Effectiveness of Botulinum Toxin for Shoulder Pain Treatment: A Systematic Review and Meta-Analysis.

[OBJECTIVE] To evaluate the current evidence of the effectiveness of botulinum toxin (BTX) treatment for shoulder pain.

[DATA SOURCES] Ovid MEDLINE In-Process and Other Non-Indexed Citations, Ovid MEDLINE, Ovid EMBASE, Web of Science, and Scopus were searched from inception through week 18 of 2015.

[STUDY SELECTION] Randomized controlled trials comparing the clinical efficacy (pain intensity and shoulder range of motion [ROM]) of BTX injection to conventional therapy (steroid or placebo injection) were included.

[DATA EXTRACTION] Two reviewers independently screened abstracts and full texts. The results of the pain intensity and shoulder ROM were extracted and presented in the form of mean and SD. We constructed random-effects models and calculated the mean difference (MD) for continuous outcomes. A total of 219 articles were identified, of which 9 articles were eligible for the final analysis.

[DATA SYNTHESIS] The analysis indicated a statistically significant decreased pain score in the BTX therapy group compared with the control group, with the MD=1.35 (95% confidence interval [CI], .80-1.91; P<.001; I(2)=81%). Patients who received BTX therapy were more likely to have a significant increase in shoulder abduction ROM than patients in the control group, with the MD=8.02 (95% CI, 1.17-14.88, P=.02, I(2)=89%).

[CONCLUSIONS] Compared with conventional (steroid or placebo injection) therapy, BTX injections have beneficial effects for adult patients with shoulder pain, evidenced by improved pain scores and ROM.