Condition: Cubital Tunnel Syndrome

Cubital tunnel syndrome is a condition where pressure or irritation of the ulnar nerve as it passes through a tunnel on the inside of the elbow, results in pain, tingling and numbness in the little and ring fingers, and later weakness of the small muscles in the hand.

The ulnar nerve passes into the forearm, running behind the bony prominence on the inner aspect of the elbow known as the medial epicondyle (the ‘funny bone’). At this point, it runs through a tight tunnel known as the cubital tunnel. This tunnel consists of a bony groove roofed by a ligament. The ulnar nerve fits tightly into this tunnel and can become compressed at this, and adjacent sites.

1. Tingling sensations (“pins and needles”), pain and numbness in the little and ring finger. Symptoms are aggravated by direct pressure on the elbow, or holding the elbow in a bent position, such as when reading, or when speaking on the telephone. In the early stages the symptoms are intermittent and sensation will return to normal.
2. As the condition progresses the symptoms become constant. Progressive numbness and weakness in the hand develops, resulting in the feeling of clumsiness, difficulty with fine tasks and dropping of objects.
3. In more advanced stages, wasting of the muscle bulk of the hand, particularly between the thumb and index finger, develops.
4. The diagnosis is normally apparent on clinical assessment, but special tests on the nerve, known as nerve conduction studies are usually required to confirm the diagnosis and particularly to be certain of the point (or points) of compression.

1. Mild cubital tunnel symptoms will sometimes resolve spontaneously, especially if any provocative activity is modified or avoided. Excessive pressure on the elbow can be prevented by the use of protective padding.
2. Splintage: Excessive bending of the elbow can be reduced by using a folded towel wrapped around the elbow at night, or through the use of a specially made splint.
3. Medication: Other initial treatment could include a trial of NSAIDS (non-steroidal anti-inflammatory drugs).
4. Surgery: If these treatments have not worked, or the symptoms are more severe, a cubital tunnel decompression operation is recommended. This operation involves releasing the structure forming the roof of the cubital tunnel, relieving pressure on the ulnar nerve. The most common method for doing this is a simple cubital tunnel decompression and is usually undertaken under a regional or general anaesthetic, as a day case procedure. An incision is made over the cubital tunnel on the inside of the elbow and the nerve is decompressed under direct vision. Occasionally, the nerve is found to be unstable following decompression and rides up over the bony prominence on the inner aspect of the elbow. In this situation the surgeon may add a procedure:

• • Moving the nerve to a new position in front of the bony prominence
  • Flattening the bony prominence so that the nerve can slide smoothly forwards and backwards with elbow bending.
  • It is necessary to move the position of the nerve so that it runs in front of the prominence, instead of behind it. This is known as an ulnar nerve transposition.

The outcome of a cubital tunnel decompression depends on the severity and duration of the symptoms.

In mild cases full resolution of symptoms can be expected. In more severe cases, tingling and pain usually resolve but other symptoms may.

Numbness and weakness in the hand that have occurred due to prolonged compression of the ulnar nerve, can improve slowly over time, but return of sensation and muscle strength may be incomplete. In general, it is wise to consider early release of any ulnar nerve compression since the risk of permanent consequences is higher than in most nerves.

It generally takes about three months to regain full strength and a fully comfortable scar, but the hand can be used normally after two weeks, although surgeons’ policies vary.