Operative illustrations of the Osborne's ligament.

The cubital tunnel syndrome is widely considered as the second most frequent compression neuropathy in the upper extremities although the existence of a compressive cause has not been determined conclusively. As far as we know, operational photography of compression of the ulnar nerve at the elbow is almost never found in the literature. In this paper, operational and pathological photographs of the Osborne's ligament as a cause of ulnar entrapment neuropathy at the elbow are presented. There is still an ambiguity as to whether compressive or tractional etiology or both of these factors may occur progressively to be a factor in the development of neuropathy. This report may be considered as concrete evidence for the compressive etiology for ulnar neuropathies.