Cubital Tunnel Syndrome

Mr Mike Hayton
FRCS(Trauma and Orth) FFSEM (UK)
Consultant Orthopaedic Hand Surgeon

Other common names

None

Who does it affect?

It can occur in any patient.

Why does it occur?

We never find out the cause in the majority of patients. However there are a number of medical conditions that predispose to Cubital Tunnel syndrome. These include pregnancy, thyroid disease, rheumatoid arthritis and wrist injuries. It is important to note that if you have one of these conditions it does not mean that you will definitely develop cubital tunnel syndrome just slightly more at risk.

Cubital tunnel syndrome occurs when the ulnar nerve is pressed at the level of the elbow on the inner side of the joint (funny bone area). The nerve passes through a narrow tunnel called the cubital tunnel. It is the area just behind the funny bone. When there is a build up of pressure in this tunnel the nerve becomes squashed and causes the symptoms of cubital tunnel syndrome.

Symptoms

Pins and needles in the little, and ring fingers and the inner side of the forearm. This commonly occurs at night and the patient is often awakened from sleep with the pins and needles and has to shake their hands to gain relief. Occasionally in severe cases the muscles on the front of the palm on the little finger side can become wasted causing a hollow. In such severe cases the thumb may be weak or clumsy.

Clinical Examination

Flexing the elbow for one minute may reproduce the pins and needles in the little and ring fingers.

Tapping the nerve in the cubital tunnel may cause tingling in these fingers.

Please click below to view an examination of cubital tunnel syndrome.

Investigations

Nerve conduction studies are used to record the speed of the nerve across the elbow joint. This can be compared to the other hand, or in cases where both hands are affected, compared to normal population data. The test takes about 20 minutes and is slightly uncomfortable.

However if a patient has classical symptoms and physical examination of cubital tunnel syndrome, I do not routinely arrange these studies.

Non-operative treatment

Simple painkillers and resting splints can offer help. If symptoms occur mainly at night, I usually recommend cutting a small hole at the far end of a pillow case and passing the arm through. The large pillow prevents the elbow from being bent in the night and prevent symptoms.

Operative treatment

Most patients who have troublesome cubital tunnel syndrome have surgery. The surgery is a day case procedure usually under general anaesthetic and takes about 20 minutes. A tourniquet is used; which is like a blood pressure cuff around the upper arm that prevents blood from obscuring the surgeons view.

Local anaesthetic is infiltrated under the skin in line with the incision. The skin is incised and then the underlying fat is retracted. Care is taken not to injure sensory nerves to the tip of the elbow. At the base of the wound is a thick band of tissue called the transverse ligament (Osborne's bands). This structure needs to be released to allow the contents of the cubital tunnel to be decompressed. Having released this ligament the elbow is bent and straightened to ensure that the nerve is stable and does not pop out from behind the funny bone. If it does the nerve needs to be brought forward in front of the funny bone permanently. The skin is sutured and a bulky dressing is applied.

Post-operative rehabilitation

The patient is fit to go home soon after the operation. The local anaesthetic will wear off after approximately 6 hours. Simple analgesia usually controls the pain and should be started before the anaesthetic has worn off. The hand should be elevated as much as possible for the first 5 days to prevent the hand and fingers swelling. Gently bend and straighten the fingers from day 1. My preference is to remove the dressing at 2 days. The wound is cleaned and redressed with a simple dressing. Avoid forced gripping or lifting heavy objects for 2-3 weeks. The sutures are absorbable. You should notice an improvement in symptoms within a week but the final result may be realised at about 3 months.

Return to activities of daily living

It is my advice to keep the wound dry until the wound has healed at 10 days.

Return to driving:

The hand needs to have full control of the steering wheel and left hand the gear stick. It is probably advisable to delay returning to driving for at least 7 days or even when the stitches are removed.

Return to work:

Everyone has different work environments.

Returning to heavy manual labour should be prevented for approximately 4 to 6 weeks. Early return to heavy work may cause the tendons and nerve to scar into the released ligament. Please ask your surgeon for advice on this.

Complications

Overall, greater than 95% are happy with the result. However complications can occur.

There are complications specific to Cubital Tunnel Release and also general complications associated with hand surgery.

General complications:

 - Infection (Less than 1%),
 - Neuroma (Less than 1%, a coiled painful nerve bundle)
 - Numbness

Chronic regional pain syndrome  (2% rare reaction to surgery with painful stiff hands - this can occur with any hand surgery from a minor procedure to a complex reconstruction.)

Specific complications:

Failure to completely resolve the symptoms (approximately 5% - this may be due to chronic scarring of the nerve due to long duration of pre-operative pressure, symptoms suggesting this include muscle wasting and severe numbness.
Numbness at the tip of the elbow (a nerve passes across the skin incision, care must be taken to avoid injury to this).
Instability of the nerve (the nerve is checked to ensure it sits behind the funny bone and does not jump out during elbow movement).