Transfer of the posterior tibial tendon to a rerouted anterior tibial tendon and transfer of the flexor digitorum longus to the extensor hallucis longus through four limited incisions in cases of drop foot

Abstract

The purpose of this study was to evaluate a technique of transfer of the posterior tibial tendon (PTT) to a rerouted anterior tibial tendon (ATT) and transfer of the flexor digitorum longus (FDL) to the extensor hallucis longus (EHL) through four limited incisions in cases of drop foot. This is a prospective case series study in which the new technique was done on ten patients with drop foot. Preoperative and postoperative functional evaluation was performed according to Stanmore grading system, and the muscle power of dorsiflexion was assessed using the Medical Research Council grading system but modified using Seddon’s method. After a mean follow up of 29.4 months (range 24–42 months), the results were excellent in five patients (50 %), good in one patient (10 %), and fair in four patients (40 %). The average Stanmore grading system score in the last follow-up was 77 (range from 62 to 90) compared to an average preoperative score of 22.8 (range from 18 to 24). The power of the transferred PTT was graded 4 in six patients (60 %) and 3 in four patients (40 %). The technique is an option for treating cases of drop foot. It avoids the problems of insufficient tendon length and uses limited incisions. The anterior transfer of the FDL to the EHL prevents drop big toe and adds to the dorsiflexion power of the PTT. However, further studies are needed to compare the technique to the conventional PTT transfer techniques.