AI-based Rehabilitation for Hip and Knee Surgery Patients

* Study Overview and Randomization This study is conducted as a multi-center, randomized, open-label trial. After providing informed consent and completing baseline assessments, eligible participants are randomly assigned to either the Experimental Group or the Control Group at a 1:1 ratio. The primary focus is to evaluate the recovery of physical mobility through different home-based rehabilitation methods.
* Technical Intervention Protocols The Experimental Group utilizes the "Exercite Rehab" mobile application, which incorporates AI-based computer vision technology. The application recognizes the participant's joint movements in real-time through the device's camera, providing immediate corrective feedback on exercise posture and automatically logging the completion of prescribed routines. In contrast, the Control Group follows the same clinical exercise protocol using traditional printed educational materials. Participants in this group manually record their daily exercise performance in a provided physical logbook.
* Longitudinal Monitoring and Follow-up Following the initial in-hospital education session, participants transition to a 12-week home-based phase. Research personnel conduct remote monitoring at specific intervals (Weeks 4 and 8) to ensure safety, assess exercise adherence, and track symptomatic changes via telephone or the application's monitoring dashboard. A final face-to-face clinical evaluation is performed at Week 12 to determine the overall efficacy of the intervention compared to the conventional method.

• Exersite Rehab (AI-based Mobile Application) (Device), also known as AI-based Home Rehabilitation System, Digital Therapeutics for Orthopedic Recovery: The "Exersite Rehab" is an AI-driven digital healthcare solution designed for post-operative rehabilitation. It utilizes computer vision technology to track the patient's skeletal movements in real-time through a smartphone camera. During the 12-week program, the device provides personalized exercise protocols, real-time posture correction, and automatic repetition counting to ensure safe and effective home-based rehabilitation for patients after hip or knee surgery.
• Printed Educational Brochure (Traditional Rehabilitation) (Behavioral), also known as Standard Care, Conventional Rehabilitation, Brochure-based Exercise Group, Traditional Home-based Exercise: Participants in the control group will receive traditional printed educational brochures containing standardized post-operative exercise protocols for hip or knee surgery. These brochures include step-by-step illustrations and written instructions for home-based rehabilitation exercises. Participants are instructed to perform the prescribed exercises independently for 12 weeks, following the same schedule and frequency as the experimental group, but without the AI-based real-time feedback or digital monitoring.

Primary outcomes

• Timed Up and Go (TUG) test [Baseline (Pre-operation) and POD 12 weeks]: The TUG test measures the time (in seconds) taken by a participant to stand up from a chair, walk 3 meters, turn around, walk back, and sit down. It is used to assess mobility, balance, and fall risk. (Note: For hip fracture patients, the baseline is measured at POD 1 week instead of pre-op.)

Secondary outcomes

• Functional Ambulation Category (FAC) [Baseline (Pre-op), POD 1 week, POD 4 weeks, POD 8 weeks, and POD 12 weeks]: Functional ambulation status assessed on a scale of 0 (non-ambulatory) to 5 (independent).
• Gait Analysis [Geometry] [Baseline (Pre-op), POD 1 week, and POD 12 weeks]: Evaluation of spatial parameters including Step length (Lt/Rt), Stride length, and Step width. • Unit of Measure: Centimeters (cm)
• Gait Analysis [Phase] [Baseline (Pre-op), POD 1 week, and POD 12 weeks]: Assessment of the percentage distribution of gait phases: Stance phase (Lt/Rt), Swing phase (Lt/Rt), and Double stance phase. • Unit of Measure: Percentage (%)
• Gait Analysis [Timing (Cadence)] [Baseline (Pre-op), POD 1 week, and POD 12 weeks]: Evaluation of temporal gait parameters focusing on cadence. It measures the number of steps taken per minute (steps/min) using a gait analysis system. • Unit of Measure: Steps per minute
• Gait Analysis [Timing (Velocity)] [Baseline (Pre-op), POD 1 week, and POD 12 weeks]: Evaluation of temporal gait parameters focusing on velocity. It measures the participant's walking speed (km/h) using a gait analysis system. • Unit of Measure: Kilometers per hour (km/h)
• Range of Motion (ROM) [Baseline (Pre-op), POD 1 week, and POD 12 weeks]: Passive and active joint angles (flexion, extension, etc.) of the hip or knee measured by a goniometer.
• Manual Muscle Test (MMT) [Baseline (Pre-op), POD 1 week, and POD 12 weeks]: Assessment of muscle strength around the hip or knee joint using a scale from 0 (no muscle contraction) to 5 (normal strength).
• Berg Balance Scale (BBS) [Baseline (Pre-op), POD 1 week, and POD 12 weeks]: A 14-item objective measure designed to assess static balance and fall risk. Total score ranges from 0 to 56.
• Physical Function (Harris Hip Score [HHS]) [Baseline (Pre-op), POD 1 week, and POD 12 weeks]: A clinician-based assessment used to evaluate hip function. The score ranges from 0 to 100, where higher scores indicate better functional outcomes and less pain. • Unit of Measure: Units on a scale
• Physical Function (Knee Society Score [KSS]) [Baseline (Pre-op), POD 1 week, and POD 12 weeks]: : A clinician-based assessment used to evaluate knee function and patient satisfaction. The score ranges from 0 to 100, where higher scores indicate better clinical outcomes and improved knee function. • Unit of Measure: Units on a scale
• Physical Function (Western Ontario and McMaster Universities Osteoarthritis Index [WOMAC]) [Baseline (Pre-op), POD 1 week, and POD 12 weeks]: A self-reported questionnaire used to evaluate the condition of patients with osteoarthritis. The score ranges from 0 to 96, where lower scores indicate better outcomes (less pain, stiffness, and physical limitation). • Unit of Measure: Units on a scale
• Pain (NRS(Numeric Rating Scale)) [Baseline (Pre-op), POD 1 week, POD 4 weeks, POD 8 weeks, and POD 12 weeks]: Patient-reported pain intensity on a scale from 0 (no pain) to 10 (the most severe pain imaginable).
• Quality of Life (Short Form-36 [SF-36]) [Baseline (Pre-op), POD 1 week, and POD 12 weeks]: A self-reported questionnaire (Short Form-36 \[SF-36\]) used to evaluate health-related quality of life, covering both physical and mental health domains. The score for each domain ranges from 0 to 100, where higher scores indicate a better quality of life and better health status. • Unit of Measure: Units on a scale
• Muscle Strength (Handgrip Strength) [Baseline (Pre-op) and POD 12 weeks]: Assessment of maximum voluntary contraction using a digital hand dynamometer. Higher values indicate better muscle strength. • Unit of Measure: Kilograms (kg)
• Physical Performance (Short Physical Performance Battery [SPPB]) [Baseline (Pre-op) and POD 12 weeks]: A standardized assessment including gait speed, chair stand test, and balance tests. The total score ranges from 0 to 12, where higher scores indicate better physical performance and mobility. • Unit of Measure: Units on a scale
• Body Composition (Bioelectrical Impedance Analysis [BIA]) [Baseline (Pre-op) and POD 12 weeks]: Evaluation of body composition, specifically focusing on skeletal muscle mass, using a Bioelectrical Impedance Analysis (BIA) device. This assessment measures the electrical impedance of body tissues to estimate muscle mass. Higher values indicate a greater amount of muscle mass. • Unit of Measure: Kilograms (kg)

Sex: All, ages: 19 Years to any

Inclusion Criteria:

* Adult patients aged 19 years or older.
* Patients scheduled to undergo hip or knee arthroplasty at Gangnam Severance Hospital or affiliated hospitals of Chung-Ang University Medical Center (Chung-Ang University Hospital, Gwangmyeong Hospital, Hyundai Hospital).
* Patients with a preoperative Functional Ambulatory Category (FAC) stage of 4 or 5 (For hip fracture cases, pre-fracture FAC stage will be considered).
* Patients capable of downloading and using mobile applications on smart devices (smartphones or tablets) independently without researcher assistance.
* Patients who fully understand the study's purpose and procedures and have voluntarily signed the informed consent form.

Exclusion Criteria:

* Individuals unable to perform exercises due to severe musculoskeletal pain.
* Individuals with severe dizziness or poor vision that prevents them from following exercise videos provided by the digital treatment.
* Individuals with visual impairment that causes difficulty in recognizing the monitor/device screen.
* Individuals requiring long-term inpatient treatment due to unstable vital signs.
* Individuals with partial or total lower-limb amputation due to trauma, disease, or congenital defects.
* Individuals classified as vulnerable subjects (as defined by clinical research ethics guidelines).
* Any other individuals deemed ineligible for participation at the discretion of the principal investigator.

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