Digitally Supported Short-Term Prehabilitation Before Total Knee Replacement

Total knee replacement (TKR) is an effective treatment for advanced knee osteoarthritis, yet postoperative recovery remains heterogeneous, with a substantial proportion of patients experiencing persistent functional limitations. Prehabilitation has the potential to optimize patients' physical and psychological readiness before surgery. However, in clinical practice, prehabilitation is often constrained by limited time between surgical indication and procedure. Digitally supported interventions may offer a feasible solution to deliver structured programs within short timeframes while supporting continuity of care across the perioperative pathway.

The Prehab2Rehab-KneeTEP trial is a single-center, randomized, two-arm feasibility study conducted at the Medizinisches Zentrum Bad Vigaun, Austria. The study aims to evaluate the feasibility, acceptability, and safety of a short-term, digitally supported prehabilitation intervention in patients scheduled for elective TKR.

Eligible patients with advanced knee osteoarthritis will be randomized in a 1:1 ratio following baseline assessment (PRE1) to either (i) a multimodal video-supported prehabilitation intervention with an additional digitally supported transition phase or (ii) usual care. Randomization will be performed using computer-generated permuted blocks with stratification for sex and baseline functional capacity assessed by the 6-minute walk test.

The intervention consists of a 10 to 14-day prehabilitation phase prior to surgery, including endurance, resistance, coordination, and gait training. The program is delivered through a combination of in-person instruction and home-based training supported by a digital application (aktivplan), which provides structured exercise guidance and enables documentation of adherence. A teleconsultation via a secure video platform (CAATS) is conducted to ensure exercise safety, provide feedback, and support progression. Sensor-based systems may be used for documentation and research-related measurements but are not used for clinical decision-making.

Following surgery and hospital discharge, participants in the intervention group enter a digitally supported transition phase lasting approximately 10 to 14 days until the start of inpatient rehabilitation (REH1). During this period, patients receive low-threshold exercise guidance and educational content via the digital application to support early recovery, maintain mobility, and promote self-efficacy. Participants in both groups receive standard surgical care and standardized inpatient rehabilitation according to institutional and national guidelines.

The total study participation duration is approximately 47 to 61 days, covering prehabilitation, hospital stay, transition, and rehabilitation phases. Outcomes are assessed at predefined time points along the perioperative pathway, including baseline (PRE1), end of prehabilitation (PRE2), hospital discharge, start of rehabilitation (REH1), and end of rehabilitation (REH2).

The primary objective is to assess feasibility across multiple domains, including recruitment, retention, adherence, fidelity, acceptability, usability of digital tools, and safety. Feasibility outcomes will be evaluated descriptively across process, resource, management, and participant engagement domains.

Secondary objectives are exploratory and include the assessment of clinical recovery indicators such as length of hospital stay, complication rate, and readmission rate, as well as patient-reported outcomes, anthropometric and body composition parameters, and functional performance measures. Given the feasibility nature of the trial, analyses will be descriptive and hypothesis-generating, without confirmatory statistical testing.

The findings of this study will inform the design and implementation of a future adequately powered randomized controlled trial evaluating the effectiveness of digitally supported prehabilitation in patients undergoing total knee replacement

• Health Assessment Questionnaire (HAQ) [Срок оценки: Baseline, prehabilitation discharge (10-14 days after baseline, before surgery), rehabilitation admission (3-4 weeks after surgery), rehabilitation discharge (6-8 weeks after surgery).]
• Barthel-Index (BI) [Срок оценки: Baseline (prior to intervention), admission to inpatient rehabilitation (3-4 weeks post-surgery), discharge from inpatient rehabilitation (6-8 weeks post-surgery)]
• Oxford Knee Score (OKS) [Срок оценки: Baseline (prior to intervention) and discharge from inpatient rehabilitation (6-8 weeks post-surgery)]
• Patient Health Questionnaire-4 (PHQ-4) [Срок оценки: Baseline (prior to intervention), after completion of prehabilitation (10-14 days after baseline, prior to surgery), admission to inpatient rehabilitation (3-4 weeks post-surgery), discharge from inpatient rehabilitation (6-8 weeks post-surgery)]
• Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) [Срок оценки: Baseline (prior to intervention), admission to inpatient rehabilitation (3-4 weeks post-surgery), discharge from inpatient rehabilitation (6-8 weeks post-surgery).]
• EuroQol-5 Dimensions-5 Levels (EQ- 5D-5L) [Срок оценки: Baseline (prior to intervention), after prehab intervention (10-14 days post-baseline)), discharge (6-12 days post-surgery), admission to inpatient rehabilitation (3-4 weeks post-surgery), discharge from inpatient rehabilitation (6-8 weeks post-surgery).]
• Rapid Assessment of Physical Activity (RAPA) [Срок оценки: Baseline (prior to intervention), and discharge from inpatient rehabilitation (6-8 weeks post-surgery).]
• Exercise Self-Efficacy Scale (ESES) [Срок оценки: Baseline (prior to intervention), after prehab intervention (10-14 days post-baseline), discharge (6-12 days post-surgery), discharge from inpatient rehabilitation (6-8 weeks post-surgery).]
• Body Fat Mass [Срок оценки: Baseline (prior to intervention) and discharge from inpatient rehabilitation (6-8 weeks post-surgery).]
• Body Lean Mass [Срок оценки: Baseline (prior to intervention) and discharge from inpatient rehabilitation (6-8 weeks post-surgery).]
• Phase Angle [Срок оценки: Baseline (prior to intervention) and discharge from inpatient rehabilitation (6-8 weeks post-surgery).]
• 6-Minute Walk Test (6MWT) [Срок оценки: Baseline (prior to intervention), admission to inpatient rehabilitation (3-4 weeks post-surgery), discharge from inpatient rehabilitation (6-8 weeks post-surgery).]