The natural history of cartilage defects in people with knee osteoarthritis

Abstract

Objectives: Cartilage defects are highly prevalent in subjects with knee osteoarthritis (GAl. Although they are associated with increased cartilage lass and Joint replacement, there is little data on the natural history of cartilage defects. The aim of Ihis study was to examine the progress ion of cartilage defects over 2 years In people with knee OA and to identify factors associated with progression. Methods:One hundred and seventeen subjects with OA underwent magnetic resonance imaging of their dominant knee at baseline and follow-up. Cartilage defects were scored (0- 4) at four sites. Bone size of themedial andlateral tibial plateau wasdetermined. Height, weIght. body mass index and physical activity were measured by standard protocols. Results:The mean cartilage defect score increased signifIcantlyover the 2-year study period in all tibiofemoral compartments (all P< 0.001). except the lateral tibial compartment with age and tibIal plateau bone area at baseline being predictors of progression. However, there was heterogeneity with 81% progressing at any site. 15% remaining stable and 4% decreasing. Conclusion: Over 2 years. cartilage defects tend to progress in people with symptomaticOA, with only a small percentage decreasing in severity. Increasing age and increased bone area are risk factors for progression. Interventions aimed at preventing cartilage defects from occurring and reducing theirseverity may result in a reduction in the severity of OA. by reducing lossof articular cartilage and subsequent requirement for knee joint replacement.