What is the primary cause of pseudogout?

The primary cause of pseudogout is calcium pyrophosphate crystal deposition in the joints, which is also known as calcium pyrophosphate dihydrate (CPPD) crystal arthropathy. This condition can lead to sudden attacks of joint pain, swelling, and inflammation, resembling gout, but is distinct due to the type of crystals involved.

In pseudogout, the accumulation of these calcium pyrophosphate crystals occurs primarily in the cartilage and synovial fluid, triggering an inflammatory response similar to that seen in gout, which is caused by uric acid crystals. The exact mechanism that leads to the deposition of calcium pyrophosphate crystals is not entirely understood, but it is often associated with aging, joint trauma, and certain metabolic and endocrine disorders.

While the other options present alternative causes or scenarios related to joint issues, they do not specifically pertain to pseudogout. Uric acid crystal deposition is the hallmark of classic gout, positional joint stress relates to mechanical strain rather than crystal formation, and infection in the joint is associated with septic arthritis, which has a different underlying pathology and presentation.