45 - Ulnar Nerve Entrapment at the Elbow

Abstract

Ulnar nerve entrapment at the elbow is one of the most common entrapment neuropathies encountered in clinical practice. Causes include compression of the ulnar nerve by an aponeurotic band that runs from the medial epicondyle of the humerus to the medial border of the olecranon, direct trauma to the ulnar nerve at the elbow, and repetitive elbow motion. Ulnar nerve entrapment at the elbow is also called tardy ulnar palsy, cubital tunnel syndrome, and ulnar nerve neuritis. This entrapment neuropathy manifests as pain and associated paresthesias in the lateral forearm that radiate to the wrist and to the ring and little fingers. Some patients also notice pain referred to the medial aspect of the scapula on the affected side. Untreated, ulnar nerve entrapment at the elbow can result in a progressive motor deficit and, ultimately, flexion contracture of the affected fingers. Symptoms usually begin after repetitive elbow motion or repeated pressure on the elbow, such as leaning on the elbow while lying on the floor. Direct trauma to the ulnar nerve as it enters the cubital tunnel may result in a similar clinical presentation. Patients vulnerable to nerve syndromes, such as diabetic and alcoholic patients, are at greater risk for the development of ulnar nerve entrapment at the elbow.