Fig. 216.—Hunch-back Deformity following Pott's disease of Thoracic Vertebræ.
(Photograph lent by Sir George T. Beatson.)
Cervico-thoracic Region.—When the lower cervical and upper thoracic vertebræ are affected, in addition to the fixed pain in the diseased bones, the patient complains of pain radiating along the distribution of the superficial cervical nerves and down the arms. There is often marked angular deformity. If an abscess forms, it may come to the surface in the lower part of the posterior triangle, or may spread into the posterior mediastinum or into the axilla. Sometimes the pus burrows behind the œsophagus and trachea, and it may find its way into the pleural cavity. The cord is not often pressed upon; when it is, the cervical sympathetic is implicated.
Thoracic or Dorsal Region.—When the disease is confined to the thoracic region, stiffness of the back and boarding of the vertebral muscles are prominent features. On being asked to pick up an object from the floor, the patient reaches it by bending his knees and hips, while he keeps his back rigid. He refuses to make any movement that involves jolting of the spine, such, for example, as jumping from a chair to the ground. Children often attempt to take the weight off the diseased vertebræ by placing the palms of the hands on the edge of a chair so that the weight is borne by the arms.
Angular deformity is often well marked, and may implicate several vertebræ. In order to maintain the head erect, the spine above and below the seat of disease becomes unduly arched forward—compensatory lordosis. In advanced cases the ribs become approximated, and the lower end of the sternum is projected forward. The antero-posterior diameter of the thorax is thus increased, while its vertical diameter is diminished. These changes, together with the telescoping of the vertebral bodies, lead to the deformity characteristic of the tuberculous hunch-back (Fig 216). The alterations in the shape of the chest may lead to functional disturbances of the heart and lungs.
Dorsal Abscess.—As already mentioned, the earliest stage of abscess is well seen in skiagrams ([Fig. 213]), especially in children. When there is an extension of the suppurative process, the pus may pass directly backwards along the posterior branches of the intercostal vessels and nerves, and come to the surface behind the transverse processes, or it may travel forward between the pleura and the ribs, and, passing along the course of the lateral cutaneous branches of the intercostals, come to the surface opposite the middle of the rib. In the latter case, the abscess is liable to be mistaken for one associated with tuberculous disease of the rib, particularly as the rib is usually found to be bare. In rare cases the pus opens into the pleura, giving rise to empyema. When the disease is on the anterior surface of the bodies of the lower thoracic vertebræ, the pus may spread down through the pillars of the diaphragm and reach the sheath of the psoas muscle.
Treatment is on the usual lines.
Fig. 217.—Attitude in Pott's disease of Thoracico-lumbar Region of Spine.
Thoracico-lumbar Region.—The symptoms are similar to those of disease in the thoracic region. Children while standing often assume a characteristic attitude—the hips and knees are slightly flexed, and the hands grasp the thighs just above the knees ([Fig. 217]). In this way the weight is partly taken off the affected vertebræ and borne by the arms. If the child is laid on its back and lifted by the heels, the spine remains rigid. By this test a projection due to tuberculous disease may be differentiated from one due to rickets, as in the latter case the projection disappears.