Abstract
Background
Carpal tunnel syndrome is a clinical syndrome manifested by signs and symptoms of irritation of the median nerve at the carpal tunnel in the wrist. Local corticosteroid injection for carpal tunnel syndrome has been studied but its effectiveness is unknown.
Objectives
To evaluate the effectiveness of local corticosteroid injection for carpal tunnel syndrome versus placebo injection or other non-surgical interventions.
Search methods
We searched the Cochrane Neuromuscular Disease Group Trials register (searched May 2006), MEDLINE (searched January 1966 to May 2006), EMBASE (searched January 1980 to May 2006) and CINAHL (searched January 1982 to May 2006).
Selection criteria
Randomized or quasi-randomized studies.
Data collection and analysis
Three authors independently selected the trials and rated their overall quality. Relative risks and 95% confidence intervals were calculated for each trial and summary relative risks and 95% confidence intervals were also calculated.
Main results
We included 12 studies with altogether 671 participants. Two high quality randomized controlled trials with altogether 141 participants demonstrated clinical improvement of carpal tunnel syndrome at one month or less following local corticosteroid compared to placebo injection (relative risk 2.58 (95% confidence intervals 1.72 to 3.87)). One trial compared local corticosteroid injection to oral corticosteroid and at 12 weeks after treatment there was significantly more improvement in the injection group (mean difference -7.10 (95% confidence intervals -11.68 to -2.52)). In one trial, the rate of improvement after one month was greater after local than systemic corticosteroid injection (relative risk 3.17 (95% confidence intervals 1.02 to 9.87)). In one trial, symptoms did not improve significantly more in the injection group at eight weeks after injection compared to treatment with anti-inflammatory medication and splinting (mean difference 0.10 (95% confidence intervals -0.33 to 0.53)). Two injections versus one injection of local corticosteroid did not provide further clinical improvement, mean difference -3.80 (95% CI -9.27 to 1.67).
Authors’ conclusions
Local corticosteroid injection for carpal tunnel syndrome provides greater clinical improvement in symptoms one month after injection compared to placebo. Significant symptom relief beyond one month has not been demonstrated. Local corticosteroid injection provides significantly greater clinical improvement than oral corticosteroid for up to three months. Local corticosteroid injection does not significantly improve clinical outcome compared to either anti-inflammatory treatment and splinting after eight weeks or Helium-Neon laser treatment after six months. Two local corticosteroid injections do not provide significant added clinical benefit compared to one injection.
Plain language summary
Local corticosteroid injection is effective in the short-term for the treatment of carpal tunnel syndrome
Local corticosteroid injection is a common non-surgical treatment for carpal tunnel syndrome. Other non-surgical treatments include the use of wrist splints, ultrasound and oral anti-inflammatory agents. Surgical intervention is also known to be effective. This systematic review confirmed the effectiveness of local corticosteroid injection for relief of symptoms for severe carpal tunnel syndrome up to one month after injection. Local corticosteroid injection provides significantly greater clinical improvement compared to oral corticosteroid up to three months after treatment. Two injections of local corticosteroid do not provide significant further clinical improvement of symptoms. Further research is required to determine length of benefit of local corticosteroid injection and benefit for mild and moderate carpal tunnel syndrome.
