退变性脊柱侧凸长节段固定矫形融合术后冠状面失平衡相关危险因素分析

Analysis of the risk factors related to coronal plane imbalance after correction of degenerative scoliosis

中文关键词:  退变性脊柱侧凸  长节段固定融合  冠状面失平衡  危险因素

英文关键词:Degenerative scoliosis  Long-segment fixation and fusion  Coronal imbalance  Risk factor

中文摘要:

  【摘要】 目的：探讨退变性脊柱侧凸患者长节段固定矫形融合术后冠状面失平衡的相关危险因素。方法：回顾性分析2014年1月～2017年2月在我院行长节段固定矫形融合术并具有完整影像学及随访资料的61例退变性脊柱侧凸患者。男24例，女37例；年龄53～78岁（59.0±6.1岁）；按鼓楼医院退变性脊柱侧凸分型：A型31例，B型19例，C型11例。固定融合范围：T10~L5 18例，T10~S1 6例，T10~S2 6例，T12~L5 14例，L1~L5 8例，L1~S1 7例，L2~S1 2例。随访18~85个月（平均36.4个月），根据末次随访时冠状面平衡情况将其分为平衡组和失平衡组，比较两组术前和末次随访时的主弯Cobb角、冠状平衡距离（CBD）、畸形矫正率和术前L5倾斜度、畸形分型、腰弯顶椎位置、顶椎旋转度、截骨级别、固定节段及数量、远端固定椎、腰骶弯Cobb角、主弯Cobb角与腰骶弯Cobb角比值等，将具有统计学差异的指标进行二元Logistic回归分析。结果：61例患者中，末次随访时8例出现冠状面失平衡加重或新发失平衡。两组患者术前主弯Cobb角、CBD、顶椎旋转度、腰弯顶椎位置、截骨级别、固定节段及数量、远端固定椎无统计学差异（P>0.05），术前腰骶弯Cobb角、术前主弯Cobb角与腰骶弯Cobb角比值、术前L5倾斜角、术后主弯Cobb角、术后CBD、畸形矫正率及畸形分型有统计学差异（P<0.05）。二元逻辑回归分析显示术后冠状面失平衡与术前主弯Cobb角、术前腰骶弯Cobb角、术前L5倾斜度呈正相关，OR值分别为1.158、1.210、1.322（P<0.05），与畸形矫正率、顶椎旋转度、固定节段数量无显著相关性（P>0.05）。结论：退变性脊柱侧凸长节段固定矫形融合术后可出现冠状面失平衡，术前主弯及腰骶弯Cobb角较大、L5倾斜角较大是退变性脊柱侧凸术后冠状面失平衡或原有失平衡加重的危险因素。

英文摘要:

  【Abstract】 Objectives: To investigate the risk factors of postoperative coronal plane imbalance in patients with degenerative scoliosis after long-segment fixation and fusion. Methods: The data of 61 patients with degenerative scoliosis underwent long-segment fixation and fusion in our hospital from January 2014 to February 2017 and with complete imaging and follow-up data were reviewed retrospectively. There were 24 males and 37 females with a mean age of 59.0±6.1(53-78 years) and a mean follow up period of 36.4 months(18－85 months). According to the classification of degenerative scoliosis of Nanjing Drum Tower Hospital, 31 cases were of type A , 19 cases of type B, and 11 cases were of type C. Ranges of segment fixation and fusion: T10-L5 in 18 cases, T10-S1 in 6 cases, T10-S2 in 6 cases, T12-L5 in 14 cases, L1-L5 in 8 cases, L1-S1 in 7 cases, and L2-S1 in 2 cases. The patients were divided into two groups of balance group and imbalance group according to the coronal plane conditions at the final follow up. The Cobb angle of main curvature, coronal balance distance(CBD), correction rate, L5 tilt, deformity classification, apical vertebrae of lumbar curvature, rotation of apical vertebrae, grade of osteotomy, number of fixed segments, lower instrumented vertebra, Cobb angle of lumbosacral curvature, and ratio of Cobb angle of main curvature to Cobb angle of lumbo-sacral curvature before operation and at the final follow up were recorded and compared between the two groups, and the differences with statistical significance were analyzed with binary Logistic regression analysis. Results: Of the 61 patients, aggravated coronal plane imbalance or new-onset imbalance occurred in 8 cases at the final follow up. There were no statistical differences between the two groups in terms of preoperative Cobb angle of main curvature, CBD, apical vertebrae of lumbar curvature, rotation of apical vertebrae, grade of osteotomy, number of fixed segments, and lower instrumented vertebra(P>0.05), while there were statistical differences in terms of preoperative Cobb angle of lumbosacral curvature, ratio of Cobb angle of main curvature to Cobb angle of lumbo-sacral curvature, postoperative Cobb angle of main curve, preoperative L5 tilt, deformity correction, and deformity classification(P<0.05). The results of binary Logistic regression analysis showed that the postoperative coronal imbalance was positively correlated with the preoperative Cobb angle of main curvature, lumbosacral angle, and L5 tilt(OR＝1.158, 1.210, 1.322; P<0.05), yet it was not correlated significantly with correction rate, rotation of the apical vertebrae, and the number of fixed segments. Conclusions: Coronal imbalance may occur after long-segment fixation and fusion surgery in the degenerative scoliosis patients. Large Cobb angles of main curvature and lumbosacral curvature before surgery, and large L5 inclination are the risk factors for postoperative coronal plane imbalance or aggravated coronal plane imbalance.