The bilateral shoulder pain of an 81-year-old Japanese woman due to falls persisted despite celecoxib treatment, and plain X-rays later showed bilateral collapsed humeral heads. After ruling out osteoarthritis, infectious arthritis, crystal-induced arthritis, neuropathic arthropathy, and osteonecrosis, we diagnosed bilateral shoulder joint rapidly destructive arthrosis (RDA). Lumbar bone mineral density showed very low T-score (-4.1). Primary osteoporosis was observed. Histology of biopsied humeral head indicated the features of fracture healing process: callus formation and osteoclasts without empty lacunae. Her history thus included an insufficiency fracture due to severe osteoporosis. Bilateral humeral head replacement was performed; her shoulder joint function improved. This case is extremely rare in that RDA was caused by simultaneous bilateral shoulder joint collapse within a very short time, with minimal or low mechanical stress and severe osteoporosis.
Keywords: differential diagnosis; humeral head replacement; osteoporosis; rapidly destructive arthrosis; shoulder joint.