Cubital Tunnel Syndrome (Does your small finger go numb?)

While carpal tunnel syndrome is the most common nerve problem, cubital tunnel syndrome is the second most common nerve problem. Cubital tunnel syndrome occurs when the ulnar nerve (the “funny bone” nerve) gets pinched at the elbow. It is a common source of nerve pain, especially at night.

What are the symptoms of cubital tunnel syndrome?
Cubital tunnel syndrome leads to tingling and numbness of the small finger, and often the ring finger. If the other fingers are involved, then carpal tunnel syndrome may also be present, as these problems often occur together. The ulnar nerve gets pinched more when the elbow is bent. Symptoms may also occur when the nerve is pressed on, 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 your physician asking you specific questions and examining your arm. A symptom that is classic for cubital tunnel syndrome is waking up in the middle of the night with the small finger tingling or “numb”. This occurs mainly because we all sleep in the fetal position, with our elbows bent. This numbness also occurs other times when the elbow is bent, like when talking on the phone. If bending your elbow or pressure on your elbow causes the small and/or ring finger to tingle, then you have cubital tunnel syndrome. Nerve conduction studies are usually obtained, but are not especially accurate, and may miss the diagnosis of cubital tunnel syndrome in up to 40-50% of cases.

How is cubital tunnel syndrome treated?
Unless your ulnar nerve is damaged, treatment for cubital tunnel syndrome starts with avoiding pressure over the cubital tunnel/funny bone area by not resting the elbow on desks or other hard objects when using the computer or driving. Prolonged elbow flexion should also be avoided. If you’re on the phone a lot, use your other hand to hold it, or get a hands-free device.

At night, try to prevent the elbow from fully bending during sleep. This is very difficult to do, and many people have trouble sleeping like this. Strategies that can be tried are rolling a towel around the elbow, wearing a tennis elbow brace over the elbow, or cutting a hole in a pillow case and putting the arm through it next to the pillow so that the pillow prevents the elbow from fully bending. If this fails and the symptoms are bothersome, 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 (ie. a medial epicondylectomy) and 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 less-invasive options available.

The literature since 2005 has shown 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. A cubital tunnel release is a simple, less invasive and less painful operation. It is very similar to a carpal tunnel release, in that it simply releases 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 a carpal tunnel release, a cubital tunnel release can be performed endoscopically, through a small incision. This is an outpatient procedure. No splint is needed, and after surgery activities can be resumed within the limits of pain. Typing and computer use can be performed immediately. In order to minimize pain and swelling, heavy activiites should probably be avoided for 2-3 weeks.

The nerve recovers just as well as it does following the bigger operations, with less pain and sufferering, a quicker return to activies and a lower complication rate in skilled hands. A video of this procedure can be viewed at Occasionally, a patient’s nerve may sublux (move) following release. While this is uncommon, I always check to see if this occurs, and if it does I transpose (move) the nerve to the front of the elbow.

Results are mainly affected by how damaged the nerve is from the compression that occurred prior to the surgery. In other words, those who had cubital tunnel syndrome longer and had more nerve damage recovered less following surgery than those with lesser degrees of nerve damage. As with most things in life, it’s usually easier and better to address problems early on, when they are still small.