Operative Technique in Plastic Surgery – Kevin C.Chung

subsheath can be opened at this point and the tendon pathology addressed.
■ A power bur is then used to deepen the distal ulnar groove by 2 to 3 mm
within the central groove. The groove is deepened until the ECU subsheath
no longer subluxates with forearm rotation.
■ An alternative method is to perforate the cortex with a small drill or K-wire
and then impact the cortex with a bone tamp so it sits deeper than the
adjacent cortex.
■ The ECU subsheath is reduced into the reconstructed groove, and two suture
anchors are placed along the ulnar margin of the groove to maintain
reduction.
■ The suture anchors are passed through the ulnar border of the ECU
subsheath in a horizontal mattress pattern, and any redundant sheath is
imbricated with the sutures.
■ The sutures are tied, and the ECU tendon with its subsheath is secured to the
distal ulna.
■ The wound is copiously irrigated with normal saline.
■ The tourniquet is let down, and hemostasis is obtained.
■ The extensor retinaculum is repaired with an absorbable braided suture, and
the subdermal and epidermal layers are then closed.
■ A long-arm splint is applied with the elbow in 90 degrees of flexion and the
wrist in neutral.
PEARLS AND PITFALLS
Approach
■ Identify and protect the dorsal cutaneous branch of the ulnar nerve
throughout the procedure.
■ Inspect the ECU subsheath for injury or attenuation and determine
if the subsheath can be repaired or will require reconstruction.
Ulnar groove
deepening
■ If the ulnar groove appears shallow, plan to perform an ulnar
groove deepening.
Stability
■ Be sure to check stability in extremes of ulnar deviation and
supination with wrist flexion to ensure the ECU is stable before
leaving the operating room.

Pitfalls
■ Avoid injury to the dorsal cutaneous branch of the ulnar nerve
with gentle retraction and protection throughout the procedure.
■ Avoid overtightening the extensor retinaculum sling. The tendon
should glide freely through the sling at the conclusion of the
operation.
■ Suture anchors placed into the deepened groove may inadvertently
capture the ECU tendon.
Postoperative
care
■ Counsel patients that recovery can take 3–6 mo from the date of
operation and they will need a period of immobilization and
therapy after the operation.
POSTOPERATIVE CARE
■ The wrist is initially immobilized in a sugar-tong or long-arm splint in the
immediate postoperative period.
■ At 2 weeks, the patient is converted to a Muenster-style orthoplast splint to
prevent pronation and supination of the forearm but to allow elbow flexion and
extension.
■ At 6 weeks, occupational therapy is initiated beginning active and active
assisted range of motion.
■ Passive range of motion and stretching are added progressively if needed.
■ The patient is advised to avoid forceful supination and flexion and heavy
lifting during the rehabilitation period.
■ Strengthening activities are initiated around 3 months postoperatively.
OUTCOMES
■ A number of case reports and small case series have described the various
techniques and outcomes for ECU tendon stabilization, but there is no level I
evidence for surgical treatment of ECU instability.
■ Allende and Le Viet reported that 23 of 28 patients had good or excellent
results at an average follow-up of 23 months after extensor retinaculum sling
stabilization of the ECU tendon.6
■ MacLennan et al.9 reported improvements in DASH scores at 31 months after
groove deepening.
COMPLICATIONS
■ Injury to the dorsal cutaneous branch of the ulnar nerve
■ Recurrent subluxation of the ECU tendon

■ Infection
■ Complex regional pain syndrome
■ Decreased range of motion
■ Decreased grip strength
REFERENCES
1. Burkhart SS, Wood MB, Linscheid RL. Posttraumatic recurrent subluxation of
the extensor carpi ulnaris tendon. J Hand Surg [Am]. 1982;7(1):1-3.
2. Iorio ML, Bayomy AF, Huang JI. Morphology of the extensor carpi ulnaris
groove and tendon. J Hand Surg [Am]. 2014;39(12):
2412-2416.
3. Taleisnik J, Gelberman RH, Miller BW, Szabo RM. The extensor retinaculum
of the wrist. J Hand Surg [Am]. 1984;9(4):495-501.
4. Ghatan AC, Puri SG, Morse KW, et al. Relative contribution of the subsheath
to extensor carpi ulnaris tendon stability: implications for surgical
reconstruction and rehabilitation. J Hand Surg [Am]. 2016;41(2):225-232.
5. Inoue G, Tamura Y. Surgical treatment for recurrent dislocation of the
extensor carpi ulnaris tendon. J Hand Surg Br. 2001;26(6):
556-559.
6. Allende C, Le Viet D. Extensor carpi ulnaris problems at the wrist—
classification, surgical treatment and results. J Hand Surg Br. 2005;30(3):265-
272.
7. Jeantroux J, Becce F, Guerini H, et al. Athletic injuries of the extensor carpi
ulnaris subsheath: MRI findings and utility of gadolinium-enhanced fat-
saturated T1-weighted sequences with wrist pronation and supination. Eur
Radiol. 2011;21(1):160-166.
8. Pratt RK, Hoy GA, Bass Franzcr C. Extensor carpi ulnaris subluxation or
dislocation? Ultrasound measurement of tendon excursion and normal values.
Hand Surg. 2004;9(2):137-143.
9. MacLennan AJ, Nemechek NM, Waitayawinyu T, Trumble TE. Diagnosis and
anatomic reconstruction of extensor carpi ulnaris subluxation. J Hand Surg
[Am]. 2008;33(1):59-64.

43
CHAPTERTrigger Finger Release
Donato Perretta, Jacques A. Machol IV, and Neal Chen
DEFINITION
■ Trigger digit, also known as stenosis tenosynovitis or tenovaginitis (tendon
sheath inflammation), is a pathology characterized by painful locking or
clicking of the fingers or thumb as a result of impaired gliding of the flexor
tendon at the level of the A1 pulley.
ANATOMY
■ The proximal edge of the A1 pulley begins approximately at the level of the
metacarpal heads of the fingers. This corresponds to the distal palmar crease.
■ For the index finger, this line can be extrapolated radially.
■ In the thumb, it is at the level of the proximal digital crease.
PATHOGENESIS
■ Trigger digit is caused by a thickening of the flexor tendon sheath, specifically
the A1 pulley.
■ The pathological change in the A1 pulley has been described as
fibrocartilaginous metaplasia.1
■ Over time, the flexor tendon can also undergo degenerative changes consistent
with tendinosis.2 The resulting imbalance in the size of the A1 pulley and the
enclosed flexor tendons causes catching and locking.
NATURAL HISTORY
■ The thumb is the most commonly involved digit.3
■ Women are more commonly affected than are men.
■ There are no long-term studies documenting the natural history of untreated

trigger finger.
■ The condition may progress from tenderness at the A1 pulley to painless
clicking to painful triggering of the finger that requires passive manual
extension.
■ Over time, flexion deformities may develop at the PIP joint due to persistent
triggering.
■ The condition is more common and progresses more often in patients with
endocrinopathies and inflammatory arthritides.2
PATIENT HISTORY AND PHYSICAL FINDINGS
■ Tenderness over the A1 pulley
■ Palpable nodule over the A1 pulley
■ Painful popping or catching of the digit with flexion
■ Inability to actively extend the PIP joint from a flexed position
■ Flexion contracture of the PIP joint with long-standing trigger finger
IMAGING
■ Imaging is not necessary.
DIFFERENTIAL DIAGNOSIS
■ Locked MP joint. The collateral ligament can become entrapped over a
metacarpal head osteophyte. This usually presents as inability to extend the
digit fully after the collateral is locked.
■ Early swan-neck deformity with snapping of lateral bands as they dislocate
dorsally
■ Subluxation of the extensor tendon after sagittal band rupture. In this situation,
the finger can be passively extended and then can be actively maintained in
extension. However, if the finger is flexed, the extensor tendon will subluxate
and the finger cannot actively extend fully.
NONOPERATIVE MANAGEMENT
■ Corticosteroid injection into or superficial to the A1 pulley is the first-line
treatment. This is usually performed using a 25-gauge needle with 0.5 cc of 1%
plain lidocaine and 5 mg of Kenalog. Injections can eliminate symptoms, but
the duration of their effect is unpredictable.
■ One study showed that after injection, 56% of the digits had a recurrence of
symptoms within a year. Recurrence was associated with younger age,

insulin-dependent diabetes mellitus, involvement of multiple digits, and a
history of other tendinopathies.
■ Symptoms often recurred several months after the injection.4
■ Taras et al. reported that extra-sheath injections may be more effective than
those administered within the sheath.5
■ Splinting the MCP joint of the affected digit in extension is another commonly
used nonoperative measure. Colbourn et al.6 demonstrated short-term
improvement in symptoms with a removable orthoplast splint in 28 patients.
SURGICAL MANAGEMENT
■ Percutaneous A1 pulley release is a well-described treatment option that has
been reported to be safe and effective.7 The A1 pulley is released under local
anesthesia using a large-bore needle while the patient intentionally triggers the
affected finger.
■ Open A1 pulley release is our preferred treatment method in a patient with
recurrent symptoms after two injections.
■ Patients with rheumatoid hand deformity often develop tenosynovitis of the
flexor tendons. In this group of patients, A1 pulley release is not
recommended, as it can result in increased ulnar drift of the fingers. Instead,
annular pulley-sparing tenosynovectomy and carpal tunnel release should be
performed. The ulnar slip of the superficialis can be resected from the middle
phalanx to reduce the bulk of tendon within the flexor sheath.8
FIG 1 • Trigger finger incisions for single-digit surgery
(A,B) and for multiple-digit surgery (C).

Positioning
■ Supine with hand table
■ The procedure may be performed with a brachial tourniquet with infiltration of
local anesthetic into the surgical site.
■ Intravenous sedation can be used as an adjunct.
Approach
■ If one digit is to be addressed, then a longitudinal or oblique incision is made
over the A1 pulley (FIG 1A,B). The pulley lies over the metacarpal head.
■ If adjacent digits are to be addressed, a transverse incision is used. Often, this
is aligned within the distal palmar crease (FIG 1C).
T E C H N I Q U E S
■ Open A1 Pulley Release
■ After skin incision, blunt dissection is made down to the A1 pulley (TECH
FIG 1A).
■ Retractors are placed on either side of the pulley to prevent damage to the
neurovascular bundles.
■ A no. 15 blade is used to incise the A1 pulley in line with the longitudinal
axis of the finger in the center of the flexor tendon/pulley (TECH FIG 1B).
■ Some surgeons describe an A0 pulley proximally or a proximal fascial band
that may result in persistent triggering.
■ One should be cautious not to release the A2 pulley distally.
■ The patient is asked to actively flex the fingers down to the palm, and the
presence of triggering is assessed. This can be done passively if the patient is
unable to comply.
■ If triggering continues once the entire A1 pulley has been released, excision
of the ulnar slip of the FDS tendon is an option. This can be performed
through a Bruner-type volar incision over the PIP joint.
■ The skin is closed with 5-0 nylon interrupted sutures.

TECH FIG 1 • A. Identification of the A1 pulley. B.
Flexor tendon is visible after A1 pulley release.
PEARLS AND PITFALLS
Incomplete
release
■ The entire A1 pulley should be divided under direct
visualization.
Persistent
triggering after
complete A1
pulley release
■ There is a band, which some call the A0 pulley, which lies
proximal to the A1 pulley. This should be released if the
finger still triggers after A1 pulley release.
■ If triggering is still present after A1 pulley, one slip of the
FDS tendon should be excised. Usually, the radial slip is
preserved and the ulnar slip excised to help avoid ulnar drift
of the digits.
Injury to
neurovascular
bundle
■ Care must be made during exposure to protect the
neurovascular bundle during A1 pulley release.
Bowstringing
■ Release of the A2 tendon sheath distal to the A1 pulley may
lead to tendon bowstringing.

POSTOPERATIVE CARE
■ A sterile dressing is placed. It is removed on postoperative day 3, and digital
motion is encouraged.
■ Sutures are removed 10 days after surgery.
■ No formal therapy is indicated.
OUTCOMES
■ Outcomes are generally excellent.
■ Recurrence rates after surgery have been reported at 3%.
■ Rates of reoperation have been reported at 1% to 2.4%.3–5
COMPLICATIONS9
■ Infection (superficial or deep)
■ Digital nerve or artery injury
■ Incomplete release
■ Persistent swelling and pain
■ Flexion contracture
■ Tendon bowstringing
REFERENCES
1. Sampson SP, Badalamente MA, Hurst LC, Seidman J. Pathobiology of the
human A1 pulley in trigger finger. J Hand Surg [Am]. 1991;16:714-721.
2. Lundin AC, Eliasson P, Aspenberg P. Trigger finger and tendinosis. J Hand
Surg Eur Vol. 2012;37:233-236.
3. Sungpet A, Suphachatwong C, Kawinwonggowit V. Trigger digit and BMI. J
Med Assoc Thai. 1999;82:1025-1027.
4. Rozental TD, Zurakowski D, Blazar PE. Trigger finger: prognostic indicators
of recurrence following corticosteroid injection. J Bone Joint Surg Am.
2008;90:1665-1672.
5. Taras JS, Raphael JS, Pan WT, et al. Corticosteroid injections for trigger
digits: is intrasheath injection necessary? J Hand Surg [Am]. 1998;23:717-722.
6. Colbourn J, Heath N, Manary S, Pacifico D. Effectiveness of splinting for the
treatment of trigger finger. J Hand Ther. 2008;21:336-343.
7. Ha KI, Park MJ, Ha CW. Percutaneous release of trigger digits. J Bone Joint
Surg Br. 2001;83:75-77.
8. Ferlic DC, Clayton ML. Flexor tenosynovectomy in the rheumatoid finger. J
Hand Surg [Am]. 1978;3:364-367.

9. Everding NG, Bishop GB, Belyea CM, Soong MC. Risk factors for
complications of open trigger finger release. Hand (N Y). 2005;10:297-300.

44
CHAPTER
First Dorsal Compartment
(de Quervain) Release
Donato Perretta, Jacques A. Machol IV, and Neal Chen
DEFINITION
■ de Quervain syndrome is defined as tenosynovitis of the first dorsal
compartment. The first extensor compartment contains the tendons of the
extensor pollicis brevis (EPB) and abductor pollicis longus (APL).
ANATOMY
■ The first dorsal compartment is the most radial extensor compartment at the
level of the wrist and contains the tendons of the EPB and APL. The extensor
retinaculum is the ceiling of the compartment.
■ The APL may have multiple slips, and there may be separate subsheaths for
both the APL and EPB.1 The APL is more radial and volar, whereas the EPB is
more ulnar and dorsal. The separate subsheath for the EPB may be missed if
one does not look for it routinely.
PATHOGENESIS
■ Although this is commonly described as tendonitis, histologic markers of
inflammation are not present. The tendon sheath of the first compartment is
thickened, and there is deposition of mucopolysaccharide, an indicator of
myxoid degeneration.2
■ The disease is also common in pregnancy and the postpartum interval. It often
is self-limited and resolves with birth or the termination of breast-feeding.3
PATIENT HISTORY AND PHYSICAL FINDINGS
■ Tenderness at the radial styloid in the first compartment
■ Positive Finkelstein test (radial wrist pain with ulnar deviation of the wrist
while the thumb is held into the palm)

IMAGING
■ Radiographs of the wrist are useful if the diagnosis is in doubt. They can help
exclude other degenerative conditions about the wrist and thumb.
DIFFERENTIAL DIAGNOSIS
■ Radiocarpal arthritis
■ Intersection syndrome (pain and crepitus in the distal forearm at the
intersection of the first and second dorsal compartments)
■ Thumb basal joint arthritis
■ Scaphoid or carpal fracture
■ STT arthritis
■ Injury or irritation of the superficial branch of the radial nerve
NONOPERATIVE MANAGEMENT
■ A forearm-based thumb spica splint is usually the first-line treatment.
■ Steroid injection into first dorsal compartment sheath is an effective treatment.
Our preference is to use 0.5 cc of 1% lidocaine and 0.5 mg of dexamethasone.
■ About 80% of patients will experience symptomatic improvement after one
injection, and half will remain symptom-free at 1 year.4
■ Steroid injection may be more effective than splinting for breast-feeding
mothers.3
■ Some pediatricians or obstetricians object to the use of steroid injections
while breast-feeding, however, and this should be discussed with other
caregivers. There is concern that trace amounts of steroid can enter the breast
milk and that lactation can be affected after injection.5
SURGICAL MANAGEMENT
■ First dorsal compartment release is indicated after failure of nonoperative
management.
■ Conservative measures such as splinting and injection should be attempted
before surgical intervention.
Positioning
■ Supine, with hand table, with brachial tourniquet. Local anesthetic infiltration
is used.
Approach

■ Release of the compartment can be accomplished with a chevron, transverse,
or longitudinal incision.
T E C H N I Q U E S
■ First Dorsal Compartment Release
■ A 2-cm incision is made 1 cm proximal to the distal extent of the radial
styloid (TECH FIG 1A).
■ The first dorsal compartment is exposed (TECH FIG 1B,C).
■ Care is taken to avoid injuring the superficial branch of the radial nerve,
which travels superficial to the extensor retinaculum.
■ Injury to the radial sensory nerve can be minimized with retractors placed
proximally and distally rather than dorsally/volarly.
■ The first dorsal compartment is released longitudinally at the dorsal edge
(TECH FIG 1D). This prevents volar subluxation of the tendons.
■ The APL and EPB are wholly inspected to ensure that all subsheathes have
been released.
■ Up to half of patients may have separate compartments for these tendons. It
is theorized that these accessory compartments predispose to de
Quervain’s.6
■ Interrupted buried 3-0 absorbable monofilament sutures are used for wound
closure, and Steri-Strips are applied.
■ A thumb spica plaster splint is applied for 7 to 10 days.

TECH FIG 1 • A. The chevron (dashed lines) is the
preferred incision for release of the first dorsal
compartment. B. Sheath of first dorsal compartment
exposed. C. Once the skin is incised, care is taken to
avoid the radial sensory nerve. The blood on the
sheath is from the preoperative local anesthetic
injection. D. First dorsal compartment tendons
exposed. The sheath is released from the dorsal side
to prevent volar subluxation of the tendons. The
forceps are holding the sheath. The APL and EPB are
visible, with the APL begin the more volar structure.
PEARLS AND PITFALLS
Nerve injury
■ Identify the superficial branch of the radial nerve. Aggressive
retraction results in a problematic injury to the nerve and persistent
pain.
Volar
tendon
■ Leave a cuff of tissue volarly when incising the sheath.

subluxation
Incomplete
release
■ Be sure to release both the EPB and APL as they often have
separate subsheaths.
POSTOPERATIVE CARE
■ The splint is removed in 7 to 10 days, and immediate at-home range-of-motion
exercises are initiated. Typically, there is no need for formal therapy.
OUTCOMES
■ A consecutive series of 94 patients found symptom resolution in 100% of
patients.
■ There were six perioperative complications, including one superficial wound
infection, one delayed wound healing, and four transient lesions of the radial
sensory nerve.7
COMPLICATIONS
■ Infection
■ Injury to superficial radial nerve
■ Scar tenderness
REFERENCES
1. Bahm J, Szabo Z, Foucher G. The anatomy of de Quervain’s disease: a study
of operative findings. Int Orthop. 1995;19:209-211.
2. Clarke MT, Lyall HA, Grant JW, Matthewson MH. The histopathology of de
Quervain’s disease. J Hand Surg Br. 1998;23:732-734.
3. Avci S, Yilmaz C, Sayli U. Comparison of nonsurgical treatment measures for
de Quervain’s disease of pregnancy and lactation. J Hand Surg [Am].
2002;27:322-324.
4. Earp BE, Han CH, Floyd WE, et al. De Quervain tendinopathy: survivorship
and prognostic indicators of recurrence following a single corticosteroid
injection. J Hand Surg [Am]. 2015;40:1161-1165.
5. Babwah TJ, Nunes P, Maharaj RG. An unexpected temporary suppression of
lactation after a local corticosteroid injection for tenosynovitis. Eur J Gen
Pract. 2013;15:248-250.
6. McDermott JD, Ilyas AM, Nazarian LN, Leinberry CF. Ultrasound-guided
injections for de Quervain’s tenosynovitis. Clin Orthop Relat Res.

2012;470:1925-1931.
7. Scheller A, Schuh R, Honle W, Schuh A. Long-term results of surgical release
of de Quervain’s stenosing tenosynovitis. Int Orthop. 2009;33:1301-1303.

45
CHAPTER
Section X: Flaps and
Microsurgery
Flap Coverage of Fingertip
Injuries
Kate Elzinga and Kevin C. Chung
DEFINITION
■ Fingertip injuries are defined as injuries that occur distal to the insertion of the
flexor and extensor tendons of the finger.1
■ Fingertip injuries are the most common hand injuries; the fingertips are
relatively unprotected compared to the rest of the hand.
■ The fingertip plays an important role in fine motor skills, precise sensation,
and hand aesthetics. Reconstruction of fingertip injuries can restore form and
function for injured patients.
■ The goals of fingertip reconstruction include the following:
■ Durable coverage
■ Preservation of sensation
■ Preservation of length
■ Maintenance of distal interphalangeal (DIP) joint function
■ Optimized appearance
■ Minimized donor-site morbidity
■ Permitting early return to work and recreational activities
■ Minimizing pain, in the short and long term
■ Fingertip flaps are used to cover injuries with exposed bone and tendon. Local
(V-Y advancement) and regional (thenar, cross-finger) flaps are useful options.
■ Local flaps, such as the Atasoy-Kleinert V-Y advancement flap,2 are the
simplest flaps used for reconstruction; immobilization is not required and

donor-site morbidity is minimal.
■ Regional flaps are employed when local flaps are not available because of the
injury geometry (regional flaps are best used for volar oblique injuries) and
size (local flaps can only be advanced 1 cm). Regional flaps require two-stage
procedures and immobilization of the injured, and often adjacent, finger.
ANATOMY
■ The volar fingertip is covered with glabrous skin. The epidermis is thick, and
papillary ridges are prominent.
■ The fingertip pulp is composed of fibrofatty tissue that is stabilized volarly by
fibrous septa that run from the distal phalanx periosteum to the dermis and
laterally by Grayson and Cleland ligaments.
■ The proper digital nerve trifurcates distal to the DIP joint, sending branches to
the nail bed, distal fingertip, and volar pulp. The proper digital artery also
trifurcates at this level, sending two branches dorsally and one branch laterally.
PATHOGENESIS
■ Trauma is the most common cause of fingertip injuries.3
■ Common mechanisms of fingertip injuries include sharp injuries from a knife,
power tool, or lawn mower and crush injuries from closing a door, a strike with
a hammer, dropping a heavy object, becoming trapped in machinery, or
sporting activities.
PATIENT HISTORY AND PHYSICAL FINDINGS
■ A careful patient history and physical examination help determine which flap
options are suitable for a particular patient.
■ Some patients may prefer rapid return to their work and avocations and will
refuse fingertip reconstruction, opting for fingertip amputation instead.
■ A focused hand history must include age, sex, hand dominance, and
occupation and recreational activities. The patients’ goals are explored,
including their need to return to work, their availability and willingness to
undergo secondary procedures and hand therapy, and the importance of
appearance.
■ Aesthetic outcome may be more important for females and patients from
certain Asian cultures.
■ Important considerations from the patient’s past medical history include
smoking, diabetes mellitus, peripheral vascular disease, connective tissue

disorders, arthritis, Dupuytren disease, and previous hand injuries.
■ The presence of comorbidities may affect reconstruction options offered
given their effect on flap vascularity and wound healing.
■ Key injury factors to consider include the time of injury, mechanism of injury
(sharp vs crush), contamination, and associated injuries.
■ On physical examination, the defect size is measured. The level of the injury is
assessed clinically and using radiographic imaging.
■ Missing tissue (skin, pulp, bone, nail) and exposed structures are
documented. The geometry of the injury is assessed and classified as volar
oblique, transverse, or dorsal oblique (FIG 1).1
■ Tissue contamination is assessed, and any early signs of infection are noted.
■ Surrounding tissues and digits are examined as potential donor sites.
FIG 1 • The angle of amputation is assessed to aid in
selection of an appropriate local or regional flap for
fingertip coverage. Volar oblique injuries with no
exposed bone (a) can heal by secondary intention.
Volar oblique injuries with exposed bone (b) can be
reconstructed with regional flaps (thenar flap, cross-
finger flap). Transverse (c) and dorsal (d) oblique
injuries with exposed bone can resurfaced with a volar

V-Y advancement flap.
■ The integrity of the flexor digitorum profundus (FDP) and extensor
digitorum communis (EDC) tendons is tested; it is important not to miss an
associated jersey finger or mallet finger injury.
IMAGING
■ Plain radiographs can identify fractures of the finger and the presence of a
foreign body.
■ Three radiographic views of the finger and amputated part should be obtained
following a fingertip amputation.
NONOPERATIVE MANAGEMENT
■ Small defects (less than 1 cm2) with no exposed bone can be treated
nonoperatively.4
■ Dressing changes are performed daily to maintain a clean moist wound bed as
the wound heals by secondary intervention over several weeks.
■ Outcomes are typically excellent in these cases as glabrous sensate skin heals
over the exposed soft tissues.5
■ Immobilization is not required and range-of-motion exercises are performed
throughout.
SURGICAL MANAGEMENT
■ Full-thickness skin grafts (FTSGs) can be considered for coverage of large soft
tissue avulsion injuries without exposed bone or tendon.
■ The glabrous skin of the hypothenar eminence is the preferred harvest site for
volar skin defects. Palmar skin is an excellent donor site for structure and
color matching of the fingertip skin; the resultant scar from the palm can be
rather imperceptible.
■ Skin grafting promotes faster wound coverage, but sensation, color, and
durability are inferior to secondary healing.5

FIG 2 • Volar oblique fingertip defects can be closed
with a V-Y flap. Distally, the fibrous septa are released
from the undersurface of the flap to allow advancement
of the flap distally into the defect, where it is sutured
over the wound.
■ Replacement of amputated tissue as a composite graft may be considered;
outcomes are best for pediatric patients younger than 6 years of age within 5
hours of the amputation.6

■ Fingertip flaps preserve finger length. Early coverage of exposed bone and
tendon decreases the risk of osteomyelitis and tendon desiccation. Protecting
the terminal phalanx with a flap preserves bone length that supports the
overlying nail.
■ The volar V-Y advancement flap (FIG 2) is well suited for transverse and
dorsal oblique fingertip injuries.
• The V-Y flap can cover defects of up to 2 cm2 and can be advanced 1 cm.
■ The thenar flap (FIG 3) and cross-finger flap (FIG 4) provide coverage for
volar oblique injuries. The thenar flap provides improved sensory recovery
and has a less conspicuous donor site compared with the cross-finger flap but
requires greater finger flexion for inset, which can cause joint stiffness,
particularly in elderly patients. However, the lack of donor-site morbidity and
predictable outcomes makes the thenar flap our first choice, if possible, over
the cross-finger flap.
• The cross-finger flap can be used for defects up to 1.5 × 2.5 cm in size.
• The thenar flap can be designed to cover the entire pulp with a width of up
to 2 cm.

FIG 3 • A. Proximally based thenar flap is elevated from
distal to proximal. B. Narrow donor sites may be closed
primarily. C. This is done prior to flap inset to the
fingertip defect to facilitate suture placement.
Preoperative Planning
■ The risks and benefits of flap coverage for fingertip injuries are discussed with
the patient during their initial assessment and reviewed again prior to their
surgery.
■ Fingertip and/or the removal of exposed bone followed by secondary intention
healing are discussed as alternative treatment options.

FIG 4 • A. The cross-finger flap is composed of skin and
subcutaneous tissue from the dorsal middle phalanx of
the adjacent finger. B. The flap donor site is closed with
an FTSG.
■ Benefits of flap coverage include preservation of finger length, provision of
durable soft tissue coverage, and good aesthetic results.
■ Drawbacks include the creation of a donor site, the possibility of flap failure,
and the need for longer immobilization.
■ Cross-finger and thenar flaps require the injured digit to be placed in flexion,
which can lead to postoperative stiffness.
■ These flaps are contraindicated in patients at high risk of joint contractures,
eg, elderly patients with arthritis or Dupuytren disease.

■ The thenar flap cannot be performed in patients without adequate passive
metacarpophalangeal (MCP) and interphalangeal joint flexion.
Positioning
■ The patient is positioned supine with the arm on a hand table.
Approach
■ Loupe magnification is helpful.
■ Incisions are planned prior to inflation of the tourniquet.
■ Exposed bone is smoothed out with a rongeur. Minimal shortening is
performed.
■ Soft tissues are debrided of all nonviable and contaminated tissue. A healthy
wound bed is established prior to flap reconstruction.
■ The sterile nail matrix should be shortened 2 mm proximal to the tip of the
distal phalanx to prevent a hook-nail deformity.7 A hook-nail deformity can
occur when there is a lack of distal support for the sterile matrix.
■ The neurovascular bundles and FDP tendon insertion are protected throughout.
T E C H N I Q U E S
■ V-Y Advancement Flap
■ The flap width is marked to match the defect width distally; proximally, it is
tapered as a V.
■ The proximal flap edge is traditionally located at volar midline of the distal
interphalangeal (DIP) joint crease; proximal extensions have been
described (see FIG 2).8
■ The injured finger is exsanguinated, and a finger tourniquet is placed.
■ The flap is incised; dissection is performed through the dermis. Once the
subcutaneous tissues are exposed, no further deep dissection is required; this
prevents injury to the bilateral neurovascular structures (TECH FIG 1A).
■ Distally, the fibrous septa are divided from the distal phalanx periosteum to
permit flap advancement.
■ The central undersurface of the flap must not be undermined to maintain flap
vascularity.

■ The flap is inset into the defect and sutured into place with 4-0
nonabsorbable monofilament suture. The flap is secured to the surrounding
intact skin and nail. Tension is avoided at the tip of the finger to lessen the
risk of a hook-nail deformity.9
■ The donor site is closed longitudinally in V-Y fashion (TECH FIG 1B).
Alternatively, the donor site can be left open to heal secondarily, particularly
if flap tension is a concern.9
■ The tourniquet is released and flap vascularity is assessed (TECH FIG 1C).
Alternating sutures may be released to lessen tension on the flap; these open
areas are left to heal by secondary intention.
■ Antibiotic-impregnated gauze is placed over all incisions and covered with
sterile gauze. A soft finger dressing is applied.
■ A light dressing can be applied daily until the incisions are healed.
■ The sutures are removed 2 weeks postoperatively.
■ Range-of-motion (ROM) exercises may be started on postoperative day 2 to
prevent finger stiffness.

TECH FIG 1 • A. The V-Y advancement is designed
with a distal width matching the width of the defect.
Proximally, the flap is tapered to a V at the volar
midline of the DIP joint crease. The dermis is incised,
exposing the subcutaneous tissues below. B. The V-Y
advancement flap is inset distally to the surrounding
intact skin and nail. The donor site is closed proximally
in a longitudinal V-Y fashion. C. The tourniquet is
released, and the vascularity of the flap is assessed.
Color, capillary refill, temperature, and turgor of the
flap are examined.
■ Cross-Finger Flap
■ A template of the defect is used to mark the flap dimensions on the dorsum

of the middle phalanx of the adjacent donor finger (TECH FIG 2A).
■ The flap is pedicled on the side of the donor finger adjacent to the defect.
■ The lateral extent of the flap can be marked as far as at the junction of the
glabrous and nonglabrous skin for larger defects.
■ The arm is exsanguinated and a tourniquet inflated.
■ The flap is elevated sharply, just above the paratenon, beginning from the
edge of the donor finger farthest from the injured finger (TECH FIG 2B).
Cleland ligament is divided.
■ The flap remains hinged to the side of the finger closest to the injured
finger, along the midaxial line (TECH FIG 2C; see FIG 4).
■ The injured finger is flexed, and the flap is secured to the flap using 4-0
nonabsorbable monofilament sutures (TECH FIG 2D,E).

E B

TECH FIG 2 • A. The fingertip defect is marked on the
dorsum of the middle phalanx of the adjacent donor
finger using a template of the wound. The flap is
hinged on the side of the donor finger closest to the
defect. B. The flap is incised sharply and elevated in
the loose areolar place above the paratenon. C. The
paratenon must be preserved to enable FTSG take at
the flap donor site. D,E. Volar and oblique views,
respectively, of a cross-finger flap from the middle
finger after inset into the defect of the index finger.
The patient also sustained an injury to the volar
middle phalanx of the middle finger that was closed
with an FTSG. F,G. A dressing change is performed 1
week postoperatively to assess the flap and flap donor
site, respectively. The flap provides durable, padded
soft tissue coverage for fingertip injuries.
■ A full-thickness skin graft (FTSG) is applied to the flap donor site. The
FTSG can be inconspicuously harvested from the groin, medial proximal
forearm, or nonglabrous hypothenar skin.
■ Antibiotic-impregnated gauze is applied to the affected digit and FTSG
donor site and covered with sterile gauze. A bolster dressing is applied over
the skin graft. A splint is applied to the injured finger and its adjacent donor
finger, immobilizing the interphalangeal joints; the metacarpophalangeal
(MCP) joints may be left free.
■ One week after the first surgery, a dressing change is performed (TECH FIG
2F,G). The bolster dressing is removed from the FTSG. A protective splint is
reapplied.
■ Two weeks after the first surgery, the flap is divided. Immobilization is not
typically required after the second surgery, and ROM exercises are started.
■ Thenar Flap
■ The injured digit is flexed into the palm (TECH FIG 3A). Maximal flexion

of the MCP and DIP joints is preferred while minimizing proximal
interphalangeal (PIP) joint flexion to decrease postoperative PIP stiffness.
■ The flap is marked over the ulnar aspect of the thenar eminence using a
template of the defect size (TECH FIG 3B).
■ Ulnar flap design is preferred on the thenar eminence to facilitate primary
closure of the donor site; skin tension is decreased by adducting the thumb.
Furthermore, designing the flap radially over the thenar eminence places
the radial neurovascular bundle of the thumb at risk of injury.
■ The flap width and length are designed 1.5 times wider and longer,
respectively, than the defect length to permit tension-free inset with
restoration of the normal rounded contour of the fingertip.
■ The flap is proximally or distally based, depending on the geometry of the
defect.
■ The arm is exsanguinated and a tourniquet inflated.
■ The skin and subcutaneous tissues of the flap are sharply incised. The flap is
elevated from distal to proximal in the subcutaneous tissue plane, above the
level of the palmar fascia, at a depth that matches the defect (TECH FIG
3C).
■ Once the flap is elevated, the flap donor site is closed longitudinally with 4-0
nonabsorbable monofilament sutures. The thumb is adducted to facilitate
primary closure of the donor site.

TECH FIG 3 • A. The flap is designed over the thenar
eminence where the finger meets the palm when
flexed. Maximal MCP and DIP joint flexion are
preferred rather than PIP flexion to enable the finger
to meet the palmar skin. Contractures of the PIP joint
are more problematic postoperatively compared to
those of the MCP and DIP joints. B. A template, cut
out of foil, Telfa (shown here), or otherwise can be
used to design the flap based on the defect size. C.
The flap is elevated from distal to proximal in the

subcutaneous plane. The palmar fascia is not violated.
The finger is flexed to bring the defect to the flap site.
D,E. Volar and oblique views, respectively, of the flap
inset to the intact skin around the defect and the nail.
F. The thenar flap is divided at its proximal base. The
proximal flap edge is inset to the proximal volar edge
of the defect with sutures. The thenar donor-site skin
is closed.
■ An FTSG can be used if the flap donor site is too large for primary closure.
■ Next, the injured finger is flexed and the flap is inset over the defect (see
FIG 3).
■ 4-0 nonabsorbable monofilament sutures are used to secure the flap to the
defect; absorbable sutures are at increased risk of breakage and subsequent
flap dehiscence.
■ Multiple sutures are used to decrease the chance of accidental fingertip
avulsion from the flap site (TECH FIG 3D,E).
■ Antibiotic-impregnated gauze is placed over all incisions and covered with
sterile gauze. A well-padded splint is applied dorsally over the injured finger
to prevent accidental avulsion of the fingertip from the thenar eminence.
■ Two weeks postoperatively, the flap is divided, and if needed, more skin is
removed from the thenar area to cover the entire fingertip that is buried
within the thenar pocket.
■ The divided flap edge is sutured to the edge of the fingertip defect, and the
thenar skin is closed with 4-0 sutures; absorbable or nonabsorbable sutures
may be used at this stage (TECH FIG 3F).
■ Immobilization is not typically required after the second surgery, and ROM
exercises are started.
PEARLS AND PITFALLS
Physical
findings
■ Carefully assess the flexion and extension of the DIP for patients
with a fingertip injury. Associated mallet injury is common.

Technique
■ Handle flaps atraumatically. The blood supply for fingertip flaps is
random from small local vessels.
■ Cross-finger flap: The cross-finger flap can be used for resurfacing
of fingertip defects of all fingers. A thumb defect is the most
difficult to inset using a flap from the index finger because of the
pronated position of the thumb relative to the other digits of the
hand. Defects of the ring finger are best resurfaced with a flap
from the middle finger, rather than the shorter small finger, for
adequate inset. A fingertip defect of the small finger requires
minimal flexion of the small finger for inset to a flap from the ring
finger.
■ Thenar flap: The thenar flap can be used for all fingers;
positioning is easiest for the index and middle fingers and most
difficult for the small finger.
■ Obtain hemostasis and close the skin while the tourniquet is down
to prevent a hematoma to optimize flap and graft survival.
■ Assess flap tension in the operating room with the hand at rest and
with passive range of motion. If surgery is performed with local
anesthesia only, active range of motion can also be assessed. Splint
the hand accordingly; avoid immobilization of uninvolved joints
that do not cause undue tension on the reconstruction when moved.
Postoperative
■ Perform second-stage flap division 2 wk after flap inset. Longer
periods of immobilization lead to worsening joint stiffness.
Therapy
■ Patients can follow a home therapy program for fingertip
desensitization.
POSTOPERATIVE CARE
■ Fingertip sensitivity is the most common patient complaint following fingertip
injury and reconstruction. Cold sensitivity can be particularly troublesome.
■ Time, reassurance, and hand therapy are beneficial.
■ Massage, desensitization exercises, and cortical retraining of the finger are
useful techniques.
■ Fingertip protectors can be worn early in the postoperative period when the
fingertip is most sensitive. They can be weaned over time as symptoms
improve.
OUTCOMES
■ V-Y advancement flap

■ Excellent contour of the fingertip can be achieved (FIG 5).
■ Near-normal sensation is restored.
■ Cross-finger flap
■ Good aesthetic outcomes are achieved following fingertip reconstruction
(FIG 6A,B).
■ Sensory recovery improves with time; protective sensation is recovered, but
tactile gnosis is not.10
■ Despite difficulty with cortical relearning and incomplete sensory recovery,
particularly in adult patients, patient satisfaction remains high.11
■ The donor site is aesthetically unappealing (FIG 6C), particularly for female
patients, and the flap color match may be poor, especially in dark-skinned
patients.
• A thenar flap is favored for female and dark-skinned patients rather than a
cross-finger flap.
■ Thenar flap
■ Donor-site tenderness can be problematic; early hand therapy is
recommended.
■ Sensory recovery in the injured finger is typically better compared to a cross-
finger flap.12
■ Aesthetic outcome of the reconstructed fingertip is excellent, and the donor
site is hidden in the palm (FIG 7).
FIG 5 • The V-Y advancement flap of the index finger
restores the contour of the fingertip with sensate,

durable soft tissue coverage. The donor site is
inconspicuous. The incisions over the volar finger pulp
can be sensitive; hand therapy may be required
postoperatively.
COMPLICATIONS
■ A shortened distal phalanx results in the loss of nail bed support. A hook-nail
deformity can result. Excision of the sterile nail matrix 2 mm proximal to the
shortened bone can help prevent this complication. The patient is taught to trim
the nail frequently.
■ If the nail remains troublesome, nail bed obliteration can be performed.
■ A V-Y advancement flap creates additional incisions over the volar finger
pulp. Hypertrophic and hypersensitive scarring can result.
■ With regional flaps, stiffness can be marked postoperatively, particularly for
older patients with arthritis and other comorbidities. Patients must be consulted
preoperatively on the need for hand therapy following a two-stage flap
reconstruction. For severe contractures, static progressive splinting can be
used.
FIG 6 • The cross-finger flap provides excellent
resurfacing for a fingertip injury, shown here volarly (A)
and laterally (B) 4 months postoperatively. C. The
appearance of the FTSG at the donor site, shown 4
months postoperatively, improves with time but remains
noticeable over the dorsal middle phalanx of the donor
finger. Aesthetic considerations must be discussed with
the patient prior to use of this flap.

FIG 7 • The appearance of the reconstructed index
fingertip and the thenar flap donor site 3 months
postoperatively shows satisfactory healing.
■ V-Y advancement and thenar flaps transfer glabrous skin to fingertip injuries;
cross-finger flaps do not. Furthermore, cross-finger flaps may transfer hair-
bearing skin to the volar skin pulp. Laser hair removal can be used once the
flap is healed.
REFERENCES
1. Fassler PR. Fingertip injuries: evaluation and treatment. J Am Acad Orthop
Surg. 1996;4(1):84-92.
2. Atasoy E, Ioakimidis E, Kasdan ML, et al. Reconstruction of the amputated
finger tip with a triangular volar flap: a new surgical procedure. J Bone Joint
Surg Am. 1970;52(5):921-926.
3. Brown RE. Acute nail bed injuries. Hand Clin. 2002;18(4):561-575.
4. Lemmon JA, Janis JE, Rohrich RJ. Soft-tissue injuries of the fingertip:
methods of evaluation and treatment: an algorithmic approach. Plast Reconstr
Surg. 2008;122(3):105e-117e.
5. Holm A, Zachariae L. Fingertip lesions: an evaluation of conservative
treatment versus free skin grafting. Acta Orthop Scand. 1974;45(3):382-392.
6. Moiemen NS, Elliot D. Composite graft replacement of digital tips. 2. A study
in children. J Hand Surg Br. 1997;22(3):346-352.
7. Kumar VP, Satku K. Treatment and prevention of “hook nail” deformity with

anatomic correlation. J Hand Surg [Am]. 1993;18(4):617-620.
8. Chao JG HJ, Wiedrich TA. Local hand flaps. J Am Soc Surg Hand.
2001;1(1):25-44.
9. Thoma A, Vartija LK. Making the V-Y advancement flap safer in fingertip
amputations. Can J Plast Surg. 2010;18(4):e47-49.
10. Nishikawa H, Smith PJ. The recovery of sensation and function after cross-
finger flaps for fingertip injury. J Hand Surg Br. 1992;17(1):102-107.
11. Kleinert HE, McAlister CG, MacDonald CJ, Kutz JE. A critical evaluation of
cross finger flaps. J Trauma. 1974;14(9):756-763.
12. Melone CP, Beasley RW, Carstens JH. The thenar flap: an analysis of its use
in 150 cases. J Hand Surg [Am]. 1982;7(3):291-297.

46
CHAPTER
Flap Coverage of Thumb
Defects
Kate Elzinga and Kevin C. Chung
DEFINITION
■ The thumb accounts for over 40% of hand function.1 Maintenance of length,
ideally beyond the neck of the proximal phalanx, is critical for stable pinch and
grasp.
■ The goals of thumb reconstruction include maximizing length, stability,
strength, mobility, sensation, durability of coverage, and appearance while
minimizing donor-site morbidity.
■ The function of the thumb is optimized following injury by restoring a sensate
thumb pulp.2
ANATOMY
■ The volar thumb is covered by thick, durable, highly innervated, glabrous skin.
■ Dorsally, the nail provides protection for the distal phalanx and
counterpressure for the pulp during pinch.
PATIENT HISTORY AND PHYSICAL FINDINGS
■ Following a thumb injury, important patient factors include age, sex,
handedness, comorbidities, medications, allergies, occupation and avocations,
and smoking status.
■ Injury factors to consider include the time and mechanism of injury, the degree
of tissue contamination and necrosis, and any previous hand injuries.
■ The patients’ goals are explored. Their desire for a rapid return to work and
their level of compliance and motivation are considered when formulating a
reconstructive plan.
■ The thumb wound is examined, noting the level of the injury and tissue loss

(skin, soft tissue, neurovascular bundles, tendons, bone, nail). Exposed
structures are evaluated and documented.
■ The thumb’s color, capillary refill, turgor, and temperature are assessed as part
of the vascular exam. The digital nerves are assessed using light touch, two-
point discrimination, or the ten test.3
■ The function of the extensor pollicis longus and that of the flexor pollicis
longus (FPL) are tested by asking the patient to actively flex and extend the
interphalangeal (IP) joint of the thumb.
■ A digital block can be used for patient comfort to facilitate the examination
following sensory testing of the thumb.
■ Donor sites are examined locally and regionally for thumb reconstruction.
IMAGING
■ Plain radiographs are performed for the thumb to assess for bony injury, level
of amputation, and presence of a foreign body.
NONOPERATIVE MANAGEMENT
■ Small defects, up to 1 cm2 without exposed bone or tendon, heal well by
secondary intention.
■ Ingrowth of glabrous skin results in durable, sensate coverage.
■ Moist, antibacterial dressings are applied daily.
■ Range-of-motion exercises are performed throughout to prevent stiffness.
■ Once healed, early use of the thumb is encouraged to help with
desensitization of the fingertip and return of function.
■ Elevation of the injured upper extremity and gentle compression decrease
edema at the thumb defect site, which expedites wound healing.
SURGICAL MANAGEMENT
■ Larger skin and subcutaneous tissue defects, over 1 cm2 without exposed
tendon or bone, can be covered with a full-thickness skin graft (FTSG).
■ Rapid healing occurs, but FTSGs are less durable and have poorer sensory
recovery compared with healing by secondary intention.
■ When tendon or bone is exposed, coverage with local and regional flaps is
necessary.
■ To restore sensate, durable coverage over an exposed distal phalanx, flap
reconstruction with a local Moberg flap can provide coverage for defects of 1.5
cm in length or up to 2.5 cm in length if a transverse proximal releasing

incision is used (FIG 1).
■ Larger defects can be covered with regional flaps such as the first dorsal
metacarpal artery (FDMA) flap (FIG 2) or the reverse homodigital flap (FIG
3) based on the dorsal radial collateral artery.
■ The FDMA flap can be harvested up to 6 × 3 cm in size.
■ The reverse dorsoradial homodigital flap has been described from 2 × 2 cm
up to 5 × 4 cm in size.4
FIG 1 • The Moberg flap is designed over the volar
thumb for coverage of distal thumb defects. A–C.
Incisions are made at the midaxial line over the radial
and ulnar digit up to the volar MCP joint crease. The
radial and ulnar digital neurovascular bundles are
elevated within the flap. The flap is elevated above the
paratenon of the FPL and advanced distally. Flexion of
the IP joint facilitates flap inset.
Approach
■ The patient is positioned supine with the arm on a hand table.
■ Loupe magnification facilitates flap dissection.
■ The flap incisions are designed using a template of the defect prior to
tourniquet inflation.
■ A tourniquet is used for flap elevation to create a bloodless field that facilitates

exposure and decreases the risk of injury to the neurovascular structures
supplying the flap.
■ Following flap elevation, the tourniquet is released. Flap perfusion is assessed.
Hemostasis is achieved prior to flap inset to prevent a hematoma that could
result in flap compromise.
FIG 2 • The FDMA flap is elevated from the dorsal
proximal phalanx of the index finger for coverage of
thumb defects. A,B. The flap can be raised as an island
flap, using a straight line, lazy S, or zigzag incision as
shown here for elevation of the pedicle back to the flap
pivot point, which is found just distal to the EPL tendon.

FIG 3 • A–C. The reverse dorsoradial homodigital flap is
based on the anastomosis connection of the dorsal
radial collateral artery and the palmar arteries of the
thumb at the middle third of the thumb proximal
phalanx. The flap is harvested as a distally based,
reverse flap for coverage of distal thumb defects.
T E C H N I Q U E S
■ Moberg Flap
■ Incisions are designed over the midaxial lines of the ulnar and radial thumb,
at the junction of the glabrous and nonglabrous skin (TECH FIG 1A; see
FIG 1). Proximally, the flap is marked to the metacarpophalangeal (MCP)
joint crease bilaterally. If further advance is necessary, the flap can be

extended proximal to the MCP, Burow triangles can be excised at the flap
base bilaterally, or the flap can be advanced as a V-Y flap5 or as an island
flap.6
■ The ulnar and radial digital nerves and arteries are elevated within the flap,
which maintains the blood supply to the flap as well as innervation (TECH
FIG 1B). The dorsal blood supply of the thumb from the princeps pollicis
artery permits safe flap elevation without compromising the thumb’s
perfusion.
■ When used as an island flap, a transverse, proximal releasing incision is
made over the proximal phalanx (PP), connecting the two midaxial incisions.
The radial and ulnar neurovascular bundles are protected. This release is
seldom necessary because the thumb interphalangeal (IP) joint can be flexed
sufficiently for the flap to cover the tip of the distal phalanx.
■ The flap is raised from distal to proximal, above the paratenon of the flexor
pollicis longus (FPL). As dissection proceeds proximally, advancement of the
flap can be tested until tension-free inset is achieved. At this point, proximal
dissection ceases.
■ The flap should not be advanced more than 2.5 cm to avoid traction on the
neurovascular bundles. To achieve advancement of 2.5 cm, a transverse
proximal releasing incision is required; the flap is then advanced as an island
flap (TECH FIG 1C,D). Without a proximal releasing incision, the first
dorsal metacarpal artery (FDMA) flap can be advanced 1.5 cm.
■ The donor site can be closed with a full-thickness skin graft (FTSG)
(TECH FIG 1E).
■ If needed, the thumb MCP and IP joints are flexed to facilitate flap inset over
the distal thumb defect.
■ Rarely, a K-wire is used to maintain the flexed position of the IP joint
(TECH FIG 1F).
■ For older patients with arthritis, limited flexion is recommended to prevent
an IP joint flexion contracture.

— Island Skin graft 2.5 cm

TECH FIG 1 • A. Loss of soft tissue following a remote
traumatic crush injury resulted in inadequate pulp
coverage of the distal phalanx tuft and patient
discomfort. A Moberg flap was designed to resurface
the distal volar tip of the thumb. B. The ulnar and
radial neurovascular bundles are elevated with the
flap. The digital arteries and nerves provide perfusion
and innervation to the flap. C,D. To permit
advancement of a Moberg flap up to 2.5 cm distally, it
is elevated as an island flap. A proximal transverse
incision is used to connect the ulnar and radial
midaxial incisions. E. The donor site is covered with
an FTSG. F. A K-wire can be used to maintain IP joint
flexion to facilitate flap inset to the distal thumb.
■ The flap is inset using 4-0 nonabsorbable monofilament suture. The flap is
secured to the intact skin surrounding the defect and to the nail.
■ If used, the FTSG is secured with a bolster dressing. Antibacterial gauze is
applied to the flap incisions followed by sterile gauze and a well-padded
thumb spica splint.
■ The splint can typically be discontinued 1 week postoperatively, and range-
of-motion (ROM) exercises are started for the MCP joint. Two weeks
postoperatively, if present, the K-wire can be removed and IP ROM is
initiated.
■ First Dorsal Metacarpal Artery Flap (see FIG 2)
■ Over the dorsal hand, distal to the anatomic snuffbox, the radial artery gives
off three branches: the dorsal carpal arch (radial branch), the princeps pollicis
(middle branch), and the FDMA (ulnar branch). After giving off the FDMA,
the radial artery dives deep between the two heads of the first dorsal
interosseous (DIO) and joins the deep palmar arch.
■ The FDMA travels within or just above the fascia of the first DIO radial to
the index finger metacarpal. A branch of the dorsal sensory branch of the

radial nerve travels with the FDMA.
■ The FDMA flap provides innervated vascularized soft tissue coverage for
large thumb or first web space defects (TECH FIG 2A,B).
■ It is designed over the dorsal PP of the index finger. Typically, the flap is
designed from the proximal interphalangeal joint to the MCP joint;
proximal extensions are possible for coverage of larger defects (TECH FIG
2C).
■ Ulnarly and radially, the flap extends to the midaxial lines of the index
finger at the junction of the glabrous and nonglabrous skin.
■ The pedicle is a proximal adipofascial extension of the flap that contains the
FDMA, two dorsal veins, a branch of the dorsal sensory branch of the radial
nerve, subcutaneous adipose tissue, and the fascia of the first DIO.
■ Alternatively, the pedicle may be designed as a dermofascial flap extension
with a 1-cm strip of overlying skin (TECH FIG 2D). In these cases, the
skin donor-site defect from the pedicle harvest can be closed primarily.
■ The pivot point of the flap is marked distal to the extensor pollicis longus at
the junction of the metacarpal bases of the thumb and index finger. A
handheld Doppler ultrasound (US) can be used to map the course of the
FDMA from the dorsoradial index finger PP to the flap pivot point. The
course of the FDMA is reliable; US mapping is optional.
■ The flap is elevated above the paratenon of the extensor digitorum
communis (EDC) and extensor indicis proprius (EIP). It is raised from
distoulnar to proximoradial toward the pedicle that enters the flap base on the
radial side of the index finger metacarpal.
■ As the dissection approaches the proximoradial aspect of the flap and the
first DIO is visualized proximal to the MCP joint, dissection must be
continued deep to the fascia of the first DIO to prevent injury to the pedicle.
■ When harvested as an island flap, a straight line, a lazy S, or a zigzag
incision can be used from the flap base to the flap pivot point for pedicle
exposure and elevation. The skin is incised and thin skin flaps are elevated
radially and ulnarly in the subdermal plane. The pedicle is raised 1 cm in
width. The subcutaneous fat and fascia are included to protect the FDMA and
accompanying veins; the FDMA is not skeletonized.
■ Our preferred approach is to harvest the flap with a dermofascial pedicle
rather than as an island flap. A 1-cm skin bridge is incised. A wider
adipofascial strip can be harvested below.

■ Including the dermis helps protect the pedicle below during dissection and
lessens the risk of pedicle kinking or compression during flap inset.
■ The pedicle is raised with the flap from distal to proximal, just above the
first DIO muscle (TECH FIG 2E).
■ When harvested with skin overlying the pedicle, the flap is inset using a skin
incision from the flap pivot point proximally to the thumb defect distally
(TECH FIG 2F).
■ When used as an island flap, the flap can be inset under a tunnel (TECH FIG
2G).
■ There is an increased risk of venous congestion of the flap when tunneled
compared to inset using a skin bridge.
■ Tension-free closure of the flap into the defect is performed using sutures
(TECH FIG 2H–J).
■ An FTSG is used to close the FDMA flap donor site (TECH FIG 2K,L). A
bolster dressing is placed over the FTSG on the dorsal index finger PP.
■ Antibacterial gauze and dry gauze are applied to the flap incisions.
■ A well-padded splint is applied, taking care to avoid pressure on the flap or
pedicle.
■ The splint can typically be discontinued 1 week postoperatively, and ROM
exercises are started as long as they do not cause undue tension on the flap.

S7x9