Rosemont, Ill. - A recent article by Dr. Domingo Ly-Pen of Madrid reports that, for three months, steroid injection is more effective than surgery in the reduction of carpal tunnel symptoms for patients with mild, new onset disease. However, after the initial success, the effectiveness of injection trends downward and at one year falls below that of surgery. If this study parallels the findings of other investigations, the success rate of injection can be expected to decline further with time while the surgery success rate remains constant or improves.
For a patient with carpal tunnel syndrome, this study raises two questions regarding the potential use of an injection as the primary form of treatment: will my hand respond positively to the injection and, if so, how long will the beneficial effect last. Previous studies, with longer-term follow-up than that provided by Ly-Pen, have shown that patients with mild carpal tunnel syndrome have a long- term positive response rate of less than 50%, whereas patients with more advanced nerve compression (loss of feeling in the fingers, weakness, and symptoms present for more than six months) have a far poorer outcome, with a less than 20% positive response rate long- term. These findings have led to hesitancy among medical providers to offer steroid injection as a potential cure for carpal tunnel syndrome. In contrast, the results of carpal tunnel surgery, as indicated by Ly-Pen's early findings, are stable over time, with 75-85% positive response rates provided long-term.
While there is no accepted treatment algorithm for carpal tunnel syndrome due to the wide variability in presentation, most members of The American Society for Surgery of the Hand utilize injection in patients with mild recent onset disease, who understand that symptoms will recur ultimately in many cases. While injection remains an option for patients with more severe compression, the modest success rate seen at greater than one year, coupled with the risk of permanent nerve damage if nerve compression persists, has led to the recommendation that surgical decompression be considered as primary treatment in these patients.