Carpal tunnel syndrome

Ly-Pen D, Andreu JL, de Bias G, Sanchez-Olaso A, Millan I. Surgical decompression versus local steroid injection in carpal tunnel syndrome: a one-year, prospective, randomized, open, controlled clinical trial. Arthritis Rheum 2005; 52:612-619.

* Clinical Question

Is local steroid injection for carpal tunnel syndrome as effective as surgery?

* Bottom Line

Patients with carpal tunnel syndrome do better with local steroid injections than with surgery in the short term, but at the end of 12 months, the outcomes appear comparable, though more than 20% of patients had discontinued the study by this time period. (Level of evidence [LOE] = 2b)

Study Design

Randomized controlled trial (nonblinded)

Allocation Concealed

Setting Outpatient (specialty)

Synopsis

Adults with carpal tunnel syndrome referred to a special carpal tunnel clinic were eligible to participate in this study if they had symptoms for more than 3 months and didn't respond to 2 weeks of nonsteroidal anti-inflammatory drugs and splinting. The authors confirmed carpal tunnel syndrome by electrodiagnostic testing. Patients were randomly assigned to surgery (n = 80) or local steroid injection (n = 83). The allocation was concealed. One surgeon performed all surgeries and another surgeon performed all the steroid injections.

The main outcome--severity of symptoms on a 100-point visual analog scale--was assessed via intention-to-treat. The authors defined treatment success as a 20% reduction in symptoms. This is consistent with other literature that suggests a 15% to 20% improvement is the minimum difference that is clinically meaningful. Since more than 80% of patients in the steroid injection group received 2 injections, the therapy in this study should be attributed to a course of 2 local steroid injections, not a single injection.

The patients in each group were similar at baseline; by the end of the study, more than one fifth of each group dropped out. After 3 months, 94% of the patients treated with steroid injections improved compared with 75% of the surgical patients (number needed to treat = 5; 95% confidence interval, 3-13). But by the end of 12 months, there was no significant difference in improvement between groups (70% and 75%, respectively). The high dropout rate in this study may confound these data.

CONTINUED

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Each month, the POEMs (Patient-Oriented Evidence that Matters) editorial team reviews 105 research journals in many specialties, and selects and evaluates studies that investigate important primary care problems, measure meaningful outcomes, and have the potential to change the way medicine is practiced. Each POEM offers a Bottom Line observation and summarizes the study's objective, patient population, study design and validity, and results. InfoPOEMs, Info-Retriever and POEMS for Primary Care are registered trademarks of InfoPOEM, Inc. POEMS and Patient-Oriented Evidence that Matters are trademarks of InfoPOEM, Inc. These POEMs are copyrighted by, and published with the express permission of InfoPOEM, Inc. and may not be copied or otherwise reproduced without the prior written consent of InfoPOEM, Inc.

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