Cubital Tunnel Syndrome

Cubital Tunnel Syndrome

Does Your Small Finger Go Numb?

Carpal tunnel syndrome is the most common nerve problem. Cubital Tunnel Syndrome is the second most common nerve problem.

What is Cubital Tunnel Syndrome?

Cubital tunnel syndrome is very similar to carpal tunnel syndrome. Cubital tunnel syndrome occurs when the ulnar (funny bone) nerve gets pinched at the elbow by the fascia (ligament-like tissue) over it. The ulnar nerve gets pinched more with elbow flexion, as flexion decreases the space under the fascia available for the nerve. Compression is also worse when pressure is placed on the nerve, such as when placing the elbow on a hard surface, as often occurs when working at a desk or while driving.

What Are the Symptoms of Cubital Tunnel Syndrome?

Cubital tunnel syndrome leads to tingling and numbness of the small finger, the ring finger, and often the small finger-side of the hand. If the other fingers are involved, then carpal tunnel syndrome may also be present, as these nerve compression problems often occur together. The ulnar nerve gets pinched more when the elbow is bent. Elbow flexion occurs at night because most of us sleep in the ‘fetal position’ with our arms bent. The elbow also gets flexed when talking on the phone and other activities of daily living. Symptoms may also occur when the nerve is pressed, such as when resting the elbow on a hard surface.

How is the Diagnosis of Cubital Tunnel Syndrome Made?

The diagnosis of cubital tunnel syndrome is made by history and physical examination (ie. by a Hand Surgeon talking to you and examining the arm). A symptom that is classic for cubital tunnel syndrome is waking up in the middle of the night with your small finger and/or part of your hand tingling or “numb”. Again, this mainly occurs because most of us sleep in the fetal position, with our elbows bent. In addition, at night, our blood pressure decreases, leading to more swelling about the nerve, which takes up space in the cubital tunnel, increasing pressure on the nerve. This numbness also occurs other times that your elbow is bent for a period of time, such as when talking on the phone.

Nerve conduction studies are usually obtained, but may miss the diagnosis of cubital tunnel syndrome in up to 40-50% of cases. Fortunately, the diagnosis of Cubital Tunnel Syndrome is fairly straightforward: If bending your elbow causes your small finger to go numb, you have cubital tunnel syndrome.

How is Cubital Tunnel Syndrome Treated?

Unless your ulnar nerve has sustained irreversible damage from compression, treatment for cubital tunnel syndrome starts with avoiding pressure over the cubital tunnel, such as not resting your elbow on desks or other hard objects when using the computer or driving. You also want to avoid prolonged elbow flexion. If you’re on the phone a lot, use your other hand to hold it, or get a handless device.

A recent Cochrane (Government-sponsored very thorough ) Review found that night splinting and nerve gliding exercises are not helpful for cubital tunnel syndrome. However, it may provide some relief if you can keep your elbow from fully bending while you sleep. This is very difficult to do, and many can’t sleep like this. Strategies that can be tried are rolling a towel around the elbow, placing a tennis elbow brace over the elbow, or cutting a hole in a pillow case and putting the arm through it so the pillow helps prevent the elbow from bending all the way.

If this fails, surgical treatment is very successful.

What Are the Different Surgeries for Cubital Tunnel Syndrome?

There are many different surgeries for cubital tunnel syndrome. Some involve removing bone (medial epicondylectomy), and these are very painful. Some involve transposing (moving) the ulnar nerve to the front of the elbow. The nerve can be placed under the skin or under the muscle. These work well, but there are equally effective, less-invasive options available that have a lower complication rate.

The literature since 2005 is clear that patients with cubital tunnel syndrome do just as well following a simple cubital tunnel release as following the bigger, more invasive, more painful operations. The cubital tunnel release is a simple, less invasive, less-painful operation that is very similar to the carpal tunnel release; it involves simply releasing the fascia (ligament-like tissue) over the nerve. This releases the nerve’s compression and allows the nerve to heal and stops the pain.

Just like the carpal tunnel release, the cubital tunnel release can be performed endoscopically, through a small incision. This is an outpatient procedure, with an early return to activities and a low complication rate. No splint is used. (VIDEO)

The nerve recovers just as well after an endoscopic cubital tunnel release as it does following the bigger operations, with much less pain and suffering and a lower complication rate. Rarely, a patient’s nerve may sublux (move) following release. I always check for this; if this occurs the ulnar nerve may need to be transposed (moved) to the front of the elbow.

A recent article confirmed that endoscopic cubital tunnel release and open cubital tunnel release have similar results, but there were fewer complications following the endoscopic cubital tunnel release.1 The results of surgery were mainly influenced by how damaged the nerve was before surgery from the cubital tunnel syndrome. People who had symptoms of cubital tunnel syndrome for greater than 6 months and those who had more nerve damage did less well following surgery than those who had surgery earlier with lesser degrees of nerve damage. As with most things in life, it’s better to address problems early on.

1) Watts AC, Bain GI: Patient-related outcomes of ulnar nerve decompression: A comparison of endoscopic and open in situ decompression. J Hand Surg 34A, 1492-1498, 2009

What can I Expect After Endoscopic Cubital Tunnel Release?

Because I inject Marcaine (numbing medicine) into the wound, your fingers will probably be numb for the entire day of surgery. You can type and use computers immediately. There are no formal activity restrictions after surgery, but I recommend taking it easy for a week or two afterwards. This surgery has minimal pain, which leads some people to overdo it.

Please keep the wound clean and dry for 24 hours. Bathing is safer than showering. Wrap a towel around the dressing in case any water gets in, then place a plastic bag over your hand and secure it tightly with rubber bands. After 24 hours the dressings can be removed and the incision can get wet in the shower. Blot it dry. There are no stitches to remove (they’re buried and absorbable). There’s a piece of tape over the wound. The tape will fall off when it’s ready. The longer it stays on, the nicer the final wound may look. Please don’t submerge the incision under water (like swimming, or putting your hand under water) for 10 days after surgery.

The absorb-able stitches aren’t quite as strong as regular stitches. So don’t do anything too hard or too fast for 2 weeks: If something’s falling, let it hit the ground; don’t reach out to catch it. It’s best to use a sling for 2 weeks while asleep (so you don’t thrash) and when you’re around other people, as others grab your arms more than you’d think. You can remove the sling whenever you’re in a controlled setting, ie. awake and alone, or when sitting and eating, etc. Otherwise, it’s best to wear the sling.

Endoscopic Cubital Tunnel Release: A cannula is placed to protect the nerves and visualize the ligament/fascia to be cut.

Endoscopic Cubital Tunnel Release: A special device is used to cut the fascia/ligament.

Endoscopic Cubital Tunnel Release: “Surgeon’s eye” view of the special blade cutting the fascia over the ulnar nerve.