Radiographic Changes of Adjacent Upper Segment Performed Short Segmental Lumbosacral Fusion: Does Total Laminectomy Influence Adjacent Upper Segmental Instability? / 대한척추외과학회지

ABSTRACT

STUDY DESIGN: Retrospective study. OBJECTIVES: The purpose of this study was to compare factors that influence degenerative changes in patients undergoing total laminectomy and patients undergoing partial laminectomy. SUMMARY OF LITERATURE REVIEW Lumbar or lumbosacral fusion with total or partial laminectomy may result in adjacent segment problems of the upper segment. However, the differences between the two procedures that may influence adjacent segment instability are still controversial. MATERIALS AND METHODS: We evaluated 95 patients, followed up for at least 2 years, who had been treated with short level (at most 2 levels) posterior lumbar interbody fusion with pedicle fixation, secondary to spinal stenosis. Treatment procedures included total laminectomy (42 cases) and partial laminectomy (53 cases). We analyzed the preoperative status of the intervertebral discs (Thompson grade), difference of disc height, and difference between preoperative segmental sagittal angle and last follow-up sagittal angle. We excluded cases that required revision secondary to infection, nonunion, or hematoma formation. However, we included cases that required revision due to adjacent segmental problems during the follow-up period. RESULTS: The mean age of the patients treated with total laminectomy was 59.0+/-10.9 years, and of the patients treated with partial laminectomy was 58.8+/-10.2 years. The preoperative Thompson grade showed no statistical difference. The difference in disc height and segmental sagittal angle between the preoperative and last follow-up examinations showed no statistical difference between the two groups. CONCLUSIONS: There was no significant difference in the radiographic or clinical outcomes based on removal or preservation of posterior structures. Nevertheless, we need further follow-up to evaluate adjacent segment degeneration.