低骨密度对Lenke Ι型青少年特发性脊柱侧凸患者手术疗效的影响

The influence of lower bone mineral density on surgical outcomes in Lenke Ⅰ type adolescent idiopathic scoliosis

中文关键词:  青少年特发性脊柱侧凸  骨密度  手术疗效

英文关键词:Adolescent idiopathic scoliosis  Bone mineral density  Surgical outcomes

中文摘要:

  【摘要】 目的：探讨低骨密度对LenkeⅠ型青少年特发性脊柱侧凸（adolescent idiopathic scoliosis, AIS）患者后路矫形内固定术后矫形疗效的可能影响。方法：选取2007年6月～2008年8月在南京鼓楼医院脊柱外科行后路椎弓根螺钉矫形内固定融合术的LenkeⅠ型AIS女性患者37例，年龄11~17岁（14.3±1.3岁），术前Cobb角40°~66°（48.9°±6.7°）。术后随访12~36个月，平均20.8±7.4个月。术前均接受双能X线吸收骨密度仪扫描测定骨密度，根据股骨颈骨密度Z值将AIS患者分为骨密度正常组（Z值>-1.0）与骨密度减低组（Z值≤-1.0），分别测量两组患者术前、术后早期（术后3个月）及末次随访时的主弯Cobb角、胸椎后凸角（TK）、腰椎前凸角（LL）、冠状位顶椎偏移（AVT）、C7中垂线与骶骨中线的距离（C7-CSVL）和C7中垂线与骶骨后上缘的距离（SVA），比较两组间的差异。结果：37例患者中，15例骨密度正常（骨密度正常组），22例骨密度减低（骨密度减低组）。两组患者术前平均年龄、Risser征、内固定节段数、置入物密度及术后随访时间均无显著性差异（Ｐ>0.05）；两组术前平均Cobb角、AVT和C7-CSVL无显著性差异（Ｐ>0.05）。术后3个月及末次随访时两组平均Cobb角和平均矫正率、末次随访时平均矫正丢失及矫正丢失率无显著性差异（Ｐ>0.05）；术后3个月及末次随访时两组平均AVT、C7-CSVL无统计学差异（Ｐ>0.05）；C7-CSVL改变亦无显著性差异（Ｐ>0.05）。两组术前、术后3个及末次随访时的平均TK、LL、SVA均无显著性差异（Ｐ>0.05），SVA改变亦无显著性差异（Ｐ>0.05）。结论：低骨密度状态对LenkeⅠ型AIS患者后路矫形内固定融合术的疗效无明显影响。

英文摘要:

  【Abstract】 Objectives: To determine the role of preoperative lower bone mineral density(BMD) in surgical outcomes of patients with Lenke Ⅰ type adolescent idiopathic scoliosis(AIS). Methods: Thirty-seven female patients with Lenke Ⅰ type AIS who underwent posterior correction and fusion with pedical screw instrumentation between June 2007 and August 2008 were included in this study. The mean age of AIS patients was 14.3±1.3 years(rang from 11 to 17 years), and the mean Cobb angle was 48.9°±6.7°(rang from 40° to 66°). BMD was assessed in every patient before surgery by dual energy X-ray absorptiometry(DEXA).　All patients were divided into 2 groups according to the Z-score of their femur neck BMD: nonosteopenic patients(Z>-1.0) and osteopenic patients(Z≤-1.0). The radiography parameters including Cobb angle, thoracic kyphosis(TK), lumbar lordosis(LL) and apical vertebral translation(AVT) were measured preoperatively and immediatly postoperatively(3 months postoperation) as well as at the latest follow-up. C7 plumb line to center sacral vertical line(C7-CSVL) was used to evaluate the coronal balance while sagittal vertical axis(SVA) was measured to assess the sagittal balance. All the parameters between two groups were compared. Results: 15 patients were included in nonosteopenic group and 22 patients in osteopenic group, respectively. The mean age, Risser sign, instrumented level, implant density and follow-up time were similar(Ｐ>0.05). No difference with respect to the Cobb angle, AVT, C7-CSVL was observed between two groups preoperatively(Ｐ>0.05). There was no difference in the mean Cobb angle, correction loss, correction loss rate, AVT, C7-CSVL or the change of C7-CSVL immediatly postoperatively and at latest follow-up(Ｐ>0.05). In addition, there was no difference in terms of the mean TK, LL, SVA or the change of SVA between these two groups preoperatively and immediatly postoperatively as well as at the latest follow-up(Ｐ>0.05). Conclusions: Preoperative lower BMD in Lenke Ⅰ type AIS patients does not play a significant role in determining the surgical outcomes after using posterior correction and fusion with pedical screw instrumentation.