Abstract
INTRODUCTION: Synovial chondromatosis is a rare, benign condition that affects the synovial lining of joints, bursae, and synovial sheaths. It commonly occurs in larger joints and presents as a metaplastic disorder affecting a single joint. This case report focuses on an unusual occurrence of synovial chondromatosis in young adults, specifically with a patellar-shaped presentation. CASE PRESENTATION: A 23-year-old male patient presented with a two-year history of right knee pain and the presence of a gradually enlarging lump. The lump, currently the size of a pingpong ball, has limited the patient's range of motion in his knee joint. An MRI scan revealed a solid mass in the hoffa's fat pad on the right knee joint suggestive of extraskeletal ossifying chondroma, as well as minimal fluid accumulation in the knee joint. The mass located in front of anterior meniscus and posterior of patellar tendon, it makes the pattelar tendon redundant and patellar alta (Insall-Salvati ratio 0.88), so we performed wide excision patellar tendon augmentation with tape (ultra high molecular weight polyethylene based) and imbrication of MPFL. Histopathological analysis confirmed osteochondromatosis measuring 6.5x5x3.5cm, resembling the shape of a patella. Post-operation x-ray examination showed no signs of ossification in the hoffa's fat area or any narrowing or sclerosis in knee joints. Furthermore, there were no visible fracture/dislocation lines or indications for osteomyelitis. The patient is now free from pain and can move without any limitations in range of motion. DISCUSSION: Synovial Chondromatosis with pattelar-like shape mass is uncommon benign tumor that rarely affects young adults. Effective surgical treatments such as wide excision and patellar tendon augmentation using UHMWPE tape with imbrication of the medial patellofemoral ligament have demonstrated favorable outcomes for cases of osteochondromatosis that have reached a significant size and are impacting adjacent tendons.