Abstract
Background
Shoulder pain is a very common symptom. A number of studies have demonstrated that botulinum toxin type A is effective in relieving shoulder pain. Therefore, this systematic review and meta-analysis aimed to synthesize scientific evidence and quantify the combined effects of ultrasound-guided botulinum toxin type A on shoulder pain.
Methods
A comprehensive literature search was conducted in databases such as PubMed, Embase, Scopus, Cochrane Central Register of Controlled Trials (CENTRAL), China National Knowledge Information Database (CNKI), Wanfang database, and VIP database (VIP) using the keywords "ultrasound", "Botulinum toxin type A", and "shoulder pain". Two reviewers independently reviewed the studies, extracted data from eligible studies, and assessed the risk of bias. A random-effects model was used to calculate the standardized mean difference (SMD) and 95% confidence interval (CI) for Visual Analog Scale (VAS), Upper Extremity Fugl-Meyer assessment (UEFMA), Range of Motion (ROM), Modified Barthel Index (MBI). Funnel plots and sensitivity analyses were also employed to evaluate the six outcome indicators above.
Results
Out of retrieved 854 records, ten studies (involving 533 patients) were finally included. Pooled analysis showed that ultrasound-guided botulinum toxin type A was associated with moderate improvements in shoulder pain (SMD = -0.96; 95% CI -1.37 to -0.55; P < 0.001), UEFMA score (SMD = 1.43; 95% CI 0.49 to 2.37; P = 0.003), ROM of shoulder flexion (SMD = 1.28; 95% CI 0.63 to 1.93; P < 0.001) and external rotation (SMD = 1.66; 95%CI, 0.83 to 2.48; P < 0.001). Mild improvements were observed in ROM of shoulder abduction (SMD = 0.8; 95%CI 0.18 to 1.43; P = 0.01) and MBI score (SMD = 1.33; 95% CI 0.22 to 2.43; P = 0.02).
Conclusions
Ultrasound-guided BoNT-A injections are beneficial for reducing pain and enhancing the upper limb function, shoulder ROM and quality of life. More high-quality studies with large sample sizes are needed to assess long-term efficacy, strengthening the evidence that ultrasound-guided BoNT-A facilitates the reduction of shoulder pain.