The role of nonvascularized toe phalanx transplantation.

Stabilization of boneless finger stumps or lengthening of partially aplastic digits in congenital malformations is difficult, because the bone graft, placed on top of the existing bone, will undergo resorption. Only the periosteum-covered proximal toe phalanx will withstand resorption and show a complete take. With the toe phalanx, including the plantar plate and the collateral ligaments of the metatarsophalangeal joint as a half-joint, it is possible to construct a new joint with the cartilage-covered distal end of the recipient bone (metacarpal or proximal phalanx) as the proximal half-joint. Flexor and extensor tendons exist in almost all cases. Between 1976 and 1990, 97 toe phalanx transplantations were performed in 57 children. The indications were boneless digital stumps with partial absence of digits and large bone defects in fingers in symbrachydactyly and ring-constriction syndrome. Follow-up examinations of 44 patients with 69 transplanted toe phalanges (95% of the patients operated on by March 1989) have shown a 100% take of the bone graft, provided it had been unsplit and the periosteal cover undamaged. The earlier in life the operation was performed, the more postoperative growth was recorded. The shortening of the donor toe was less because a tendon interposition was used. A joint construction was attempted in 64 digits with variable results. The range of active motion varied between 0 (fusion) and 90 degrees.