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.
Milwaukee shoulder frequently affects older women, often with a history of trauma to the region.
Symptoms are usually comparatively mild, despite rapid and marked progression of radiographic features.
Radiographic findings are striking and almost resembles a neuropathic joint, with advanced articular surface destruction with intra-articular loose bodies, subchondral sclerosis, soft tissue swelling and rotator cuff disruption. Cases often demonstrate superior subluxation of the humeral head in relation to the glenoid fossa . The superior subluxation can also result in a pseudoarthrosis with the distal clavicle and/or acromion .
MRI findings mirror those of the plain radiographs and include:
- large shoulder joint effusion
- complete rotator cuff tear
- narrowing of the glenohumeral joint
- thinning of cartilage
- destruction of subchondral bone
Treatment and prognosis
No specific treatment is available, only supportive treatment for symptom relief .
History and etymology
Regius Professor of Surgery, Dr Robert Adams (1791 -1875) was an Irish surgeon who first described this pathology in his own textbook published in 1857 .
In 1981, a group of Milwaukee based researchers encountered four cases of rotator cuff loss, shoulder arthropathy and joint effusions containing calcium phosphate crystals and hence coined the term 'Milwaukee shoulder' .
General imaging differential considerations include