Lenke1型青少年特发性脊柱侧凸融合术中顶椎确定下固定椎

目的 分析Lenke1型青少年特发性脊柱侧凸融合术中顶椎确定下固定椎的可行性.方法 82例Lenke1型患者,分为两组,按Cobb角度、Risser征、中立椎和下终椎配对.实验组以顶椎所处的节段作为依据选择下固定椎,对照组以中立椎为依据选择下固定椎.均行后路内固定和脊柱融合术,在站立位片上测量手术前后侧凸畸形矫正率和脊柱平衡;平均随访时间为3年.结果 冠状面Cobb角度和颈7距骶中线距离、矢状面胸5～胸12椎体后凸角度矫正参数差异无统计学意义.但是,对照组失平衡数较实验组多3个.结论 Lenke1型侧凸患者顶椎可以作为选择下固定椎的依据.     

特发性脊柱侧凸患者两侧椎旁肌横截面积的CT测量

目的:观察特发性脊柱侧凸(IS)患者凸、凹侧椎旁肌横截面积是否存在差异,探讨椎旁肌改变与脊柱侧凸的关系.方法:IS患者31例,女20例,男11例,年龄12～18岁,Cobb角范围28°～76°,平均53°±12°,在CT片上测量上终椎、顶椎、下终椎双侧椎旁肌横截面积.同龄非脊柱畸形患者(对照组)20例,女8例,男12例,年龄5～15岁,在CT片上测量T8、T10双侧椎旁肌横截面积.比较两组双侧椎旁肌的横截面积.结果:IS患者上终椎、顶椎、下终椎凸侧椎旁肌横截面积均大于凹侧,差异有统计学意义(P<0.05);凸/凹侧椎旁肌横截面积比值顶椎>上终椎>下终椎;Cobb角>50°和<50°患者顶椎水平凸,凹侧椎旁肌横截面积比值无统计学意义(P>0.05),顶椎水平凸/凹侧椎旁肌横截面积比值与Cobb角无显著相关性.对照组双侧椎旁肌横截面积差异无统计学意义(P>0.05),左/右侧椎旁肌横截面积比值亦无统计学意义(P>0.05).结论:特发性脊柱侧凸患者双侧椎旁肌发育不对称,凸侧椎旁肌横截面积大于凹侧,且在顶椎水平差异最大,但顶椎水平椎旁肌横截面积凸,凹侧比值与Cobb角无明显相关性.     

Ponté截骨联合椎间隙颗粒骨打压植骨治疗陈旧性胸腰椎骨折后凸畸形

 目的 探讨Ponté截骨联合椎间隙颗粒骨打压植骨矫正陈旧性胸腰椎骨折后凸畸形的有效性与安全性。方法 2010年6月至2013年3月,手术治疗陈旧性胸腰椎骨折后凸畸形13例,男7例,女6例;年龄32~78岁,平均54.5岁;伤椎为T₁₁ 1例、T₁₂ 4例、L₁ 5例、L₂ 3例。均存在进行性加重的腰背部疼痛、后凸畸形及不等程度的神经功能障碍。采用Ponté截骨,椎间隙松解并完整保留前纵韧带及尽量保留骨性终板,椎间隙内颗粒骨打压植骨实现初步矫形,再利用矫形棒进行二次矫形矫正后凸畸形。采用后凸Cobb角变化、植骨融合情况、视觉模拟评分(visual analog scale,VAS)、Oswestry功能障碍指数(Oswestry disability index,ODI)、ASIA神经功能分级评价疗效。结果 均获得9~36个月的随访,平均(20.0±9.1)个月。随访12个月时均获得骨性融合。脊柱局部后凸角由术前平均42.2°(26°~54°)改善为术后平均7.1°(-7°~13°),平均矫正率为83.2%。骶骨后上角至脊柱矢状轴线的距离由术前平均2.91 cm(-3.0~7.8 cm)减小至术后1.35 cm(-0.5~3.8 cm),胸椎后凸角、腰椎前凸角、骶骨水平角均有不等程度地改善。VAS评分由术前平均(6.38±0.87)分降低至末次随访时平均(2.23±0.83)分,ODI评分由术前平均(55.0±12.1)分降低至末次随访时平均(20.6±7.3)分,差异均有统计学意义。ASIA分级术前C级6例(术后D级2例、E级4例)、D级7例均为E级。 结论 应用Ponté截骨联合椎间隙颗粒骨打压植骨治疗陈旧性胸腰椎骨折后凸畸形具有矫正角度大、融合率高、手术创伤小、并发症少等优势。     

不同Risser征的胸弯青少年特发性脊柱侧凸前路矫形术后矢状面重建

 目的 探讨不同Risser征的胸弯青少年特发性脊柱侧凸(adolescent idiopathic scoliosis, AIS）行前路矫形术后胸椎及远端腰椎矢状面的重建模式。
方法 分析2002年6月至2006年11月行胸弯前路矫形内固定术且有2年完整随访资料的L enke 1型AIS患者43例,男3例,女40例;年龄11~18岁,平均（14.1±1.7）岁;胸弯Cobb角39°~ 65°,平均46.0°±7.5°。按照患者Risser征评分分为：A组（Risser 0）、B组（Risser 1～3）和C组（Risser 4～5）。分别测量这三组患者术前及术后历次随访时的胸弯Cobb角、腰弯Cobb角、胸椎后凸角、腰椎前凸角、内固定远端交界性后凸角、胸腰椎交界性后凸及骶骨后上缘与C 7铅垂线的距离。
结果 三组患者均获得随访,随访时间24~60个月,平均27.4个月。末次随访时,A组胸腰椎交界性后凸角为6.6°,较术前的- 1.7°增大8.3°;B组为0.6°,较术前的- 7.3°增大7.9°;C组术后历次随访与术前均无显著性差异。三组患者胸椎后凸角分别为21.2°、18.4°和14.7°,胸椎后凸角历次随访时的变化无统计学差异。三组患者的内固定远端交界性后凸角均表现为前凸丢失,后凸增大。
结论 低Risser征的Lenke 1型AIS患者行前路矫形内固定术后胸椎后凸角及胸腰椎交界性后凸增加,可能与胸椎后份生长后矢状面重建引起的胸腰椎交界区失代偿有关。     

重度陈旧性胸椎结核后凸患者影像学参数与迟发性神经功能损伤的相关性

目的探讨重度陈旧性胸椎结核后凸患者的影像学参数与神经功能的相关性,筛选出与迟发性神经功能损伤相关的影像学指标。方法回顾性分析2013年1月-2018年7月收治的56例重度陈旧性胸椎结核后凸畸形患者的一般临床资料和影像学资料。根据患者入院时是否出现下肢神经功能症状分为症状组(41例)和无症状组(15例)。术前在全脊柱正侧位X线片上测量胸椎后凸Cobb角,在术前胸椎MRI上测量顶椎区脊髓夹角(SA)、脊髓矢状径比(SDR)、脊髓横截面积比(SAR)。采用二元logistic回归分析影像学参数是否为出现神经功能症状的主要相关因素。所有患者均在重力牵引后采用胸椎后凸截骨术治疗,采用Frankel分级评估神经功能。结果症状组顶椎区脊髓SDR和顶椎区SA均低于无症状组(0.476±0.081 vs. 0.772±0.097,78.0°±12.4° vs. 97.3°±15.5°),差异有统计学意义(P < 0.05);2组间胸椎后凸Cobb角和顶椎区脊髓SAR差异无统计学意义(P > 0.05)。症状组顶椎区脊髓SDR ≥ 0.476者术后Frankel分级改善情况优于顶椎区脊髓SDR < 0.476者,差异有统计学意义(P < 0.05)。二元logistic回归分析结果显示,顶椎区脊髓SDR < 0.476是出现神经功能症状的独立相关因素(比值比=15.666,95%置信区间为7.426~33.048,P < 0.05)。结论重度陈旧性胸椎结核后凸会出现迟发性神经损伤,顶椎区脊髓SDR与神经功能症状的出现密切相关,当患者脊髓SDR< 0.476时建议手术治疗。     

特发性脊柱侧凸共平面技术的初步临床应用及文献回顾

目的 探讨脊柱共平面技术（vertebral coplanar alignment,VCA）对特发性脊柱侧凸的应用效果。方法 回顾性分析在我院接受VCA技术矫形的5例特发性脊柱侧凸病人的临床资料。其中男1例,女4例,平均年龄为16.3岁（14~25岁）。收集术前、术后及最近一次随访时的站立位脊柱全长正侧位X线片及CT,测量主弯Cobb角、顶椎偏移、冠状面平衡、胸椎后凸角（TK）、矢状面平衡、顶椎椎体胸廓比值（apical vertebral body-rib ratio,AVB-R）、顶椎旁肋骨弥散间距（apical rib spread difference,ARSD）、剃刀背（rib hump,RH）及椎体旋转角（rotational angle to sacrum,RAsac）。结果 主弯Cobb角由术前的55.7°矫正至术后的14.7°,TK由术前的26.7°矫正至19.0°。术前Lenke矢状面形态为“+”的病人矫正至“N”,而术前Lenke矢状面形态为“N”的病人仍维持正常的TK。AVB-R、ARSD、RH及RAsac的矫正率分别为36.0%、60.1%、56.7%、54.9%。在24个月的随访期间,无明显矫形丢失,无冠状面、矢状面失代偿发生。结论 VCA技术应用于特发性脊柱侧凸的矫形可获得满意的椎体去旋转和矢状面重建效果。目前针对VCA技术的研究多为初步应用经验,其适应证的选择还需要在今后的临床应用中进一步总结。     

骨质疏松性椎体压缩骨折在退变性脊柱侧凸的分布及危险因素

 目的 总结骨质疏松性椎体压缩骨折在退变性脊柱侧凸中分布的规律性,分析退变性脊柱侧凸患者发生椎 体压缩骨折的危险因素。方法 回顾性分析2004年7月至2012年7月治疗136例退变性脊柱侧凸患者资料,根据术前是 否发生骨质疏松性椎体压缩骨折分为骨折组和无骨折组。骨折组34例,男9例,女25例;年龄(71.7±1.7)岁。无骨折组 102例,男23例,女79例;年龄(63.3±6.7)岁。采用视觉模拟评分(visual analogue scale, VAS)评估胸背部疼痛程度,采 用双能X线骨密度仪测定骨密度T值,测量侧凸Cobb角,观察侧凸范围内骨桥发生情况。采用二分类Logistic逐步回归分析方 法筛选出骨折发生的危险因素。结果 骨折组发生T₁₁骨折3例,T₁₂骨折12例,L₁骨折15例 ,T₁₂及L₁两个椎体骨折4例。 无骨折组平均年龄低于骨折组(t=17.20,P<0.001),两组的性别组成并无差异(χ²=0.218,P=0.641),胸背部 疼痛的VAS评分小于骨折组(t=9.30,P< 0.001),侧凸Cobb角与骨折组相比无差异(t=1.84,P=0.08),骨质疏松的严重程度 低于骨折组(t=5.63,P<0.001),骨桥发生率低于骨折组(χ²=12.333,P< 0.001)。Logistic回归分析显示外伤 史(OR=1.36;95%CI,1.09～2.11)、骨桥形成(OR=3.31;95%CI,2.10～5.38)、骨质疏松(OR=2.45;95%CI,1.58～4.36) 会增加退变性脊柱侧凸患者发生骨质疏松性椎体压缩骨折的机会。结论 在退变性脊柱侧凸患者中,骨质疏松性椎体压缩骨折好 发于胸腰段椎体,外伤 史、骨质疏松以及侧凸范围内骨桥形成是骨折发生的危险因素。     

脊柱侧凸椎旁肌肌纤维不对称性分布的研究

目的　对特发性脊柱侧凸两侧椎旁肌肌纤维分布进行比较 ,并探讨其与脊柱侧凸病因学可能存在的关系。方法　本实验分三组 ,特发性脊柱侧凸组 :2 0例 ,平均年龄 15 .3岁 ,平均Cobb角为 5 6 .8° ,顶椎位于T7～12 。其中Cobb角 >5 0° 11例 ,Cobb角≤ 5 0° 9例。先天性脊柱侧凸组 :11例 ,平均年龄 13.9岁 ,平均Cobb角为 6 6 .7° ,顶椎位于T7～12 。对照组 :取 10例非脊柱侧凸病例作为对照。特发性脊柱侧凸和先天性脊柱侧凸组取顶椎区两侧椎旁肌 ,对照组取非病变区两侧椎旁肌 ,进行病理分析。结果　特发性脊柱侧凸和先天性脊柱侧凸组凸侧椎旁肌Ⅰ型肌纤维含量和横截面积均显著大于凹侧 (P <0 .0 5 ) ,对照组两侧无显著差异 (P >0 .0 5 ) ,特发性脊柱侧凸组中Cobb角 >5 0°的病例凸侧Ⅰ型肌纤维含量显著高于Cobb角≤ 5 0°的病例 (P <0 .0 5 )。结论　脊柱侧凸两侧椎旁肌肌纤维分布不对称系继发性改变     

微创经椎间孔椎间融合术联合单、双侧内固定治疗单间隙腰椎退变性疾病

 目的 探讨微创经椎间孔椎间融合术（minimally invasive transforaminal lumbar interbody fusion,MIS-TLIF）联合单侧或双侧内固定治疗单节段腰椎退行性疾病的临床及影像学疗效。方法 回顾性分析 2009年 10月至 2011年 12月期间,采用 METRx-MD（Microscopic Endoscopic Tubular Retractor System）进行 MIS-TLIF治疗单节段腰椎退行性疾病并获得长期随访的 65例患者的相关资料。根据内固定方式分为两组,单侧固定组（31例）采用 MIS-TLIF联合单侧内固定技术,双侧组（34例）采用 MIS-TLIF联合双侧经皮内固定技术。采用 Oswestry功能障碍指数（Oswestry disability index,ODI）评价腰椎功能情况,采用疼痛视觉模拟评分（visual analogue scale,VAS）分别对腰痛及下肢痛进行评估;在 X线片上测量手术前后的腰椎前凸角度、手术节段前凸角度、腰椎侧凸角度、手术节段侧凸角度,计算腰椎前凸指数及椎间高度指数。结果 所有患者均顺利完成手术,术后随访 18~36个月,平均 26.6个月。所有患者术后 12个月均获得骨性融合。两组患者术后 VAS及 ODI评分均较术前有明显改善,两组间术前及随访期间 VAS及 ODI评分的差异无统计学意义。影像学测量结果显示两组间腰椎前凸角度、手术节段前凸角度、腰椎侧凸角度、手术节段侧凸角度、腰椎前凸指数及椎间高度指数的差异均无统计学意义,腰椎前凸角度与腰椎前凸指数呈线性相关。结论 对于治疗单间隙腰椎退变性疾病,MIS-TLIF联合单侧或双侧经皮内固定技术具有相似的临床及影像学疗效。     

单平面椎弓根螺钉矫正Lenke 5型青少年特发性脊柱侧凸顶椎旋转

目的对单平面椎弓根螺钉和万向椎弓根螺钉矫正Lenke 5型青少年特发性脊柱侧凸(AIS)顶椎旋转的效果进行对比分析。方法回顾性分析2010年1月—2013年12月收治的72例应用万向/单平面椎弓根螺钉行后路三维矫形植骨融合内固定术的Lenke 5型AIS患者的临床资料,其中使用万向椎弓根螺钉治疗(A组)43例,使用单平面椎弓根螺钉治疗(B组)29例。记录手术前后腰椎侧凸Cobb角和腰椎前凸角,并计算侧凸矫正率。术前使用Nash-Moe法评估顶椎旋转程度,术后根据Upasani等提出的X线椎体旋转分级标准评价顶椎去旋转的效果。结果所有患者均顺利完成手术。2组患者术前侧凸Cobb角及腰椎前凸角差异无统计学意义(P 0.05);2组术后2周及1年侧凸Cobb角及腰椎前凸角均较术前显著改善,差异有统计学意义(P 0.05);A组术后1年侧凸矫正率为79.2%,B组为81.4%,差异无统计学意义(P 0.05)。2组患者术前顶椎旋转程度差异无统计学意义(P 0.05);术后2周及1年顶椎去旋转程度B组优于A组,差异有统计学意义(P 0.05)。结论两种椎弓根螺钉都能很好地矫正Lenke 5型AIS患者冠状面侧凸,单平面椎弓根螺钉在矫正及维持顶椎去旋转效果方面优于万向椎弓根螺钉。     

Anterior surgery for adolescent idiopathic scoliosis

Anterior open scoliosis surgery using the dual rod system is a safe and rather effective procedure for the correction of scoliosis (50–60 %). Thoracic hypokyphosis and rib hump correction with open anterior rather than posterior instrumentation appear to be the better approaches, although the latter is somewhat controversial with current posterior vertebral column derotation devices. In patients with Risser grade 0, hyperkyphosis and adding-on may occur with anterior thoracic spine instrumentation. Anterior thoracoscopic instrumentation provides a similar correction (65 %) with good cosmetic outcomes, but it is associated with a rather high risk of instrumentation (pull-out, pseudoarthrosis) and pulmonary complications. Approximately 80 % of patients with adolescent idiopathic scoliosis (AIS) curves of >70° have restrictive lung disease or smaller than normal lung volumes. AIS patients undergoing anterior thoracotomy or anteroposterior surgery will demonstrate a significant decrease in percentage of predicted lung volumes during follow-up. The thoracoabdominal approach and thoracoscopic approach without thoracoplasty do not produce similar changes in detrimental lung volume. In patients with severe AIS (>90°), posterior-only surgery with TPS provides similar radiographic correction of the deformity (44 %) with better pulmonary function outcomes than anteroposterior surgery. Vascular spinal cord malfunction after segmental vessel ligation during anterior scoliosis surgery has been reported. Based on the current literature, the main indication for open anterior scoliosis instrumentation is Lenke 5C thoracolumbar or lumbar AIS curve with anterior instrumentation typically between T11 and L3.     

Differential rod contouring on thoracolumbar/lumbar curvature in patients with adolescent idiopathic scoliosis: An analysis with intraoperative acquisition of three-dimensional imaging

BackgroundDifferential rod contouring (DRC) is useful for periapical vertebral derotation and decreasing rib hump in patients with thoracic adolescent idiopathic scoliosis (AIS). However, it is unknown whether DRC in the thoracolumbar/lumbar spine also contributes to derotation. We assessed the contributions of rod contouring and of DRC to the reduction of apical axial vertebral body rotation in patients with AIS with thoracolumbar/lumbar curvatures.MethodsForty-five (Lenke type 3 or 4, 17; Lenke type 5 or 6, 28) were analyzed for the contribution of DRC to thoracolumbar/lumbar spinal derotation. Rod contouring was assessed by comparing the preinsertion x-ray with the post-operative CT images. Intraoperative C-arm fluoroscopic scans of the periapical vertebrae of the thoracolumbar/lumbar curve of the scoliosis (135 vertebrae) were taken post-rod rotation (RR) and post-DRC in all patients. Three-dimensional images were automatically reconstructed from the taken x-ray images. The angle of vertebral body rotation in these apical vertebrae was measured, and the contribution of DRC to apical vertebral body derotation and rib hump index (RHi) for lumbar prominence was analyzed.ResultsThe pre-implantation convex rod curvatures of both Lenke 3/4 and 5/6 groups decreased after surgery. The mean further reductions in vertebral rotation with post-RR DRC were 3.7° for Lenke 3/4 and 4.4° for Lenke 5/6 (P < 0.01). Both changes in apical vertebral rotation and in RHi for evaluating lumbar prominence were significantly correlated with the difference between concave and convex rod curvature in preimplantation. Vertebral derotation was significantly higher in curves with a difference >20° (P < 0.05).ConclusionsDRC following rod rotation contributed substantial additional benefit to reducing vertebral rotation and decreasing lumbar prominence in thoracolumbar/lumbar scoliosis.     

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

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。     

Thoraco-lumbar selective fusion in adolescent idiopathic scoliosis with Lenke C modifier curves: clinical and radiographic analysis at 10-year follow-up

Purpose

To examine the radiological and clinical outcomes of a single-center case series of selective thoracic fusions (STF) in adolescent idiopathic scoliosis with Lenke C modifier curves, with a long-term follow-up.

Methods

We evaluated at 6 months and 10 years different radiological parameters on both thoracic and lumbar districts: coronal curves, sagittal curves, apical vertebral translation (AVT), and apical vertebral rotation (AVR). The clinical outcome was determined using the SRS 22 score. Data were also analyzed dividing the patients by their Risser and Lenke scores.

Results

In examining 90 patients we reported a radiological benefit from STF on both thoracic and lumbar districts. The corrections in the values of both coronal curves, AVT, and AVR are relevant at 6 months and do not significantly vary at the latest follow-up. Sagittal curves are not relevantly affected at any time point. All the SRS 22 score evaluations showed significant improvement at 6 months, in particular, the self-image analysis. A further improvement was also reported at 10 years, in particular in pain and function scores. At no time point were significant differences retrieved by comparing SRS 22 results as divided by Risser or Lenke grading systems.

Conclusions

STF is an effective treatment option both in clinical and radiographical terms. The results at 10-year follow-up confirm both the stability of the correction and the improvement of the clinical outcome scores. Risser and Lenke grading systems are not relevant variables predictive of clinical efficacy.

     

Computerized tomography imaging in adolescent idiopathic scoliosis: prone versus supine

Background

The aim of the present study was to assess the degree of apical vertebral rotation values in Adolescent Idiopathic Scoliosis (AIS) that were obtained on CT scans, and to analyze the influence of patient position (supine versus prone) on the degree of rotation.

Methods

The study included 50 apical vertebra rotation measurements of 34 patients with Type 1A and Type 3C curvature according to the Lenke classification. CT imaging was applied to the patients in supine and prone positions to measure the apical vertebral rotation (AVR). The average AVR angles were measured using the Aaro–Dahlborn method and the results were compared.

Results

No significant differences were found between the vertebral rotation measured in the prone and supine positions for the Lenke 1A subgroup and the Lenke 3C thoracic group (p = 0.848; p = 0.659, respectively). In the Lenke 3C lumbar group, however, the vertebral rotation in the supine position was found to be significantly lesser than that in the prone position (difference ?1.40° ± 1.79°, p = 0.007).

Conclusion

The assessment of the apical vertebra rotation is crucial in AIS. Even though the vertebral rotation in the supine position was found to be significantly lesser than that in the prone position, CT imaging in a prone position could not be considered clinically more relevant than the CT images in a supine position as there was less than 3° difference.

     

Spine slenderness and wedging in adolescent idiopathic scoliosis and in asymptomatic population: an observational retrospective study

The origin of the deformity due to adolescent idiopathic scoliosis (AIS) is not known, but mechanical instability of the spine could be involved in its progression. Spine slenderness (the ratio of vertebral height to transversal size) could facilitate this instability, thus playing a role in scoliosis progression. The purpose of this work was to investigate slenderness and wedging of vertebrae and intervertebral discs in AIS patients, relative to their curve topology and to the morphology of control subjects. A total of 321 AIS patients (272 girls, 14 ± 2 years old, median Risser sign 3, Cobb angle 35° ± 18°) and 83 controls were retrospectively included (56 girls, median Risser 2, 14 ± 3 years). Standing biplanar radiography and 3D reconstruction of the spine were performed. Geometrical features were computed: spinal length, vertebral and disc sizes, slenderness ratio, frontal and sagittal wedging angles. Measurement reproducibility was evaluated. AIS girls before 11 years of age had slightly longer spines than controls (p = 0.04, Mann–Whitney test). AIS vertebrae were significantly more slender than controls at almost all levels, almost independently of topology. Frontal wedging of apical vertebrae was higher in AIS, as expected, but also lower junctional discs showed higher wedging than controls. AIS patients showed more slender spines than the asymptomatic population. Analysis of wedging suggests that lower junctional discs and apex vertebra could be locations of mechanical instability. Numerical simulation and longitudinal clinical follow-up of patients could clarify the impact of wedging, slenderness and growth on the biomechanics of scoliosis progression. These slides can be retrieved under Electronic Supplementary Material.     

Evaluation of postoperative change in lung volume in adolescent idiopathic scoliosis: Measured by computed tomography

Background:

Change in total lung volume after surgical correction in adolescent idiopathic scoliosis (AIS), measured by computed tomography (CT), has not been studied previously. The primary objective of this study was to measure the change in lung volume between pre and postoperative AIS using low-dose CT and secondary objective was to investigate its relationship to postoperative pulmonary complications.

Materials and Methods:

55 AIS patients underwent surgery for correction and fusion using a posterior only approach and pedicle screws. Pre and postoperative lung volumes were measured using a 3-dimensional (3D) whole spine CT (low dose protocol: Tube current, 60 mA; tube voltage 120 kV). Postoperative low dose CT was undertaken at 4 weeks after operation to evaluate the acute changes of postoperative lung volumes and pulmonary complications. The software that was used recognizes the “air density shade” of the lung and the volume of every section of the lung. The software then automatically calculates total lung volume by summation of all section volumes. The relationships between postoperative pulmonary complications and changes in lung volume on low dose CT as well as preoperative forced vital capacity (FVC) and forced expiratory volume in 1 s (FEV₁) were calculated using logistic regression analysis.

Results:

There was a decrease of 12% ± 23.2% in total lung volume postoperatively on 3D low dose CT (P < 0.001). Thirteen patients had increased lung volume while 42 had decreased lung volume postoperatively. Pulmonary complications were treated without severe sequale. Lung volume increased by 19.65% ± 19.84% in 13 patients and decreased by 21.85% ± 13.32% in 42 patients (P = 0.647). Lung volume was increased in patients whose preoperative lung volume, FEV₁ and FVC were lower than in patients whose values were higher (r = −0.273, −0.291 and − 0.348; P = 0.044, 0.045 and 0.015, respectively). Postoperative lung volume was also increased when intraoperative fluid administration was larger and operative time was longer (r = 0.354, 0.417 and P = 0.008, 0.002, respectively). There was a statistically significant negative correlation in the change of lung volume in female patients when compared with male patients (r = −0.294, P = 0.03).

Conclusion:

Patients with AIS who have preoperative reduced lung volumes or lung functions can achieve further increased lung volume after surgical correction. Pulmonary complications during perioperative period were mostly treated with proper management without severe sequale. Therefore, although surgery for AIS is considered to be a high risk procedure, we can recommend to correct spine deformity in patients with severe AIS in order to improve lung function and long term prognosis.     

Effectiveness of cross-linking posterior segmental instrumentation in adolescent idiopathic scoliosis: a 2-year follow-up comparative study

Background contextSurgeons continue to debate the need for a cross-link (CL) in posterior spinal instrumentation constructs with segmental pedicle screws in adolescent idiopathic scoliosis (AIS). Advantage of CLs is increased stiffness of the construct, and disadvantages include added expense and risk of late operative-site pain and pseudarthrosis.PurposeTo compare the effectiveness of using CLs versus using no cross-links (NCLs) in posterior segmental instrumentation in AIS.Study designRetrospective comparative study, level of evidence 3.Patient sampleSeventy-five AIS patients less than 21 years of age, who underwent posterior spinal instrumentation with segmental pedicle screws (25 with CLs and 50 with NCLs) at a single institution with 2-year follow-up, are described.Outcome measuresPhysiologic measures include imaging: thoracic and lumbar Cobb angles, correction rate, apical vertebral translation (AVT), and apical vertebral rotation (AVR); self-report measures include Scoliosis Research Society (SRS) domain outcome scores.MethodsPreoperative (pre-op) and postoperative first erect, 1-year, and 2-year follow-up radiographs were measured. Instrumentation-related complications and normalized SRS scores were recorded. Independent sample t test, χ² test, and repeated-measures analysis of variance were used for analyses.ResultsThe average age at surgery was 14 years, the mean pre-op Cobb angle was 57°, and the mean number of levels fused was 10.9. The groups were similar preoperatively with respect to age, sex, Lenke curve, Cobb angle, AVT, and Risser grade and were similar intraoperatively for levels fused and anchor density. There was no difference in AVR, Cobb angle, correction rate, or AVT between the groups (p>.05). Complications included one wound infection in the CL group and one painful scar in the NCL group. There were no differences in SRS domain scores.ConclusionWe observed no differences in maintenance of correction, SRS scores, and complications with or without cross-linking posterior segmental instrumentation in AIS patients over 2-year follow-up. Further follow-up is necessary.     

The mechanisms underlying the variety of preoperative directionalities of shoulder tilting in adolescent idiopathic scoliosis patients with double thoracic curve

Purpose

Preoperative directionality of shoulder tilting seems to be independent of the radiographic features of proximal thoracic (PT) curve in adolescent idiopathic scoliosis (AIS) patients. To date, no study had investigated the mechanisms underlying the variety of preoperative directionalities of shoulder tilting in AIS patients. The purpose of this study was to evaluate the differences of radiographic features between Lenke type 2 (double thoracic curve) AIS patients with different preoperative directionalities of shoulder tilting.

Methods

A total of 130 Lenke type 2 AIS patients were included in this study and were divided into two groups according to the value of radiographic shoulder height (RSH). There were 78 cases (71 females and 7 males) with RSH less than 0 cm in Group A and 52 cases (44 females and 8 males) with RSH equal to or more than 0 cm in Group B. Preoperative standing anteroposterior X-ray films of the spine were obtained in all these subjects and were analyzed with respect to the following parameters: T1 tilt, PT Cobb angle, main thoracic (MT) Cobb angle, the apical level of PT curve, the apical level of MT curve, and RSH. These parameters were compared between these two groups and the correlations between RSH and the other parameters were analyzed in all of these subjects.

Results

No significant difference was found between these two groups with respect to PT Cobb angle or the apical level of PT curve (P > 0.05). The apical level of MT curve was significantly more proximal in Group A compared with Group B (P < 0.05). The MT Cobb angle was significantly larger in Group A compared with Group B (P < 0.05). Both the T1 tilt and the PT Cobb angle/MT Cobb angle ratio in Group A were significantly smaller than those in Group B (P < 0.05). The RSH was positively associated with T1 tilt, the apical level of MT curve, and the PT Cobb angle/MT Cobb angle ratio, but was negatively associated with MT Cobb angle (P < 0.05).

Conclusion

The directionality of shoulder tilting is diverse in Lenke type 2 AIS patients. The preoperative directionality of shoulder mainly depends on the profile of MT curve rather than that of PT curve. The RSH should be carefully evaluated before making a surgical plan in these patients.

     

The change in ratio of convex and concave lung volume in adolescent idiopathic scoliosis: a 3D CT scan based cross sectional study of effect of severity of curve on convex and concave lung volumes in 99 cases

To study the effect of the degree of scoliosis, degree of hypokyphosis/lordosis and rotation of apical vertebra on individual lung volume (measured with CT scan) in asymptomatic adolescent idiopathic scoliosis (AIS) patients. Individual (right and left) lung volume, angle of kyphosis and rotation of apical vertebra, were measured in 77 asymptomatic AIS patients having right thoracic curve, using modern computed tomography (CT) scan. To compare, lung volumes were measured in 22 normal persons (control group). The ratio of “right to left lung volume (convex to concave side)” was obtained and compared among these groups. With increased Cobb’s angle, ratio of convex to concave lung volume increased. For Cobb’s angle more than 40°, it was increased significantly (P = 0.0042). A significant degree of correlation was found between axial rotation angle of apical vertebra and right to left lung volume ratio (P = 0.0067, r = 0.271). A significant inverse correlation was found between the angle of kyphosis and right to left lung volume ratio, i.e., as the angle of kyphosis decreased the convex to concave lung volume ratio increased (P = 0.0109, r = −0.255). In asymptomatic, AIS patients, with increase in degree of curvature, and rotation of apical vertebra, the ratio of convex to concave side lung volume increases; indicating concave side lung volume is comparatively more affected (decreased) than convex side lung volume. On the other hand with decrease in the angle of kyphosis the convex to concave lung volume ratio increases indicating kyphotic angle has an inverse relation to convex to concave lung volume ratio. An erratum to this article can be found at