Provision of knee bracing for knee osteoarthritis (PROP OA): multicentre, parallel group, superiority, statistician blinded, randomised controlled trial

Objective To determine whether adding compartment specific knee bracing with an adherence intervention to advice, written information, and exercise instruction (AIE+B) is superior to advice, written information, and exercise instruction (AIE) only in improving patient reported outcomes in people with knee osteoarthritis.

Design Multicentre, parallel group, superiority, statistician blinded, randomised (1:1; block; stratified; centralised web based) controlled trial.

Setting Recruitment through general practices and the community in Cheshire, Manchester, North Tyneside, and Staffordshire, England; enrolment 25 November 2019 to 16 September 2022.

Participants 466 adults aged ≥45 years with symptoms of knee osteoarthritis.

Interventions AIE was delivered in one in-person consultation by a trained physiotherapist. Individuals randomised to the AIE+B group were also fitted with a patellofemoral, tibiofemoral unloading, or neutral stabilising knee brace, according to their predominant compartmental distribution of knee osteoarthritis, and were offered a two week follow-up consultation. Brief motivational interviewing with targeted text reminders supported brace adherence.

Main outcome measures The primary outcome was a composite patient reported Knee Osteoarthritis Outcomes Score (KOOS)-5 (0-100) at six months after randomisation. Key secondary outcomes were KOOS-5 at three and 12 months, KOOS-5 subscale scores, and pain on weight bearing activity at three, six, and 12 months.

Results 466 participants (mean age 64 (standard deviation 9) years; 46% female participants) were randomised, with 401 (86%), 394 (85%), and 370 (79%) participants followed up with analysable data at three, six, and 12 months, respectively. At six months, greater improvement in KOOS-5 was seen in the AIE+B group than in the AIE group (adjusted mean difference 3.39, 95% confidence interval (CI) 0.96 to 5.82; effect size 0.24). Secondary outcomes showed the benefits of AIE+B over AIE that diminished over time. The largest effects observed were for pain reduction (KOOS pain (0-100) adjusted mean difference at six months 6.13, 95% CI 3.36 to 8.91; effect size 0.39). Adverse events were minor and expected.

Conclusions Adding compartment specific knee bracing and an adherence intervention to advice, written information, and exercise instruction resulted in small improvements in patient reported outcomes among individuals with knee osteoarthritis. This safe intervention offers a potential treatment option for this common condition.

Trial registration ISRCTN28555470.