Metacarpal-Like Hand: Classification and Treatment Guidelines for Microsurgical Reconstruction with Toe Transplantation

The metacarpal-like hand is a severe hand injury, never addressed before. It describes a hand that has lost a significant degree of prehension through a wide array of amputations, involving all digits proximal to the functional length except in one finger or in two digits, including the thumb. The thumb condition can be used to differentiate between two types. In type I, the thumb is intact or amputated at or distal to the interphalangeal joint (functional length); therefore, the reconstruction is focused mainly on fingers. In type II, the thumb is amputated proximal to the interphalangeal joint; therefore, the reconstruction is focused on both the thumb and fingers. Thumb amputation level, integrity of the first basal joint, and functionality of the thenar muscles can be used to subdivide type II. Functional reconstruction should consider the patient's desire and vocational needs. The finger left with adequate functional length is assessed for its location, level of amputation, and joint motion, especially the proximal interphalangeal joint. The goal is to use the reliable techniques of toe-to-hand surgery to reconstruct more opposable units, at least two fingers, whether adjacent to each other or not, and the thumb, when needed, to achieve a functionally and aesthetically better hand instead of a functionally adequate hand, with a more acceptable to ideally natural hand cascade. Strategic, individualized toe transfer(s) is the key element in fulfilling the goals of this operation whether single or multiple toes are transplanted.