Cubital Tunnel Syndrome
Cubital tunnel syndrome is a condition where a nerve gets compressed as it passes by the inner side of the elbow. When the nerve gets compressed, people experience a variety of symptoms including numbness and weakness of the hand and pain around the elbow. Often the symptoms are brought on by keeping the elbow in a flexed position or by direct pressure on the inner side of the elbow. For example, many people notice symptoms while sleeping with the elbow bent or while talking on the telephone.
The particular nerve involved is called the ulnar nerve. The ulnar nerve provides the feeling to the ring and small fingers. When you accidentally hit the “funny bone” on inside of the elbow and feel pins and needles in this area, you are really hitting the ulnar nerve and not a bone at all. The ulnar nerve also carries the signals that control the many of the small muscles between the metacarpal bones of the hand and many of those that control the pinky. For example, crossing your fingers for good luck is an ulnar nerve function. The ulnar nerve passes by the inner side of the elbow through a channel called the cubital tunnel. The floor of the tunnel is a groove in the end of the arm bone known as the humerus. The roof is a dense, fibrous sheet of soft tissue.
The exact cause of cubital tunnel syndrome is not known. Occasionally it can occur in reaction to an injury or repetitive pressure around the inner elbow, but most cases develop slowly without a specific event.
For mild cases, simply avoiding specific arm positions that bring out the symptoms may be all that is needed. Examples would include avoiding resting on the elbow while seated and keeping the elbow straight while sleeping. If simple measures are not keeping the symptoms under control, surgery may be a consideration. Although a variety of surgical techniques are commonly used, they all share the goal of opening the roof of the tunnel to create more room. This is sometimes combined with a repositioning of the nerve to keep it from stretching with elbow movement. Cubital tunnel surgery can be safely performed in an outpatient setting.
Commonly, symptoms arise while sleeping or talking on the telephone.
Figure: Ulnar Nerve at elbow joint (inner side of elbow)
Photos used with permission from www.assh.org