Treatment of medial ligament injuries of the knee

Abstract

The anatomic structures of the knee form a complex transmission system that coordinates joint position and provides stability for knee function. Ligament injury produces abnormal kinematic states that interfere with normal knee function. Because of the unequal load-sharing between the ligaments and musculotendinous units that occurs with ligament injury, complex instability patterns can develop, compromising the functional capability of the knee. Joint damage can also develop. The surgeon must restore stability to the knee by providing the appropriate tension in the anatomic structures, thus stabilizing the tibiofemoral joint and reestablishing a more normal load-sharing function of the capsular envelope and intra-articular ligaments. Isolated, limited instability, grade III medial ligament injuries can be treated nonoperatively with bracing that allows limited motion and with a high-repetition exercise program. The examiner must be aware that complex problems also can occur with grade III injuries, adversely affecting nonoperative outcome and leading to chronic instability. For more severe acute medial ligament injuries, the surgeon can accomplish acute surgical restoration of the anatomy including the mid-third capsular ligament, tibial collateral ligament, posterior oblique ligament, semimembranosus complex, and other injured knee structures (ie, anterior cruciate ligament, meniscus, vastus medialis obliquus, and semimembranosus). A well-supervised rehabilitation program follows treatment. Reconstruction of chronic medial ligament tears produces poor results.