ABSTRACT
Hydroxyapatite (HA) crystal deposition disease (HADD) is a well-recognized systemic
disease of unknown etiology that is caused by para-articular and/or intra-articular
deposition of HA crystals. The disease is clinically manifested by localized pain,
swelling, and tenderness about the affected joint along with variable limitation of
joint motion, although not all patients are symptomatic. Plain radiographs may show
calcifications of varying size and shape in the para-articular tendons, bursae, and
capsule. The disease may be mono- or polyarticular in distribution. The shoulder is
most commonly involved with calcification in the supraspinatus tendon. When intra-articular,
HA crystals can cause joint destruction. Any joint can be involved; the shoulder is
most commonly affected, resulting in "Milwaukee shoulder." Treatment of HADD usually
requires use of analgesics, local heat, needling with or without aspiration of the
calcific deposits, steroid injections, and, at times, even surgery for relief of pain.
KEYWORDS
Hydroxyapatite arthritis - bursitis - tendinitis - crystal deposition disease - calcific
arthritis - calcific tendinitis - Milwaukee shoulder