Fig. 7.

Prefemoral fat pad impingement in a 44-year-old woman with chronic, anterior pain of the left knee. (A) Sagittal and (B) axial fat-suppressed T₂-weighted images show enlargement and high signal intensity of the inferolateral aspect of the prefemoral fat pad (solid arrow) associated with full-thickness cartilage loss (arrowhead) and a bone marrow lesion (dashed arrow) of the patellar apex. Note shallow trochlear groove (empty arrow) consistent with patellofemoral maltracking. (C) Sagittal proton density MR image shows high riding patella with modified Insall Salvati ratio: distance between distal patellar articular surface and distal patellar tendon insertion (dashed double end arrow) / patellar length (solid double end arrow) measured at 2.1 (greater than 2) also consistent with patellar maltracking.