On the basis of chronaximetric, myomechanical, and histological examination of the long spinal muscles we assume that idiopathic scoliosis is due to muscle imbalance at the level of its primary curve. This dystonia of muscles may result from asymmetrical congenital, or sometimes inherited, segmental abnormalities of innervation of spinal muscles, or from reflex spasm induced by inflammatory lesions within the vertebral column or in its vicinity, in lungs, or in mediastinal organs.
The convexity of the angulation is always directed toward the weakened muscles. The muscles of the Scapula and of the arm have no influence on the production of scoliosis. The imbalance of the anterolateral abdominal muscles leads to lateral shifting of the trunk.
Scoliosis may be cured or its progress prevented only by early restoration of muscle balance. For this purpose the definitively damaged muscles must be replaced by transplantation of healthy muscles of the scapula or the arm (the trapezius, rhomboidei, or latissimus dorsi). The hyperactive muscles should be weakened by section or denervation. The secondarily and temporarily weakened muscles must be strengthened by the introduction of artificial muscles. This muscle alloplasty leads, in scoliosis of the first degree, to full regression of the angulation or at least to considerable improvement and stabilization. In scoliosis of the second degree springplasty should be performed after stretching of the angulation of less than 30 degrees by conservative measures or by the spine-liberation operation after Mayer's method with temporary application of the screw-spring device or distracter.
In scoliosis of the third degree after maximal correction of the angulation by conservative measures or by spine liberation and distraction, the excess bone of the laminae and of the vertebral bodies must be removed and pulling springs must be applied in the second operation.
The lateral shifting of the trunk due to dystonia of the obliquus externus and internus abdominis muscles may be successfully reduced by oblique fascial transplant after the method of Lowman, with the use of the latissimus dorsi, serratus anterior, trapezius, or tensor fasciae latae muscles.
Copyright 1958 by The Journal of Bone and Joint Surgery, Incorporated