Needed: Valid and Reliable Instrument to Measure Before and After Results of Surgical Treatment for Cubital Tunnel Syndrome
Wanted: Instrument to Measure Results of Treatment for Cubital Tunnel Syndrome

You've heard it over and over from us: doctors, physical therapists, and other individuals dedicated to research are seeking evidence to show what treatment works best for each orthopedic condition or problem. Today, we report on the results of information gathered about cubital tunnel syndrome. Are patients happy with the results? Does their satisfaction match the surgeon's view of the results?

Cubital tunnel syndrome is a condition that affects the ulnar nerve where it crosses the inside edge of the elbow. Another way to describe this problem is ulnar nerve entrapment. The symptoms are very similar to the pain that comes from hitting your funny bone. When you hit your funny bone, you are actually hitting the ulnar nerve on the inside of the elbow. There, the nerve runs through a passage called the cubital tunnel. When this area becomes irritated from injury or pressure, it can lead to cubital tunnel syndrome.

In this systematic review results from studies around the world were gathered, analyzed, and reported on. The authors intended to compare patients' level of satisfaction after surgery for cubital tunnel syndrome with surgeons' satisfaction. But they found there was too much variation in how the results were reported to do so. So, instead, they ended up looking at the measures used to report patient satisfaction after surgery for this condition.

The hope was to find one instrument, tool, or method that is reliable and valid and could be used over a range of studies. Then the results could be compared across all studies. That, in turn, would make it possible to compare the results of each type of surgery done to treat this problem. And in the end, surgeons might be able to identify one surgical technique that works best for cubital tunnel syndrome.

The goal of surgery is to release the pressure on the ulnar nerve where it passes through the cubital tunnel. There are different kinds of surgery for cubital tunnel syndrome. A simple nerve decompression involves removing any adhesions from around the nerve or cutting any soft tissues that might be pressing on the nerve. A second procedure is called an ulnar nerve transposition. In this procedure, the surgeon forms a completely new tunnel from the flexor muscles of the forearm. The ulnar nerve is then transposed (moved) out of the cubital tunnel and placed in the new tunnel.

The third approach is to remove the medial epicondyle (bony bump) on the inside edge of the elbow, a procedure called medial epicondylectomy. By getting the medial epicondyle out of the way, the ulnar nerve can then slide through the cubital tunnel without pressure from the bony bump. It is not clear whether one operation is better than the other.

Using several electronic databases, the authors selected articles that pertained to surgery for cubital tunnel syndrome in adults. Small studies with fewer than 20 patients were not included. Out of a possible 141 studies, 42 met the final criteria for inclusion. These studies were published over a span of 10 years between 1997 and 2007.

Most of them were Level 4 evidence, which means they were mostly case series, not the higher quality randomly controlled trials or blinded studies. They came from all over the world including Turkey, Greece, Australia, Korea, the Netherlands, France, Japan, Germany, England, Sweden, Canada, and the United States. They were published in peer reviewed high quality medical journals.

Data collected was classified as patient satisfaction, activities of daily living (ADLs), symptom scales, and non-disease-specific measures. Symptom scales included pain, weakness, numbness, ability to work, and sensation. Non-disease-specific measures included sports or performing arts (e.g., dance) as well as self-reported ratings of physical and mental health.

The authors were unable to complete the task they set out to do: they could not find one method that was consistently used to measure before and after patient satisfaction for patients having surgery for cubital tunnel syndrome. Right now, there is not one standardized test available that could be used to assess results of surgical treatment for ulnar neuropathy.

Not only that, there's some question of whether the evidence already reported can really be considered evidence. That's because the way most results were measured was simply on the basis of a scale rating outcomes as poor, fair, good, or excellent. From a statistical research point-of-view, if this scale hasn't been tested and proven reliable and valid, then the reported evidence may not be a real measure of results.

The authors suggest what is really needed is a validated instrument sensitive to changes made in symptoms and satisfaction from before treatment to after treatment. It should be easy to use, reliable, and responsive to small changes while still showing a trend in the patient's overall progress. Data collected should also include patient's perception of symptom severity, ability to work and perform daily activities, strength, and satisfaction.

In summary, this systematic review set out to accomplish one thing and ended up with a different final result. Instead of being able to compare patient satisfaction with surgeon satisfaction for patients who had surgery for cubital tunnel syndrome, they made a recommendation for the development of an instrument that could allow for such an assessment on the part of patients and/or surgeons. This would require a series of steps involving focus groups, expert review and consensus, testing of the tool, and reporting results. With such a tool, new evidence could be generated around this topic that could be relied upon for future patient management.

References: Sheina A. Macadam, MD, et al. Outcomes Measures Used to Assess Results After Surgery for Cubital Tunnel Syndrome: A Systematic Review of the Literature. In The Journal of Hand Surgery. October 2009. Vol. 34A. No. 8. Pp. 1482-1491.