Avulsion injuries of the thumb: survival factors and functional results of replantation.

Twenty-seven cases of replantation for avulsion injuries of the thumb from 1979 to 1987 were analyzed retrospectively. Inclusion criteria required all thumbs to have tendinous attachments (either the extensor pollicis longus or the flexor pollicis longus) to the amputated part. Thirteen replants survived for an overall survival rate of 48%. Avulsions at or proximal to the metacarpophalangeal joint had a survival rate of 83% compared with a 38% survival rate distal to the metacarpophalangeal joint. This difference was not statistically significant. Of the 13 patients with surviving replanted thumbs, 11 (85%) achieved protective sensation only and 2 attained a two-point discrimination <10 mm. Of the 13 replanted thumbs that survived, 7 were treated with primary arthrodesis, 4 at the level of the interphalangeal joint and 3 at the metacarpophalangeal joint. The other 6 thumbs were treated with primary or secondary tendon transfers. In a literature review of thumb avulsion injuries, survival rates range from 26% to 100%. In this study, tendon transfers and primary arthrodesis were useful adjuncts in the management of thumb avulsions, and the majority of patients with successfully replanted thumbs attained protective sensation only. Larger studies are needed to better define statistically significant relationships affecting replantation survival.