M12.211

Clinical Causes: The exact cause of villonodular synovitis is unknown; it is believed to involve abnormal cell proliferation within the synovial membrane. Some research suggests that trauma or joint injury may contribute to the development of the condition. Genetic or cellular factors leading to inflammation and proliferation of synovial tissue. It may also be associated with other inflammatory joint diseases, although it often occurs independently.

Key Symptoms: Persistent joint swelling, often noticeable as a lump around the shoulder. Joint pain that can worsen with activity or over time. Reduced range of motion in the affected shoulder, leading to stiffness. A sensation of catching, locking, or instability within the joint. Warmth or tenderness around the shoulder area. Potential periods of joint stiffness, especially after periods of inactivity.

Diagnosis Path: A thorough physical examination to assess swelling, tenderness, and joint movement. Magnetic resonance imaging (MRI), which is highly effective in detecting abnormal growths and distinguishing pigmented villonodular synovitis from other joint conditions. X-rays to rule out other causes of shoulder pain and to examine bone structures. Biopsy of the synovial tissue may be necessary to confirm the diagnosis and identify characteristic pigmented, hemosiderin-laden tissue. Blood tests are generally not definitive but may be used to exclude other inflammatory conditions.

Treatment Protocols: Surgical removal of the proliferative synovial tissue, often through arthroscopic (minimally invasive) procedures. Open surgery may be required if the abnormal tissue is extensive. Post-surgical physical therapy to regain strength and mobility in the shoulder. Medications, such as non-steroidal anti-inflammatory drugs (NSAIDs), can help manage pain and inflammation. In some cases, radiation therapy may be considered if the lesion recurs after surgery. Close follow-up is necessary due to the potential for recurrence of villonodular synovitis.