Local corticosteroid injection for carpal tunnel syndrome.

BACKGROUND

Carpal tunnel syndrome (CTS) is a clinical syndrome manifested by signs and symptoms of irritation of the median nerve at the level of the carpal tunnel in the wrist. Treatment of CTS can be surgical or non-surgical. Local corticosteroid injection for CTS has been previously studied but most studies have been either retrospective or uncontrolled. The effectiveness and duration of benefit of local corticosteroid injection for CTS remain unknown.

OBJECTIVES

To evaluate the effectiveness of local steroid injection for carpal tunnel syndrome versus placebo injection or other non-surgical interventions in improving clinical outcome and to determine the length of symptom relief post injection.

SEARCH STRATEGY

We searched the Cochrane Neuromuscular Disease Group register, MEDLINE, EMBASE and CINAHL.

SELECTION CRITERIA

Studies using either a randomized or quasi-randomized methodology were eligible for inclusion. The studies included participants with the diagnosis of carpal tunnel syndrome and the treatment intervention was local corticosteroid injection. The primary outcome measure was clinical improvement after injection.

DATA COLLECTION AND ANALYSIS

Three reviewers independently selected the trials to be included in the study. Studies were rated for their overall quality independently by the reviewers. Studies were compared for heterogeneity using the chi square statistic. Relative risks and 95% confidence intervals were calculated for each trial and summary relative risks and 95% confidence intervals (CI) were also calculated.

MAIN RESULTS

We identified four randomized controlled trials studying local corticosteroid injection for the treatment of CTS. Two trials were excluded. One did not include clinical assessment as an outcome and the other did not provide patient outcomes, but only statistical values. Each of the remaining two trials had demonstrated clinical improvement of CTS at one month following local corticosteroid injection compared to placebo injection. The pooled relative risk (RR) favouring treatment was 3.62 (95% CI 1.94 to 6.73).

REVIEWER'S CONCLUSIONS: Local corticosteroid injection for CTS provides greater clinical improvement in symptoms one month after injection compared to placebo. Symptom relief beyond one month compared to placebo has not been demonstrated. The effectiveness of local corticosteroid injection has not been compared to other non-surgical or surgical interventions for CTS in randomized controlled trials.