Determining the feasibility of a full-scale randomised controlled trial evaluating rehabilitation for people after acute patellar dislocation

After an acute patellar dislocation, patients are routinely referred for exercise-based rehabilitation to help them recover. Despite this, no high-quality evidence exists to inform rehabilitation practice and patient outcomes vary. A full-scale randomised controlled trial (RCT) evaluating different rehabilitation interventions is needed to inform clinical practice. This thesis aimed to determine if conducting this full-scale RCT was feasible. First, supervised (four to six physiotherapy sessions of tailored advice and exercise) and self-managed (one physiotherapy session that enabled self-management) rehabilitation interventions were developed, drawing on established intervention development approaches and frameworks. Next, because there is no consensus on what outcomes should be measured in trials in this area, a systematic review of outcomes reported in patellar dislocation trials was conducted to inform outcome selection for the full-scale RCT. This identified 69 RCTs that used 141 unique outcomes, 42 different patient-reported outcome measures, and variable outcome measurement timepoints. To investigate the full-scale RCT’s feasibility, a multicentre parallel-group external pilot RCT that compared supervised versus self-managed rehabilitation was conducted. Fifty participants aged ≥14 years with an acute first-time or recurrent patellar dislocation were recruited and randomised 1: 1 to the interventions. Follow-up was three, six, and nine months after randomisation. Quantitative feasibility outcome results were 1.) willingness of eligible patients to be randomised: 57% (95% confidence interval (CI) 46% to 67%), 2.) recruitment rate: mean 1.4 (95% CI 0.6 to 1.8) participants per site per month, 3.) nine-month retention: 62% (95% CI 48% to 74%), and 4.) proportion of supervised rehabilitation participants that attended ≥4 physiotherapy sessions and self-managed rehabilitation participants that attended ≥1 session: 72% (95% CI 58% to 83%). An embedded qualitative study, involving semi-structured interviews with nine pilot RCT participants, found that the experience of patellar dislocation recovery was conveyed through the themes ‘coming to terms with the initial injury’ and ‘regaining my former self’. Findings also indicated that the pilot RCT interventions and follow-up methods were seen as acceptable, though there was some variation. This suggests that the low retention may have been for reasons other than the outcome measurement instruments and follow-up methods used. The main finding of this thesis was that a full-scale RCT evaluating rehabilitation is feasible. However refinements are necessary, particularly to improve retention. These refinements should be informed by wider stakeholder consultation.