Introduction
Rare destructive shoulder arthropathy characterised by pain, large joint or bursa effusion associated with the deposition of calcium hydroxyapatite crystals
- Typically occurs in elderly patients aged 60–90 years
- Female preponderance of 4 : 1
History
The term Milwaukee shoulder syndrome (MSS) was first used in 1981 to describe four elderly women in Milwaukee in the state of Wisconsin, USA, with recurrent bilateral shoulder effusions, radiographic evidence of severe destructive changes of the glenohumeral joints, and massive tears of the rotator cuff. The term rapid destructive arthritis of the shoulder was introduced in 1982 to describe six elderly females with spontaneous large glenohumeral effusions, mild pain, and tears of the rotator cuff. Apatite-associated destructive arthritis and idiopathic destructive arthritis were introduced to illustrate rotator cuff tear arthropathy of the shoulder in 1983.
Aetiology
Risk factors:
- Trauma/overuse
- Calcium pyrophosphate dehydrate crystal deposition
- Neuroarthropathy
- Dialysis arthropathy
- Denervation
- Female gender
- Advanced age
Pathophysiology
Characterised by intra-articular or periarticular hydroxyapatite crystals and rapid destruction of the rotator cuff and the glenohumeral joint.
- Intraarticular/periarticular hydroxyapatite crystals
- Rapid destruction of the rotator cuff and the glenohumeral joint
Intra-articular calcium hydroxyapatite deposition
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Release of lysosomal enzymes
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Damage to periarticular tissues, including rotator cuff
Clinical features

Diagnosis
Radiograph:

USG:
- Exuberant subacromial bursitis
- Rotator cuff tear

Bursa aspiration:
- Haemorrhagic non-inflammatory fluid and hydroxyapatite crystals were identified with alizarin red staining
- Serohematic synovial fluid with low cellularity (<2000 leucocytes/mL) cells.

Differential diagnosis
- Rapidly destructive or progressive arthropathy
- Septic arthritis
- Neuropathic arthropathy
- Osteonecrosis
- Inflammatory arthritis
- Crystal-associated arthropathy
- Arthropathy of late syphilis
Management
Supportive management:
- Physiotherapy: provides the required exercise to maintain the range of motion and strengthen the surrounding muscles
Medical management:
- NSAIDs
- Colchicine
- Arthrocentesis
Surgical management (severe/advanced degenerative changes):
- Partial/complete arthroplasty