Targeting rehabilitation to improve outcomes after total knee arthroplasty in patients at risk of poor outcomes: randomised controlled trial

OBJECTIVE To evaluate whether a progressive course of outpatient physiotherapy offers superior outcomes to a single physiotherapy review and home exercise based intervention when targeted at patients with a predicted poor outcome after total knee arthroplasty. DESIGN Parallel group randomised controlled trial. SETTING 13 secondary and tertiary care centres in the UK providing postoperative physiotherapy. PARTICIPANTS 334 participants with knee osteoarthritis who were defined as at risk of a poor outcome after total knee arthroplasty, based on the Oxford knee score, at six weeks postoperatively. 163 were allocated to therapist led outpatient rehabilitation and 171 to a home exercise based protocol. INTERVENTIONS All participants were reviewed by a physiotherapist and commenced 18 sessions of rehabilitation over six weeks, either as therapist led outpatient rehabilitation (progressive goal oriented functional rehabilitation protocol, modified weekly in one-one contact sessions) or as physiotherapy review followed by a home exercise based regimen (without progressive input from a physiotherapist). MAIN OUTCOME MEASURES Primary outcome was Oxford knee score at 52 weeks, with a 4 point difference between groups considered to be clinically meaningful. Secondary outcomes included additional patient reported outcome measures of pain and function at 14, 26, and 52 weeks post-surgery. RESULTS 334 patients were randomised. Eight were lost to follow-up. Intervention compliance was more than 85%. The between group difference in Oxford knee score at 52 weeks was 1.91 (95% confidence interval -0.18 to 3.99) points, favouring the outpatient rehabilitation arm (P=0.07). When all time point data were analysed, the between group difference in Oxford knee score was a non-clinically meaningful 2.25 points (0.61 to 3.90, P=0.01). No between group differences were found for secondary outcomes of average pain (0.25 points, -0.78 to 0.28, P=0.36) or worst pain (0.22 points, -0.71 to 0.41, P=0.50) at 52 weeks or earlier time points, or of satisfaction with outcome (odds ratio 1.07, 95% confidence interval 0.71 to 1.62, P=0.75) or post-intervention function (4.64 seconds, 95% confidence interval -14.25 to 4.96, P=0.34). CONCLUSIONS Outpatient therapist led rehabilitation was not superior to a single physiotherapist review and home exercise based regimen in patients at risk of poor outcomes after total knee arthroplasty. No clinically relevant differences were observed across primary or secondary outcome measures.