Efficacy of Real-Time Feedback Exercise Therapy in Patients Following Total Hip Arthroplasty: Protocol for a Pilot Cluster-Randomized Controlled Trial

Background: Osteoarthritis of the hip joint is an increasing functional and health-related problem. The most common surgicaltreatment is hip replacement to reduce pain and improve function. Rehabilitation after total hip arthroplasty (THA) is not regulatedin Austria and mostly depends on the patient's own initiative and possibilities. Functional deficits, such as valgus thrust of theleg, functional Trendelenburg gait, or Duchenne limp, are characteristic symptoms before and, due to the performance learningeffect prior to surgery, also after the operation. Addressing these deficits is possible through neuromuscular-focused exercisetherapy. The efficacy of such therapy relies significantly on the quality of performance, the frequency of exercise, and the durationof engagement. Enhancing sustainability is achievable through increased motivation and real-time feedback (RTF) on exerciseexecution facilitated by digital feedback systems. Objective: This study will be performed to quantify the medium-term effectiveness of digital home exercise feedback systemson functional performance following THA. Methods: A clinical trial with a cluster-randomized, 2-arm, parallel-group design with an 8-week intervention phase andsubsequent follow-ups at 3 and 6 months postsurgery will be conducted. Feedback during exercising will be provided through ablended-care program, combining a supervised group exercise program with a self-developed digital feedback system for homeexercise. In total, 70 patients will be recruited for baseline. The primary outcome parameters will be the frontal knee range ofmotion, pelvic obliquity, and lateral trunk lean. Secondary outcomes will be the sum scores of patient-reported outcomes andrelevant kinematic, kinetic, and spatiotemporal parameters. Results: The trial started in January 2024, and the first results are anticipated to be published by June 2025. RTF-supportedhome exercise is expected to improve exercise execution quality and therapeutic adherence compared to using paper instructionsfor excise guidance. Conclusions: The anticipated findings of this study aim to offer new insights into the effect of a blended-care programincorporating digital RTF on exercise therapy after unilateral THA, in addition to knowledge on the functional status 3 and 6months postsurgery, for further improvement in the development of rehabilitation guidelines following THA