Scoliosis means lateral curvature of the spine which may occur in the lumbar, thoracolumbar, or thoracic regions. The higher the location of the scoliosis in the vertebral column, the greater the likelihood of severe deformity and of disturbance of cardiopul monary function (heart failure of the hunchback). Lumbar scoliosis is relatively benign. Thoracic scoliosis is associated with rotation of the spine and prominence of the posterior angles of ribs which form the hump or gibbus, and gives rise to the hunchback appearance. Although commonly called kyphoscoliosis, forward angulation of the spine or kyphosis is usually not the major of kyphoscoliosis; indeed marked lumbar or cervical lor dosis is characteristic.
Etiology and Mechanism of Scoliosis
Four types of scoliosis are recognized. The largest group is idiopathic, developing in childhood and forms 80 per cent. of all scoliosis. When idiopathic scoliosis occurs in infancy, boys predominate in the ratio of 6 to 4, and the curvature is usually to the left; when it occurs in adolescence, girls predominate in the ratio of 9 10 1 and the curvature is usually to the right.
Genetic abnormalities may be due to autosomal domi- nant conditions such as neurofibromatosis, osteogenesis imperfecta, Marfan’s and Ehlers-Danlos syndromes, or autosomal recessive conditions, including Morquio’s dis- ease, Hurler’s syndrome, and diatrophic dwarfism. The mechanism of the deformity is probably a combination of abnormal bone growth, usually in the vertebrae, and altered distribution of muscular forces. The importance of each factor will vary according to the type of scoliosis.
The degree of deformity varies between individuals and at different ages. In one series, two thirds of the patients with thoracic idiopathic scoliosis had curvature of the spine greater than 70 degrees, and in over a fourth it was greater than 100 degrees. Scoliosis may also follow fibrotic disease of the lungs and pleura, e.g., tuberculous empyema. This is not as severe as the scoliosis that may develop in the aforementioned varieties, and cardio• pulmonary disturbances are due largely to the thoracic disease.
The factors which influence the progres- Sion of minor degrees of scoliosis in childhood are poorly understood. In some it may disappear, but in others, ap- parently similar, rapid deformity may develop pulmonary abnormalities are most likely with thoracic deformities, especially when due to muscular paralysis and when the deformity has occurred in infancy and early childhood rather than later in life.
Treatment of Scoliosis.
Progress of the deformity is usually preventable by a Milwaukee brace (frame) in growing patients with idiopathic curves of less than 50 degrees. With more severe curves operation may be required to reduce the curvature. At best about 50 per cent reduction in the curvature may be obtained, but there is no general agreement on the best surgical procedure. Prevention and treatment of recurrent bronchitis (see Ch. 503) is important as the pulmonary damage is additive to the effects of the deformity.
Cardiopulmonary Failure of Scoliosis
The treatment of acute cardiopulmonary failure is similar to that provided in chronic obstructive bronchitis. It includes the treatment of bronchial infection and retained secretions with antimicrobial drugs and physiotherapy, con- trolled administration of oxygen, venesection for polycythemia, and diuretics. Chronic cardiopulmonary failure requires attention to bronchial toilet, diuretics, and digitalis, and repeated venesection to maintain the hematocrit below 55 per cent.
Surgical correction of the deformity at this late stage is not feasible; surgery is usually restricted to the prevention of paraplegia if early signs of spinal cord damage appear. A period of assisted ventilation may be necessary for acute cardiorespiratory failure, but intubation may be difficult owing to the marked cervical lordosis. Intermittent positive pressure inspirations have caused increased lung compliance, but the effect lasted only up to three hours, and the clinical significance, if any, has not been assessed.