Scoliosis induced by asymmetric lordosis and rotation - An experimental study

Study Design. An experimental study of the influence of intrinsic muscle imbalance on the spinal column of a growing rabbit. Objectives. To create an in vivo experimental model of scoliosis for comparison with human scoliosis. Summary of Background Data. There is evidence that asymmetric lordosis may produce scoliosis and that there is muscle imbalance in scoliotic patients. Methods. Surgical tethering of the spinous apophysis and transverse apophysis of rabbits was performed at three upper levels on the same side of the spine to simulate dominance of one side of the paravertebral musculature over the other. Results. All animals exhibited scoliosis that was convex toward the side opposite that receiving surgery. Radiography showed the curve to increase with time. Postmortem examination pf vertebrae revealed structural alterations similar to those produced in human scoliosis. Conclusions. Intrinsic muscle imbalance in the spinal column of the experimental growing animal may produce scoliosis with characteristics similar to those of human idiopathic scoliosis.