Abstract
Objective Commonly used methods for measuring proprioception have resulted in conflicting reports regarding knee proprioception with anterior cruciate ligament (ACL) rupture and the influence of ACL reconstruction. Methods One hundred subjects (50 patients with radiologically and arthroscopically confirmed unilateral ACL rupture and 50 normal controls) were assessed with regards to proprioception using dynamic single-leg stance postural stabilometry. Instrumented knee ligament laxity and knee outcome scores were also measured. Of the 50 patients in the ACL group, 34 underwent reconstruction and were reassessed postoperatively. Results There was a significant proprioceptive deficiency in the ACL group compared with their contralateral knee ( p < 0.001) and to the control group ( p = 0.01). There was a significant improvement in knee proprioception following ACL reconstruction compared to preoperative findings ( p = 0.003). There was no correlation between ligament laxity measurements and outcome scores. A significant correlation was found preoperatively between outcome scores and proprioception measurements. This correlation was not found post-operatively. Pre-operative proprioception testing had a significant correlation (r = 0.46) with post-operative proprioception ( p = 0.006). Conclusion Patients with an ACL rupture had a proprioceptive deficit which improved following ligament reconstruction. Knee outcome scores had a better correlation with proprioception than ligament laxity. Proprioception may be a superior objective measure than ligament laxity in quantifying functional knee deficits and outcomes in patients with ACL ruptures. Level of Evidence III Therapeutic Study; Prospective Longitudinal Case-Control Study.