A Closer Look At The Use Of Interference Screws For Lateral Ankle Stabilization
Reconstructive procedures require sacrifice of a tendon to simulate the function of the damaged ligaments. Indications for this reconstructive procedure include evidence of both anterior talofibular ligament and calcaneofibular damage, heavier patients, or failed previous direct repair.4 In general, procedures fall into two categories: tendon transfer procedures or anatomic repairs.
The Broström procedure is for primary and secondary repair of ruptured lateral ligaments. Surgeons have modified this procedure to reinforce the construct, including incorporation of the capsular structures into the repair for added strength.7 Bell and colleagues studied 39 patients for a 67-month period.8 All patients underwent the Broström-Gould procedure. There was one poor outcome, two reports of wound dehiscence, six patients with edema for greater than six months and one patient had continued pain, stiffness and recurrent sprains. Study researchers found the modified Broström procedure provided good to excellent results in 91 percent of patients at a 26-year follow-up.8
Despite the favorable outcomes of the Broström procedure, it is not always possible to perform it due to over-attenuation of lateral soft tissues or poor quality of soft tissues due to previous surgery.7,8
When primary repair of torn ligaments is not possible, many surgeons will turn to tendon transfers or free tendon grafts. Elmslie described one of the first procedures, a technique in which surgeons weave fascia lata grafts through drill holes in the calcaneus, distal fibula and talus to reconstruct the calcaneofibular and the anterior talofibular ligaments.9
Chrisman and Snook modified this technique by using a split peroneus brevis graft rather than the fascia lata.10 One would insert the split peroneus brevis graft retrograde through the distal fibula and then back antegrade through a tunnel in the calcaneus. Then the surgeon would sew the graft back upon the insertion of the peroneus brevis at the base of the fifth metatarsal.
Westlin and co-workers described a technique utilizing the extensor digitorum brevis muscle to recreate the anterior talofibular ligament.11 Their study included 13 ankles in 10 patients with a mean follow-up of 10 years. While all patients reported an excellent or good outcome, the study authors noted a decreased supination range of motion postoperatively in comparison to the non-surgical side.
Expert Insights On Interference Screw Fixation
The orthopedic literature recognizes interference screw fixation as one of the standard techniques of graft fixation.12 Surgeons frequently use it in anterior cruciate ligament (ACL) reconstruction. Studies on ACL graft healing concluded that the graft tissue heals within the bone tunnel and new bone forms adjacent to the graft and bioabsorbable screw.13,14 No inflammatory reaction occurred. Osteointegration occurs between six and 15 weeks after surgery.
In recent years, interference screws have been in use in foot and ankle surgery for various graft fixations as well. Schuberth and colleagues reported on a technique utilizing an interference screw with a split peroneus longus tendon.6 This reconstruction is designed to augment repair of the anterior talofibular and calcaneofibular ligaments without restricting subtalar motion. The surgery restores mechanical stability in the ankle with resulting postoperative improvement in function. Patients maintain eversion strength and subtalar joint motion after surgery.