The Relationship Between Suprapatellar Fat Pad Edema/Mass Effect and Sagittal Alignment of the Patellofemoral Joint

Objective: This study aimed to compare the measurements of the sagittal alignment of the patellofemoral joint on magnetic resonance (MR) images between patients with suprapatellar fat pad edema/mass effect and a gender and age-matched control group of patients without suprapatellar fat pad edema.
Methods: A total of 55 patients with suprapatellar fat pad edema/mass effect was compared with the control group with anterior knee pain. Suprapatellar fat pad edema/mass effect and sagittal alignment of the patellofemoral joint were evaluated from the sagittal MR images. Sagittal alignment was evaluated using the Insall-Salvati (IS) ratio, patella-patellar tendon (P-PT) angle, and quadriceps tendon-P (QT-P) angle. The measurements were also compared between the two groups.
Results: The mean IS ratio, and P-PT angle did not significantly differ between the two groups (p>0.05). The mean QT-P angle was significantly higher in patients with suprapatellar fat pad edema/mass effect than in the control group (p=0.01).
Conclusion: The suprapatellar fat pad edema/mass effect is not associated with the sagittal alignment of the patellofemoral joint. The QT-P angle was higher in patients with a mass effect on the suprapatellar fat pad.