Abstract / Summary
Abstract Background Patellofemoral osteoarthritis (PFOA) is a common source of anterior knee pain and may present sex-related differences in symptom severity and disability, particularly during the early stages of the disease. However, the interaction between psychosocial factors, pain perception, disability, and cartilage composition assessed through T2 mapping magnetic resonance imaging (MRI) remains poorly understood in early-stage PFOA. Methods A cross-sectional analytical study was conducted in 57 participants diagnosed with early-stage PFOA (Kellgren–Lawrence grade 1), including 35 men and 22 women. Pain perception was assessed using the Visual Analog Scale (VAS), disability through the Western Ontario and McMaster Universities Arthritis Index (WOMAC), and fear of movement using the Tampa Scale for Kinesiophobia (TSK-11). Patellar cartilage composition was evaluated using 3T MRI T2 mapping. Pearson correlation analyses and multiple linear regression models with bootstrap resampling (5,000 samples) were performed to identify predictors of pain and disability. Results Fear of movement showed a significant positive association with both pain perception and disability. The pain perception regression model explained 81.4% of the variance (adjusted R 2 = 0.807, p < 0.001), with TSK demonstrating a significant association (β = 0.419, p < 0.001), whereas sex was not significantly associated with pain ( p = 0.277). The disability model explained 84.8% of the variance (adjusted R 2 = 0.842, p < 0.001). In this model, both TSK (β = 0.479, p < 0.001) and sex (β = -0.210, p = 0.014) were significantly associated with disability, reflecting higher WOMAC scores in women compared with men. Cartilage T2 mapping demonstrated excellent reliability (ICC > 0.94) and revealed only minor sex-related differences. Conclusions Women with early-stage PFOA presented greater disability than men, despite the absence of significant sex differences in pain perception. Fear of movement was consistently associated with both pain and disability, suggesting that psychosocial factors may play a more relevant role in symptom severity than structural cartilage alterations detected by exploratory T2 mapping MRI at this early stage. These findings support the implementation of multidimensional and individualized assessment strategies in early-stage PFOA management.