Presentation
Anterior knee pain.
Patient Data
Increased signal intensity of the suprapatellar fat pad, with a convex posterior border and mass effect over the suprapatellar joint recess.
There is no significant joint effusion.
Annotated sagittal PD
Left: anterior suprapatellar fat pad edema
Right: normal anterior suprapatellar fat pad
Case Discussion
The anterior suprapatellar fat pad is an intracapsular, but extrasynovial structure, located just posterior to the quadriceps tendon, anterior to the prepatellar joint recess, and superior to the patellar base and retropatellar cartilage, usually triangular in shape.
Anterior suprapatellar fat pad signal abnormalities and mass effect (indicating edema), with no other significant findings, and the clinical presentation in this case, are compatible with anterior suprapatellar fat pad impingement syndrome.