Recovery of sensation in replanted digits--time of recovery and degree of two-point discrimination.

Even if good motor function returns in a replanted digit, if no useful sensation returns, the digit cannot be considered fully functional. In such cases sensory reconstruction with nerve grafts may be necessary, but it is difficult to determine the optimal time for such surgery. Therefore, we studied 37 replanted digits in which the palmar digital nerves had been severed bilaterally and anastomosed at the replantation procedure. Our findings indicate a correlation between the time at which sensation returned to the digits and the degree of two-point discrimination (2PD) that returned. In digits in which sensation returned less than four months after replantation, a 2PD of less than 15 mm returned in more than 50% of cases, but when more than four months passed before the return of sensation, a useful degree of 2PD seldom returned. We believe, therefore, that if the recovery of sensation in a replanted digit has not been satisfactory by four months after replantation, reconstructive surgery should be considered.