Treating Ulnar Nerve Compression in the Elbow

The elbow is where you find your "funny bone." If you hit this spot in just the right place, your lower arm goes numb and you have a tingly feeling for a few seconds to a couple of minutes. While it's not painful, it's not comfortable either. What you're hitting isn't really a bone, but a nerve, called the ulnar nerve. The ulnar nerve reaches from the collarbone down to the lower arm through the inside of the elbow, through the cubital tunnel.

Ulnar nerve compression is a very common injury and is caused when the ulnar nerve is pressed upon in the elbow by either a mass or cyst that shouldn't be there, swelling, bone spurs, or older bone breaks that didn't heal quite right. Although doctors don't have an exact number, they estimate that about 1 percent of people in the United States have ulnar nerve compression.

People who frequently lean on their elbows on a desk, for example, are at higher risk of developing nerve compression, as are people who work at jobs or activities that make them bend and relax their elbow often, especially if there is a force at the same time, such as while playing tennis.

Usual treatment for ulnar nerve compression at the elbow is to splint the elbow so the patient can't bend it, giving the elbow a rest from the bending motion. However, that is a difficult treatment to follow through because splinting an arm so it can't be bend is very uncomfortable and inconvenient for most people. So, if the nerve compression is severe enough for treatment, surgery is an option for many patients. The actual procedure though, is often debated among surgeons as to which is the best approach.

One procedure involves decompression of the nerve, which simple removes the cause of the pressure. This is considered a good, safe approach because of the limited risk of affecting nerves and blood supply to the area. However, the drawback is that the actual problem, what caused the pressure in the first place and the tension on the nerves aren't fixed and may make it necessary for repeat surgeries.

A modified procedure is called decompression with transposition, whereby the surgeon moves the nerve to a new area of the elbow that has less trauma or scarring, so the nerve can't catch on it as the elbow is bent and relaxed. This also stretches the nerve a bit. Of course, like all procedures, this one has a drawback as well. In this case, the drawback is that the blood supply to the area is interrupted and not as much blood as is necessary may reach the area. Surgeons are also concerned about what the long-term effect of moving the nerve is and that this may just move the problem to another section of the elbow as more scarring occurs.

As far as can be told, there are no randomized controlled trials that compared the two procedures, but some neurosurgeons in Europe and Australia have performed trials comparing the decompression with transposition alone. One researcher, Nabhan and colleagues, studied 32 patients who had decompression alone and 34 who had a procedure called anterior transposition procedure. The researchers found that there was no difference between the two groups when they assessed the patients three and nine months after surgery. Another small trial with the same procedures, done by Gervasio and colleagues, studied 70 patients, half who had decompression and half who had the transposition. This group of researchers found that the simple decompression group rated the results as: 54 percent excellent, 26 percent good, 20 percent fair. In the transposition group, the results were 51 percent excellent, 31 percent good, and 18 percent fair.

Finally, a third smaller study by Biggs and colleagues looked at 23 patients who had decompression and 21 who had transposition. They also had similar findings to the two earlier studies. The interesting finding in this study, though, was that three patients who had transposition experienced deep wound infections and the decompression group had no reported infections.

Other researchers looked at reviews of studies and also came to the same conclusion: there was not much difference between the findings between the two procedures. Therefore, most recommend that the easier of the two procedures, the decompression, be done. That being said, none of the studies that were found were of "high" quality. The three studies mentioned above were quite small, which doesn't give a good representation of statistics. The two reviews were also problematic because the studies were of poor or low quality.

The author of this article wrote that further studies are needed and they should be larger, multi-center designed studies for researchers to begin seeing any significant differences between the surgeries.

References: Kevin C. Chung, MD. Treatment of Ulnar Nerve Compression at the Elbow. In The Journal of Hand Surgery. November 2008. Vol. 33. No. 9. Pp. 1625-1628.