CUBITAL TUNNEL SYNDROME
What is it?
Cubital tunnel syndrome (CTS) is when there is increased pressure on the ulna nerve at the level of the elbow causing pain, pins and needles, numbness and weakness in the fingers.
What causes it?
It is caused by increased pressure on the ulnar nerve. This can happen because the ulnar nerve sits just behind a bony prominence on the inside of the elbow (medial epicondyle) and has very little padding here and can be pressed on easily (see figs. 2 and 3).
What are the symptoms?
Pain, pins and needles, numbness and weakness in the fingers are the most common symptoms. Most commonly, the little finger and ring finger are affected (this is where the ulnar nerve supplies sensation to in the hand- see fig.1).
How is it diagnosed?
The specialist can usually diagnose it on clinical examination. A number of clinical tests can aid diagnosis including tapping over the ulnar nerve which sits just behind the inside part of the elbow. The specialist might refer you for nerve conduction studies to assess how much the nerve is compressed.
How is it treated?
The treatment of this condition depends on how severely the patient is affected by the compression of the nerve and the nerve conduction study results. If the compression is severe, it is recommended that the nerve be decompressed in the form of surgery. This is a day-case procedure involving a general anaesthetic. A small cut is made on the inside part of the elbow. The tight bands pressing on the nerve are released and the pressure relieved. The main aim of surgery is to prevent further degeneration of the nerve (as if there is severe compression of the nerve, the nerve’s blood supply also gets compressed and the nerve supply to the muscle gets progressively weaker). After the surgery, the elbow is wrapped up in dressings. The patient is free to move the elbow as tolerated. A clinic appointment is made in two weeks to check on the wound healing, followed by referral to physiotherapy. Sometimes the ulnar nerve is found to be very mobile and it can dislocate out of it’s groove when the elbow is flexed. If this is the case, the nerve may need to be stabilised in a different position. This is called ulnar nerve transposition. If the ulnar nerve compression is mild, surgery may be avoided and physiotherapy and splints (see fig.4)