THE SIGNIFICANCE OF THE INTERVERTEBRAL DI SC FOR THE LOSS OF CORRECTION IN OPERATIVELY STABILIZED FRACTURES OF THE THORACOLUMBAR SPINE

In 112 patients with a traumatic fracture of the thoraco-lumbar spine operatively treated with different dorsal stabilization techniques fro m 1983 to 1988, the frontal and sagittal planes of the spine were anal yzed over a follow-up period of 5 years. In 14 cases Harrington instru mentation was used, in 81 cases, transpedicular plates, and in 17 case s, a fixateur interne. With regard to the frontal plane the overall lo ss of correction was 2.3-degrees: with Harrington stabilization 0.7-de gree, with fixateur interne 2.6-degrees, and with plate fixation 3.7-d egrees. In the sagittal plane the height of the damaged spinal segment and the kyphotic angulation were determined. The mean height loss aft er operative repositioning was 12%. With Harrington stabilization it w as 16%, with plate fixation 12%, and with fixateur interne 9%. Kyphosi s of 9.6-degrees was determined before surgery, and 0.9-degrees after. The angle subsequently deteriorated, reaching 12.6-degrees by the end of 5 years. The loss of correction was 9.3-degrees in the fixateur in terne group, 10.9-degrees in the Harrington stabilization group, and 1 5-degrees in patients in whom plate fixation had been performed. The c ause of deterioration was destruction of the invertebral disc in 66% o f cases, and angulation of the fractured vertebral body in only 33%. O nly in the first 2 years after operation was loss of reposition in the vertebral body observed. In conclusion, stabilization should be compl emented by removal of the damaged adjacent disc and intercorporeal aut ogenous bone grafting from the dorsal or ventral approach.