Arthroscopic assessment of the medial collateral ligament complex of the elbow.

The extent that the medial collateral ligament complex could be visualized by arthroscopy was determined in 10 fresh cadaveric elbows from 10 individuals. We carefully exposed the medial collateral ligament complex through a muscle-splitting incision before performing arthroscopy. The anterior and posterior bundles were identified and marked by placing 4.0 nylon sutures deep to the bundles to aid in arthroscopic visualization. A portion of the anterior bundle was visible in only one elbow and in that elbow only the most anterior 25% of the anterior bundle was seen. Attempts to visualize the anterior bundle through additional portals were unsuccessful. Varying the flexion angle of the cadaveric elbow from 0 degrees to 130 degrees also failed to improve visualization. Conversely, the entire posterior bundle, including humeral and ulnar insertion sites, could be seen in all 10 specimens using the posterior portals. We also noted that direct pressure was placed on the ulnar nerve in all specimens when the arthroscope or any arthroscopic instrument was advanced into the posteromedial gutter in contact with the posterior bundle because of its proximity immediately adjacent to the ulnar nerve. The inability to reliably see the anterior bundle and the humeral or ulnar insertion sites of this ligament may limit the value of the arthroscope when assessing medial collateral ligament injuries. Additionally, great care should be taken when using the arthroscope or other instruments in the posteromedial gutter because the ulnar nerve lies immediately adjacent to the thin posterior bundle and capsule.