Superolateral Hoffa's fat pad (SHFP) edema and patellar cartilage volume loss: quantitative analysis using longitudinal data from the foundation for the national institute of health (FNIH) osteoarthritis biomarkers consortium

Abstract

Purpose: To determine the association of superolateral Hoffa's fat pad (SHFP) edema and patellofemoral joint structural damages in participants of Foundation for the National Institute of Health Osteoarthritis Biomarkers Consortium study. Methods: Baseline and 24-month MRI of 600 subjects were assessed. The presence of SHFP edema and patellar morphology metrics were determined using baseline MRI. Quantitative patellar cartilage volume and semi-quantitative MRI Osteoarthritis Knee Score (MOAKS) variables were extracted. The associations between SHFP edema and patellar cartilage damage, bone marrow lesion (BML), osteophyte, and morphology were evaluated in cross-sectional model. In longitudinal analysis, the association between edema and cartilage volume loss (defined using reliable change index) and MOAKS worsening were evaluated. Results: In cross-sectional evaluations, SHFP edema was associated with simultaneous lateral patellar cartilage/BML defects and inferior-medial patellar osteophyte size. A significant positive correlation between the degree of patella alta and SHFP edema was detected. The presence of edema was associated with 24-month cartilage volume loss (odds ratio(OR):2.11, 95%confidence interval:1.46–3.06) and medial patellar BML size (OR:1.92(1.15–3.21)) and number (OR:2.50(1.29–4.88)) worsening. Conclusions: The presence of SHFP edema could be considered as a predictor of future patellar cartilage loss and BML worsening, and an indicator of simultaneous cartilage, BML, and osteophyte defects.