腰骶弯椎体角度水平化在退行性脊柱侧凸冠状位矫正中的意义

The significance of lumbosacral curve vertebral body leveling in coronal correction of degenerative scoliosis

中文关键词:  退行性脊柱侧凸  腰骶弯  冠状倾斜角  冠状面平衡距离

英文关键词:Degenerative scoliosis  Lumbosacral curve  Coronal tilt  Coronal balance distance

中文摘要:

  【摘要】 目的：分析脊柱融合术对成人退行性脊柱侧凸患者术后冠状面失衡的矫正情况，探讨腰骶弯最倾斜椎体（L4或L5椎体）角度水平化对冠状面失衡矫正的影响。方法：回顾性分析2019年1月~2023年3月在天津市人民医院行矫正手术的61例退行性脊柱侧凸患者的临床资料，男17例，女44例；年龄51~78岁（63.57±8.41岁）；体重指数15.79~35.55kg/m2（25.83±3.69kg/m2）。根据术前Obeid分型及融合节段的长短将患者分为凹型长节段组（17例），凹型短节段组（15例）；凸型长节段组（15例），凸型短节段组（14例）。在术前、术后3d全脊柱正侧位X线上测量冠状面影像学参数[Cobb角、冠状面平衡距离（coronal balance distance，CBD）、冠状倾斜角）]和矢状面影像学参数（矢状面轴向距离、胸椎后凸角、腰椎前凸角、骨盆入射角、骨盆倾斜角、骶骨倾斜角），比较各组术后冠状面及矢状面平衡矫正情况。使用Pearson相关分析分别对凹型和凸型两组病例中腰骶弯最倾斜椎体角度（即L4或L5最大冠状倾斜角）矫正比例和术后CBD的关系进行研究；比较四组患者的手术时间、术中出血量以及术前术后的疼痛视觉模拟量表（visual analogue scale，VAS）评分。结果：凹型长节段组、凸型长节段组、凸型短节段组术后冠状面Cobb角、CBD以及L4或L5最大冠状倾斜角与术前比较差异均有统计学意义（P＜0.05）；凹型短节段组术后冠状面Cobb角以及L4或L5最大冠状倾斜角与术前比较差异均有统计学意义（P＜0.05），CBD与术前比较差异无统计学意义（P=0.085）。Pearson相关分析显示凸型患者术后CBD和冠状倾斜角矫正比例存在显著负相关性（r=-0.570，P<0.01），术后CBD=32.81-（28.38×冠状倾斜角矫正比例）；凸型患者L4或L5冠状最大倾斜椎体角度矫正比例超过45%时，预测CBD能够矫正至20mm以内。凹型患者术后CBD和冠状倾斜角矫正比例相关性不显著（r=0.098，P=0.59）。凸型组及凹型组短节段手术患者手术时间和出血量均小于长节段手术患者，四组患者术后疼痛VAS评分均有显著性改善（P＜0.05）。结论：成人退行性脊柱侧凸中凸侧失衡患者短节段或长节段融合均能矫正冠状面失衡，而凹侧失衡患者需要长节段融合才能矫正冠状面失衡。为获得更好的术后冠状面平衡，凸侧失衡患者L4或L5冠状最大倾斜椎体矫正比例应超过45%。

英文摘要:

  【Abstract】 Objectives: To analyze the correction of postoperative coronal imbalance in adult degenerative scoliosis patients undergoing spinal fusion surgery, and to explore the impact of leveling of the most tilted vertebra(L4 or L5) in the lumbosacral curve on the correction of coronal imbalance. Methods: A retrospective analysis was conducted on 61 patients(17 male and 44 female; aged 51 to 78 years, mean 63.57±8.41 years; body mass index 15.79-35.55kg/m2, mean 25.83±3.69kg/m2) who underwent degenerative scoliosis correction surgery between January 2019 and March 2023 in Tianjin Union Medical Center. The patients were categorized based on the Obeid classification and the length of fusion segments into concave long segment group(17 cases), concave short segment group(15 cases), convex long segment group(15 cases), and convex short segment group(14 cases). Coronal radiographic parameters[Cobb angle, coronal balance distance(CBD), coronal tilt angle] and sagittal radiographic parameters(sagittal vertical axis, thoracic kyphosis, lumbar lordosis, pelvic incidence, pelvic tilt, sacral slope) were measured on full spine anteroposterior and lateral X-rays preoperatively and on 3d postoperatively. The postoperative coronal and sagittal imbalance corrections were compared between groups. Pearson correlation analysis was performed to investigate the relationship between the correction ratio of the maximal coronal tilt angle in the lumbosacral curve(L4 or L5) and postoperative CBD. The operative time, blood loss, and visual analogue scale(VAS) pre- and postoperatively were compared between the four groups. Results: The postoperative coronal Cobb angle, CBD, and maximal coronal tilt angle at L4 or L5 of the concave long segment group, convex long segment group, and convex short segment group were statistically different from those before operation(P<0.05). In the concave short segment group, the postoperative coronal Cobb angle and maximal coronal tilt angle at L4 or L5 were significantly different from those before operation(P<0.05), while no significant difference was found between pre- and postoperative CBD(P=0.085). Pearson correlation analysis revealed a significant negative correlation(r=-0.570, P<0.01) between postoperative CBD and coronal tilt correction ratio in the convex group, with the linear regression equation being postoperative CBD=32.81-28.38 × coronal tilt correction ratio. When the correction ratio of the maximal coronal tilt angle at L4 or L5 exceeding 45% in convex coronal malalignment patients, it′s predicted that the CBD could be corrected to within 20mm. No significant correlation was found between postoperative CBD and the coronal tilt correction ratio in the concave group(r=0.098, P=0.59). Patients in both the convex and concave short segment groups had shorter operative time and less blood loss than long segment groups. Postoperative VAS scores improved significantly in all groups(P<0.05). Conclusions: In adult degenerative scoliosis patients with convex coronal malalignment, both short and long segment fusions are capable of correcting coronal imbalance. Concave coronal malalignment patients require long segment fusion for the correction of coronal imbalance. To achieve optimal coronal balance in convex coronal malalignment patients, a correction ratio of the maximal coronal tilt angle at L4 or L5 shall exceed 45%.