Experimental structural scoliosis.

Progressive structural scoliosis in growing rabbits has been produced. Tethering the thoracic spine into the form of an asymmetric lordosis produces a slowly progressive structural scoliosis by purely mechanical means. The addition of a contralateral release of the paraspinal muscles leads to a very progressive deformity with early cardiorespiratory failure. This release, however, was performed with an electric soldering iron and subsequent study showed that in those animals with severe progressive deformity there was localised spinal cord damage. We suggest that it is this neural damage and not the muscle release which leads to rapid progression. The clinical implications are important in that neurological dysfunction seems to render the spinal column less able to resist mechanical buckling and may be the crucial factor differentiating severely progressive from more benign curves.