[A cross-sectional study on the correlation between MRI signal for IPFP and knee osteoarthritis]

To investigate the correlation between MRI signal for infrapatellar fat pad (IPFP) and pathological changes in knee osteoarthritis (KOA), and to analyze the role of IPFP in the development of knee osteoarthritis.
 Methods: A total of 114 subjects (without special knee disease) were enrolled for this study. The intensity of MRI signal for IPFP was determined by fat-suppressed proton-density-weighted turbospin-echo magnetic resonance imaging. Based on the cartilage defects and osteophytes of knee joint, the subjects were divided into a KOA group and a control group. The difference of MRI signal for IPFP between two groups was analyzed.
 Results: After excluding the potential confounders of age, gender and BMI, the intensity of MRI signal for IPFP was positively correlated with defections in patellar, medial femur, lateral tibial or knee joint (OR 1.333 to 2.168, P 0.006 to 0.023); the intensity of MRI signal for IPFP was also positively correlated with osteophytes in patellar, medial femur, lateral tibial or knee joint (OR 1.309 to1.781, P 0.004 to 0.046); the intensity of MRI signal for IPFP in the KOA group was significantly higher than that in the control group (P=0.028).
 Conclusion: The increase in the density of MRI signal for IPFP is an imaging manifestation for knee degeneration. IPFP inflammation and endocrine abnormalities may play an important role in KOA.