What Is Arthritis

Most bones of the body interact with others at a site called the joint. Most joints are so constructed as to permit some freedom of motion; this freedom may be very extensive (as in the shoulder or the elbow) or quite restricted (as in the joints found in the spinal column). In many, though not all, joints the bony surface concerned is covered by a layer of cartilage (gristle) and the joint may have a special delicate lining (the synovium).

Diseases of the joints are termed “arthritis.” Despite their relatively simple structure, the joints are involved in a great many local and general disorders. Some are related to the allergic disorders, as is seen in the acute arthritis of rheumatic fever or of a penicillin reaction. Damage to a joint, as through a fall or blow. may produce fractures in the bones, as well as a filling-up of the joint with an increased amount of secretion; this is spoken of as traumatic arthritis. In gout, deposits of a chemical (uric acid) may occur in and about the joints, leading to the condition known as gouty arthritis.

It is also important to know that not all of the pains and discomforts around joints are due to arthritis; many are due to disorders of the muscular tendons and are known as tendonitis. (Tendonitis in the shoulder joint is frequently referred to as “Charley-horse,”) The two major forms of arthritis which must be reckoned with are osteoarthritis and rheumatoid arthritis.