Calcium pyrophosphate dihydrate crystal deposition and other crystal deposition diseases.

Recent advances in understanding the pathogenesis and mechanisms of tissue damage related to calcium-containing crystals are highlighted in this review. The clinical spectrum of diseases related to crystal deposition has broadened and includes distinct neurologic syndromes associated with hypertrophy and calcification of the ligamentum flavum or posterior longitudinal ligament in the cervical spine. Diagnostic methods of crystal identification are also reviewed.