral acoustic
schwannomas.
PATIENT HISTORY AND PHYSICAL FINDINGS
■ Schwannoma typically presents in the middle decades of life as a well-
circumscribed, firm, painless, slow growing tumor. It is rarely associated with a
neurologic deficit.
■ Typically, schwannoma is a mass that appears in line with the nerve trunk.
Therefore, it is mobile in the transverse direction but not in the longitudinal
plane.2
■ Although schwannomas are usually solitary, they have been found to occur as
multiple lesions. These tumors usually have no mass effect or ischemic effect
of the involved nerve.5
■ On exam, it can appear to have a cystic consistency often being misdiagnosed
as a ganglion.3,5
■ Intraoperatively, the tumor can easily be shelled out, distinguishing it from
other nerve tumors (FIG 1A).
■ Schwannomas appear within the digital nerve approximately half the time.
However, it is uncommon to find one distal to the proximal interphalangeal
joint of the fingers or distal to the interphalangeal joint of the thumb (FIG
1B).3

FIG 1 • A. Schwannomas are well-circumscribed tumors
that can easily be enucleated from the involved nerve.
B. Approximately half of schwannomas are found within
digital nerves.
FIG 2 • MR images of an ulnar nerve schwannoma. A.
T2-weighted image with bright appearance of the
schwannoma. B. T1-weighted image has an
intermediate signal intensity due to the presence of fat
within the tumor.
IMAGING

■ MRI is the standard to localize the tumor and delineate the surrounding
anatomy for surgical planning.
■ The lesion appears bright on T2-weighted images though the presence of
adipose tissue within the lesion will give an intermediate signal intensity on
T1-weighted images (FIG 2).
■ The similar appearance on MRI makes it difficult to distinguish between a
schwannoma, neurofibroma, and a malignant nerve sheath tumor.
■ High-frequency ultrasound will show schwannomas as masses of low
echogenicity with distal enhancement.2
DIFFERENTIAL DIAGNOSIS
■ Ganglion cyst
■ Neurofibroma
■ Giant cell tumor
■ Lipoma
■ Epidermal inclusion cyst
NONOPERATIVE MANAGEMENT
■ For asymptomatic schwannomas, observation is acceptable.
■ Any malignant features on MRI imaging should prompt a discussion with the
patient for surgical excision.
SURGICAL MANAGEMENT
■ Surgery is indicated for definitive diagnosis, for symptom control, or to
exclude malignancy.
■ An excisional biopsy is performed by enucleation of the tumor following an
intraneural dissection.
■ Schwannomas are noninfiltrative and can be freed from adjacent fascicles
without injury.3
■ If the tumor is adherent to the surrounding tissue or is not well encapsulated,
the diagnosis should be questioned.
■ An incisional biopsy should be performed with definitive treatment delayed
until after a permanent pathologic examination.1
Preoperative Planning
■ Preoperative imaging, typically MRI, can be used to identify the extent of the
lesion and its proximity to other vital structures.

■ The possibility of postoperative neurologic deficit, though uncommon, must
be discussed with the patient.
Positioning
■ The patient is positioned supine on the operating table, and the extremity is
positioned on a hand table.
■ The extremity is prepped and draped circumferentially.
■ The appropriate anesthesia is administered (general, regional block, digital
block) and a tourniquet is applied.
Approach
■ The location of the lesion dictates the technique and the approach chosen.
■ Palmar lesions are best approached with a zigzag incision.
■ A midaxial approach is most effective for digital nerve lesions for best
visualization and protection of the adjacent digital vessel.
■ Median nerve lesions should be excised with an open carpal tunnel incision.
T E C H N I Q U E S
■ Schwannoma Enucleation
■ Expose the involved nerve and its nerve fascicles proximal and distal to the
tumor. Fascicles will be seen draping over the mass and may have a
multilobulated or pedicled appearance.
■ Completely inspect the nerve to determine the location where there is a
splaying of fascicles that would be the best resection plane (TECH FIG 1A).
■ Incise the nerve sheath longitudinally, taking care to avoid injury to the
fascicles and vessels running within the epineurium.
■ Carefully peel away the fascicles from the tumor circumferentially until the
tumor can be shelled out from the nerve (TECH FIG 1B).
■ Following resection, inspect the nerve to confirm fascicular continuity
(TECH FIG 1C).
■ In cases of digital nerve, an operating microscope is needed to preserve
axons.
■ Identify normal nerve fibers proximally.

■ Trace axon bundles distally and carefully dissect them free from the mass.
■ The specimen should have no nerve fascicles within it (TECH FIG 1D).
■ Close the incision with interrupted 4-0 nylon sutures and place a bulky
dressing.
TECH FIG 1 • Schwannoma of the ulnar nerve. A.

Splaying of the nerve fascicles around the lesion. A
clean plane exists between the mass and the
fascicles. B. The mass is shelled out carefully
between the splayed fascicles. C. Following resection
of the schwannoma, all nerve fascicles remain intact.
D. Schwannoma specimen.
PEARLS AND PITFALLS
Indications
■ Diagnosis—exclude malignancy
■ Symptom control
Diagnosis
■ Misdiagnosis is common—often confused with a ganglion.
■ MRI is the best imaging modality.
Surgical
approach
■ Loupe magnification or an operative microscope will facilitate
microdissection to minimize axonal injury.
■ If the mass is adherent to the nerve, question the preoperative
diagnosis and consider malignancy.
POSTOPERATIVE CARE
■ A bulky dressing is typically adequate. Early hand elevation and early finger
motion are encouraged.
■ The sutures are removed at approximately 10 days and range-of-motion
exercises begin at this time.
OUTCOMES
■ Recurrence is very rare.
■ Transient paresthesias are common, but long-term nerve dysfunction is very
uncommon.
COMPLICATIONS
■ Incidence of postoperative neurologic deficit is 4%.4
■ Inadvertent nerve resection can occur if the diagnosis is not considered
preoperatively.

REFERENCES
1. Forthman CL, Blazar PE. Nerve tumors of the hand and upper extremity.
Hand Clin. 2004;20(3):233-242.
2. Kehoe N, Reid R, Semple J. Solitary benign peripheral-nerve tumours: review
of 32 years’ experience. J Bone Joint Surg Br. 1995;77(3):497-500.
3. Rockwell GM, Thoma A, Salama S. Schwannoma of the hand and wrist. Plast
Reconstr Surg. 2003;111(3):1227-1232.
4. Donner TR, Voorhies RM, Kline DG. Neural sheath tumors of major nerves. J
Neurosurg. 1994;81(3):362-373.
5. Phalen GS. Neurilemmomas of the forearm and hand. Clin Orthop Relat Res.
1976;(114):219-222.

76
CHAPTER
Excision of Malignant Skin
Tumors
Paymon Rahgozar and Kevin C. Chung
DEFINITION
■ Basal cell carcinoma (BCC), the second most common cutaneous malignancy
of the hand, arises from the basal layer of the epithelium or from the external
root sheath of the hair follicle.
■ Squamous cell carcinoma (SCC) is the most common malignant cutaneous
tumor of the hand.
■ Melanomas are aggressive tumors of the epidermis that account for 3% of all
hand tumors.
■ Both SCC and melanoma can invade locally, involve regional lymph nodes, or
metastasize to distant sites.
ANATOMY
■ BCCs most often occur in sites with higher concentrations of pilosebaceous
follicles.
■ Up to 87% of the tumors appear on the dorsum of the hand between the wrist
crease and the metacarpal heads.1
■ SCC derives from the epidermal keratinocyte cell layer but can also develop in
the nail matrix.
■ Although dorsal hand involvement is common for SCC, the tumors can also
be found on the nails, fingers, interdigital skin, or dorsal wrist with relative
frequency.1,2
■ Melanoma is from a neural crest origin developing from the dendritic cell
within the epidermis. The melanocytes can migrate to both cutaneous and
noncutaneous locations, such as the nail matrix.
■ Subtypes include superficial spreading (most common), nodular (most

aggressive), lentigo maligna, acral lentiginous, and amelanotic melanoma.
■ Skin tumors found in the palm are most commonly the acral lentiginous
subtype.1,3
PATHOGENESIS
■ Malignant tumors of the hand are rare, often leading to a delay in diagnosis
and treatment.
■ Risk factors for malignant skin tumors are similar and include sun/ultraviolet
exposure, fair skin, male gender, or advancing age.
■ Although basal cell cancer is the most common cutaneous malignancy, only
2% to 3% of all BCC appear in the upper extremities.2 Therefore, in the hand,
squamous cell cancer is the most common cutaneous malignancy.
■ A history of severe burns, chronic ulcers, or immune compromise can lead to
SCC.
■ Those with a personal history of skin cancer, family history of melanoma,
history of a changing mole, or exposure to coal tar, arsenic compounds, or
radiation have an increased risk of melanoma.
NATURAL HISTORY
■ Basal cell carcinoma
■ In comparison to SCC or melanoma, BCC does not arise from malignant
changes of pre-existing structures. It originates from the basal layer of the
epithelium or the root sheath of a hair follicle.2
■ High-risk lesions include the superficial, micronodular, morpheaform, and
infiltrative subtypes.3 Nodular BCC is the most common low-risk subtype.
■ The metastatic rates in BCC are as low as 0.1%, presumably because the
reticular dermis functions as a relative barrier to its spread.2,4
■ Squamous cell carcinoma
■ Seventy-five percent of skin cancers that appear in the hand are SCC with a
male-to-female ratio of 4:1.5
■ SCCs originate from the spindle cell layer of the epithelium.2 The tumor will
typically begin as a nodule and will progress to develop areas of necrosis.
■ High-risk lesions are those with a diameter greater than 2 cm, vertical depth
greater than 4 mm, rapid growth, perineural invasion, or presence of poorly
differentiated cells.4,5
■ The risk of metastases involving the extremities is 2% to 5%.6
■ Melanoma

■ The incidence of melanoma is increasing at a rapid rate, nearly doubling
every 8 to 10 years.3,6
■ The lifetime probability of developing melanoma is 1 in 49 for males and 1
in 73 for females.
■ Prognosis is dependent on the vertical thickness (Breslow classification) or
the anatomic level of invasion (Clark classification).
PATIENT HISTORY AND PHYSICAL FINDINGS
■ Basal cell carcinoma
■ BCCs are characteristically found in middle-aged and elderly light-skinned
individuals who report a history of multiple skin malignancies.
■ The typical appearance is that of a raised maculopapular lesion in the setting
of skin atrophy, skin discoloration, and telangiectasias, with raised pearly
borders and eventual ulceration (FIG 1A).
■ Squamous cell carcinoma
■ SCC may appear as a slow-growing, verrucous, exophytic lesion or as a
rapid-growing, nodular, indurated lesion with raised borders and early
ulceration (FIG 1B).
■ The slow-growing variety has a higher propensity to metastasize.

FIG 1 • A. Basal cell carcinoma on the dorsum of the
hand. Note the raised pearly borders. B. Squamous cell
carcinoma of the dorsum of the hand with ulceration. C.
Squamous cell carcinoma with nail involvement. Often,
this is misdiagnosed as a chronic paronychia or other
benign pathology. D. Subungual melanoma with a
Hutchinson sign, extension of pigment from the nail bed
to the proximal nail fold.
■ With time, most untreated SCCs will eventually become an inflamed,
indurated lesion with central ulceration.
■ The frequency of lesions on the dorsum of the hand is consistent with its
association with sun exposure.
■ It can be distinguished from basal cell cancer by the lack of a well-defined
edge when placing stretch on the tumor with two hands.5

■ Involvement of the nail unit presents as a chronic ulcer and is often
misdiagnosed as a chronic paronychia, pyogenic granuloma, or verruca
vulgaris5 (FIG 1C).
■ Similar to melanoma, regional lymph nodes should be evaluated to evaluate
for lymphadenopathy.
■ Melanoma
■ Evaluation involves the ABCs (asymmetry, borders, color) with regard to a
changing mole.
■ Critical findings include asymmetry, irregularity, diameter greater than 6 mm,
or presence of satellite lesions.
■ Regional lymph nodes must be examined to evaluate for metastasis.
■ Subungual melanoma may present with a Hutchinson sign (extension of
brown/black pigment from the nail bed onto the cuticle or nail fold) (FIG
1D). It can also appear as a pigmented streak of the nail bed that is wider
than 3 mm.
IMAGING
■ Plain films can reveal bony involvement, particularly with nail bed
involvement.
■ Other imaging studies are typically performed to rule out distant disease (CT,
PET, MRI).
DIFFERENTIAL DIAGNOSIS
■ Hemangioma
■ Dermatofibroma
■ Blue nevus
■ Seborrheic keratosis
■ Kaposi sarcoma
■ Metastasis
■ Subungual lesions: chronic paronychia, pyogenic granuloma, onychomycosis,
glomus tumor, hematoma
NONOPERATIVE MANAGEMENT
■ Basal cell carcinoma
■ Small or superficial lesions can be considered for treatment with
electrodessication and curettage, cryotherapy, radiotherapy, or CO2 laser.
■ Nonoperative management is contraindicated in morpheaform or sclerosing

subtypes.
■ Squamous cell carcinoma
■ Small, low-risk, or in situ squamous cell lesions can be managed
conservatively in patients who are high-risk operative candidates with
electrodessication and curettage, cryosurgery, or 5-FU.
■ Radiation therapy may also be used to treat inoperable lesions or recurrences.
■ Melanoma
■ There is no role for nonoperative management in melanoma.
SURGICAL MANAGEMENT
■ Basal cell carcinoma
■ Small (no more than 2 cm) BCCs should be resected with at least 4-mm
margins.
■ Large (over 2 cm) BCCs or those with high-grade features require a 6-mm
margin or the use of Mohs micrographic surgery to maximize preservation of
uninvolved tissue.
■ Mohs micrographic surgery should be applied in the setting of tumors with
aggressive malignant features and for morpheaform or sclerosing subtypes.2
■ Squamous cell carcinoma
■ Because of the more aggressive nature of SCC, a wider margin of resection is
typically necessary as compared to BCC.
■ A 3- to 10-mm margin of disease-free tissue should be maintained.
■ Mohs micrographic excision results in the highest cure rate and the best
preservation of uninvolved tissue. It should be performed for high-risk
lesions.
■ If the nail matrix is involved, amputation at the DIP joint is necessary.
■ Melanoma
■ The depth of the lesion (Breslow thickness) dictates margin of resection:
• In situ tumors: 0.5-cm margin
• Less than 1 mm deep: 1-cm margin
• 1 to 4 mm deep: 2-cm margin
• More than 4 mm deep: 2- to 3-cm margin
• For melanomas deeper than 0.76 mm, treatment includes intraoperative
lymph node mapping with sentinel lymph node biopsy, followed by
completion of lymphadenectomy if positive.
■ For nail matrix melanomas, the digit should be amputated proximal to the

DIP joint.
■ In proximal digital melanomas with perineural invasion or bone
involvement, a complete digital amputation or ray amputation is typically
necessary.
■ Large excision reconstruction can involve primary closure, skin graft,
locoregional flap, or free flap (FIGS 2 and 3C).
Preoperative Planning
■ Preoperative imaging, if necessary, should be performed to identify the extent
of the lesion and the involvement of any vital structures.
■ In cases of malignancy, the extremity should not be exsanguinated with the use
of an Esmarch bandage to avoid a theoretical risk of seeding malignant cells.
Positioning
■ The patient is positioned supine on the operating table, and the extremity is
positioned on a hand table.
■ The extremity is prepped and draped circumferentially, including the axilla if
sentinel lymph node biopsy is planned.
■ The appropriate anesthesia is administered (general, regional block, digital
block), and an appropriate tourniquet is applied (upper arm or digit).
Approach
■ The location of the lesion dictates the technique and the approach chosen.
■ Wide local excision involves excision of the lesion with a predetermined
perimeter of normal tissue (FIG 3A).
■ It is important to mark the specimen to orient the pathologist (FIG 3B).
■ If any margins are positive, the pathology will dictate the location for repeat
excision.
■ To facilitate primary closure, if the anatomy and the size of the lesion permit,
the excision should be an ellipse.
■ The incision for a biopsy should be designed longitudinally so that the biopsy
site can be resected at the time of definitive treatment.
■ Mohs micrographic surgery has good results for BCC and SCC. A Mohs-
trained surgeon can excise the lesion and perform immediate pathologic
analysis for critical areas where tissue preservation is important.

FIG 2 • SCC excision requiring a local flap for closure.
A. Preoperative markings for a rhomboid flap for
reconstruction. B. Closure after advancement of the
flap.

FIG 3 • Wide local excision of a SCC. A. The inner
circle represents the boundaries of the lesion and the
outer circle is the excision of a margin of normal tissue.
B. The specimen is marked with sutures for pathologic
orientation. C. Closure of dorsal hand defect with a
split-thickness skin graft.
T E C H N I Q U E S
■ Mohs Micrographic Surgery
■ Remove all evidence of gross tumor.
■ Excise a thin 2- to 3-mm margin with the tissue (TECH FIG 1A). Bevel the
peripheral skin edge such that it is in the same horizontal plane as the deep
margin.

■ Using a color-coded three-dimensional orientation, map the tissue for
reference (TECH FIG 1B).
■ Examine the deep and peripheral margin by frozen section analysis to
determine the precise anatomic location of any residual tumor (TECH FIG
1C).
■ Re-excise any residual tumor and repeat pathologic evaluation until margins
are negative (TECH FIG 1D–F).

TECH FIG 1 • Mohs micrographic surgery. A. Gross
tumor with a thin margin is excised. B. The sample is
divided and mapped with color to help pinpoint any
areas of residual tumor with frozen section analysis.
C. Microscopic evaluation reveals that there is
residual tumor in segment 4. D–F. The process is
repeated, focusing on re-excision of the involved
quadrant until all clear margins are obtained.
PEARLS AND PITFALLS

Incision
■ Be certain of diagnosis before committing to a transverse incision
for resection. This will make a limb-sparing incision more
challenging for definitive resection if the lesion is malignant.
Basal cell
carcinoma
■ Telangiectasias with raised pearly borders are characteristic.
Melanoma
■ Always consider amelanotic melanoma as part of the differential of
a nonpigmented skin lesion.
■ Before committing to a definitive reconstruction, perform
temporary coverage until the final pathology confirms negative
margins.
■ Sentinel lymph node biopsy is often part of the management
algorithm.
Squamous
cell
carcinoma
■ Biopsy tissue in a chronic or nonhealing skin or nail matrix lesion
Mohs
micrographic
surgery
■ Very low recurrence rates for BCC and SCC
POSTOPERATIVE CARE
■ The hand is placed in a bulky dressing from the proximal forearm to the MP
joints. Early hand elevation and early finger motion are encouraged.
■ The splint and sutures are removed at 1 week, and range-of-motion exercises
begin at this time.
■ In cases of melanoma, the patient should follow up at regular 3-month
intervals for 2 years, 6-month intervals for the following 2 years, and annually
thereafter.
OUTCOMES
■ Basal cell carcinoma
■ Cure rates for primary BCC treated with Mohs surgery have been reported as
high as 99%.2
■ Recurrence rates are higher for lesions with increasing size or for those with
more aggressive clinical subtypes.
■ Squamous cell carcinoma
■ The risk of metastasis and recurrence is higher on the upper extremity than

SCC at other locations on the body.
■ Excision with Mohs micrographic surgery has recurrence rates as low as
2.4%. However, periungual lesions have comparatively higher recurrence
rates.4
■ The histologic risk factors associated with recurrence include degree of
cellular differentiation, depth of tumor invasion, and presence of perineural
invasion.2
■ Melanoma
■ Prognosis is dependent on depth of tumor invasion, presence of nodal
disease, and presence of metastatic disease.
■ The approximate 5-year survival rate for a melanoma less than 0.76 mm thick
is 98%. Survival drops to 30% with nodal involvement and less than 10% if
there are metastases.6
COMPLICATIONS
■ Incomplete resection on final pathology warrants re-excision.
■ With lymphadenectomy, there is a risk of hematoma, seroma, lymphocele, or
lymphedema. Although the risk is also present with sentinel lymph node
biopsies, it is much less commonly encountered.
REFERENCES
1. Maciburko SJ, Townley WA, Hollowood K, Giele HP. Skin cancers of the
hand. Plast Reconstr Surg. 2012;129(6):1329-1336.
2. TerKonda SP, Perdikis G. Non-melanotic skin tumors of the upper extremity.
Hand Clin. 2004;20(3):293-301.
3. Kakar S, Endress R. Skin cancer of the hand. J Am Acad Orthop Surg.
2015;23(5):307-316.
4. Henderson MM, Neumeister MW, Bueno R Jr. Hand tumors: I. Skin and soft-
tissue tumors of the hand. Plast Reconstr Surg. 2014;133(2):154e-164e.
5. Sobanko JF, Dagum AB, Davis IC, Kriegel DA. Soft tissue tumors of the
hand. 2. Malignant. Dermatol Surg. 2007;33(7):771-785.
6. Perdikis G, TerKonda SP. Pigmented skin lesions of the upper extremity.
Hand Clin. 2004;20(3):283-291.

Operative Techniques in
Plastic Surgery
VOLUME III
Kevin C. Chung, MD, MS
EDITOR-IN-CHIEF
Chief of Hand Surgery, Michigan Medicine
Director, University of Michigan Comprehensive Hand Center
Charles B. G. de Nancrede Professor of Surgery
Professor of Plastic Surgery and Orthopaedic Surgery
Assistant Dean for Faculty Affairs
Associate Director of Global REACH
University of Michigan Medical School
Ann Arbor, Michigan

PART 7
Lower Limb Reconstruction and
Amputation

(Trang không có chữ)

1
CHAPTER
Section I: Anesthesia and
Emergency Procedures
Femoral and Adductor
Canal Blocks
Sarah Madison and Jean-Louis Horn
DEFINITION
■ A peripheral nerve block is an analgesic technique in which local anesthetics
are injected percutaneously in proximity to a sensory nerve.
■ The location of the injection determines the distribution of analgesia.
■ Femoral nerve block may be used for postoperative analgesia for procedures
on the anterior thigh, knee, medial leg, or medial ankle.
■ Adductor canal block may be used for postoperative analgesia for procedures
on the knee or medial leg.
■ A continuous infusion of local anesthetic via a perineural catheter can provide
analgesia for several days after surgery.
■ Nerve blocks are often part of a multimodal regimen that also includes
systemic medications.
■ Nerve blocks can reduce pain and opioid consumption and enhance
satisfaction and recovery.1
■ Depending on the location and extent of surgery, nerve blocks may be used for
surgical anesthesia.
ANATOMY
■ The femoral nerve arises from the lumbar plexus and is formed by the ventral
rami of L2-L4.
■ In the area of the femoral triangle, the femoral nerve lies deep to the fascia

iliaca, lateral to the femoral artery, and superficial to the iliacus muscle.
■ The femoral nerve divides into anterior and posterior divisions and descends
as the saphenous nerve to the medial leg.
■ The posterior branch provides motor innervation to the quadriceps muscles as
well as sensory articular branches to the knee joint.
■ The saphenous nerve, obturator nerve (posterior division), and the nerve to the
vastus medialis lie within the adductor canal.
■ The adductor canal is bounded by the sartorius and the vasto-adductor
membrane medially, the vastus medialis anteriorly, and adductor longus and
magnus muscles posteriorly.
■ The adductor canal also contains the femoral artery and vein.
■ The saphenous nerve and the nerve to the vastus medialis supply sensory
branches to the knee.2
PATIENT HISTORY AND PHYSICAL FINDINGS
■ A preoperative history and physical must be performed prior to any anesthetic
technique.
■ A thorough history and physical exam will include anesthetic history, exercise
tolerance, cardiopulmonary examination, and airway examination.
■ Any pre-existing neuropathies in the distribution of the block should be
defined and documented.
■ Any local infections, masses, previous surgeries, or other irregularities at the
site of injection should be identified.
IMAGING
■ Ultrasound imaging confers efficiency and increases the success rate of most
peripheral nerve blocks.
■ Using a high-frequency linear transducer, scan in a transverse orientation at
the level of the inguinal crease. The femoral artery and femoral nerve should
be easily identified in cross-section (FIG 1).
■ The adductor canal block is often performed in a location that is proximal to
the true adductor canal, near the point at which the sartorius muscle covers the
femoral vessels. The nerve can be visualized next to the femoral artery, just
deep to the sartorius muscle (FIG 2).
NONOPERATIVE MANAGEMENT
■ The balance of risks and benefits must be considered before any nerve block.

Sometimes, it is more appropriate to only employ systemic medications for
pain control.
■ Opioids and nonopioid adjuvant medications may be used when medically
appropriate, with or without a nerve block.
SURGICAL MANAGEMENT
■ Femoral nerve block is indicated for postoperative analgesia of the anterior
thigh, knee, medial leg, or medial ankle, or for surgical anesthesia of the
anterior thigh.
■ When combined with a sciatic block, it can be used for surgical anesthesia of
the foot/ankle.
■ Local anesthetics will affect both motor and sensory nerves. Blocking the
femoral nerve at the level of the inguinal crease results in quadriceps weakness.
■ Adductor canal block is indicated for postoperative analgesia of the knee,
medial leg, or medial ankle.
■ It can be used as a surgical anesthetic in conjunction with a sciatic block for
procedures on the foot/ankle.
FIG 1 • Ultrasound image of femoral nerve block. FN,
femoral nerve; A, femoral artery.

FIG 2 • Ultrasound image of adductor canal block. SN,
saphenous nerve; SM, sartorius muscle; A, femoral
artery; V, femoral vein.
■ A nerve block in the adductor canal is less likely to cause quadriceps weakness
than a femoral nerve block; however, local anesthetic may spread proximally
and affect motor nerves.
■ The nerve to the vastus medialis is reliably anesthetized with an adductor
canal block, but the overall effect on quadriceps function is minimal.3
Preoperative Planning
■ Surgical site, extent of incision, anticipated degree of pain, and any pre-
existing conditions that increase risk of complications should be considered
before offering the patient a nerve block.
■ Postoperative ambulatory status should be determined to optimize dosing.
■ Crutch training, if appropriate, should take place prior to surgery.
■ Inpatients should be labeled as a “fall risk” and should not get out of bed
without assistance.
■ Femoral nerve blocks for outpatients should be carefully considered and only
performed with close follow-up and an otherwise low risk of falls.
■ The use of crutches and a knee immobilizer may attenuate fall risk with
ambulation after a femoral nerve block.
Positioning
■ The patient should be positioned supine with the operative leg slightly
externally rotated.

■ The bed should be flat with hips extended.
■ The patient’s ipsilateral hand may be kept out of the sterile field by lightly
taping it to the chest.
■ The operator should stand on the side to be blocked, with the ultrasound
machine on the other side of the patient.
Approach
■ With the use of ultrasound, the nerve may be approached either in-plane
(needle parallel to transducer surface) or out-of-plane (needle perpendicular to
transducer surface) with the ultrasound probe placed in a transverse orientation.
■ When a nerve stimulator technique is used, the needle approach is generally
with the long axis of the nerve, at a 45-degree angle to the skin.
T E C H N I Q U E S
■ Femoral Block: Ultrasound-Guided Technique
■ Position the patient as described above, with ASA (American Society of
Anesthesiologists) standard monitors and supplemental oxygen applied.
■ IV sedation, usually with fentanyl and midazolam, may be titrated to patient
comfort.
■ Using a high-frequency linear transducer, scan at the level of the inguinal
crease in a transverse orientation to visualize the femoral artery and nerve in
cross-section.
■ The best image may be obtained in a location proximal to the bifurcation of
the femoral artery where the neurovascular bundle is closest to the skin.
■ Identify the fascia lata, fascia iliaca, femoral nerve, and iliacus muscle.
■ Slowly tilt the ultrasound transducer to optimize nerve imaging.
■ Estimate the depth of the nerve in the ultrasound image.
■ After sterile skin preparation, place a skin wheal just lateral to the ultrasound
probe.
■ The depth of the nerve should guide the insertion site; start closer to the
probe for more superficial targets, and farther away if the target is deeper.
■ Insert the block needle in the plane of the ultrasound image, visualizing the
tip of the needle in real-time as the target is approached (TECH FIG 1).

■ The needle should pass through the fascia iliaca just lateral to the nerve.
■ Tactile feedback through the needle may include a “pop” as the needle
traverses fascial layers.
TECH FIG 1 • Positioning and approach for
ultrasound-guided in-plane femoral nerve block.
■ Take care to avoid the lateral edge of the nerve. The patient may
experience a paresthesia if the nerve is contacted directly.
■ The lateral circumflex femoral artery or one of its branches may be in the
needle path or pass through the nerve, and should be avoided.
■ After careful aspiration, inject a small amount of local anesthetic.
■ Local anesthetic spread should appear as hypoechoic fluid filling the space
deep to fascia iliaca and surrounding the nerve.
■ The needle may be advanced closer to the nerve as a local anesthetic
pocket is formed (hydrodissection); this reduces the risk of needle-nerve
contact.
■ When the needle is positioned in close proximity to the nerve, and local
anesthetic spread is confirmed around the nerve, an additional 10 to 15 mL
of local anesthetic can be injected.
■ Local anesthetic selection and volume of injection depend on the goals of the
block.
■ For a surgical block, use 20 to 30 mL of 1.5% mepivacaine, 2% lidocaine,
0.5% bupivacaine, or 0.5% ropivacaine.
■ For an analgesic block, use 15 to 20 mL of 0.25% bupivacaine or 0.25%
ropivacaine.

■ A catheter may be placed for continuous local anesthetic infusion.
■ Use 0.2% ropivacaine or 0.125% of bupivacaine at 4 to 6 mL/h for
continuous infusion, with a patient-controlled bolus of 2 to 4 mL every 30
minutes.
■ Infusions are generally continued for 2 to 3 days following surgery.
■ Femoral Block: Nerve Stimulator Technique
■ Following patient positioning and preparation described above, identify and
mark the inguinal crease.
■ Standing near the patient’s hip and facing the head, palpate the femoral pulse
along the crease.
■ After sterile prep, place a local anesthetic skin wheal 2 cm lateral to the
femoral artery pulse.
■ Insert a stimulating block needle at a 45 to 60 degree angle to the skin in a
cephalad direction (TECH FIG 2).
■ A quadriceps twitch (“patellar snap”) should be elicited at a current of 0.2
to 0.5 mA. Redirect the needle until the appropriate stimulation is
observed.
■ Sartorius contraction indicates a needle placement on the anterior division
of the femoral nerve. Further advancement of the needle toward the
posterior division of the nerve will usually solve this.
■ Aspiration of blood indicates intravascular placement. Reposition the
needle.
■ Muscle contraction at a current of greater than 0.5 mA usually indicates
inadequate needle-nerve proximity and may result in an incomplete or
failed block.