Posttraumatic osteoarthritis after athletic knee injury: A narrative review of diagnostic imaging strategies.

Intraarticular knee injuries and subsequent posttraumatic arthritis (PTOA) are common in athletes. Unfortunately, PTOA may significantly affect performance and overall function, but this condition remains difficult to characterize. In this review, we provide an overview of imaging modalities used to evaluate PTOA among athletes and physically active individuals following knee injury, with the goal to discuss the strengths and limitations of their application in this population. A literature search was performed to identify clinical studies focusing of knee injuries in athletes and athletic persons, specifically using imaging for diagnosis or monitoring disease progression. A total of 81 articles were identified, and 23 were included for review. Studies on plain radiographs (n = 8) and magnetic resonance imaging (MRI) assessed arthritic burden (n = 13), with MRI able to depict the earliest cartilage changes. Few studies (n = 2) leveraged ultrasound. Challenges persist, particularly regarding standardization and reliability across different radiographic grading systems. Additionally, further research is needed to establish the clinical significance of techniques to assess cartilage composition on MRI, including ultrashort echo-time enhanced T2*, T1rho and T2 imaging. Addressing these challenges through standardized protocols and intensified research efforts will enhance the diagnostic utility of imaging modalities in musculoskeletal medicine and enable high-quality prospective studies.