Hip Restricted Range of Motion in Physical Examination: A Possible Risk Factor For Non-Contact ACL Injury

Background: There is significant evidence of hip and knee kinematic influence on each other. In some studies, hip restricted range of motion is a risk factor of anterior cruciate ligament (ACL) tear. Objectives: This study was designed to compare hip range of motion in physical examination between non-contact ACL injured patients with normal population. Patients and Methods: One hundred and forty patients with arthroscopically confirmed primary ACL ruptures were evaluated to assess their hip range of motion; these findings were compared with a control group of 100 patients with non ACL injury. Results: All parameters of hip range of motion (internal rotation, abduction and adduction) except external rotation were decreased significantly in ACL injured group compared with control group. Patients with sum of internal and external rotation lower than 80° had an increased odds ratio of having ACL injuries (OR = 2.64; 95% CI, 1.4 to 4.7). Conclusions: There was an association between non-contact ACL rupture and decreased hip range of motions including internal rotation, abduction and adduction as well as sum of internal and external rotation. Therefore, it may be possible to use hip physical exam finding as a predictor of ACL rupture.