Early Diagnosis and Biomarker Advances in Post-Traumatic Osteoarthritis after Knee Joint Injury

Post-traumatic osteoarthritis (PTOA) is a common long-term consequence of knee joint injuries, particularly those involving the anterior cruciate ligament (ACL), meniscus and cartilage. It can develop in relatively young individuals and progressively impair joint function and quality of life. However, conventional imaging methods, particularly X-ray, have limited sensitivity to early biochemical and soft-tissue changes. This review examines current approaches to the early detection and treatment of PTOA, with particular emphasis on imaging techniques and biomarkers. X-ray and ultrasound can provide useful information about structural changes, but their ability to detect early disease is limited by their sensitivity, anatomical coverage and operator dependence. Biomarkers may provide earlier evidence of cartilage degradation, tissue remodelling and inflammation. Catabolic biomarkers such as C2C, CTX-II and COMP, anabolic biomarkers such as NTX-1, and inflammatory biomarkers including IL-6, IL-7, IL-8 and TNF have shown potential, although their clinical value remains inconsistent. Current treatments targeting inflammation and chondrocyte apoptosis may help slow disease progression, but limitations including side effects and poor drug retention remain. Future research should combine imaging with blood or synovial-fluid biomarkers, standardise diagnostic methods, establish clinically meaningful thresholds and validate multi-biomarker panels through large-scale longitudinal studies. Earlier identification of high-risk patients may allow intervention before irreversible joint damage occurs.