Botulinum toxin is a proven and widely used treatment for numerous conditions characterized by excessive muscular contractions. Recent studies have assessed the analgesic effect of botulinum toxin in joint pain and started to unravel its mechanisms.
LITERATURE-SEARCH-METHODOLOGY: We searched the international literature via the Medline database using the term "intraarticular botulinum toxin injection" combined with any of the following terms: "knee", "ankle", "shoulder", "osteoarthritis", "adhesive capsulitis of the shoulder".
RESULTS: Of 16 selected articles about intraarticular botulinum toxin injections, 7 were randomized controlled trials done in patients with osteoarthritis, adhesive capsulitis of the shoulder, or chronic pain after joint replacement surgery. Proof of anti-nociceptive effects was obtained in some of these indications and the safety and tolerance profile was satisfactory. The studies are heterogeneous. The comparator was usually a glucocorticoid or a placebo; a single study used hyaluronic acid. Pain intensity was the primary outcome measure.
DISCUSSION-CONCLUSION: The number of randomized trials and sample sizes are too small to provide a satisfactory level of scientific evidence or statistical power. Unanswered issues include the effective dosage and the optimal dilution and injection modalities of botulinum toxin.
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.
BACKGROUND: Botulinum toxin type A (BoNTA) is a neurotoxin that acts by inhibiting the release of neurotransmitters acetylcholine at neuromuscular junctions, thus reducing muscular contractions. Recent evidence suggests that BoNTA can reduce nociceptive activities of sensory neurons in animal models by inhibiting release of certain neuropeptides. Despite the therapeutic benefit of BoNTA in alleviating painful muscle spasms, its efficacy in other musculoskeletal pain conditions is less clear.
OBJECTIVE: We aim to examine the efficacy of BoNTA in reducing chronic musculoskeletal pain.
METHODS: Studies for inclusion in our report were identified using MEDLINE, EMBASE, PUBMED, Cochrane Central Register of Controlled Trials, CINAHL, and reference lists of relevant articles. Studies were considered eligible for inclusion if they were randomized controlled trials (RCTs), evaluating the efficacy of BoNTA injections in pain reduction. All studies were assessed and data were abstracted independently by paired reviewers. The outcome measures were baseline and final pain scores as assessed by the patients. The internal validity of trials was assessed with the Jadad scale. Disagreements were resolved through discussions.
MAIN RESULTS: Twenty-one studies were included in the systematic review and 15 of them were included in the final meta-analysis. There was a total of 706 patients in the meta-analysis, represented from trials of plantar fasciitis (n = 1), tennis elbow (n = 2), shoulder pain (n = 1), whiplash (n = 3), and myofascial pain (n = 8). Overall, there was a small to moderate pain reduction among BoNTA patients when compared to control (SMD = -0.27, 95% CI: -0.44 to -0.11). When the results were analyzed in subgroups, only tennis elbow (SMD = -0.44, 95% CI: -0.86 to -0.01) and plantar fasciitis (SMD = -1.04, 95% CI: -1.68 to -0.40) demonstrated significant pain relief. Although not in the meta-analysis, one back pain study also demonstrated positive results for BoNTA. Lastly, BoNTA was effective when used at ≥ 25 units per anatomical site or after a period ≥ 5 weeks.
CONCLUSION: In our meta-analysis, BoNTA had a small to moderate analgesic effect in chronic musculoskeletal pain conditions. It was particularly effective in plantar fasciitis, tennis elbow, and back pain, but not in whiplash or shoulder pain patients. However, more evidence is required before definitive conclusions can be drawn. On the other hand, there is convincing evidence that BoNTA lacks strong analgesic effects in patients with myofascial pain syndrome. A general dose-dependent and temporal response with BoNTA injections was also observed.
BACKGROUND: Recent evidence suggests an anti-nociceptive effect of botulinum toxin. OBJECTIVES: To compare the efficacy and safety of botulinum toxin in comparison to placebo or other treatment options for shoulder pain. SEARCH STRATEGY: We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library), Ovid MEDLINE, CINAHL (via EBSCOhost), Ovid SPORTDiscus, EMBASE and Science Citation Index. SELECTION CRITERIA: Randomized controlled trials (RCTs) comparing botulinum toxin with placebo or active treatment in people with shoulder pain were included. DATA COLLECTION AND ANALYSIS: For continuous measures we calculated mean difference (MD), and for categorical measures risk ratio (RR) (with 95% confidence interval (CI)). MAIN RESULTS: Six RCTs with 164 patients were included. Five RCTs in participants with post-stroke shoulder pain indicated that compared with placebo, a single intramuscular injection of botulinum toxin A significantly reduced pain at three to six months post-injection (MD -1.2 points, 95% CI -2.4 to -0.07; 0 to 10 point scale) but not at one month (MD -1.1 points, 95% CI -2.9 to 0.7). Shoulder external rotation was increased at one month (MD 9.8 degrees , 95% CI 0.2 to 19.4) but not at three to six months. Shoulder abduction, external rotation or spasticity did not differ between groups, nor did the number of adverse events (RR 1.46, 95% CI 0.6 to 24.3).One RCT in arthritis-related shoulder pain indicated that botulinum toxin reduced pain severity (MD -2.0, 95% CI -3.7 to -0.3; 10 point scale) and shoulder disability with a reduction in Shoulder Pain and Disability Index score (MD -13.4, 95% CI -24.9 to -1.9; 100 point scale) when compared with placebo. Shoulder abduction was improved (MD 13.8 degrees, 95% CI 3.2 to 44.0). Serious adverse events did not differ between groups (RR 0.35, 95% CI: 0.11, 1.12). AUTHORS' CONCLUSIONS: The results should be interpreted with caution due to few studies with small sample sizes and high risk of bias. Botulinum toxin A injections seem to reduce pain severity and improve shoulder function and range of motion when compared with placebo in patients with shoulder pain due to spastic hemiplegia or arthritis. It is unclear if the benefit of pain relief in post-stroke shoulder pain at three to six months but not at one month is due to limitations of the evidence, which includes small sample sizes with imprecise estimates, or a delayed onset of action. More studies with safety data are needed.
Botulinum toxin is a proven and widely used treatment for numerous conditions characterized by excessive muscular contractions. Recent studies have assessed the analgesic effect of botulinum toxin in joint pain and started to unravel its mechanisms.
LITERATURE-SEARCH-METHODOLOGY:
We searched the international literature via the Medline database using the term "intraarticular botulinum toxin injection" combined with any of the following terms: "knee", "ankle", "shoulder", "osteoarthritis", "adhesive capsulitis of the shoulder".
RESULTS:
Of 16 selected articles about intraarticular botulinum toxin injections, 7 were randomized controlled trials done in patients with osteoarthritis, adhesive capsulitis of the shoulder, or chronic pain after joint replacement surgery. Proof of anti-nociceptive effects was obtained in some of these indications and the safety and tolerance profile was satisfactory. The studies are heterogeneous. The comparator was usually a glucocorticoid or a placebo; a single study used hyaluronic acid. Pain intensity was the primary outcome measure.
DISCUSSION-CONCLUSION:
The number of randomized trials and sample sizes are too small to provide a satisfactory level of scientific evidence or statistical power. Unanswered issues include the effective dosage and the optimal dilution and injection modalities of botulinum toxin.
Systematic Review Question»Systematic review of interventions
