Milwaukee Shoulder

Milwaukee shoulder is the combination of

• Complete tear of the rotator cuff
• Osteoarthritic changes
• Noninflammatory joint effusion with calcium hydroxyapatite and calcium pyrophosphate dihydrate crystals
• Synovial hyperplasia
• Destruction of cartilage and subchondral bone
• Multiple osteochondral loose bodies

It typically affects older women with a history of trauma who present with rapidly progressive, destructive arthritis of the shoulder.

Imaging studies reveal joint space narrowing, subchondral sclerosis with cyst formation, destruction of subchondral bone, soft-tissue swelling, capsular calcifications, and intraarticular loose bodies. Calcium pyrophosphate dihydrate crystal deposition of the knees is also commonly seen.

The process is also known as cuff arthropathy in the orthopedic literature, where the etiology is thought to be chronic rotator cuff tear that results in upward migration of the humeral head and subsequent changes in the humeral head and inferior surface of the acromion.

References

• McCarty DJ, Halverson PB, Carrera GF, et al. "Milwaukee shoulder": association of microspheroids containing hydroxyapatite crystals, active collagenase, and neutral protease with rotator cuff defects. Arthritis Rheum 1981; 24:464-473.
• Llauger J, Palmer J, Rosón N, Bagué S, Camins A, Cremades R. Nonseptic monoarthritis: imaging features with clinical and histopathologic correlation. Radiographics. 2000; 20 Spec No:S263-278.