POTT'S DISEASE, or SPINAL CARIES. A tuberculous inflammation of the bodies of the spinal vertebra., named after Dr. Percival Pott (q.v.), the surgeon who first accurately de scribed the condition and its nature. In this affection as the tubercular tissue replaces the normal bone-tissue of the vertebn:-e, softening re sults together with marked deformity of the spine. This deformity is usually seen as an angular projection or hump in the upper part of the back. It is caused from compression or erosion of the softened bodies of the vertebra:, allowing them to be pressed more closely to gether, which in turn causes their sharp spinous processes to project posteriorly beyond the line of the spines above and below the affeeted area. The most common period of development of Pott's disease is in childhood and youth, while the body is undergoing rapid growth. The formation of pus is a not infrequent accom paniment of tuberculosis in the spinal region, as in other localities, and this pus often collects itself together into an abscess, spoken of very often as a cold abscess (see ABSCESS), from the fact that the inflammatory reaction present is not severe. These abscesses sometimes point in the back adjacent to the vertebra, and often occupy the posterior mediastinal space (see CHEST and PLEURA ) , where they are known as abscesses. Occasionally the pus in
spinal caries burrows downward beneath the muscles of the back and may appear in the lumbar region, constituting a lumbar abscess, or following the psoas muscle it may pass for ward through the pelvis and appear near the attachment of that muscle in the groin ; in this case it is known as a psoas abscess. When the disease is located in the cervical vertebra and an abscess forms, it appears frequently in the pharynx. After recovery takes place in tuber culosis of the vertebrae, ankylosis is present in the joints, involved from adhesions between con tiguous bony surfaces. In the treatment of Pott's disease constitutional measures must re ceive the most thorough consideration. General hygienic measures must be combined with abun dance of fresh air, nutritious food, tonics, mas sage, and as great amount of exercise as the con ditions permit. The surgical treatment consists of immobilization of the spinal column by means of frames, the plaster of Paris jacket, the jury mast, etc. Such measures attain their results by giving rest to the diseased parts, allaying irri tation, preventing attrition and crushing of soft ened bones. and in limiting the amount of de formity after the disease process has become quiescent.