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Metacarpal hand refers to the hand that has lost its prehensile ability through amputation of all fingers with or without amputation of the thumb. Functional restoration can be achieved by a wide variety of microvascular toe transfer techniques. When deciding which procedure should be used, careful consideration must be given to the level of amputation of the fingers as well as the functional status of the remaining thumb. In this article we propose a classification for the various patterns of the metacarpal hand along with guidelines for selection of the proper toe transfer procedure.

Microsurgical toe transfer is an established method for reconstruction of missing thumbs. However, there is little agreement on which of the various techniques represents the ideal transfer. Basically, selection of technique requires balancing the patient's functional needs, appearance of the reconstructed thumb, and donor-site cosmesis. Based on our experience with 103 toe-to-thumb transfers performed over the past 9 years, this paper attempts to provide guidelines for appropriate selection among the four most commonly employed toe transfer techniques (e.g., second toe, total great toe, great toe wrap-around, trimmed great toe) so that optimal results and patient's acceptance can both be achieved.

From 1982-1989, 152 mutilated distal digits were reconstructed with microsurgical foot tissue transfers in 121 patients. These various foot tissues included wrap-around flaps or pulp from the great toe, second toe, or third toe, as well as partial toe, nail, web space skin, and other portions of the foot. The reconstructions were carried out primarily and secondarily in 78 and 74 patients respectively. The immediate success rate was 98%. Most of the patients were satisfied with both the cosmetic appearance and the functional result. This relatively minor microsurgical foot tissue transfer proved to be an ideal reconstructive option for distal digital defects.

Three successful digital replantations were performed on a patient after 84, 86, and 94 hours of prolonged cold ischemia time. Both the intraoperative and postoperative courses were smooth. Functional evaluation 8 months after operation revealed a normal speed of sensory recovery and nail growth. The atrophic changes in all three replants are mild. Total active movement was 45, 100, and 70 degrees in the replanted left thumb, left index finger, and right thumb, respectively. There is no cold intolerance. The overall functional result is satisfactory. Replantation of an amputated digit that is properly cooled immediately after injury should be attempted in selected patients even after prolonged ischemia time.

The trimmed-toe transfer is a new modification of the existing great-toe transfer technique for thumb reconstruction. This procedure was devised to circumvent patient concerns regarding overly large reconstructed digits following total great-toe-to-hand transfer. This technique involves reduction of both the bony and soft-tissue elements along the medial aspect of the transferred great toe in order to produce a more normal sized thumb. Follow-up of the initial 20 patients from 1983 to 1986 demonstrates good stability, grip strength, and pinch strength. Although compared with total great-toe transfer a modest reduction in joint motion of trimmed toes has been observed, the overall appearance and usefulness of the reconstructed thumbs have been excellent.

Our experience with simultaneous transfer of two or more toe units to the same hand where multiple digits were missing is presented. Forty-six toes from 38 feet were transferred to reconstruct 19 hands in 19 patients. The transfers consisted of 7 combined second and third toe units and 32 single toes. Three patients had a primary and 16 patients had a secondary reconstruction. There was one complete and one partial failure. The two-point discrimination ranged from 6 mm to protective sensation. Total active movement averaged 57 degrees in the thumb and 127, 93, 71, and 68 degrees, respectively, in the fingers reconstructed at middle phalanx, proximal phalanx, metacarpophalangeal joint, and metacarpal head. Pulp-to-pulp pinch averaged 2.4 kg in patients who had thumbs reconstructed and averaged 3.0 kg in patients who had normal thumbs. There was no cold intolerance, and no significantly disabled foot occurred except one with scissoring deformity. Simultaneous multiple toe transfer in hand reconstruction is feasible without increased complications both in primary and secondary wound conditions. It is time-effective and cost-effective.