Gender differences in knee cartilage volume as measured by magnetic resonance imaging

Objective: The aim of this study was to analyze sex differences in knee car tilage volume. Methods: Articulate cartilage volumes were determined by processing images acquired in the sagittal plane using T1-weighted fat saturation magnetic re sonance on an independent work station. The knees of 28 subjects (17 male, 11 female) who underwent MRI for clinical indications (pain <3 months) but who had a normal X-ray and structurally normal MRI were examined. Results: Males had significantly larger cartilage volumes than females, wit h difference in cartilage volume remaining statistically significant after adjusting for age, height, weight and bone volume. The differences for male s relative to females were: femoral cartilage volume [4.1 mi 95% CI (2.0, 6 .1)]; and patella cartilage volume [1.4 mi (0.2, 2.7)]. Although not statis tically significant, the tibial cartilage volume also showed these sex diff erences. Exploratory analysis indicated an increasing gender difference wit h increasing age for patellar cartilage volume. Conclusion: Men have significantly larger knee cartilage volume than women, independent of body and bone size. The mechanisms for this will need to be determined.