What is it?

Cubital tunnel syndrome is a condition caused by the compression or irritation of the ulnar nerve in a tunnel on the inside of the elbow. The ulnar nerve provides sensation to the little finger and part of the ring finger, and power to the small muscles within the hand. Compression to the ulnar nerve can result in numbness and weakness of the hand.

Causes

In most cases, there is no obvious cause. In some cases, the tunnel where the nerve passes through can be narrowed by ganglion or by bony spurs or thickened joint synovium from elbow arthritis or by an old injury or fractures.

Symptoms

In the beginning, numbness or tingling of the little and ring fingers are the symptoms. It is usually intermittent symptoms, but may become constant with time. These symptoms can be provoked by leaning on the elbow or holding the elbow in a bent position (e.g. on the telephone, playing guitar). Sleeping with the elbow habitually bent can also aggravate the symptoms.

In the later stages, the numbness is constant and the hand becomes weak with loss of ddexterity. There may be visible loss of muscle bulk in severe cases, particularly noticeable on the back of the hand between the thumb and index finger.

Diagnosis

Diagnosis is mainly based on clinical symptoms and examinations of the sensory loss and muscle weakness from the ulnar nerve compression. Provocative tests on the nerve can help with the diagnosis. Occasionally, investigations may be necessary such as X-rays of the elbow and nerve conduction studies.

Non surgical Treatment

You must avoid or modify any provocative activity that triggers the symptoms where appropriate. For example, avoid leaning on the inside of the elbows or wear protective pads around elbow. Excessive bending of the elbow at night can be minimised by a folded towel wrapped around the elbow, or by a splint provided by a therapist.

Surgery

Surgery to decompress the nerve is required in severe cases, or in those that do not respond to the non-surgical treatments. Surgery frequently improves the numbness, but its chief objective is to prevent the progressive muscle weakness and wasting that tends to occur in severe untreated cases. Several options are available, including opening of the roof of the tunnel (decompression), moving the nerve into a new location at the front of the elbow (transposition) and widening the tunnel by removing some of its bony floor (medial epicondylectomy). Your surgeon can advise you on the technique most appropriate to your problem.

 The outcome depends upon the severity of the compression being treated. Numbness frequently improves, though the improvement may be slow. Surgery generally prevents worsening of the muscle weakness, but improvements in muscle strength are often slow and incomplete.