The Relationship between Knee Hyperextension and Articular Pathology in the Anterior Cruciate Ligament Deficient Knee

Abstract

The purpose of this study was to determine whether there was a relationship between knee hyperextension and intra-articular pathology in 100 consecutive patients whose sole ligament injury was an arthroscopically confirmed anterior cruciate ligament (ACL) rupture. Hyperextension of both knees was measured using a supine heel-height measurement of high reliability. There was more articular damage to the total joint, lateral joint, and lateral meniscus in patients who hyperextended than in those who did not. There was more articular damage to the total joint and medial joint in patients who were chronically ACL deficient than in those who were acutely or subacutely ACL deficient. The results demonstrate that individuals with ACL injuries whose knees hyperextend 3 cm or more sustain significantly more joint damage at the time of injury than in those whose knees hyperextend less than 3 cm. This study further defines the role of knee hyperextension in ACL injuries and offers a useful and reliable means of measuring knee hyperextension.