Intra-articular botulinum toxin A injection for painful base-of-thumb osteoarthritis: a double-blind, randomised, controlled, phase 3 trial (RHIBOT)

SummaryBackground Intra-articular botulinum toxin A injection might have analgesic effects in patients with joint diseases. We aimed to compare the of intra-articular those saline for painful base-of-thumb osteoarthritis. Methods RHIBOT was a double-blind, randomised, controlled, phase 3 trial conducted at Cochin Hospital, Paris, France. recruited adult x-ray evidence trapeziometacarpal osteoarthritis who fulfilled 1990 American College Rheumatology criteria hand and reported pain intensity score least 30 on an 11-point numeric rating scale (0: no 100: maximal pain). Participants were randomly assigned (1:1), using computer-generated randomisation list permuted blocks variable size (4 or 6), receive ultrasound-guided either (50 Allergan units) 1 mL (experimental group) alone (control joint, addition custom-made rigid splinting. The primary outcome mean change from baseline previous 48 h months after injection, analysed by intention treat. This study is registered ClinicalTrials.gov, NCT03187626. Findings Between Nov 2, 2018, 3, 2020, we assessed 370 individuals eligibility 60 (16%) participants (mean age 64·9 years [SD 9·4], 47 [78%] women 13 [22%] men), whom (50%) experimental group control group. At baseline, 60·0 100·0 (SD 15·9). months, reduction –25·7 (95% CI –35·5 –15·8) –9·7 (–17·1 –2·2) (absolute difference –16·0 [–28·1 –3·9]; p=0·043). Overall, 51 adverse events both groups: 27 (53%) 24 (47%) During follow-up, 14 two (7%) mild transient motor deficit thenar muscle. No serious reported. Interpretation Botulinum could be considered as fast-acting, therapy targeting chronic Future studies are needed investigate potential mechanism observed this trial, replicate our findings, assess repeated injections over time their clinical effectiveness, including analysis cost-effectiveness. Funding Assistance Publique-Hôpitaux de Paris.