gms | German Medical Science

Objectives/Interrogation: A stable 1st CMCJ has been considered a mandatory factor for a successful toe to hand transplantation. The base of metacarpal bone is absent for hypoplasia type IIIb - V, therefore, toe to hand transplantation is not recommended. Tan and Tu 2013 described a technique for toe-to hand transplantation for thumb hypoplasia patients IIIb-V but overall results were not better than pollicization. The aim of this study is to describe a new technique for thumb reconstruction with a second toe transfer with metatarsophalangeal joint arthrodesis, which can provide a 5-digit hand and restore the functionality of the thumb for thumb hypoplasia IIIb - V.

Methods: A total of five patients with thumb hypoplasia stage IIIB V were included in study. All patients underwent long-term (3-5 years) follow-up evaluation. VAS was used for an aesthetic evaluation, patients and their parents were asked to give a score from 1 to 10 (more is better) points to two questions, "Does the transplanted toe look like a thumb?" and "Does the transplanted toe work like a thumb?". To establish functionality patients were asked to complete the DASH survey, objectively ROM in 3 thumb's joints, the strength of the grasp and pinch grip were measured, and two-point discrimination test was performed. To find out overall population's perspective on aesthetic outcomes between a 4-digit hand after the pollicization and a 5-digit hand with a transplanted thumb internet survey was created. The survey to evaluate aesthetical outcome for transplantation method and pollicization method was completed by 290 respondents. Statistical evaluation was performed using the Student's t-test and Wilcoxon-Mann-Whitney test.

Results and Conclusions: Patients with toe-to hand transplantation scored average DASH 9,35 (8,0-10,7) points. Patients who had pollicization procedure gave average DASH 19,8 (6-26,7) points. The aesthetical survey was completed by 290 respondents. VAS for the toe transplantation was 7,04 (3-10), whereas for the pollicization - 5,84 (1-10).

Stable and long 1st metacarpal bone created using MTPJ arthrodesis is an option provided by our technique. Then PIPJ and DIPJ of transplanted toe becomes IPJ and MCPJ of new thumb what works similar to pollicization technique.Overall population rates transplantation's aesthetic outcomes higher than pollicization's (the scores is statistically significant (p<0.0001).