The ulnar nerve goes from your shoulder to your little finger. At the back of your elbow the nerve passes through a tight tunnel, between the muscles of your forearm, and at this point it is particularly vulnerable to becoming trapped or compressed (cubital tunnel syndrome). It can also become trapped at the wrist (ulnar tunnel syndrome). Damage to this nerve, which is responsible for causing the strange “funny bone” sensation when you hit your elbow, can result is permanent numbness or a tingling feeling in your elbow. It can also cause a loss of function in the muscles of the hand.
If you have ulnar nerve entrapment, a physiotherapist can recommend some simple exercises to relieve symptoms and you can also change some of your postural habits to relieve pressure on your elbow. However, for a severe or long-standing condition you may need ulnar nerve decompression surgery.
Ulnar nerve decompression is a surgical procedure to explore the region around the elbow through which the ulnar nerve passes and remove anything that is compressing the nerve and causing dysfunction. Compression may occur around the triceps muscle in the upper arm, in the bony groove in the elbow and in another passage through the muscle in the forearm. Ulnar nerve decompression explores these three areas and removes any constrictions that are trapping the nerve.
It is performed under local, regional or general anaesthetic. If you have open ulnar nerve decompression surgery, a 3-4 inch incision is made along the elbow, revealing the ulnar nerve. The orthopaedic surgeon then examines the nerve and removes any tissue that is causing compression. The nerve may then be moved in front of the medial epicondyle to prevent it from being pinched or irritated when the elbow is bent, which is called a transposition. The incisions are closed with sutures.
Alternatively you may be offered endoscopic or keyhole surgery which uses much smaller incisions and an endoscope, which has a camera at one end. The surgeon will be able to see inside your joint using the endoscope and will perform surgery using miniature surgical instruments. This minimally invasive form of surgery generally results in quicker recovery.
You might need surgery if you have severe or long-standing ulnar nerve entrapment. This can occur as the result of strain caused by repetitive movements with your arm or hand. Bending your elbow stretches your ulnar nerve behind the bump of your funny bone and keeping it bent for extended periods can cause irritation. This can occur if you hold a phone up to your ear for long periods of time or use a tool in a fixed position, for example. Other possible causes include an injury to your elbow, arthritis or a cyst. Wrist entrapment may also be caused by a cyst, which puts pressure on your wrist joint as it grows.
Among the factors that put you at greater risk of ulnar nerve entrapment are:
- High blood pressure
- Autoimmune conditions
- Thyroid conditions
You can normally go home the same day, however, the arm needs to be kept elevated for 24-48 hours after surgery to prevent swelling and you may need to wear a splint on your elbow for a few weeks while the area heals. The sutures are removed after ten to fourteen days. You can normally resume light everyday activities soon after surgery and you should be able to return to work within one or two weeks, depending on the nature of your job. Recovery times will vary from person to person, from weeks to months depending on your age, health and the extent of the problem. Symptoms may improve quickly but in some cases they can take up to six months to go away fully. In some severe cases, some symptoms may persist after surgery.
Ulnar nerve decompression is a routine surgical procedure that can lead to a complete or substantial reduction in the symptoms of ulnar nerve entrapment.