High dose soft orthosis for thumb carpometacarpal osteoarthritis in addition to best practice usual care: A...

Carpometacarpal osteoarthritis (CMC OA) is a common problem in mid-older aged adults. Existing guidelines are ambiguous with respect to materials, design and duration of use of orthoses to manage hand OA. A limitation of studies to date is the low dose (hours per day) of orthosis wearing. This study aimed to evaluate the feasibility of investigating the effectiveness of a soft prefabricated orthosis worn at high dose in conjunction with best practice usual care for CMC OA.

Study design: Pragmatic, 2-arm parallel-group feasibility RCT. Adults aged ≥40 years with symptomatic CMC OA were randomised to either best practice usual care or usual care in conjunction with a soft neoprene orthosis prescribed to wear 20 h per day, for 4 weeks. A priori feasibility criteria were: (1) enrolment of 30 participants in 4 months; (2) retention >85% at 6 months; (3) intervention adherence on >80% days; (4) interventions acceptable >90% of participants. Outcome measures were collected at baseline, 4 weeks, and 6 months; analysis used descriptive statistics.

Thirty participants were enrolled within 4 months; 97% retained at 6 months. Orthosis wearing achieved ≥20 h on 68% of days. Exercise adherence was 80% on ≥89% of days in both groups. Interventions were acceptable. Clinically significant improvements in pain occurred in both groups.

High dose orthosis wearing may be acceptable and feasible for managing CMC OA. Orthosis amendments and a wear target of 18 h are recommended for future investigation of this intervention.