Background

Equinovarus deformity in the foot results from muscle fibrosis and peroneal nerve injury. Transfer of the posterior tibial tendon anteriorly and percutaneous Achilles tendon lengthening is a useful technique to manage drop foot.

Case Presentation

A 44-year-old man has a left drop foot secondary to deep peroneal nerve transection 8 years ago as a result of previous compartment releases. The patient has been using an ankle-foot orthosis for ambulation. The patient has a steppage gait, no active ankle dorsiflexion, some foot eversion, excellent motor strength with plantar flexion and inversion, 5/5 motor strength in the posterior tibial tendon, and intact pulses. Radiographs demonstrate no fractures, dislocations, or arthritic changes in the ankle or hindfoot.

Assessment

Physical examination reveals a left ankle equinus contracture, a left drop foot, and a left accessory navicular.

Procedure

A posterior tibial tendon transfer through the interosseous membrane to the dorsum of the foot is performed in combination with Achilles tendon lengthening and a hemi-resection technique.

Postoperative Rehabilitation

The patient's ankle is splinted in neutral dorsiflexion, and a cast is applied for 6 to 8 weeks postoperatively, after which the patient is transitioned to a CAM boot with weight bearing permitted as tolerated. Physical therapy is initiated 3 months postoperatively.