The recovery of patients with dorsiflexion paralysis of the foot can be helped with tendon transfers to restore the functional loss. In order for the tendon transfer to be successful, the patient should have a stable skeletal alignment and adequate passive dorsiflexion of the foot.

Loss of foot dorsiflexion can occur from: Neurologic etiology

Loss of muscle function caused by

Lower motor neuron-type paralysis can be caused by trauma to peripheral nerves, most commonly the common or deep peroneal nerve at the level of the knee. In these patients, the surgeon should allow for ample time for recovery of function after the injury before performing any tendon transfers (10). These patients should be treated with splinting of the foot and ankle to prevent a fixed plantarflexion deformity and physical therapy methods including muscular electrical stimulation with the aim to preserve as much muscle tissue as possible. Electrodiagnostic studies will aid in predicting and following any neurologic recovery. The transferred muscle should be expendable and of sufficient strength and excursion to replace the functional loss. The line of pull of the tendon transfer
should be as direct as possible from origin to the new insertion. Antagonist or out-of-phase muscles can be utilized when synergistic muscles are not available for transfer (2,4, 5 and 6,11).

The posterior tibial muscle is the third strongest muscle below the knee behind the medial gastrocnemius and soleus (12). Watkins (13) described a posterior tibial tendon transfer through the interosseus membrane to the dorsum of the foot with bony insertion on the cuboid or cuneiform bones. During this procedure it is difficult to balance the foot in valgus or varus (4, 5 and 6,14). Other authors have reported on various degrees of successful results with the procedure described by Watkins (3,8,9,15, 16, 17 and 18). Several authors (1,2,11) proposed performing a triple arthrodesis prior to the tendon transfer procedure to balance the foot after the tendon transfer and to improve the functional results. Riordan (7) described a posterior tibial tendon transfer through the interosseus membrane with attachment to the anterior tibial and peroneus longus tendon above the ankle and no direct bone insertion of the posterior tibial tendon on the foot. He named this procedure a Bridle procedure. This procedure was also reported by others (3).

This author (4, 5 and 6,14) modified the Riordan Bridle procedure by direct insertion of the posterior tibial tendon into the middle cuneiform bone preventing stretching of the tendon transfer to the foot that can occur without direct bone insertion (3, 4, 5 and 6,14) and also suturing the posterior tibial to the anterior tibial and peroneus longus tendons above the ankle. The result is a well-balanced foot (Fig. 46.1). Gellman et al. (10) reported on this modification of the original Bridle operation.

The gastrocnemius recession operation is considered when there is a gastrocnemius equinus contracture in addition to the footdrop. In the past, many of these operations were performed in pediatric patients with neuromuscular diseases. Recently, this operation has been advocated for various diagnoses, such as posterior tibial tendon dysfunction with flatfoot, neuropathic ulcers in the forefoot, metatarsalgia, and plantar fasciitis. The operation involves sectioning the aponeurosis of the gastrocnemius transversely, leaving the soleus muscle intact. It was popularized by Strayer in 1950 (19). The gastrocnemius contracture is evident when ankle dorsiflexion is normal with the knee bent, but is −5° of dorsiflexion (or more severe contracture) with the knee straight. If there is isolated gastrocnemius equinus, then lengthening the Achilles tendon may decrease plantarflexion strength.

Patients with dorsiflexion paralysis of the foot from multiple causes can be treated by this procedure. The posterior tibial muscle should be of sufficient strength, and significant bony deformities of the foot should be corrected prior to this procedure. A plantarflexion contracture from a tight Achilles tendon or gastrocnemius should be corrected before or at the time of the tendon transfer. Contraindications to this procedure include: