Hydroxyapatite Crystal Deposition Disease: Understanding a Little-Known Joint Condition
Hydroxyapatite Crystal Deposition Disease (HADD) is a relatively uncommon but significant musculoskeletal condition characterized by the accumulation of tiny calcium phosphate crystals—specifically hydroxyapatite—in soft tissues such as tendons, ligaments, and bursae. Although many people are familiar with conditions involving calcium buildup like kidney stones or osteoporosis, HADD often remains overlooked, despite its ability to trigger sudden pain and restrict mobility. Understanding this disorder can help individuals recognize symptoms early and seek appropriate care.
Hydroxyapatite is a natural mineral that forms the structural foundation of human bones and teeth. In a healthy body, it contributes to skeletal strength and resilience. However, when these crystals migrate to regions where they do not belong, they can cause inflammation and tissue irritation. The shoulder is the most commonly affected area, especially the rotator cuff tendons, but HADD can also appear in the hips, wrists, knees,…