Introducing a specified on-line multimodal prehabilitation approach for total knee replacement surgery candidates using data from the COVID-19 pandemic: An exploratory field-based, pre-post, mixed methods implementation pilot study.

Rationale: Individuals waiting for total-knee-replacement surgery are at risk of developing morbidities and frailty which may affect their postoperative recovery. Multi-modal prehabilitation could mitigate these unintentional effects.

Aims and objectives: To implement and evaluate a specified online multi-modal prehabilitation intervention in patients waiting for total-knee-replacement surgery in a large urban acute hospital trust.

Method: A non-randomised, pre/post analysis implementation pilot with a nested qualitative study was conducted and is reported following the standards for implementation studies (StaRI) guidance. Of 35 listed cases, 12 (34%) were eligible, recruited, and completed an 8-week multi-modal online intervention incorporating 5 modalities (i) cardiovascular exercise, (ii) strength/balance function, (iii) smoking cessation, (iv) opioid use, (v) nutritional intake. Interventions were specified using the Rehabilitation Treatment Specification System, where rehabilitation treatment theory accounts for discrete treatment components. Two participated in an online qualitative interview post-intervention. Process evaluation included intervention fidelity, eligibility/recruitment/retention rates, and clinical outcomes included knee function, frailty, gait velocity, anxiety/depression, and quality of life.

Results: Five participants (42%) completed the intervention and were retained at follow-up. The intervention was delivered online at specified doses, frequency/durations indicative of high respective adherence, quantity, and exposure fidelity. There was significant improvement in median oxford knee score (p = 0.015), gait velocity (p = 0.040) and anxiety (p = 0.023). The interview revealed 5 themes; surgery preconceptions, motivation, acceptability, postoperative experiences, and future recommendations confirming acceptance of the intervention by virtue of adhering to the treatment exposure delivered as planned.

Conclusion: The specified multi-modal prehabilitation was acceptable, implementable, and demonstrated evidence of preliminary efficacy. Further experimental pilot work that represents the spectrum of frailty, obesity, quality of life, and comorbidities associated with total-knee-replacement surgery is indicated.