Caries

Caries, derived from a Latin word signifying rottenness, decay, is a term applied to the gradual destruction of a bone by ulceration. It must be distinguished from necrosis, in which portions of bone perish en masse. With a view to emphasising this difference, caries has been described as the molecular death of bone, imperceptible portions of inflamed bone being destroyed and removed in the form of purulent exudation, while in necrosis Actual masses of dead bone become separated. Thus the two terms caries and necrosis as applied to bone, correspond to the terms ulceration and gangrene as applied to other tissues. As the result of the carious process an abscess is formed, which usually discharges externally, leaving an open sinuous track at the bottom of which the dead bone is exposed. Caries is particularly apt to attack the vertebrae, leading to the various forms of spinal abscess, and to the deformity known as angular curvature of the spine. This form of bone ulceration usually occurs in strumous subjects, in whom the spinal mischief, serious as it is of itself, is very frequently associated with disease of other parts of the body. Strumous caries may also affect the joint ends of long bones and the bones of the carpus, and of the foot.