Arthropathies are called polyarticular (multiarticular) when involving many joints and monoarticular when involving only a single joint. Arthritis is the leading cause of disability in people over the age of 55. There are many different forms of arthritis, each of which has a different cause. The most common form of arthritis, osteoarthritis (also known as degenerative joint disease), occurs following trauma to the joint, following an infection of the joint or simply as a result of aging and the deterioration of articular cartilage. Furthermore, there is emerging evidence that abnormal anatomy may contribute to early development of osteoarthritis. Other forms of arthritis are rheumatoid arthritis and psoriatic arthritis, which are autoimmune diseases in which the body is attacking itself. Septic arthritis is caused by joint infection. Gouty arthritis is caused by deposition of uric acid crystals in the joint that results in subsequent inflammation. Additionally, there is a less common form of gout that is caused by the formation of rhomboidal-shaped crystals of calcium pyrophosphate. This form of gout is known as pseudogout. Temporomandibular joint syndrome (TMJ) involves the jaw joints and can cause facial pain, clicking sounds in the jaw, or limitation of jaw movement, to name a few symptoms. It is caused by psychological tension and misalignment of the jaw (malocclusion), and may be affecting as many as 75 million Americans. History
Etymology
The English word joint is a past participle of the verb join, and can be read as joined.
Institute of Technology, a university in Bangalore, India
Providence Elementary School, an elementary school in Chesterfield County, Virginia

Computing
Pro Evolution Soccer, a multi-platform video game series developed by Konami
Packetized elementary stream, part of the MPEG communication protocol
Peripheral Event System, an implementation of autonomous peripheral operations in microcontrollers
PSTN Emulation System for IP Multimedia Subsystem (IMS)

Organizations
Postal Express Service, United States military mail during World War I
Power Engineering Society, now the Power & Energy Society of the Institute of Electrical and Electronics Engineers
Premier Election Solutions, formerly Diebold Election Systems
Party of European Socialists, a centre-left pan-European political party
Social Encounter Party, a Mexican former political party
Solidarity Encounter Party, a Mexican former political party

Science
Pallasite Eagle Station, a pallasite meteorite grouplet
Photoemission spectroscopy, a measurement of a substances binding energy using the photoelectric effect
Poly(ethylene succinate), a type of polyester
Polyester, an artificially produced organic chemical that is spun and woven to make fabric
Polyethersulfone, a thermoplastic polymer
Potential energy surface, in physics and chemistry
Programmed electrical stimulation, a type of electrophysiologic study
Pseudoexfoliation syndrome, an eye problem

Other
PES (director) (born 1973), film director and animator born Adam Pesapane
Passenger Environment Survey, quality-control system for transit systems
Payment for ecosystem services, incentives offered to farmers or landowners
Pensarn railway station, Gwynedd, Wales, by National Rail station code
Price elasticity of supply, a measure used in economics
PULHHEEMS, a system of grading physical and mental fitness used by Britains armed forces

See also
Pez (disambiguation)