Digitally Supported Short-Term Prehabilitation Before Total Knee Replacement

Prehab2Rehab: Digitally Supported Short-Term Prehabilitation Before Total Knee Replacement - A Randomized Controlled Feasibility Trial

This study evaluates the feasibility of a short-term, digitally supported prehabilitation program for patients scheduled for elective total knee replacement (TKR). Osteoarthritis is a leading cause of disability, and recovery following TKR remains heterogeneous, with a substantial proportion of patients experiencing delayed functional recovery. Prehabilitation may improve perioperative outcomes, but its implementation is often limited by short preoperative time windows.

The Prehab2Rehab-KneeTEP trial is a single-center, two-arm, randomized controlled feasibility study conducted in Austria. Patients will be randomized (1:1) to either a multimodal video-supported prehabilitation program or usual care. The intervention consists of a 10 to 14-day preoperative exercise program including strength, endurance, coordination, and gait training, supported by a digital application, and is complemented by a digitally supported transition phase after hospital discharge until the start of inpatient rehabilitation.

The primary objective is to assess feasibility in terms of recruitment, retention, adherence, fidelity, acceptability, and safety. Secondary exploratory outcomes include clinical recovery indicators, functional performance, and patient-reported outcomes assessed across the perioperative pathway.

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

Inclusion Criteria:

Eligibility will be determined during the outpatient consultations at the Medical

Center in Bad Vigaun. Patients will be screened against the following criteria:

• Age ≥18 years at the time of enrolment.
• Clinically diagnosed with advanced osteoarthritis and with a medical indication for elective TKR.
• Either a scheduled surgery or a documented intention to undergo TKR within the recruitment period.
• Elective surgery is scheduled for at least 14 days after enrolment to allow completion of the 10 to 14-day prehabilitation intervention.
• Physical ability to safely perform the prescribed exercise program, as confirmed by the treating physician.
• Willingness to participate in a digitally supported training intervention at either the center or home-based.
• Sufficient digital literacy and access to internet-enabled devices (smartphone, tablet, or computer).
• Adequate German language proficiency to follow exercise instructions and study procedures.

Exclusion Criteria:

Patients will be excluded if any of the following apply:

• Pregnancy at the time of enrolment.
• Emergency, revisional, or non-elective surgery.
• Surgery scheduled less than 14 days after enrolment.
• Severe physical impairment or medical contraindication to exercise training (e.g., unstable cardiovascular disease, uncontrolled hypertension, acute musculoskeletal injury).
• Patients with contraindications outlined in the Medizinisches Leistungsprofil (MLP) 2.0 that preclude rehabilitation and/or surgery.
• Participation in another clinical study that could interfere with the intervention or study outcomes.