Surgical versus functional treatment for acute ruptures of the lateral ligament complex of the ankle in young men: a randomized controlled trial.

Background: Some have recommended surgical treatment of Grade-III lateral ligament injuries in very active individuals with high functional demands on the ankle. The purpose of this study was to establish whether surgery provides better long-term results than functional treatment for acute ruptures of the lateral ligaments of the ankle.

Methods: Physically active Finnish men (mean age, 20.4 years) with an acute Grade-III lateral ligament rupture of the ankle were randomly allocated to surgical (n = 25) or functional (n = 26) treatment. Ligament injury was confirmed with stress radiographs. Surgical treatment comprised suture repair of the injured ligament(s) within the first week after injury. A below-the-knee plaster cast was worn for six weeks with full weight-bearing. Functional treatment consisted of the use of an Aircast ankle brace for three weeks. The main outcome measures included final follow-up examinations, calculation of an ankle score, stress radiographs, and magnetic resonance imaging scans.

Results: Fifteen (60%) of twenty-five surgically treated patients and eighteen (69%) of twenty-six functionally treated patients returned for long-term follow-up (mean duration, fourteen years). All patients in both groups had recovered their preinjury activity level and reported that they could walk and run normally. The prevalence of reinjury was one of fifteen in the surgical group and seven of eighteen in the functional treatment group (risk difference: 32%; 95% confidence interval: 6% to 58%). The mean ankle score did not differ significantly between the groups (mean difference: 8.3 points; 95% confidence interval: -0.03 to 16.6 points). Stress radiographs revealed no difference between groups with regard to the mean anterior drawer (-1 mm in the surgical group and 0 mm in the functional treatment group; mean difference: 0.7 mm; 95% confidence interval: -1.4 to 2.7 mm) or mean tilt angle (0° in both groups; mean difference: 0.1°; 95% confidence interval: -3.2° to 3.5°). Grade-II osteoarthritis was observed on magnetic resonance images of four of the fifteen surgically treated patients and in none of the eighteen functionally treated patients (risk difference: 27%; 95% confidence interval: 4% to 49%).

Conclusions: These findings indicate that, in terms of recovery of the preinjury activity level, the long-term results of surgical treatment of acute lateral ligament rupture of the ankle correspond with those of functional treatment. Although surgery appeared to decrease the prevalence of reinjury of the lateral ligaments, there may be an increased risk for the subsequent development of osteoarthritis.