Milwaukee shoulder refers to a destructive shoulder arthropathy due to deposition of hydroxyapatite crystals, and identification of these crystals in synovial fluid is the cornerstone of diagnosis
- Extensive deposition of BCP crystals in large joints is associated with progressive joint destruction.
- Gradual onset of joint pain, sometimes precipitated by injury or overuse.
- It is more common in women than in men
- Severe pain and disability, associated with joint destruction.
- End-stage avascular necrosis
- Chronic sepsis or neuropathic joint.
- X-rays show joint space narrowing, osteophytes and calcification.
- Aspiration: non-inflammatory fluid containing abundant BCP aggregates and often cartilage fragments.
- FBC, U&E, LFT, CRP normal.
- Synovial fluid cultures are negative.
- Treatment is with analgesics, intra-articular injection of glucocorticoids, local physical treatments and physiotherapy.
- Many need joint replacement.
- The deposition of BCP crystals activates collagenase and other proteases in articular cells, which are responsible for the tissue damage