Joseph J. Schreiber, MD

Cubital Tunnel syndrome

Cubital tunnel syndrome is a common condition where one of the major nerves to the forearm and hand (the “ulnar nerve”) gets compressed as it passes along the inner side of the elbow.  Irritation of the “funny bone” nerve can cause numbness or tingling into the ring and small finger. This oftentimes happens at night when sleeping, and can severely disrupt the quality of their sleep. It can also result in the hand feeling weak and clumsy.

Common causes

• Elbow flexion - keeping the elbow flexed for extended periods of time, such as when sleeping or talking on the phone, can “kink” the ulnar nerve at the elbow. This decreases normal flow and signals along the nerve, and causes pain and tingling in the small and ring fingers.

• Pressure - putting direct pressure on the nerve for prolonged periods of time can irritate the nerve. Common culprits are armrests and the console of your car.

• Abnormal anatomy - scarring, prior surgery, or presence of an extra muscle can compress the ulnar nerve at the elbow.

• Hypermobile nerve - in some people, the ulnar nerve will snap along the inside of the elbow when it is bent. This instability can be normal for some patients, but in others it can cause nerve irritation.

Diagnosis

• Cubital tunnel syndrome can oftentimes be diagnosed by talking with your doctor and having them examine your hand and arm. Occasionally a nerve test (EMG or nerve conduction study) can be used to assess the function of the nerve and determine if its being compressed.

Non-Surgical Treatment

• Minimize irritation of the ulnar nerve

  • Avoid pressure on the "funny bone" along the inside of your elbow (e.g. arm rests of chairs, leaning on the console of your car)

  • Limit prolonged periods of elbow flexion

• Wear a splint at night to keep the elbow straight

• Ulnar nerve gliding exercises (see below)

Surgery

Occasionally, surgery may be needed to release the compressed or pinched nerve. Typically a 1-2 inch incision is made along the inside of the elbow.  The "roof" of the tunnel is released, which eliminates compression of the nerve.

More rarely, if symptoms are associated with the ulnar nerve snapping or moving along the inside of the arm when then elbow is bent, the nerve may be surgically moved to the front of the elbow. A band of tissue is used to hold the nerve in place and stabilize it. This technique requires a longer incision.

Absorbable sutures are placed underneath the skin, and Dermabond (medical grade "Super Glue") is used to seal the incision. A bandage is placed which remains in place for 3 days.

The hand can be used for normal light activities immediately, and you can get the incision wet once the bandage is removed. More demanding activities (e.g. lifting weights, gardening, manual labor) should be avoided until the skin heals (~10-14 days).

If caught early, improvements in numbness and tingling are typically immediate. In more severe cases, nerve recovery can be gradual.  Optimal nerve recovery may take several months after surgery, and if symptoms are very advanced, they may not completely go away. 

Dr. Schreiber is a board certified orthopedic surgeon specializing in hand, wrist, and elbow conditions. Dr. Schreiber practices at the Raleigh Orthopaedic Clinic in Raleigh, North Carolina.