Hand Osteoarthritis in the Elderly: The Prevalence of Articular Cartilage Defects in Radiographically Normal and Affected Joints

Background: Hand osteoarthritis (OA) is a highly prevalent disease that significantly impairs quality of life among many patients. The direct evaluation of cartilage defects associated with OA in vivo is challenging, and indirect assessments using X-ray images are commonly employed. The aim of this study was to evaluate the relationship between X-ray images of finger joints and cartilage defects. Methods: This study included 42 hands from cadavers that were fixed with alcohol and formalin. After X-ray posteroanterior images of all the finger joints were taken, the extent of the cartilage defects was observed macroscopically. On X-ray images, OA was defined as a modified Kellgren–Lawrence scale score of 2 or higher. Histological examinations were performed on several joints with cartilage defects to confirm whether the macroscopic cartilage defects corresponded to the histological cartilage defects. Results: A total of 588 joints were evaluated. On X-ray images, OA was observed in 20.2% of the joints, and cartilage defects were present in 45.1%. Among joints with cartilage defects, the prevalence of joints without radiographic OA was 55.1%. On the other hand, 31.1% of joints without radiographic OA had cartilage defects. Cartilage defects were identified in all joints with radiographic OA. Conclusions: The use of X-ray images to evaluate OA is beneficial; however, when interpreting radiographic OA, it is important to note that early or partial OA may not be detectable. Additionally, when OA findings are present on X-ray images, cartilage defects are always present.