The Effect of Therapeutic Exercise on Cartilage Morphology and Physical Function for Individuals at High Risk of Knee Osteoarthritis

Background: Degenerative meniscus tears are common in individuals over 35 and are associated with early stages of knee osteoarthritis (OA) (1,2). Metabolic and microstructural changes within the cartilage occur before surface breakdown, which can now be detected using advanced MRI techniques such as T2 mapping. Exercise therapy, specifically progressive resistance and aerobic exercises, has shown benefits for knee OA patients, but its effects on early cartilage degeneration are poorly understood.

Objective: The primary objective of this study is to determine the efficacy of PRE and aerobic exercises on the metabolic function and microstructure of cartilage in individuals with degenerative meniscus tears but without radiographic evidence of knee OA. Secondary objectives include evaluating the impact of these exercises on clinical outcomes, such as pain, disability, and physical function, and assessing the feasibility of recruitment and retention for a larger trial.

Methods: The study will enroll 54 participants, who will be randomized into three groups: PRE, aerobic exercise, and control. Each group will undergo a 3-month supervised exercise program. MRI scans will be used to measure changes in cartilage composition, while clinical outcomes will be assessed using patient-reported and performance-based measures.

Intervention Groups:

Group 1 (PRE): Participants will perform progressive resistance exercises focusing on strengthening the quadriceps. The exercises will be adjusted based on the Daily Adjustable Progressive Resistance Exercise (DAPRE) technique.

Group 2 (Aerobic Exercise): Participants will engage in aerobic exercise sessions using a stationary bike, aimed at improving cardiovascular fitness and knee joint mobility.

Group 3 (Control): Participants will receive standard of care, including general strength and balance exercises as per current clinical guidelines.

Assessments:

MRI Imaging: Advanced MRI techniques (T2 mapping) will be used at baseline and after 3 months to assess changes in cartilage composition.

Clinical Outcomes: Patient-reported outcomes will include the Knee Injury and Osteoarthritis Outcome Score (KOOS) and the International Knee Documentation Committee (IKDC) score. Performance-based outcomes will include the single-leg squat, single-leg hop test, sit-to-stand on a one-foot test, step-up test, and Bruce treadmill test.

Inclusion Criteria:

Adults aged 35-55 years Symptomatic degenerative medial meniscus tears. No radiographic evidence of knee OA (Kellgren-Lawrence grade 0-1). Ability to provide informed consent. Willingness to participate in the exercise intervention.

Exclusion Criteria:

Existing diagnosis of knee OA (Kellgren-Lawrence grade 2 or higher). Repairable meniscus injuries or prior meniscus repair. Previous knee surgery or significant knee injury within the past 6 months. Presence of inflammatory arthritis or other significant comorbidities. Contraindications to MRI or inability to participate in exercise programs.

Study Outcomes:

Primary Outcomes: Changes in T2 relaxation times in the cartilage, indicating alterations in cartilage composition and health.

Secondary Outcomes: Improvements in clinical outcomes, including pain, disability, and physical function as measured by KOOS, IKDC, and performance-based tests.

Feasibility Metrics: Recruitment rates, adherence to the exercise program, and retention rates over the study period.

Analysis: A mixed ANOVA will be used to compare changes in outcomes between groups, with adjustments for multiple comparisons. Baseline characteristics will be compared using t-tests and chi-square tests.

• Single leg hop test for a distance [Срок оценки: Baseline, 6-week, immediately post-intervention, 6-month, 9-month, and 5 years follow-ups.]
• Single Leg Squat Test [Срок оценки: Baseline, 6-week, immediately post-intervention, 6-month, 9-month, and 5 years follow-ups.]
• The Timed Stair Climbing Test (SCT) [Срок оценки: Baseline, 6-week, immediately post-intervention, 6-month, 9-month, and 5 years follow-ups.]
• The Single Leg Chair Rise (SLCR) test [Срок оценки: Baseline, 6-week, immediately post-intervention, 6-month, 9-month, and 5 years follow-ups.]
• Maximal voluntary isometric contraction test [Срок оценки: Baseline, 6-week, immediately post-intervention, 6-month, 9-month, and 5 years follow-ups.]
• The Modified Bruce Treadmill Testing Protocol [Срок оценки: Baseline, 6-week, immediately post-intervention, 6-month, 9-month, and 5 years follow-ups.]
• International Knee Documentation Committee Subjective Knee Form (IKDC) [Срок оценки: Baseline, 6-week, immediately post-intervention, 6-month, 9-month, and 5 years follow-ups.]
• The Knee injury and Osteoarthritis Outcomes Score (KOOS) [Срок оценки: Baseline, 6-week, immediately post-intervention, 6-month, 9-month, and 5 years follow-ups.]