Cubital Tunnel Syndrome

Cubital tunnel syndrome is the compression of the ulnar nerve at the level of the elbow.

Pathology

Cubital tunnel syndrome is the compression of the ulnar nerve at the level of the elbow. Common Causes of Cubital Tunnel Syndrome:

  • Direct trauma to the nerve
  • Keeping the elbow bent for prolonged periods of time:
    • Extensive computer use
    • Constantly placing hand under chin while elbow is bent
    • Using a handheld phone for extended periods of time
    • Sleeping with elbow bent under the side of the head

When the elbow is bent more than 90 degrees, it is has been experimentally demonstrated that the ulnar nerves blood supply is strangulated, which causes ulnar nerve symptoms to develop.

17% of the population has an ulnar nerve that slips (sub luxes) in and out of its groove, called the cubital tunnel. This subluxation occurs when the elbow goes from a straight to a bent position. The subluxation causes mechanical irritation of the nerve over time and ulnar nerve symptoms can develop.

Ulnar Nerve Symptoms

  • Ring and small fingers begin to tingle. In time they become progressively numb.
  • Hand grip strength weakens
  • Forearm experiences cramping
  • Pain occurs on the small finger side of the forearm

Pain is commonly diffusing. It begins in the elbow, but can also radiate to the arm pit in one direction and to the hand in the other.

Cubital tunnel syndrome is often confused with carpal tunnel syndrome because of the popularity of carpal tunnel syndrome.

Cubital tunnel syndrome can also occur in the presence of carpal tunnel syndrome and is second only to carpal tunnel in occurrence. Cubital tunnel syndrome accompanies carpal tunnel syndrome around 25-50% of the time.

Sorting out the syndromes differences is done by a thorough history, physical exam and the use of an electrical nerve test called an EMG nerve conduction study. The EMG nerve conduction study evaluates the muscles innervated by the ulnar nerve and the sensory fibers feeding the ulnar nerve distribution.

Treatment

Nonsurgical Treatment Program

  • Based on two ergonomic changes:
    • Proper sleeping posture
    • Correct daytime habits

Role of Therapists

Therapists teach patients ergonomically correct work habits. This involves adjusting the patients workstation configuration and recommending adaptive equipment to avoid direct pressure on the ulnar nerve and bending the elbow excessively. This works for most patients, but it takes about three months to demonstrate any improvement.

Surgery is recommended if:

  • The measured nerve compression is severe enough
  • Excessive nerve mobility exists involving subluxation on elbow flexion causing persistent symptoms
  • All nonsurgical attempts have failed to resolve the symptoms

Most patients can be surgically treated for cubital tunnel syndrome with an in situ release of the nerve. This requires an incision that is less than one-inch long on the inside of the elbow.

After Surgery

Immediately after surgery patients are encouraged to use their arm and hand. One week after surgery, a home exercise program is begun. In the second week after surgery, the elbow sutures are removed and the patient can return to work.

Ulnar Nerve Transportation

This procedure transfers the ulnar nerve from its normal position into a healthy environment surrounded by a rich blood supply.

Ulnar nerve transportation is necessary under special circumstances:

  • Ulnar nerve subluxation is present; the ulnar nerve is slipping in and out of its groove
  • Patient has had a prior failed ulnar nerve surgery

Techniques of Ulnar Nerve Transportation

  • Subcutaneously – Under the skin
  • Intra-muscularly – In the muscle
  • Sub-muscular – Beneath the first muscle layer of the flexor pronator mass

All types of ulnar nerve surgeries are performed as an outpatient procedure.

After surgery, a light soft dressing is placed over the wound. A therapist is normally consulted for postoperative rehab with an ulnar nerve transposition since this is a more extensive operation. An ulnar nerve transposition takes about three months for a patient to feel much better, whereas with the in situ release, the patient is close to normal within weeks to a month after surgery.