Bridle Procedure for Treatment of Foot Drop (PREPRINT) 0

Johnson JE1, Yee A2

November 4, 2016

Disclosure: No authors have a financial interest in any of the products, devices, or drugs mentioned in this production or publication.

Peroneal nerve injury is a frequent neuropathy in the lower extremity and injury to the common peroneal nerve presents with foot drop and steppage gait. This results in the functional loss of the anterior and, often, lateral compartment musculature of the leg. There has been limited success with nerve transfer for foot drop and the standard operative restoration of dorsiflexion in patients with peroneal nerve palsy is dynamic tendon transposition. The Bridle procedure for foot drop is a modification of the tibialis posterior tendon transfer that includes a tri-tendon anastomosis with the tibialis anterior and transposed peroneus longus. This procedure was designed to create balanced attachment points with the addition of these two tendons for a more even distribution of pull on the dorsum of the foot, thereby avoiding a varus or valgus deformity from tendon overpull. This modification often avoids the need for a triple arthrodesis or other procedure to stabilize the foot in neutral. Also, many patients complain of 'ankle instability' in addition to the lack of active ankle dorsiflexion. The two additional attachment points of the transfer improves the stability of the ankle in the coronal plane. In this case, a 65-year-old female presented with bilateral lower extremity neuropathy and has a complicated and unusual history. She previously underwent a L4-5 fusion and unfortunately continued to have progressive motor weakness in both lower extremities. Electrodiagnostic studies indicated a severe right peroneal neuropathy without residual or recurrent lumbar radiculopathy and with no fibrillations or motor unit potentials. On clinical examination, she had a foot drop gait with MRC 5/5 motor strength in the tibial-innervated muscles, which included the posterior tibialis muscle, but 0/5 anterior compartment and 3/5 lateral compartment strength. The patient was managed with a Bridle procedure for treatment of right foot drop. This video demonstrates the technical nuisances of this procedure, however does not include specifics for gastrocnemius/soleus lengthening as the patient passed the Silfverskiold's Test for contractures that are typical in patients with foot drop.

Keywords: tendon transferSilfverskiold's Testdressingperoneal nervebridletibialis posterior tendonfoot dropArthrexcommon peroneal nerve

Standard Edition

    Table of Contents

    Extended Edition

      Table of Contents

      Dressing Tutorial

      The procedure for dressing and casting the foot and ankle following a Bridle procedure is extremely important. The most critical part of the post-operative management and casting procedure is to hold the ankle in neutral until 6 weeks and then prevent passive plantar flexion of the ankle until at least 3 months post-operatively. This will prevent failure of the tendon attachment or premature stretching of the transfer. The dressing and casting procedure involves several layers described in this video. The initial cast applied in the operating room is bivalved for safety and to allow post-operative swelling. At 10-14 days post-operative, the cast and skin sutures are removed and the second cast is applied with the same procedure without the bivalve. The second cast is removed at 6 weeks post-operatively, and the patient is placed in a removable walker boot and night split while beginning physical therapy.

        POST-OPERATIVE MANAGEMENT

        Following the Bridle procedure, a well-padded short-leg non-weight-bearing cast is applied with the ankle in neutral. The first and initial cast is bivalved in the operating room to prevent complications from swelling. This helps promote patient compliance with the patient knowing that the cast could be expanded to accommodate post-operative swelling. However, the most important part of the post-operative management is to prevent passive plantar flexion of the ankle until at least 3 months post-operatively, as this will prevent any premature stretching of the tendon transfer. The first bivalve cast and skin sutures are removed at 10-14 days post-operatively with the foot being held in neutral. A second synthetic cast is applied without being bivalved for another 4 weeks, where the patient is allowed toe-touch weight bearing. The second cast is removed at 6 weeks post-operatively, where the patient is placed in a removable walker boot and allowed to progress to full weight bearing as tolerated. At 6 weeks, physical therapy begins for reeducation of the tibialis posterior tendon transfer with active and active-assisted dorsiflexion and active plantar flexion. It is again important to avoid passive ankle joint plantar flexion until 3 months post-operatively. A night split is worn from 6 weeks until 3 months post-operatively to prevent premature stretching of the tendon transfer. As swelling improves, a custom molded ankle-foot orthosis (AFO) is fabricated or the patient's former foot drop AFO is worn in an athletic shoe to allow earlier discontinuation of the walker boot. The custom AFO or walker boot is used until at least 3 months post-operatively or until strength allows for the discontinuation of the foot brace.

        MATERIALS

        Arthrex Bio-Tenodesis Screw System
        https://www.arthrex.com/tenodesis-screws

        REFERENCES

        1. Johnson JE, Paxton ES, Lippe J, Bohnert KL, Sinacore DR, Hastings MK, McCormick JJ, Klein SE. Outcomes of the Bridle Procedure for the Treatment of Foot Drop. Foot Ankle Int. 2015 Nov;36(11):1287-96. PMID: 26160388.
        2. Hastings MK, Sinacore DR, Woodburn J, Paxton ES, Klein SE, McCormick JJ, Bohnert KL, Beckert KS, Stein ML, Strube MJ, Johnson SE. Kinetics and kinematics after the Bridle procedure for treatment of traumatic foot drop. Clin Biomech (Bristol, Avon). 2013 Jun;28(5):555-61. PMID: 23684087.

        Leave a Comment