Objective: To determine the efficacy of 20, 40 and 60 mg methylprednisolone injections in patients with the carpal tunnel syndrome.
Methods: Included were patients with signs and symptoms of carpal tunnel syndrome of more than 3 months duration confirmed by electrophysiological tests. Patients were in a double blind trial randomised to treatment consisting of injections proximal to the carpal tunnel with 20, 40 or 60 mg methylprednisolone. Primary outcome was improvement of symptoms requiring no further treatment. These patients were followed for one year.
Results: There were no significant differences in the treatment response between the three randomised groups at one-year follow-up (log rank analysis 1.51, 2 df, 0.4711). In the 20, 40 and 60 mg treatment groups, 56%, 53% and 73% of the patients respectively were free of important symptoms at six months follow-up. Of the patients treated with one or two injections 22% were finally referred to surgery within one year of the first treatment. No side effects were recorded.
Conclusion: A single local injection of methylprednisolone 20, 40 or 60 mg results in long lasting improvement in approximately half of the patients. There is a trend in favour of the highest dose. A second injection may further reduce the number of patients requiring surgery.