Jammed joints and constricted heart: The science of tribology and missing lubricin. A case report on camptodactyly-arthropathy-coxa vara-pericarditis syndrome.

An autosomal recessively inherited noninflammatory arthropathy known as camptodactyly, arthropathy, coxa vara, and pericarditis (CACP) syndrome was discovered in 1999. It is distinguished by synoviocyte hyperplasia and subcapsular fibrosis of the synovial capsule, which results in a shortage of lubricin production. The resulting lack of joint lubrication induces increased mechanical stress, causing progressive deformities that become evident with weight-bearing and heightened joint activity.