上胸段半椎体切除术后远端冠状面S畸形进展的危险因素

Horizontalization of UIV as a factor predicting the progression of distal coronal S-type scoliosis after upper thoracic hemivertebra resection and short fusion

中文关键词:  半椎体畸形  上胸段  冠状面远端畸形进展

英文关键词:Hemivertebra  Upper thoracic  Coronal caudal curve progression

中文摘要:

  【摘要】 目的：分析上胸段半椎体切除术后远端冠状面S畸形进展的发生率、特点及危险因素。方法：回顾性分析2005年1月~2015年1月于我院行后路半椎体切除术治疗的上胸段半椎体患者的临床及影像学资料68例。其中男性42例，女性26例；手术时年龄4.4±1.1岁（3~6岁），随访时间均在5年以上。所有患者均具有完整的术前及术后各次随访临床及影像学资料。根据术后终末随访时是否出现S畸形（≥20°），且远端代偿性胸弯（caudal thoracic curve，CTC）或远端代偿性腰弯（caudal lumbar curve，CLC）任一进展较术后2周≥20°为界限，将患者分为进展组（progressive group，PG）与非进展组（non-progressive group，NPG）。分别比较两组患者的性别、年龄、Risser征、半椎体位置、融合节段数、顶椎旋转分级、平均随访时间等临床资料及术前及术后各次随访局部侧凸Cobb角、远端胸弯Cobb角、远端腰弯Cobb角、躯干平衡（trunk shift，TS）、近端固定椎倾斜角（upper instrumented vertebra tilt，UIV tilt）、远端固定椎倾斜角（lower instrumented vertebra tilt，LIV tilt）、远端固定椎椎隙成角（LIV/LIV+1 disc angle）、T1倾斜角（T1 tilt）、头部倾斜（head shift）、颈部倾斜（neck tilt）、肩部平衡（radiographic shoulder height，RSH）等影像学资料，分析上胸段半椎体畸形切除术后UIV水平化对远端冠状面畸形进展的影响。结果：上胸段半椎体切除联合后路内固定融合术平均矫正率（74.3±15.3）%，终末随访平均丢失率（4.3±2.2）%。术后冠状面失代偿6例，均为新发S畸形，发生率为8.8%。根据患者是否发生S畸形将患者分为畸形进展组（6例）与非进展组（62例），两组患者初次手术的性别、年龄、Risser征、半椎体位置、融合节段数、是否存在顶椎旋转、平均随访时间均无统计学差异（P>0.05）。两组术前冠状面影像学参数：局部侧凸Cobb角、冠状面平衡、远端代偿性胸弯、远端代偿性腰弯、T1倾斜角、头部倾斜角、颈部倾斜角、肩部平衡均无统计学差异（P>0.05）。两组间术后各次随访的局部侧凸Cobb角、近端固定椎倾斜角及T1倾斜角均有统计学差异（P<0.05）。进展组患者近端固定椎倾斜角及T1倾斜角从术后至终末随访时逐渐增大，术后5年及终末随访对比术后2周有统计学差异（P<0.05）；术后进展组患者术后半年及之后各次随访的腰段代偿弯逐渐增大，与非进展组对比有统计学差异（P<0.05）；术后进展组患者术后1年及之后各次随访的胸椎代偿弯逐渐增大，与非进展组对比有统计学差异（P<0.05）；术后5年及终末随访进展组患者颈部倾斜逐渐增大，与非进展组对比有统计学差异（P<0.05）。术后各次随访TS、最下固定椎倾斜角、远端固定椎椎间隙成角、头部倾斜、肩部平衡均无明显变化，无统计学差异（P>0.05）。结论：上胸段半椎体切除不彻底引起的UIV水平化不足可能是术后融合远端S曲线进展的危险因素。

英文摘要:

  【Abstract】 Objectives: To analyze the incidence, characteristics and risk factorsof postoperative coronal S-type scoliosis progression after upper thoracic hemivertebra resection and short fusion. Methods: Retrospective analysis was made on the clinical and imaging data of 68 patients with upper thoracic hemivertebra treated by posterior hemivertebra resection combined with internal pedicle screw fixation in our hospital from January 2005 to January 2015. There were 42 males and 26 females with a mean age of 4.4±1.1 years (3-6 years). All patients had 5 years follow-up at least. All patients had complete preoperative and postoperative follow-up clinical and imaging data. The patients were divided into two groups: progressive group(PG) and non-progressive group(NPG) according to whether there was S-type scoliosis (≥20°) at the final follow-up and the progression of either caudal thoracic curve(CTC) or caudal lumbar curve(CLC) was ≥20° compared with that of 2 weeks after surgery. Clinical data including gender, age, Risser sign, location of hemivertebra, number of fusion segments, Nash-Moe classification, and mean follow-up time, as well as imaging data such as preoperative and postoperative follow-up visits of local scoliosis cobb angle, distal thoracic curvature cobb angle, distal lumbar curvature cobb angle, trunk shift(TS), upper instrumented vertebra tilt(UIV tilt), lower instrumented vertebra tilt(LIV tilt), LIV/LIV+1 disc angle, T1 tilt, head shift, neck tilt, and radiographic shoulder height(RSH) were compared between the two groups to analyze the influence of UIV leveling on the progression of distal coronal plane deformity after upper thoracic hemivertebra resection and short fusion. Results: Of all the patients, the average postoperative correction rate was (74.3±15.3)%, the average loss rate at the end of follow-up was (4.3±2.2)%, and the incidence rate of coronal plane decompensation after surgery was 8.8%(6 casesof S-type scoliosis progression). There were no statistical differences in gender, age, Risser sign, location of hemivertebra, number of fusion segments, presence of apical vertebral rotation, and average follow-up time between the two groups in the first operation(P>0.05). The preoperative coronal imaging parameters such as local scoliosis cobb angle, coronal plane balance, caudal thoracic curve, caudal lumbar curve, T1 tilt, head shift, neck tilt and shoulder height had no statistical differences between the two groups(P>0.05). There were significant differences of the postoperative parameters at each follow-up between the two groups, including: local curve, UIV tilt, and T1 tilt(P<0.05). In the progressive group, UIV and T1 tilt increased gradually from postoperative to the final follow-up, and the differences between two weeks after surgery and five years and the final follow-up were of statistical significance(P<0.05). The curve of the lumbar segment of the patients in the progressive group increased gradually in the six months after surgery and in the follow-up visits, and it′s with statistical difference in comparison of that of the non-progressive group(P<0.05). There were significant differences of CTC between the two groups from 1 year postoperatively to the final follow-up(P<0.05), and CTC was increased from 1 year postoperatively to the final follow-up in progressive group. There were significant differences between the two groups of neck tilt at 5 years postoperatively and the final follow-up(P<0.05), and the neck tilt was increased from 5 years postoperatively to the final follow-up in progressive group. There was no significant difference between the two groups of postoperative TS, LIV tilt, LIV disc angle, head shift and RSH(P>0.05). Conclusions: Insufficient horizontalization of UIV according to incomplete upper thoracic hemivertebra resection could be a predicting factor of postoperative caudal coronal S curve progression.