Correlation of Patellofemoral Chondromalacia and Body Mass Index (BMI) in Relation to Sex and Age Analysis of 1.5T and 3.0T Magnetic Resonance (MR) Images Using the Outerbridge Scale.

BACKGROUND Cartilage disease (chondromalacia) is most commonly found in the patellofemoral joint. Non-invasive magnetic resonance imaging methods are used to assess the severity of chondromalacia. The available literature lacks papers describing the predilection of chondromalacia changes to BMI assessed on the basis of geometric data that can be assessed by 1.5T and 3.0T MRI. The aim of this study was to assess the relationship between the severity of chondromalacia of the patellofemoral joint and age, sex, and BMI assessed on the 1.5T and 3.0T MRI scanners. MATERIAL AND METHODS The study involved 324 patients, including 159 (49%) women and 165 (51%) men, aged 8-87 years (mean age: 45.1±20.9). The studied group had a BMI in the range of 14.3-47.3 (M: 27.7±5.02). A 1.5T and 3.0T MRI scanner were used in the study. To assess the cartilage of the patellofemoral joint, Outerbridge scales were used. RESULTS The age of the patients showed a significant correlation (Spearman's rank, P<0.0001) with Outterbridge grade for each surface of patellofemoral joint. Higher correlation between BMI and Outerbridge grade was noted in the patella (rho=0.4139) than in the femur (rho=0.2890). There were no significant differences between women and men in the Outerbridge assessment of the knee joint (P>0.05).  Significant more degeneration was found at the 1.5T scanner compared to the 3.0T MRI (P<0.0025). CONCLUSIONS The severity of chondromalacia significantly depends on age and BMI level. There is a stronger correlation between the degree of chondromalacia and BMI in women than in men.