Lateral capsualr ligament complex: anatomical and surgical considerations.

Acute avulsion of the bony attachment of the lateral capsular ligament was observed on x-ray films in September 1975. Seven instances were confirmed at surgery during the following 29-month period. The avulsion was reproduced in six amputation specimens which were dissected to identify the components of the lateral capsular complex. Dynamic studies were performed on a set of amputation specimens to determine the role of the various structures contributing to lateral rotary instability. The dissection revealed that the lateral capsular ligament complex has vertical and horizontal components. The dynamic studies showed that lateral pivot shift was produced by a lateral capsular release, a complete section of the anterior cruciate ligament, and a partial tibial collateral ligament release. Based on these observations, 30 patients have subsequently had reconstructive surgery to eliminate their lateral rotational instability. In the reconstruct procedure, both the bony attachment of the lateral capsular ligament and the iliotibial tract with Gerdy's tubercle have been moved anteriorly and inferiorly without separating their interconnections or any attachments. Clinical experience in these 30 patients supports the evidence obtained in the dynamic studies. Restoration of stability is secure when both the lateral capsular ligament and the iliotibial tract are advance with their anatomical connections intact.