Functional anatomy of the medial ligamentous complex of the elbow. Its role in anterior posterior instability

The question remains unanswered regarding the role of repair of medial liga ment injuries associated with subluxation of the elbow and non-reconstructa ble radial head fracture and whether or not this will decrease the risk of chronic instability and cubitus valgus. The goal of this study was to defin e the role of the medial ligamentous complex of the elbow in elbow instabil ity and to describe the anatomy of the complex in 35 fresh-frozen cadaver e lbows. We documented medial ligamentous complex anatomy and compared our re sults to those in the literature. 25 elbows were dissected in order to desc ribe the different bundles of the medial ligament complex and to precise th e positions of the elbow that placed each in tension; section of the differ ent ligamentous bundles was done to study the role of each in elbow stabili ty. 10 other elbows were dissected and used for the ligamentous section stu dies which were performed subcutaneously. We found two bundles at the level of the anterior portion and termed them superficial and deep. Section of t he anterior bundle lead to posterior subluxation of the elbow at 30-100 deg rees flexion in both supination and pronation. Posterior subluxation was ob tained after an anterior capsulotomy; medial epicondylectomy did not compro mise the stability of the elbow after a complete section of the insertion o f the deep fibers of the anterior bundle. Elements thus required for stabil ity of the elbow are integrity of the articular surface of the humerus and the ulna, and the anterior bundle of the medial ligamentous complex.