Orthopedics Oncology cases synovial chondromatosis

 

 

                              

A 45-year-old male presents to your office with right hip pain. The pain worsens with activity and started indolently about 2 years ago, without a preceding traumatic event. He also reports clicking and catching of the hip joint. He is worried that he has osteoarthritis and is anxious about getting a hip replacement at such a young age. X-rays are shown in Figure 8–32A and B.

 

Figure 8–32 A–B

 

Based on these x-rays, what is his most likely diagnosis?

1. PVNS

2. Destructive osteoarthritis

3. Chondrosarcoma

4. Synovial chondromatosis

 

Discussion

The correct answer is (D). Synovial chondromatosis is a metaplastic proliferation of hyaline cartilage nodules in the synovial membrane. It causes pain and mechanical symptoms such as clicking, popping, and stiffness. It is most common in the hip and knee but has been reported in other joints. Initially the cartilage nodules are not visible on plain radiographs, and MR is required to visualize them. However, over time, the nodules calcify and become radiopaque. Erosions and joint destruction can occur over time.

What should you tell him about the natural history of his condition?

1. It is generally a benign process, but one that can damage the joint

2. It is a locally aggressive tumor that must be followed with serial radiographs and should be excised only if it appears suspicious for malignant transformation

3. The most common presentation of this condition is recurrent atraumatic hemarthroses, but it can occasionally present with these radiographic findings

4. Xanthine oxidase-inhibiting medications such as allopurinol should be started to prevent recurrence

Discussion

The correct answer is (A). Synovial chondromatosis is a benign metaplastic process. The calcified nodules within a tight joint space can be extremely destructive to the cartilage surfaces of the joint and therefore either open or arthroscopic synovectomy and loose body removal is recommended when this condition is diagnosed; for this reason, observation is not recommended. Malignant transformation has been reported, but is extremely rare. PVNS commonly presents with recurrent atraumatic hemarthroses. Xanthine oxidase inhibitors treat gout, not synovial chondromatosis.

 

Objectives: Did you learn...?

 

 

To recognize clinical features and radiology of synovial chondromatosis? Natural history and etiology of synovial chondromatosis?