WSI-titan 장치를 이용한 하부요추질환의 치료

Abstract

Introduction. The implants for spinal segmental instrumentation have been developed and changed many times since their birth. The WSI-titan system was developed under the aims of easy handling and providing stable fixation with short instrumentation. Objectives. The purposes are to introduce new device for spinal segmental instrumentation, the WSI-titan system, and to study the biomechanical features of WSI-titan system. And we checked bone mineral density, preoperatively and somatosensory evoked potentials, intraoperatively, to lessen the complications of the transpedicular screw fixation in spine surgery, which resulted from osteoporosis and malposition of screws. Materials and methods. We operated 16 cases of lower lumbar spinal diseases with WSI-titan system from November 1994 to August 1995 and the clinical results were analysed. Results Of the 16 cases, the mean age of the patients was 55 years old and three cases were male and 13 cases were female and average follow up periods was 16 months. Eight cases were diagnosed spinal stenosis and the levels of lesion were lumbar stenosis in six cases and lumbosacral stenosis in two cases. Eight cases were diagnosed spondylolisthesis, and among them, five cases were isthmic type and three cases were degenerative type, and anterior slippage occurred at IA in four cases and at L5 in four cases. The extents of fusion area were one segment in seven cases, two segments in eight cases, and three segments in one case. The cases which were measured bone mineral density lower than O.75g/㎤ (about -3 of young age in Z score) were excluded. Preoperative somatosensory evoked potentials were all normal and no significant change in intraoperative somatosensory evoked potenatials. Radiologic union was observed at six months of follow up in five cases, at nine months insix cases, at 12 months in four cases, and at 15 months in one case. The clinical results were excellent in seven cases, good in eight cases, and fair in one case. Conclusion. The segmental spinal instrumentation with WSI-titan system in treatment of lower lumbar spinal diseases was highly successful method with providing rigid stability, biocompatibility, and easy handling. And the measurement of preoperative bone mineral density was useful in selection of patient for preventing from loosening of pedicular screws. And intraoperative somatosensory evoked potential was also useful in preventing from nerve damage at pedicular screw insertion.