Effects of Ultrasound-Guided Administration of Botulinum Toxin (IncobotulinumtoxinA) in Patients with Lateral Epicondylitis.

How effective and safe are incobotulinumtoxinA injections in adult patients with lateral epicondylitis refractory to other treatments? In this experimental study, ultrasound-guided incobotulinumtoxinA 10⁻30 U/muscle was injected into extensor carpi ulnaris, extensor digiti minimi, extensor digitorum longus and extensor carpi radialis brevis muscles. Pain (visual analogue scale [VAS], 0 to 10 [no pain to severe pain]) and upper-limb functionality (QuickDASH scale, 0 to 100 [best to worst]), assessed at baseline, 1, 3 and 6 months post-treatment, were analysed using repeated-measures analysis of variance (ANOVA) and Tukey post-hoc tests. Secondary analyses stratifying patient population by sex and baseline VAS were performed. Adverse events were reported. Twenty-four patients (mean [standard deviation] age 46.8 years) were included. Compared with baseline, mean VAS and QuickDASH scores improved at all follow-ups (p < 0.001 and p = 0.001, respectively; repeated-measures ANOVA). Secondary analyses revealed significant differences between baseline and all follow-ups in the group with baseline VAS ≥ 6 and in males and females (all p < 0.05, Tukey post-hoc test). No adverse events, except for the expected third finger weakness, were reported. In conclusion, ultrasound-guided incobotulinumtoxinA injections may be an effective treatment for lateral epicondylitis in the appropriate patient population.