Synovial chondromatosis is a monoarticular disease, with the knee, hip, shoulder and elbow being the most common joints in order of prevalence. Synovial chondromatosis of the hip joint is rare and has a low incidence, and according to statistics, synovial chondromatosis accounts for 6.7% of synovial tumors and tumor-like lesions. According to the pathology, the disease is divided into three stages: Stage I: active synovial lesions; Stage II: transitional synovial lesions combined with synovial chondromas and free bodies; Stage III: stationary synovial lesions, with most free bodies formed. Other symptoms include joint stiffness, joint swelling, limited joint mobility, joint popping, interlocking, and sometimes a movable mass may be found. X-rays: The number of chondromas of varying sizes in the joint cavity, with smooth edges, clear boundaries, and round, oval speckled or mass-like calcification shadows, CT and MRI: round, oval speckled dense shadows of varying sizes in the joint cavity or soft tissues around the joint. Long-term irritation of the free body may cause wear and tear of the articular cartilage, degeneration, joint swelling and pain, and different degrees of functional impairment. Therefore, early surgical removal of the free body and removal of the diseased synovial membrane should be performed.