Anterior Knee Pain and Oedema-like Changes of the Suprapatellar Fat Pad: Correlation of the Symptoms with MRI Findings.

Abstract

The aetiology of anterior knee pain is multifactorial, and any patellofemoral structure can be the cause of the symptoms. For the last decades, the suprapatellar fat pad is studied as a potential cause of anterior knee pain. Since the results in the literature are contradictory, in this study, we tried to reevaluate the role of the suprapatellar fat pad in the development of anterior knee pain. Total 156 knee MRIs of 150 patients from December 2015 to July 2019 were retrospectively evaluated by a radiologist for the configuration of the suprapatellar fat pads. The population was divided into two groups according to the presence of anterior knee pain. Maximum craniocaudal, anteroposterior and oblique diameters, and relative signal intensity indexes of the suprapatellar fat pads were measured and compared between the groups. Configurations of the fat pads were recorded, and measurements of the triangular-shaped and convex posterior bordered suprapatellar fat pads were compared. A student t-test was used for statistical analysis. Statistically, significant differences and correlations were defined as p<0.05. The diameters and relative signal intensity indexes of the fat pads showed no significant difference between the groups (p=0.588, 0.744, 0.874, and 0.201, respectively). Anteroposterior and oblique diameters and relative signal intensity indexes of the suprapatellar fat pads were correlated with the convex posterior border (p=0.001, 0.003, and 0.000, respectively). Oedema-like changes of the suprapatellar fat pad seen at knee MRIs are correlated with the configuration of the fat pad but are rarely associated with anterior knee pain.