Simon Richards

orthopaedic surgeon


your Specialist in conditions


of the arm & hand


Ulnar Nerve Entrapment (Cubital Tunnel Syndrome)

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The Ulna nerve passes through a tight tunnel (Cubital tunnel) behind the inner aspect of the elbow (“funny bone”).

Ulnar Nerve Entrapment is otherwise knows as Cubital Tunnel Syndrome

What is it?
The ulnar nerve provides sensation to the little and ring fingers and activates many of the small muscles in the hand. The nerve passes behind the inner aspect of the elbow where it can be felt. This area is often referred to as the “funny bone”. At the elbow, it runs through a tight tunnel, the cubital tunnel.
In some people, this tunnel is too tight for the nerve. Mild pressure causes occasional “pins and needles”, especially at night. Severe pressure causes the fingers to become numb and the muscles of the hand waste away which causes weakness and difficulty in straightening the fingers.
The nerve gradually withers if the condition is not treated. This causes permanent loss of sensation and wasting of hand muscles which cannot be relieved by surgery.

What can be done?
Often nerve tests are carried out to confirm the diagnosis, and to give an idea of how severe the compression is. This is important as it will give an indication of the chances of success with surgery.
Correction of this problem involves cutting the roof of this tunnel, to relieve the pressure on the nerve. Occasionally the nerve is transferred in-front of the funny bone at the time of surgery to avoid further nerve damage and instability.

Surgery is usually carried out with a general anaesthetic, and as a day case. You will have a small curved scar on the inside of your elbow. Sutures used are usually dissolvable. Occasionally non-dissolvable will be used.

Post-operative care
Local anaesthetic is injected around the site of surgery and therefore this area and possibly some of the fingers will remain numb for up to ten hours after surgery.
You will be discharged with a bulky dressing. Occasionally a Plaster of Paris will be used. These will be removed at 2 weeks. Sutures, if required, will be removed at 2 weeks.
Finger and hand movement should be started immediately after surgery. You should perform normal light activities after the operation, as pain allows.
Timing of your return to work is variable according to your occupation and you should discuss this. If improvement in symptoms does occur, it can take an extended period of time. This can be as much as a year post-operatively.

You will have a scar on the inside of the elbow. This will be somewhat firm to touch and tender for 6-8 weeks. This can be helped by massaging the area firmly with the moisturizing cream.

This can occur after any operation and would be treated by antibiotics.

A small nerve running in the region can be damaged during the surgery and form a painful spot in the scar (neuroma). This complication is very rare but may require a further operation to correct.

About 5% of people are sensitive to hand/elbow surgery and their arm may become swollen, painful and stiff after an operation (Complex regional pain syndrome). This problem cannot be predicted but will be watched for afterwards and treated.

Improvement after surgery can be modest, particularly in patients who have more severe compression. Muscles that have wasted rarely recover. Recovery of feeling is slow and often incomplete. The operation is mainly intended to prevent further deterioration.