Long-Term Study of CartiPRO for Knee Pain Due to Osteoarthritis or Cartilage Damage

This clinical trial aims to evaluate and compare the efficacy and safety of CartiPRO, an approved intra-articular atelocollagen injection, versus Synovian injection for the relief of knee pain in patients with knee osteoarthritis. The investigational device is administered intra-articularly, with a second injection given 24 weeks after the first dose. Primary and secondary endpoints include changes in pain scores (VAS), functional assessments (WOMAC, SF-36), and safety evaluations over a 36-week period.

Inclusion Criteria * Age 19 years and older * Diagnosed with unilateral or bilateral knee osteoarthritis according to American College of Rheumatology (ACR) criteria, with at least 3 of the following 6 features: * Age ≥50 years * Morning stiffness \7%) * Surgical procedures (including arthroscopy) on target knee within 1 year (surgery on contralateral knee or hip may be exclusionary if it could affect target knee assessment) * Intra-articular corticosteroid injection into target knee within 12 weeks * Systemic corticosteroid use within 4 weeks (topical and inhaled corticosteroids permitted) * Surgery or radiation therapy to knee joint within 12 weeks, or not fully recovered from side effects * Immunosuppressive therapy (e.g., Cyclosporine A, Azathioprine) within 6 weeks * Intra-articular injections (e.g., hyaluronic acid) into knee joint within 6 months * Prohibited concomitant medications within 2 weeks (unless washout period is adequate) * Anticoagulants (e.g., warfarin, NOACs), antiplatelet agents (e.g., aspirin \>100 mg/day, clopidogrel; low-dose aspirin ≤100 mg/day permitted), thrombolytic agents (e.g., urokinase, alteplase), or Vitamin E \>1000 IU/day within 2 weeks (unless adequate washout) * Habitual use (≥3 months) of psychoactive drugs or narcotic analgesics that may affect pain perception * History of cell therapy or gene therapy to target joint * Planned cell therapy or gene therapy to target joint * Abnormal laboratory values at screening: * ALT, AST, BUN, or serum creatinine \>2× upper limit of normal * Engaged in high-intensity aerobic or heavy anaerobic exercise that may affect the knee joint * Dermatological disease at injection site or site deemed unsuitable for injection * Ligament instability of Grade II or higher in target knee (Grade 0: none; Grade I: 0-5 mm; Grade II: 5-10 mm; Grade III: \>10 mm) * Known hypersensitivity to investigational product or its components * Pregnant or breastfeeding women * Women or men of childbearing potential unwilling to use acceptable contraception during study (acceptable methods: intrauterine device, tubal ligation, sterilization surgery, condom or diaphragm with spermicide, natural family planning) * Participation in another clinical trial within 4 weeks * Cognitive impairment or dementia preventing informed consent * Any other condition that makes the subject unsuitable for study participation per investigator judgment