Hoffa's Fat Pad Ganglion Cyst Causing Infrapatellar Impingement in a Collegiate Athlete: A Report of a Rare Case.

Ganglion cysts are benign, fluid-filled lesions most frequently arising from the wrist and hand, while occurrence within Hoffa's (infrapatellar) fat pad of the knee is rare. When present in the knee, these cysts may lead to localized irritation, mechanical infrapatellar impingement, restricted range of motion, and anterior knee pain. We present the case of a 19-year-old collegiate basketball player with chronic anterior right knee pain without any prior history of trauma, unresponsive to initial conservative management. Initial clinical evaluation suggested patellofemoral pain syndrome; however, advanced imaging via MRI and musculoskeletal ultrasound revealed a ganglion cyst impinging on Hoffa's fat pad and abutting the posterior patellar tendon. Given persistent functional impairment despite conservative therapy, arthroscopic excision was performed. Postoperatively, the patient achieved complete resolution of symptoms and successfully returned to competitive athletic activity without limitation. This case demonstrates the value of early imaging and consideration of intra-articular ganglion cysts in the differential diagnosis of anterior knee pain in young athletes. Early recognition through appropriate imaging is essential for optimizing functional outcomes in young athletes.