Surgical restoration of drop foot deformity with tibialis posterior tendon transfer

Objectives: The transfer of the tibialis posterior tendon to the paralysed tendons on the anterior aspect of the ankle not only restores the function of the paralyzed muscles, but also removes the deforming force on the medial aspect of the foot. In this study, we evaluated patients who under¬went tibialis posterior tendon transfer for the treatment of drop foot. Methods: The study included 41 patients (24 males, 17 fe¬males; mean age 32 years; range 11 to 73 years) who un¬derwent tibialis posterior tendon transfer for drop foot. The mean duration of paralysis was 51.5 months (range 4 to 240 months). The mean preoperative drop foot angle was 30.9° (range 15 to 55 degrees). The tibialis posterior tendon was first detached from its insertion and carried proximally on the crural midline, then transferred to the dorsum of the foot through the circumtibial route, where it was split into two parts. One strip was attached to the tibialis anterior tendon, and the other to the extensor hallucis longus, extensor digi¬torum longus, and peroneus tertius tendons. The results were evaluated according the criteria of Carayon et al. The mean follow-up was 107.9 months (range 12 to 254 months). Results: The mean postoperative active dorsiflexion was 7.6°, plantar flexion was 21.8°, and their sum was 30.4°. The results were excellent in six feet (14.6%), good in 23 feet (56.1%), moderate in seven feet (17.1%), and poor in five feet (12.2%). Conclusion: Tibialis posterior tendon transfer in drop foot yields highly successful results in the restoration of active dorsiflexion and prevention of flexion deformity in the toes.