A Case of Prefemoral Fat Pad Impingement Syndrome Caused by Hyperplastic Fat Pad

Figure 5

Anatomical movement of the patella from full extension to flexion. (a) In the anterior view, the patella moves from the proximal to the distal center and engages with the trochlear groove. (b) When the fat pad is large, PFIS occurs on the proximal side of the patella. (c) In the lateral view, patella moves distally as the knee flexes. A normal-sized prefemoral fat pad does not demonstrate impingement. (d) When the prefemoral fat pad is larger than normal with good mobility, the fat pad can get caught by the PF joint regardless of whether the patella shows normal movement, resulting in symptoms.

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