Routine spinal navigation for thoraco–lumbar pedicle screw insertion using the O-arm three-dimensional imaging system improves placement accuracy

Modern image-guided spinal navigation employs high-quality intra-operative three dimensional (3D) images to improve the accuracy of spinal surgery. This study aimed to assess the accuracy of thoraco-lumbar pedicle screw insertion using the O-arm (Breakaway Imaging, LLC, Littleton, MA, USA) 3D imaging system. Ninety-two patients underwent insertion of thoraco–lumbar pedicle screws guided by O-arm navigation over a 27 month period. Intra-operative scans were retrospectively reviewed for pedicle breach. The operative time of patients where O-arm navigation was used was compared to a matched control group where fluoroscopy was used. A total of 467 pedicle screws were inserted. Four hundred and forty-five screws (95.3%) were placed within the pedicle without any breach (Gertzbein classification grade 0). Sixteen screws (3.4%) had a pedicle breach of less than 2 mm (Gertzbein classification grade 1), and six screws (1.3%) had a pedicle breach between 2 mm and 4 mm (Gertzbein classification grade 2). The grade 2 screws were revised intra-operatively. There was no incidence of neurovascular injury in this series of patients. The mean operative time for O-arm patients was 5.25 hours. In a matched control group of fluoroscopy patients, the mean operative time was 4.75 hours. The difference in the mean operative time between the two groups was not statistically significant (p = 0.15, paired t-test). Stereotactic navigation based on intra-operative O-arm 3D imaging resulted in high accuracy in thoraco–lumbar pedicle screw insertion.     

O-arm导航辅助与徒手后路椎弓根螺钉复位内固定治疗寰枢椎骨折的疗效比较

目的探讨O-arm导航辅助下后路椎弓根螺钉复位内固定治疗寰枢椎骨折的疗效。方法采用回顾性病例对照研究分析2016年1月至2018年6月河北医科大学第三医院收治的37例寰枢椎骨折患者临床资料,其中男22例,女15例;年龄29~68岁[(50.9±9.8)岁]。24例行O-arm导航辅助下后路椎弓根螺钉复位内固定术(导航组),13例行徒手后路椎弓根螺钉复位内固定术(徒手组)。比较两组手术时间和术中出血量。术前、术后7 d及末次随访采用日本骨科学会(JOA)评分和颈椎功能障碍指数(NDI)评分对患者临床疗效进行评估。观察患者并发症情况。采用Neo分级评价螺钉位置分级及皮质穿透率。结果者均获随访24~38个月[(27.7±4.0)个月]。导航组手术时间[(189.8±35.4)min]显著短于徒手组[(221.5±48.6)min](P<0.05),术中出血量[300.0(250.0,537.5)ml]〖显著少于徒手组[500.0(425.0,625.0)ml](P<0.05)。两组患者术后7 d及末次随访JOA评分较术前显著升高(P<0.05),NDI评分较术前显著降低(P<0.05)。而组间差异无统计学意义(P>0.05)。术中未见神经、血管损伤等严重相关并发症。导航组共置入椎弓根螺钉86枚,包括Neo分级0级83枚,1级2枚,2级1枚;徒手组共置入椎弓根螺钉44枚,包括Neo分级0级36枚,1级5枚,2级2枚,3级1枚(P<0.05)。导航组螺钉皮质穿透率为3%(3/86),徒手组为18%(8/44)(P<0.05)。结论对于寰枢椎骨折,在行后路椎弓根螺钉复位内固定术时,应用O-arm导航辅助可以显著缩短或减少手术时间和术中出血量,提高椎弓根螺钉置入的精确率。     

Novel method for selecting slices of the same cross-sectional view from digital tomosynthesis for monitoring posterior spinal instrumentation

BackgroundA method to evaluate pedicle screw loosening on digital tomosynthesis images is yet to be established owing to lack of methods for selecting slices of the same cross-sectional view. We aimed to develop an objective method for selecting slices of the same cross-sectional view on digital tomosynthesis images.MethodsFirst, an objective method of pixel selection was developed by measuring the size of glass disk and titanium alloy screw on digital tomosynthesis images followed by comparison with the actual sizes. Second, a method for selecting slices of the same cross-sectional view was explored on a bone model with posterior spinal instrumentation using the screw centerline and rod curvature as indicators of the same cross section. The angle between the screw centerline and rod was calculated to verify the accuracy in obtaining the same cross-sectional view. Third, the method for selecting slices of the same cross-sectional view was applied to six patients after posterior lumbar spinal instrumentation.ResultsThe pixel selection method enabled objective determination of a pixel on the peripheral lines of objects with an error as low as 200 μm in distance measurements on titanium alloy and glass. The mean differences of rod-screw angles between two slices were less than 1° and were not statistically significant in the bone model and patient images.ConclusionA method for selecting slices of the same cross-sectional view on digital tomosynthesis images was successfully developed. This method can enable objective and quantitative evaluations of pedicle screw loosening.     

基于ASTM F543-17标准测试的医用接骨螺钉旋动扭矩计算模型

目的研究医用接骨螺钉的旋动扭矩计算模型。方法分析自攻型接骨螺钉在旋入过程中的3个主要阶段,对螺纹形成阶段的扭矩与扭转角进行力学建模与模拟计算;同时,根据ASTM F543-17(YY/T 1506-2016)标准的要求,对来自3个厂家的规格均为φ2.9×12接骨螺钉在不同等级聚氨酯实验块上开展螺钉体外旋入实验,将实验结果与计算结果进行比较分析。结果理论模型所得与实验测得最大旋入扭矩偏差值分别为5、12 m N·m,小于实验测得扭矩的10%,在可接受的误差范围内。结论所开发的接骨螺钉旋动力学计算模型能够模拟并预测研发与临床应用中的旋动扭矩,结合体外扭动实验,能够为接骨螺钉的研发与设计提供一种有效途径。     

Magnetic resonance appearance of bioabsorbable anchor screws for double row arthroscopic rotator cuff repairs

Background:

Little is known about the bioabsorbable, anchor related postoperative changes in rotator cuff surgery, which has become more popular recently. The purpose of the present study was to use magnetic resonance imaging (MRI) to analyze the degradation of bioabsorbable anchors and to determine the incidences and characteristics of early postoperative reactions around the anchors and their mechanical failures.

Materials and Methods:

Postoperative MRIs of 200 patients who underwent arthroscopic rotator cuff repair were retrospectively analyzed. The tissue reactions around the bioanchors included fluid accumulations around the anchor, granulation tissue formation and changes in the condition of the surrounding osseous structure. The condition of the bioanchor itself was also examined, including whether the bioanchor failed mechanically. In the case of mechanical failure, the location of the failure was noted. Serial MRIs of 18 patients were available for analysis.

Results:

The total number of medial row bioanchors was 124, while that of the lateral row was 338. A low signal intensity rim suggestive of sclerosis surrounded all lateral row bioanchors. Ninety three lateral row bioanchors (27%) showed a rim with signal intensity similar to or less than that of surrounding bone, which was granulation tissue or foreign body reaction (FBR). Similar signal intensity was seen around nine medial row bioanchors (7%). Fluid accumulation was seen around 4 lateral row bioanchors (1%) and around 14 medial row bioanchors (11%). Five lateral row bioanchors showed the breakage, while there was none in the medial row bioanchors. There were nine cases with a cuff re-tear (4.5%). There was no evidence of affection of glenohumeral articular surfaces or of osteolysis around any bioanchor. In serial MRI, there was no change in appearance of the bioanchors, but the granulation tissue or FBR around four bioanchors and the fluid around one bioanchor showed a decrease in successive MRI.

Conclusion:

This study highlights the normal and adverse reactions to Bioabsorbable anchors that surgeons can expect to see on MRI after rotator cuff repairs.     

单侧椎弓根螺钉固定与联合对侧椎板关节突螺钉固定应用于下腰椎单节段病变的临床研究

目的:对比单侧椎弓根螺钉固定并椎间融合器植骨与单侧椎弓根螺钉联合对侧椎板关节突螺钉固定并椎间融合器植骨两种手术方法治疗下腰椎单节段病变的临床优缺点。方法:选择2008年1月至2009年6月收治的62例下腰椎单节段病变患者,男16例,女46例;年龄27～72岁,平均51.6岁。其中腰椎间盘退行性病变22例,腰椎间盘突出症术后原位复发13例,腰椎间盘突出伴椎管狭窄症12例,巨大型腰椎间盘突出症5例,腰椎退行性滑脱(Ⅰ度)10例。L_3,4 5例,L_4,5 42例,L₅S₁ 15例。采用单侧椎弓根螺钉固定并椎间融合器植骨治疗30例(A组),采用单侧椎弓根螺钉联合对侧椎板关节突螺钉固定并椎间融合器植骨治疗32例(B组).对比两组患者的一般情况包括切口长度、手术时间、术中出血量、术后引流液量。根据影像资料观察内固定有无松动或断裂、椎间融合器有无移位、椎间融合情况,并比较两组患者术前、术后5 d和末次随访时病变节段椎间隙高度变化,以及术前和末次随访时腰椎冠状面和矢状面的Cobb角。对比两组病例术后72 h腰部切口疼痛程度,并采用JOA下腰痛评分系统评价临床疗效。结果:两组病例术后切口无感染及皮肤坏死。未出现神经根或马尾损伤,以及下肢神经功能恶化现象。两组在切口长度、术中出血量和术后切口引流液量方面差异无统计学意义,而A组手术时间少于B组(P<0.05).术后72 h腰部切口VAS评分两组间比较差异无统计学意义(P>0.05).两组病例均获随访,随访时间12～48个月,平均27.5个月。在椎间隙高度方面,两组病例术后5 d与术前相比,均获得良好的恢复,且末次随访时与术后5 d相比,均获得良好的维持。两组病例均未出现椎弓根螺钉或椎板关节突螺钉松动、移位、断裂,亦未出现椎间融合器移位现象。两组融合率比较差异无统计学意义(P>0.05).两组病例末次随访时均获得良好的功能恢复,JOA评分与术前相比,差异有统计学意义(P<0.05),两组间相比差异无统计学意义(P>0.05).结论:两种手术方式均具有切口小、创伤小、操作简单、稳定性可、植骨融合率高、恢复快、临床效果好及并发症少等优点。而且,与单侧椎弓根螺钉联合对侧椎板关节突螺钉固定方式相比,单侧椎弓根螺钉固定方式操作步骤少,不需要特殊器械,因而,在严格把握手术适应证、提高手术技巧的前提下,可在部分腰椎单节段病变的固定融合治疗中选择性应用。     

体感诱发电位对强直性脊柱炎胸腰椎后凸矫形术中体位性臂丛神经损伤的监测作用

目的:探讨体感诱发电位(somatosensory evoked potentials,SEP)对强直性脊柱炎(ankylosing spondylitis,AS)胸腰椎后凸畸形患者经椎弓根椎体截骨术(pedicle subtraction osteotomy,PSO)中体位性臂丛神经损伤的监测作用。方法:选取2013年10月~2014年6月行单节段PSO治疗并有完整术中SEP监测数据及术前、术后临床资料的AS胸腰椎后凸畸形患者28例,其中男27例,女1例。术中均行双上肢正中神经SEP监测,SEP阳性改变标准为波幅降低超过50%和/或潜伏期延长超过10%。结果:PSO术中闭合截骨面复位后,上肢正中神经SEP监测及时发现了3例体位性单侧臂丛神经损伤,SEP波幅降低分别为100%、65%及90%。经体位垫调整后5min,2例SEP波幅降低分别为100%及65%的患者上肢正中神经SEP恢复正常,术后未出现臂丛神经损伤症状;SEP波幅降低90%的患者虽经体位调节,SEP波幅稍有好转,但仍降低70%,术后出现单侧上肢疼痛、乏力的臂丛神经损伤症状,经康复训练及药物治疗后3个月神经功能完全恢复。术中无手术操作引起的神经系统并发症。结论:术中双上肢正中神经SEP监测能及时发现AS胸腰椎后凸畸形PSO术中体位性臂丛神经损伤,经及时处理能有效减轻臂丛神经损伤程度。     

后路截骨矫形治疗低龄先天性脊柱后凸畸形的疗效分析

目的:评价经后路截骨内固定术治疗低龄(10岁以下)先天性脊柱后凸畸形的临床效果。方法:2009年10月~2013年5月采用经后路截骨椎弓根螺钉内固定治疗先天性脊柱后凸患者17例,男6例,女11例,手术时年龄64±21个月(37~109个月)。根据Winter分型:Ⅰ型8例,Ⅱ型4例,Ⅲ型5例。后凸顶椎均位于T10~L2之间。5例伴神经系统畸形。8例行后路椎体切除(PVCR),5例行经椎弓根截骨(PSO),4例行Ponte截骨,截骨后均采用后路自体骨或同种异体骨植骨椎弓根螺钉内固定。统计手术时间、术中出血量及手术并发症,观察矫形效果、内固定并发症、椎体融合情况等。结果:手术时间210±46min(130~300min),出血量650±330ml(200~1300ml);固定融合节段4.9±0.8个(4~6个)。随访34.7±10.4个月(24~51个月),矢状面节段性后凸Cobb角由术前61.5°±14.3°(42°~92°)矫正至术后20.7°±9.0(5°~42°),矫正率为(66.3±8.7)%,末次随访时为17.5°±9.5°(1°~36°),矫正率为(71.5±10.7)%,手术后Cobb角得到显著性改善(P0.01);矢状面平衡术前为-41.3±31.8mm,术后为-43.5±30.4mm,与术前比较无显著性变化(P0.05),末次随访时为-25.6±26.7mm,较术前明显改善(P0.05)。术后出现双下肢无力1例,排尿困难1例,术后2周恢复。术前腰背痛5例、排尿异常1例,术后6个月症状好转。1例患者术后7个月出现近端交界性后凸。随访期间未发现假关节及内固定相关并发症。结论:对低龄先天性脊柱后凸畸形患者早期行后路截骨、椎弓根螺钉内固定可显著改善后凸畸形,但术后不能立即达到脊柱矢状面平衡,而是在术后随生长发育逐渐恢复矢状面平衡。     

单侧椎弓根钉联合对侧关节突螺钉内固定治疗下腰椎退行性疾病

目的探讨单侧椎弓根钉结合对侧椎板关节突螺钉固定在治疗下腰椎退行性疾病中的临床价值。方法回顾我院2011-06-2012-06年间收治的60例下腰椎退行性疾病患者,随机分为2组。30例观察组患者在微创系统下以椎弓根钉联合对侧的椎板关节突螺钉固定术对患者进行治疗;30例对照组患者以后路双侧弓根螺钉内固定术进行治疗。以Oswestry功能障碍指数(ODI)、疼痛视觉模拟评分(VAS)对两组的疗效进行对比;并对两组患者切口大小、手术用时、出血量、引流量、住院天数以及椎体稳定性、再手术率进行对比分析。结果术后1周,观察组患者VAS得分显著性高于对照组,P0.05,术后3、6个月,两组患者VAS和ODI评分无显著性差异,P0.05;观察组患者的切口大小、手术用时、出血量、引流量、住院天数等都显著性少于对照组患者,P0.05;两组患者的融合率比较无显著性差异;观察组患者椎体稳定性高于对照组,P0.05;观察组患者椎体再手术率低于对照组,P0.05。结论单侧椎弓根钉联合对侧椎板关节突螺钉内固定术临床操作简单、创部出血量少、稳定可靠、疗效确切,值得推广。     

两种固定方式治疗下腰椎病变3年随访结果分析

目的：比较单侧椎弓根螺钉暨经皮对侧椎板关节与双侧椎弓根螺钉两种固定方法联合椎间融合器植骨治疗下腰椎病变的3年随访结果。方法手术治疗62例单节段下腰椎病变患者,其中30例行单侧椎弓根螺钉暨经皮对侧椎板关节突螺钉固定联合椎间融合器植骨术（A 组）,32例行双侧椎弓根螺钉固定联合椎间融合器植骨术（B 组）,比较两组患者手术创伤和临床疗效。结果两组手术切口长度、手术时间、术中出血量、术后引流量比较 A 组优于 B 组,差异均有统计学意义（P ＜0．05）。两组融合率比较差异无统计学意义（P ＞0．05）。腰痛 VAS 评分与 JOA 评分：术后各时点（术后1周和术后6、12、24、36个月）两组较术前明显改善（P ＜0．05）,两组之间比较差异无统计学意义（P ＞0．05）。结论单侧椎弓根螺钉暨经皮对侧椎板关节与双侧椎弓根螺钉两种固定方法联合椎间融合器植骨术治疗下腰椎病变3年随访疗效均满意;单侧椎弓根螺钉联合对侧经皮椎板关节突螺钉固定具有操作简单、创伤小、稳定性好、融合率高和并发症少等优点,是部分下腰椎病变固定融合的较好选择。