Hoffa disease is the traumatic or inflamatory changes in the infrapatellar fat pad due to impingement. Acute or repetetive trauma to the fat pad causes hemorrhage and inflamation. As a result scarring, fibrosis, hypertrophy and rarely calcification may ensue. This may cause pain, swelling and restricted motion.

Case Report

A 36 years old professional soccer player complained about pain and swelling at antero lateral side of patella. Examination showed mild tenderness.

MR images (figure 1-4) revealed the lesion in the infrapatellar fat pad. Lesion has a mass affect, which has high signal on T2 weighted SE images due to effusion and inflammation, hypointense linear components on both T2 and T1 W images may be related with fibrosis or hemosiderin.

The differential diagnosis of Hoffa Disease include localized nodular synovitis, postarthroscopy and postsurgery fibrosis, shear injury, articular disorders (intraarticular bodies, parameniscal cyst, ganglion cyst, cyclops lesion), synovial abnormalities (pigmented villonodular synovitis, hemophilia, synovial hemangioma, primary synovial chondromatosis, lipoma arborescens, synovitis associated with primary osteoarthritis).


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3) Jacobson JA, Lenchik L, Ruhoy MK, Schweitzer ME, Resnick D. MR imaging of the infrapatellar fat pad of Hoffa. Radiographics (1997); May-Jun; 17(3): 675-91.