Evidence exists that patients who undergo surgery for carpal tunnel syndrome are likely to fare better than those who do not. But knowledge about the disease process over the long term is relatively scarce, and questions remain about the lasting benefits of surgical and nonsurgical treatments.

University of Maryland School of Medicine Assistant Professor Raymond A. Pensy, MD, and his coauthors addressed that issue by comparing long-term results (at 6 years) for patients who did or did not undergo surgery for carpal tunnel syndrome. They presented their results at the 2010 American Society for Surgery of the Hand (ASSH) annual meeting.

Both groups of patients were participants in the same original study, which sought to determine the effect of symptom duration and age on the outcome of carpal tunnel surgery. Of the 800 patients enrolled, 90 did not proceed to surgery for a variety of reasons, such as apprehension, resolution of symptoms, and fear of job loss.

For this study, researchers were able to locate 36 of the nonsurgical patients and match them with 24 patients in the original surgical cohort by sex, age, and preoperative Levine-Katz (LK) scores. The LK questionnaire, which is self-administered and assesses the severity of symptoms and functional status in patients who have carpal tunnel syndrome, was given to both groups at an average of 6 years follow-up.

Both surgical and nonsurgical patients experienced a significant decrease in symptom severity and functional status scores (p < 0.001), indicating notable improvements in symptoms and function. Surgical patients, however, had a greater decrease (improvement) in symptom severity than nonsurgical patients (Fig. 1). Additionally, the surgical patients experienced significant improvement by 6 months, and the improvement remained level at 6 years.

“Although the current study shows there is a benefit to decompression over the long term, the loss to the nonoperative group is modest,” note the authors. If symptoms are relatively mild or social pressures dictate avoiding time off work, a conservative approach may be effective. They conclude that the overall improvement experienced by both groups, with a superior outcome achieved with surgery, “is likely a more representative account of the natural history of the disease process.”

The study, however, does not provide data as to what, if any, treatments were used by the nonsurgical patients. Also, a bias exists in that only about one-third of the original 90 patients who declined surgery were available for follow-up.

Dr. Pensy’s coauthors for “The Long-term Outcome of Operative Versus Nonoperative Treatment of Carpal Tunnel Syndrome” include Frank D. Burke, MD; Mary J. Bradley, MSc; Norman H. Dubin, PhD; and E.F. Shaw Wilgis, MD. The authors report no conflicts.

The AAOS clinical practice guidelines on the diagnosis and treatment of carpal tunnel syndrome can be found at www.aaos.org/guidelines