Reconstruction of traumatic absence of the thumb in the adult by pollicization.

Amputation of the thumb is a severe handicap. In an emergency situation, thumb amputation must be treated by means of reimplantation when possible. If reimplantation cannot be performed or fails, several methods of thumb reconstruction can be used according to various factors. These include the number of surviving fingers and the level of the thumb amputation. Pollicization is the first choice for amputations proximal to the metacarpophalangeal joint when four and even three fingers are present. It is the easiest and safest operation that supplies the best results both from the motor and sensory points of view. Pollicization can be done even in an emergency situation in selected patients. The index finger is preferred because it can be pollicized without palmar scar or tendons, vessels, or nerves crossing over. If a damaged finger is present, it is preferred to the index finger to leave one more sound finger; a damaged finger can frequently be used, because the thumb is shorter than the other fingers, and although its mobility is very important at the trapeziometacarpal joint, it is less important at the metacarpophalangeal and interphalangeal joint levels. It is preferable to take as much second metacarpal bone as necessary to place the transferred second metacarpophalangeal joint at the position of the thumb metacarpophalangeal joint so that the tendons of the index interosseous muscles can be sutured to the intrinsic muscles of the thumb. According to this concept, the distal phalanx of the transferred finger should be amputated. In this manner, the new thumb will have a normal size, only two phalanges, only one extrinsic flexor, and normal insertion of the muscles of the thumb.