Hoffa fat pad impingement syndrome occurs secondary to patellar maltracking or imbalance of the forces between medial and lateral vastus muscles causing impingement of the superolateral aspect of Hoffa fat pad between the inferior patella and the lateral femoral condyle.

Radiological findings include focal area of high T2 signal (edema) at the inferolateral aspect of the patellofemoral joint, within the superolateral portion of the infrapatellar fat pad. Associated findings include lateral patellar subluxation and patella alta.