Calcium pyrophosphate dihydrate deposition disease (CPPD) is an arthritis variant. CPPD consists of the deposition of calcium pyrophosphate crystals into soft tissue. It has been found in high concentrations in hyaline cartilage, synovial tissue, capsule, meniscus, labrum, ligamentum flavum and soft tissue of the hand.
Estimates vary widely on the frequency of CPPD disease in the USA. It has been described as being present in 4% to more than 25% of the population by age 80 years. Prevalence clearly increases with age. CPPD presents clinically approximately one half as often as gout in the typical practice setting. The male-to-female ratio is approximately 1.4:1.