Cubital Tunnel Syndrome

The cubital tunnel is an area on the inner elbow through which the ulnar nerve passes. Cubital tunnel syndrome is caused by compression on the nerve and may also be known as ulnar nerve compression or hitting your 'funny bone'.

Symptoms

Symptoms come and go to start with, only to become more persistent over time. Tingling or numbness on the outer border of the hand, into the little finger and that side of the ring finger is felt.

The patient may experience weakness in gripping and difficulty with tasks requiring fine motor control. There may or may not be pain at the elbow and partial clawing of the ring and little finger. Prolonged compression may result in muscle wasting in the forearm and hand. Symptoms are often worst at night and the patient may be woken by tingling sensations into the hand.

Causes

On the inside of the elbow, the medial epicondyle of the humerus can be felt as a bony lump. At the back of the elbow the olecranon process can be felt. The ulna nerve runs in the tunnel between these two bones. Below the elbow the ulnar nerve passes into the hand and the little and ring fingers, supplying several forearm muscles on it's way.

The medial epicondyle of the humerus is often known as the 'funny bone'. It is due to the presence of the ulna nerve that causes knocking this spot to be so acutely tender and to produce tingling or shooting sensations. The nerve may be compressed by a number of causes, these include:

    • It may be associated with medial epicondylitis (golfer's elbow).
    • Bony spurs.
    • Narrowing of the tunnel due to osteoarthritis or rheumatoid arthritis.
    • Cubitus valgus - an increased angle at the elbow.
    • Tight bands of fascia over the tunnel.
    • Tumours.
    • Leaning on the elbows repeatedly.
    • Repetitive elbow bending / straightening.
    • Guitar playing.
    • Subluxation of the nerve over the medial epicondyle.

Cubital tunnel syndrome may also occur following a fracture of the humerus or ulna due to compression of the nerve by a displacement of the fracture or by excess swelling and bleeding.

Treatment

Rest from aggravating activities such as leaning on elbows, guitar playing and manual work. Apply ice or cold therapy to help reduce pain and inflammation. A doctor may prescribe anti-inflammatory medication. A splint may be recommended to keep the elbow still to allow the nerve to heal. Surgery is used in many cases and will usually involve a decompression operation to release the ulnar nerve.