Toxina botulínica tipo A guiada por ecografía para el dolor de hombro: un metaanálisis de ensayos controlados...

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.

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 four outcome indicators above.

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 large improvements in shoulder pain (SMD = -1.1; 95% CI -1.47 to -0.73; 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).

Our meta-analysis has shown ultrasound-guided BoNT-A injections have potential benefits for reducing shoulder pain and improving upper limb function, range of motion, and quality of life. However, these findings should be interpreted cautiously due to small sample size, measured differences, substantial heterogeneity and possible publication bias. More high-quality studies with large sample size are needed to assess long-term efficacy, strengthening the evidence that ultrasound-guided BoNT-A facilitates the reduction of shoulder pain.