Presentation
Painless prepatellar swelling.
Patient Data
Well-circumscribed oval-shaped fluid-filled sac of low signal on T1, high signal on T2 and PD fat sat, located anterior to the patella and patellar tendon with surrounding edematous infiltration.
Normal appearance of the meniscal, cruciate and collateral ligaments.
Full-thickness cartilage loss of the anteromedial aspect of the lateral femoral condyle with cortical erosion and subchondral bone marrow edema (grade IV according to the modified Outerbridge grading chondromalacia).
Case Discussion
MRI features most consistent with prepatellar bursitis.
Prepatellar bursitis is defined as an inflammation with accumulation of fluid collection within the prepatellar bursa, located between the patella and the overlying subcutaneous tissue.