This study was a multicenter, retrospective analysis of preoperative and postoperative (1.5-6 months) full-body imaging of 237 primary total hip arthroplasty (standing and sitting positions). Patients were categorized as 1) stiff spine (standing sacral slope sitting sacral slope < 10°) and 2) normal spine (standing sacral slope-sitting sacral slope ≥ 10°). Results were compared using the paired t-test. The posthoc power analysis showed a power of 0.99.
The difference in mean standing and sitting sacral slope between the preoperative and postoperative measurements was 1°. However, in standing position, this difference was more than 10° in 14.4% of patients. In the sitting position, this difference was more than 10° in 34.2% of patients and more than 20° in 9.8% of patients. Postoperatively, 32.5% of patients switched groups based on the classification, which rendered the preoperative planning suggested by the current classifications flawed.
Current preoperative planning and classifications are based on a single acquisition of preoperative radiographs without the incorporation of possible postoperative changes in SPT. Validated classifications and planning tools should incorporate repeated measurements to determine the mean and variance in SPT and consider the significant postoperative changes in SPT.
方法:这项研究是一个多中心,回顾性分析237例原发性THA(站立和坐位)的术前和术后(1.5-6个月)全身影像学检查。患者分为:1)脊柱僵硬(站立骶骨斜坐骶骨斜度<10°)和2)正常脊柱(站立骶骨斜坐骶骨斜度≥10°)。使用配对t检验比较结果。事后功率分析显示功率为0.99。
结果:术前测量值和术后测量值之间的平均站立和坐姿骶骨斜率差异为1°。然而,在站立位置,14.4%的患者这一差异超过10°.在坐姿,该差异在34.2%的患者中超过10°,在9.8%的患者中超过20°.术后,32.5%的患者根据分类切换组,这使得当前分类建议的术前计划存在缺陷。
结论:目前的术前计划和分类是基于一次术前X线片的采集,而不考虑术后可能的SPT变化。经过验证的分类和计划工具应包括重复测量,以确定SPT的均值和方差,并考虑术后SPT的显着变化。