Manual of Surgery Volume Second: Extremities—Head—Neck. Sixth Edition.

by Alexis Thomson; Alexander Miles

Rigidity.—The pain produced by movement of the diseased portion of the spine causes reflex contraction of the muscles passing over it, and the affected segment of the column is thus rendered rigid. If the palm of the hand is placed over the painful area while the patient attempts to make movements of stooping, nodding, or turning to the side, it is found that the vertebræ implicated move en bloc instead of gliding on one another. This rigidity of the diseased portion of the column with “boarding” of the muscles of the back is one of the earliest and most valuable diagnostic signs of Pott's disease.

Deformity.—The most common and characteristic deformity is an abnormal antero-posterior curvature, with its convexity backwards. The situation, extent, and acuteness of the bend vary with the region of the spine affected, the situation of the disease in the bone, and the number of vertebræ implicated. When the disease has destroyed the bodies of one or two vertebræ, a short, sharp, angular deformity results; when it affects the surface of several bones, a long, wide curvature.

Lateral deviation is occasionally met with in the early stages of the disease as a result of unequal muscular contraction, and in the later stages from excessive destruction of one side of a vertebra, or from partial luxation between two diseased vertebræ.

Abscess Formation.—Spinal abscesses occur with greater frequency and at an earlier stage in adults than in children, because in adults the disease usually begins on the surface of the vertebræ. Pyogenic infection of such abscesses after they have burst externally constitutes one of the chief risks to life in Pott's disease.

X-Ray Appearances.—These, when considered along with the clinical signs, usually afford valuable information as to the exact seat and nature of the lesion and the number of vertebræ involved. It is recommended to compare the skiagram with that of the normal spine from the same region and from a patient of approximately similar age. The outlines of the bodies are woolly or blurred; in the early stage there may be clear areas corresponding to cheesy foci. In progressive cases the bodies may be altered in shape and in size, and from destruction and collapse of the bones there is altered spacing, both of the bodies and of the ribs. In the interpretation of skiagrams, help is often obtained from an alteration in the axis of bodies, an angular deviation often drawing attention to the lesion which is located at the “angle.” In children ([Fig. 213]) there is often a spindle-shaped shadow, outlined against the vertebral column, which is due to a cold abscess, and which extends above and below the bodies actually involved in the tuberculous process. The fusion of the bodies by new bone, which accompanies repair, can be followed in skiagrams taken at intervals.

Fig. 213.—Radiogram of Child's Thorax, showing spindle-shaped shadow at site of Pott's disease of fourth, fifth, and sixth thoracic vertebræ.

Cord and Nerve Symptoms.—When the spinal cord is pressed upon, the motor fibres are first affected as they lie superficially on the antero-lateral aspects of the cord, and are more sensitive to pressure. There is at first weakness or paresis of the muscles supplied from the part of the cord below the seat of pressure. The knee-jerks and plantar reflexes are exaggerated, and there is marked ankle clonus. Later, there is paralysis of the spastic type, varying in extent and sometimes amounting to complete paraplegia, and this may come on gradually or quite suddenly. There is wasting of muscles from disuse, and later a tendency to contracture and the development of deformities, as a result of sclerosis or descending degeneration of the cord.

The sensory fibres usually escape, although in some cases there is partial anæsthesia and perversion of sensation. When there is also myelitis, loss of sensibility to pain (analgesia) below the level of the lesion is one of the most characteristic symptoms. In severe cases there is incontinence of urine and of fæces, as the patient loses control of the sphincters. Acute bed-sores are not uncommon.