Abstract: Objective To investigate the relationship between structural changes and imaging changes of quadriceps fat pad (QFP) and prefemoral fat pad (PFP) in patients with knee osteoarthritis.Methods A retrospective analysis was conducted on the clinical data of 100 patients with knee osteoarthritis admitted to our hospital from June 2020 to June 2022,all of whom underwent magnetic resonance examination.100 patients had a total of 150 knees,and the 150 knees were divided into two groups:non-knee radiologic Osteoarthritis (ROA) group and ROA group.The basic data, QFP and PFP parameters of the two groups were compared, and the correlation between each parameter and KLG grade, Hoffa synovitis and exudative synovitis was analyzed.Results The head and tail diameter of QFP in ROA group was significantly longer than that in non-ROA group,the number of QFP high signal and PFP patellofemoral high signal cases was significantly higher than that in non-ROA group,the number of QFP mass effect cases was significantly lower than that in non-ROA group,and the maximum thickness of PFP was significantly lower than that in non-ROA group.QFP high signal and PFP patellar high signal were positively correlated with KLG grading (r=0.271, 0.399). The maximum thickness of PFP was negatively correlated with KLG grade（r=-0.418）.QFP high signal was positively correlated with Hoffa synovitis (r=0.330).QFP mass effect and PFP maximum thickness were negatively correlated with Hoffa synovitis (r=-0.291, -0.441).PFP maximum thickness was negatively correlated with exudative synovitis (r=-0.561).  PFP patellar high signal was positively correlated with cartilage defects at different sites (r=0.320, 0.418, 0.358, 0.410, 0.291). QFP mass effect and PFP maximum thickness was negatively correlated with different sites of cartilage defects (r=-0.358,-0.287, -0.287, -0.287, -0.170, -0.399, -0.438,-0.498, -0.457, -0.350).The anteroposterior diameter of the QFP was negatively correlated with the medial tibial cartilage defect (r=-0.260).Conclusion Imaging changes of QFP and PFP are closely related to KLG grade,synovitis,articular cartilage defect,and subchondral myelopathy in patients with knee osteoarthritis,and play an important role in the occurrence and development of knee osteoarthritis.

Key words: knee osteoarthritis, structural change, quadriceps fat pad, prefemoral fat pad, imaging changes, correlation