Surgical treatment of Degenerative Lumbar Spinal Disorders Using the Graf System: over three year results

Kim, Ki Soo; Choi, Young Soo; Kim, Do Yong; Chung, Yang Min; Chung, Sun Yong

Abstract

The Graf system has supposed advantages with its flexible nature, as compared with rigid fixation. But there have been no reports about effects in the adjacent motion segment after soft stabilization. The purpose of this study was to evaluate the radiologic changes occuring in the adjacent segments of the Graf system and to assess its ability stabilizing the lumbar spine. A retrospective review of radiographs and medical records was undertaken in 32 cases who had been treated with the Graf system in degenerative lumbar spinal disorders. The average age at operation was 52.5 years and the average follow up period was 49.6 months. The results of this study were as follows: clinical assesments based on the Kirkaldy-Willis criteria revealed excellent in 13 cases (40.6%), good in 16 cases (50%), fair in 2 cases (6.3%) and poor in 1 case (3.1%). Radiologically we analysed the adjacent segments in 25 cases except the cases which did not have the correspondence between the clinical findings and the radiological findings, and the fixated segments in 32 cases. The acceleration of degenerative changes were found in the above adjacent segments in 11 cases (44%) and in the below adjacent segments in 5 cases (27.7%). Also, those changes were found in the fixated segments with discectomy in 19 cases (50%) and in the fixated segments without discectomy in 9 cases (37.5%). In conclusion, we think that the Graf system in a lumbar region may biomechanically influence the adjacent segments. The mechanical effects of the device could be changed by the polyester bands which were followed for a longer period of time in the fixated segments. Therefore, randomized prospective studies comparing the Graf system to other treatement methods could provide clear indications for lumbar spinal disorders.