Prehabilitation for frail patients undergoing total hip or knee replacement: protocol for the Joint PREP feasibility randomised controlled trial.

Background: Approximately, 8% of community-based adults aged ≥ 50 years in England are frail. Frailty has been found to be associated with poorer outcomes after joint replacement. Targeting frailty preoperatively via exercise and protein supplementation has the potential to improve outcomes for people undergoing joint replacement. Prior to proceeding with a randomised controlled trial (RCT), a feasibility study is necessary to address key uncertainties and explore how to optimise trial design and delivery.

Methods: The Joint PRehabilitation with Exercise and Protein (Joint PREP) study is a feasibility study for a multicentre, two-arm, parallel group, pragmatic, RCT to evaluate the clinical and cost-effectiveness of prehabilitation for frail patients undergoing total hip or knee replacement. Sixty people who are ≥ 65 years of age, frail according to the self-reported Groningen Frailty Indicator, and scheduled to undergo total hip or knee replacement at 2-3 hospitals in England and Wales will be recruited and randomly allocated on a 1:1 ratio to the intervention or usual care group. The usual care group will receive the standard care at their hospital. The intervention group will be given a daily protein supplement and will be asked to follow a home-based, tailored daily exercise programme for 12 weeks before their operation, in addition to usual care. Participants will be supported through six follow-up calls from a physiotherapist during the 12-week intervention period. Study questionnaires will be administered at baseline and 12 weeks after randomisation. Embedded qualitative research with patients will explore their experiences of participating, reasons for nonparticipation, and/or reasons for withdrawal or treatment discontinuation. Primary feasibility outcomes will be eligibility and recruitment rates, adherence to the intervention, and acceptability of the trial and the intervention.

Discussion: This study will generate important data regarding the feasibility of a RCT to evaluate a prehabilitation intervention for frail patients undergoing total hip and knee replacement. A future phase-3 RCT will determine if preoperative exercise and protein supplementation improve the recovery of frail patients after primary joint replacement.

Trial Registration: ISRCTN11121506, registered 29 September 2022.