Can we decrease the duration of basal thumb joint distraction for early osteoarthritis from 8 to 6 weeks? Study protocol for a non-inferiority randomized controlled trial

BACKGROUND: To our knowledge, to date, 52 patients with thumb carpometacarpal osteoarthritis (CMC1 OA) were treated with joint distraction. So far, most patients experienced improved physical function and less pain. After 2 years, only 1 patient proceeded to trapeziectomy. This study assesses if we can safely lower the distraction duration from 8 to 6 weeks for CMC1 joint distraction, maintaining the improvement in physical function and pain. METHODS: This is a monocenter randomized controlled non-inferiority trial that includes patients younger than 65 years of age with ongoing symptoms of CMC1 OA and an established indication for surgery. All patients will be treated with CMC1 joint distraction. The primary outcome is to assess whether 6 weeks of joint distraction is not inferior to 8 weeks in terms of physical function at 1 year after surgery. Secondary outcomes will identify differences between groups at 1 year in pain intensity, patient satisfaction, hand health status, adverse event rates, treatment failure, differences in thumb strength and range of motion, and radiographic changes. DISCUSSION: If safe, the duration of basal thumb joint distraction can be reduced to 6 weeks, reducing patient burden. Because this is a relatively new treatment, this trial will provide greater knowledge of potential adverse events. This knowledge allows for more informed decision making for patients considering CMC1 distraction treatment. Future studies can directly compare joint distraction to other treatments of CMC1 joint arthritis like splinting and trapeziectomy. TRIAL REGISTRATION: Central Committee on Research Involving Human Subjects (CCMO), NL68225.100.18; registered on 9 August 2019. Medical Research Ethics Committees United (MEC-U), R19.003; registered on 9 August 2019. Netherlands Trial Register, NL8016; registered on 15 September 2019. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s13063-021-05283-9.