A Device for Prehabilitation of Total Knee Replacement Surgery (Slider): Usability Study (Preprint)

Abstract

BACKGROUND Rehabilitation is widely promoted as beneficial before (“prehabilitation”) and after knee replacement surgery. However, the demand for this service has outstripped the supply in recent years. The Covid 19 pandemic exacerbated this mismatch leading to increased use of web or app-based videos and wearables in an attempt to compensate for a lack of in-person sessions. Problems with these non-guided techniques include usability, objective tracking of patient engagement, the need for calibration/special positioning, and complications arising from contact with the user’s skin. In this study, we evaluate the usability of a simple low contact device (Slider®) which gamifies and objectively measures prehabilitation exercises. OBJECTIVE This real-world validation study measured the usability of the Slider®, a novel device that measures and gamifies engagement in physiotherapy exercises while avoiding contact with the skin of the user’s leg and thigh. METHODS A total of 17 patients on the UK National Health Service (NHS) waiting list for knee replacements at a major teaching hospital were non-randomly chosen. They used the Slider® for two weeks and then completed an online questionnaire on usability and acceptability. RESULTS All participants completed the two-week study, with 76% finding the Slider® easy to learn to use. Satisfaction was reported by 94% of the patients, and all the participants found that the Slider® provided for their pre-operative physiotherapy needs. All agreed that they would use the Slider® again. None of the patients had safety concerns or experienced adverse effects. The study revealed a possible ambiguity in the standard usability questionnaire error recovery evaluation. CONCLUSIONS The study suggests that the Slider® is usable by patients having knee replacements to perform pre-operative physiotherapy exercises in a self-managed manner outside the hospital environment. A more extensive study across a wider demographic is needed to increase confidence in the findings. The usability questionnaire needs to be refined to ensure that findings about error recovery are better understood.