The Effect of Modified Brostrom-Gould Repair for Lateral Ankle Instability on In Vivo Tibiotalar Kinematics

Background: Lateral ankle instability leads to an increased risk of tibiotalar joint osteoarthritis. Previous studies have found abnormal tibiotalar joint motions with lateral ankle instability that may contribute to this increased incidence of osteoarthritis, including increased anterior translation and internal rotation of the talus under weightbearing loading. Surgical repairs for lateral ankle instability have shown good clinical results, but the effects of repair on in vivo ankle motion are not well understood. Hypothesis: The modified Brostrom-Gould lateral ligament reconstruction decreases anterior translation and internal rotation of the talus under in vivo weightbearing loading conditions. Study Design: Controlled laboratory study. Methods: Seven patients underwent modified Brostrom-Gould repair for unilateral lateral ankle instability. Ankle joint kinematics as a function of increasing body weight was studied with magnetic resonance imaging and biplanar fluoroscopy. Tibiotalar kinematics was measured in unstable ankles preoperatively and postoperatively at a mean follow-up of 12 months as well as in the uninjured contralateral ankles of the same patients. Results: Surgical repair resulted in statistically significant decreases (expressed as mean +/- standard error of the mean) in anterior translation of the talus (0.9 +/- 0.3 mm; P = .018) at 100% body weight and internal rotation of the talus at 75% (2.6 degrees +/- 0.8 degrees; P = .019) and 100% (2.7 degrees +/- 0.8 degrees; P = .013) body weight compared with ankle kinematics measured before repair. No statistically significant differences were detected between repaired ankles and contralateral normal ankles. Conclusion: The modified Brostrom-Gould repair improved the abnormal joint motion observed in patients with lateral ankle instability, decreasing anterior translation and internal rotation of the talus.