Calcium pyrophosphate dihydrate crystal deposition diseaseCalcium pyrophosphate dihydrate (CPPD) crystal deposition disease, also known as pseudogout and pyrophosphate arthropathy, is a rheumatologic disease which is thought to be secondary to abnormal accumulation of calcium pyrophosphate dihydrate crystals within joint soft tissues. The knee joint is most commonly affected. The disease is metabolic in origin and its treatment remains symptomatic. CPPD has also been classified as an Autoimmune Paraneoplastic Manifestation of Myelodysplastic Syndrome.
Joint effusionA joint effusion is the presence of increased intra-articular fluid. It may affect any joint. Commonly it involves the knee. The approach to diagnosis depends on the joint involved. While aspiration of the joint is considered the gold standard of treatment, this can be difficult for joints such as the hip. Ultrasound may be used both to verify the existence of an effusion and to guide aspiration. File:Knee effusion.jpg|Skyline view of the patella demonstrating a large joint effusion as marked by the arrow.
Synovial fluidSynovial fluid, also called synovia,[help 1] is a viscous, non-Newtonian fluid found in the cavities of synovial joints. With its egg white–like consistency, the principal role of synovial fluid is to reduce friction between the articular cartilage of synovial joints during movement. Synovial fluid is a small component of the transcellular fluid component of extracellular fluid. The inner membrane of synovial joints is called the synovial membrane and secretes synovial fluid into the joint cavity.
Septic arthritisAcute septic arthritis, infectious arthritis, suppurative arthritis, pyogenic arthritis, osteomyelitis, or joint infection is the invasion of a joint by an infectious agent resulting in joint inflammation. Generally speaking, symptoms typically include redness, heat and pain in a single joint associated with a decreased ability to move the joint. Onset is usually rapid. Other symptoms may include fever, weakness and headache. Occasionally, more than one joint may be involved, especially in neonates, younger children and immunocompromised individuals.
GoutGout (gaʊt ) is a form of inflammatory arthritis characterized by recurrent attacks of a red, tender, hot and swollen joint, caused by the deposition of needle-like crystals of uric acid known as monosodium urate crystals. Pain typically comes on rapidly, reaching maximal intensity in less than 12 hours. The joint at the base of the big toe is affected (Podagra) in about half of cases. It may also result in tophi, kidney stones, or kidney damage. Gout is due to persistently elevated levels of uric acid (urate) in the blood (hyperuricemia).
