Beyond Osteoarthritis: A Case of a Massive Intraarticular Ganglion Cyst in the Knee.

Intraarticular ganglion cysts of the knee are rare, typically incidental findings, and often asymptomatic. However, large cysts may be of clinical interest due to their potential mass effect on surrounding structures. We present the case of a 54-year-old female with a three-year history of osteoarthritis-related knee pain unresponsive to conservative management who ultimately underwent a total knee arthroplasty (TKA). Preoperative imaging revealed a massive, multiloculated intraarticular ganglion cyst extending from Hoffa's fat pad to the medial joint capsule. While the cyst did not interfere with the TKA, its size and location raise important considerations regarding the possible role of intraarticular ganglion cysts in osteoarthritis progression and symptomatology. This case highlights the significance of recognizing and characterizing these lesions and reviewing their potential implications in the setting of advanced knee degeneration.