Fat Pads as a Cause of Adolescent Anterior Knee Pain

Anterior knee pain is one of the most frequently encountered symptoms in pediatric sports medicine. The fat pad is a structure with mounting evidence supporting its dynamic involvement in many pathological states in the anterior knee. There are three peripatellar fat pads that occupy much of the extra-synovial space of the knee. This review explores the anatomy, innervation, vasculature, function, imaging, and pathology of these fat pads. Fat pad pathology is likely underestimated given the limited literature on such disease in the pediatric population. In particular, the prefemoral fat pad is the least described of the fat pads with only a few reports detailing chronic pathological processes. To highlight the relevance of the fat pad, particularly in the pediatric population, we describe an atypical case of a self-limiting acute prefemoral fat pad impingement due to a hyperextension injury in a young athlete.