What type of crystals are indicative of CPPD disease, also known as pseudogout?

In the context of CPPD disease, or pseudogout, the presence of rhomboid shaped positively birefringent calcium pyrophosphate crystals is definitive. These crystals are formed when there is an excess of calcium pyrophosphate in the joint fluid, which is a hallmark of this condition.

The term "positively birefringent" refers to the way these crystals interact with polarized light, which helps distinguish them from other types of crystals during microscopic examination. The characteristic rhomboid shape of these crystals further aids in their identification, differentiating them from other crystalline arthropathies such as gout, where typical crystals are needle-shaped and exhibit a different birefringence pattern.

Understanding the specific characteristics of the crystals associated with CPPD is crucial for accurate diagnosis and management of the disease, making this identification essential for healthcare providers in the rheumatology field.