Injection therapy for carpal tunnel syndrome: A systematic review and network meta-analysis of randomized controlled trials

Abstract

Various injectants are available for the treatment of carpal tunnel syndrome. This systematic review and network meta-analysis was conducted to investigate the effectiveness of different injection therapies in alleviating the symptoms of carpal tunnel syndrome. Various databases were searched for relevant studies from inception until May 10, 2023. Eligible studies were identified using the patient (P), intervention (I), comparison (C), and outcomes (O) model, which involved (P) participants with carpal tunnel syndrome, (I) an intervention based on injection therapy, (C) the use of placebo or another injectant as a control treatment, and (O) the measurement of clinical and electrodiagnostic outcomes of interest. A total of 18 studies were included in the analysis. The network meta-analysis revealed that platelet-rich plasma is effective in the treatment of carpal tunnel syndrome in terms of symptom and pain relief and functional improvement in both the short and long term, whereas steroids are effective only in the short term. Additionally, injections of dextrose solution may offer long-term pain relief as well as short- and long-term symptom alleviation and functional improvement. The study findings suggest that platelet-rich plasma should be used as the first-line treatment for carpal tunnel syndrome, with dextrose and steroids serving as alternative treatment options.

Fig 1. Changes in BCTQ-SSS score.

(1A) Network diagram (short-term) displaying at least one placebo-controlled trial for each injectant, except for ozone, insulin, and 17-alpha-hydroxyprogesterone. (1B) Forest plot (short-term) indicating that dextrose, insulin, ozone, platelet-rich plasma, and steroids yielded significantly more favorable outcomes than placebo. (1C) Network diagram (long-term) displaying at least one placebo-controlled trial for each injectant, except for ozone and 17-alpha-hydroxyprogesterone. (1D) Forest plot (long-term) indicating that dextrose, hyalase, and platelet-rich plasma yielded significantly more favorable outcomes than placebo. SMD, standard mean difference; CI, credible interval; BCTQ-SSS, Boston Carpal Tunnel Syndrome Questionnaire Symptom Severity Scale.

Fig 2. Changes in BCTQ-FSS score.

(2A) Network diagram (short-term) displaying at least one placebo-controlled trial for each injectant, except for ozone, insulin, and 17-alpha-hydroxyprogesterone. (2B) Forest plot (short-term) indicating that dextrose, hyalase, insulin, ozone, platelet-rich plasma, and steroids yielded significantly more favorable outcomes than placebo. (2C) Network diagram (long-term) displaying at least one placebo-controlled trial for each injectant, except for ozone and 17-alpha-hydroxyprogesterone. (2D) Forest plot (long-term) indicating that dextrose, hyalase, and platelet-rich plasma yielded significantly more favorable outcomes than placebo. SMD, standard mean difference; CI, credible interval; BCTQ-FSS, Boston Carpal Tunnel Syndrome Questionnaire Functional Status Scale.

Fig 3. Changes in pain score.

(3A) Network diagram (short-term) displaying at least one placebo-controlled trial for each injectant, except for ozone, platelet-rich plasma, and 17-alpha-hydroxyprogesterone. (3B) Forest plot (short-term) indicating that platelet-rich plasma and steroids yielded significantly more favorable outcomes than placebo. (3C) Network diagram (long-term) displaying at least one placebo-controlled trial for each injectant, except for ozone, platelet-rich plasma, and 17-alpha-hydroxyprogesterone. (3D) Forest plot (long-term) indicating that dextrose and platelet-rich plasma yielded significantly more favorable outcomes than placebo. SMD, standard mean difference; CI, credible interval.