3 Cross-Finger Flap Design: Vascular supply: Skin and subcutanous tissue Designed over dorsal aspect middle phalynxVascular supply:Dorsal digital arteryDigital perforators
4 Cross-Finger Flap Clinical Applications Coverage of volar aspect of adjacent digits’ middle phalangeal areaDistal digital tip coverageVolar oblique fingertip amputations with exposed bone or tendon
5 Anatomy Dorsal Digital Artery (1mm) Dorsal skin distal to the distal proximal phalynx depends on perforating branches from digital arteriesCourse through Cleland’s ligamentSupplies the flapDigital Perforators passing dorsally around finger ( mm)The vascular supply of the dorsal skin distal to the distal portion of the proximal phalynx depends on perforating vessels from the digital arteries. These dorsal branches supply the flap. The perforating vessels course through Cleland’s ligament and anterior dorsal network, where they support a rich dermal and subdermal plexus. This supplies a laterally based cross-finger flap. There are two to four perforators over the proximal phalynx, midportion of the middle phalynx and distal third of the middle phalynx
6 Design and Markings Designed with base adjacent to injured finger Proximal and distal flap marked transverselyConnect these with a longitudinal line just dorsal to mid-axis of dorsum of finger3-sided rectangleIncisions made to encompass whole surface of middle phalynx
8 DissectionIncise skin based on markings down to SC fat until loose areolar planeElevate flap in this plane, taking care to leave the paratenon behindDissect to Cleland’s ligament; may need to divide ligament to increase pedicle lengthCover donor site with skin graftInset flapDivide flap 2-3 weeks later
10 Reverse Cross-Finger Flap For adjacent dorsal digital wound coverageElevate flap in subdermal planeAdipofascial flap to cover dorsal defect
11 Thenar Flap To cover defects on the index and long fingers Green’s: “Use where preservation of length is considered important and other techniques that have less potential for complications are not applicable”
13 Thenar FlapDonor site found by taking tip of index or ring finger and placing it against thenar eminanceDraw circle around area of contactDraw H or curved incision at this pointElevate flaps in subcutaneous planeInset flapDivide in daysFor the H flap, the proximal flap covers the finger defect and distal flap advanced to cover donor
15 Points about the Thenar Flap To avoid potential for joint stiffness or unsightly scar in donor area:Design flap near the MP crease of the thumb; avoid the midpalmar areaFully flex the MP joint with whatever amount of flexion is required in the IP joints of the recipient fingerDetach pedicle days post-op and start immediate AROMTo avoid the potential for joint stiffness with a permanent flexion contracture or unsightly scar in the donor area, one must keep in mind the three cardinal technical principles outlined by Melone and colleagues: (1) design the flap near the metacarpophalangeal (MP) crease of the thumb and avoid the midpalmar area; (2) fully flex the MP joint with whatever amount of flexion is required in the IP joints of the recipient finger; and (3) detach the pedicle 10 to 14 days postoperatively and begin immediate active range of motion.Contraindications to either the cross-finger flap or the thenar flap would be any general condition that might lead to finger stiffness, such as rheumatoid arthritis, Dupuytren's contracture, any connective tissue disease involving the hand, and advanced age with its concomitant degenerative changes. Complications seem to be more prevalent in those patients older than 30 years of age with a greater tendency for the development of joint stiffness. We believe that the risk of this complication is a relative contraindication to the use of the thenar flap in patients older than age 30.
16 First Dorsal Metacarpal Artery Flap Classification:Type A fasciocutaneous flapFrom dorsal skin over proximal phalynx (FDMA)Clinical Applications:For defects in the thumb
17 FDMA Dominant Pedicle: Minor Pedicle: Nerve Supply: First dorsal metacarpal artery (FDMA)Minor Pedicle:Cutaneous perforators of the FDMANerve Supply:Dorsal sensory branches of the radial and ulnar nerves
18 Anatomy Dorsal metacarpal arteries From dorsal carpal arch formed from dorsal carpal arteriesGives rise to 4 dorsal metacarpal arteriesThese course over dorsal interosseous musclesCommunicates with deep palmar archProximal to web space divides into 2 dorsal digital branchesThen divide into terminal branches midway along proximal phalynxThe dorsal carpal arch is formed from dorsal carpal arteries arising from the ulnar and radial arteries. The vessels anastamose across the dorsum of the distal carpal row to form a vascular arcade that gives rise to four dorsal metacarpal arteries. Each metacarpal vessel courses distally over the dorsal interosseous muscle bellies to supply the skin and subcutaneous tissues covering the dorsum of each finger and its adjacent dorsal web space. The first dorsal metacarpal artery (FDMA) tends to be a discrete terminal branch of the radial artery rather than arising directly from that dorsal carpal arch. The fifth dorsal metacarpal artery may also arise as a terminal branch of the ulnar artery.From its origin, each vessel courses distally toward the web space and communicates through the interosseous space with the deep palmar arch. Proximal to the web space, each of the second, third and fourth dorsal metacarpal arteries divide into two dorsal digital branches, on to each adjacent side of the index, middle, ring and little fingers. The FDMA supplies the dorsum of the thumb and radial side of the index finger, and the fifth dorsal metacarpal artery supplies the ulnar side of the little finger. Traveling distally along each side of the finger, the vessels divide into terminal branches midway along the proximal phalynx. The vessels supply the dorsal skin of the finger as far as the proximal interphalangeal (PIP) joint. Distally, the dorsal skin is supplies by branches of the palmar digital arteries.
19 AnatomyThe first dorsal metacarpal artery (FDMA) tends to be a discrete terminal branch of the radial artery rather than arising directly from that dorsal carpal archFound in the first intermetacarpal space, just distal to the extensor pollicis longus tendonSupplies the dorsum of the thumb and radial side of the index finger
21 Flap Markings From MCP joint to the PIP joint of index Radial & ulnar borders 1st the midlateral lines on either side of digit
22 Flap Dissection Incision in 1st dorsal web space, down to FDMA Elevate flap distal to proximal, just above paratenonFascia and fat adjacent to 2nd metacarpal kept intact to protect vesselsTransfer and inset flapCover donor with skin graftAn incision is then made in thedorsal first web space, and dissection is carried downto the first dorsal metacarpal artery, which arises fromthe radial artery. With a very complete dissection, apedicle of 7 to 8 cm can be created. The flap is thenincised and elevated at the level of the paratenon froma distal to proximal direction. Fascia adjacent to thesecond metacarpal along with adjacent fat are keptintact along the course of the vessels. A subcutaneoustunnel is created from the donor site to the recipientsite, and the flap is brought through, with care takennot to kink or twist the pedicle. The dorsal proximalphalanx is covered with a full-thickness skin graft