Gender differences in knee joint cartilage thickness, volume and articularsurface areas: assessment with quantitative three-dimensional MR imaging

Objective: To compare the cartilage thickness, volume, and articular surfac e areas of the knee joint between young healthy, non-athletic female and ma le individuals. Subjects and design. MR imaging was performed in 18 healthy subjects without local or systemic joint disease (9 female, age 22.3 +/-2. 4 years, and 9 male, age 22.2 +/-1.9 years.), using a fat-suppressed FLASH 3D pulse sequence (TR=41 ms, TE=11 ms, FA=30 degrees) with sagittal orienta tion and a spatial resolution of 2x0.31x0.31 mm(3). After three-dimensional reconstruction and triangulation of the knee joint cartilage plates, the c artilage thickness (mean and maximal), volume, and size of the articular su rface area were quantified, independent of the original section orientation . Results and conclusions: Women displayed smaller cartilage volumes than men , the percentage difference ranging from 19.9% in the patella, to 46.6% in the medial tibia. The gender differences of the cartilage thickness were sm aller, ranging from 2.0% in the femoral trochlea to 13.3% in the medial tib ia for the mean thickness, and from 4.3% in the medial femoral condyle to 1 8.3% in the medial tibia for the maximal cartilage thickness. The differenc es between the cartilage surface areas were similar to those of the volumes , with values ranging from 21.0% in the femur to 33.4% in the lateral tibia . Gender differences could be reduced for cartilage volume and surface area when normalized to body weight and body weightxbody height. The study demo nstrates significant gender differences in cartilage volume and surface are a of men and women, which need to be taken into account when retrospectivel y estimating articular cartilage loss in patients with symptoms of degenera tive joint disease. Differences in cartilage volume are primarily due to di fferences in joint surface areas (epiphyseal bone size), not to differences in cartilage thickness.