Section 5. Bone, Joint, and Muscle Disorders

Chapter 71. Hand Disorders

Topics: Introduction | Ganglia | Deformities | Carpal Tunnel Syndrome | Cubital Tunnel Syndrome | Radial Tunnel Syndrome | Kienböck's Disease | Shoulder-Hand Syndrome | Injuries | Infections

Cubital Tunnel Syndrome

Cubital tunnel syndrome (ulnar nerve palsy) is a disorder caused by compression of the ulnar nerve at the elbow.

The ulnar nerve passes close to the surface of the skin at the elbow ("funny bone") and is easily damaged by repeatedly leaning on the elbow, by bending the elbow for prolonged periods, or sometimes by abnormal bone growth in the area. Baseball pitchers are prone to cubital tunnel syndrome because of the extra twist of the arm required to throw a slider.

The symptoms include pain and numbness of the elbow and a pins-and-needles sensation of the ring and little fingers. Eventually, weakness of the ring and little fingers may develop. Weakness may also interfere with the ability to pinch using the thumb and index finger, because most of the small muscles in the hand are controlled by the ulnar nerve. Severe, chronic cubital tunnel syndrome can lead to muscle wasting (atrophy) and a clawlike deformity of the hand.

Nerve conduction studies (see Section 6, Chapter 77) can help pinpoint the exact area of nerve damage. Mild cases of cubital tunnel syndrome are usually treated with physical therapy (including a splint at night to avoid overbending the elbow) and by avoiding pressure over the elbow; an elbow pad can be helpful. People who do not respond to splinting or who have more severe cases of nerve compression may benefit from surgery, which usually consists of releasing pressure on the nerve and moving the nerve from the back to the front of the elbow. Surgery is successful in about 85% of people.