Background
Thumb performs 40% of hand functions. Preserving the length, Stability and sensation are the most important aspects of Thumb reconstruction. FDMA based flap is the mainstay of soft tissue reconstruction. In this study we summarize 7cases of thumb resurfacing with this flap either as a kite flap or as a Cross finger flap.
Methodology
This is a case series conducted as a prospective descriptive study. Two children(10y,12y) with thumb IPJ skin contractures and three adults(45y,48y,51y) with traumatic trans-distal phalanx amputations were included for kite flap. Two adults(36y & 52y) with distal tip defects were included for the cross finger technique.
After the debridement or releasing the contracture, FDMA kite flap was raised and mobilized up to the pre Doppler marked perforator at the base of the 2nd metacarpal bone. In 3 cases pedicle was tunneled.
In cross finger design, FDMA Doppler marked up to the radial aspect of the Index MCPJ and flap raised as for the kite flap but radial-lateral MCPJ skin kept undivided. A cup flap designed before inserting to the thumb tip defect as a cross finger flap. Secondary site FTSG done. Division performed in 2-3 weeks with attempts of coaptation of SRN branches to digital nerves.
Results
Flaps were observed for viability and healing initially and subsequently for function and sensation. One child developed a congested flap and managed with chemical leaching. Kite flaps achieved better quality pain and touch sensations. Cross finger flaps developed protective pain sensations. With pressure and scar therapy cross finger cup flap achieved a better pulp contour.
Discussion/Conclusion
Kite flap design of the FDMA flap reaches volar IPJ level of the thumb comfortably and results in the best sensory outcome. Cross finger flap is better for thumb tip reconstructions as it gives more tissues as a cup flap.