Circumtibial tibialis posterior tendon transfer with tri-tendon anastomosis and tendon-to-bone fixation for foot drop: A case report and literature review

Foot drop (FD) results from neurological, muscular, or skeletal disorders, with common peroneal nerve (CPN) palsy as a frequent cause. Tibialis posterior tendon (TPT) transfer has become a standard surgical treatment in refractory cases, with various techniques available for tendon transfer and fixation. We report a case of a 54-year-old female with FD due to CPN palsy, who presented with progressive dorsiflexion weakness and failed conservative management. A modified TPT transfer using CT route was performed, along with tri-tendon anastomosis to tibialis anterior (TAT) and peroneus longus (PL) tendons, and tendon-to-bone fixation on the intermediate cuneiform. The technique involved small incisions and tendon-with-Z-lengthening (TWZL) to address TPT length insufficiency. Postoperative recovery was uneventful, with functional restoration and progressive mobilization initiated at 4 weeks. Both CT and IO routes are effective for TPT transfer, with IO route widely favored for its physiological line of pull. However, CT route remains valuable due to its ease of use, lower risk of vascular injury and applicability in patients with calcified IO membranes. CT route can carry risks of varus recurrence. Our approach, a modified Bridle procedure via the CT route, minimized extensive dissection and associated vascular risks, achieving stable fixation with an optimized mechanical advantage. Though successful, further studies are warranted to validate this combined technique's long-term efficacy. This case supports CT TPT transfer with tri-tendon anastomosis and tendon-to-bone fixation as an effective approach for FD management with reduced complication risks.