Magnetic resonance imaging of the infrapatellar fat pad: correlation with patellar articular cartilage abnormalities.

We tried to demonstrate an association between magnetic resonance imaging findings of the Hoffa fat pad and patellar chondropathy. Parallely, we checked the correlation between the diagnosis of patellar chondropathy on magnetic resonance imaging and during arthroscopy. Our study is a retrospective review of the records of 135 patients who underwent an arthroscopy and MRI study at our institution between October 1997 and January 2001. Magnetic resonance images of the Hoffa fat pad were interpreted and typewritten arthroscopy reports were recorded. A patellar chondropathy assessed during arthroscopy was present in 64 of 135 patients. Twenty of them had abnormal signal intensity in Hoffa fat pad with a sensitivity of the magnetic resonance imaging findings of 31% and a specificity of 73%. We didn't find any significant association in the different correlations between signal abnormalities of Hoffa fat pad and patellar chondropathy. On the other hand, there was a significant association between the results of patellar chondropathy on magnetic resonance imaging findings and during arthroscopy. No significant association was shown between the MRI findings of Hoffa fat pad and the patellar chondropathy.