枢椎椎弓峡部引导下寰椎椎弓根置钉的CT测量及其应用

目的:探讨在枢椎椎弓峡部引导下实施寰椎椎弓根螺钉置钉的可行性及安全性。方法:对48例成人寰枢椎行三维CT重建,取枢椎椎弓峡部内上缘与寰椎的横断面图像。测量椎管正中线至寰椎椎弓根内壁、外壁及枢椎椎弓峡部内壁、外壁的距离,分别为L1、D1、L2、D2;0°内倾角置钉时,以枢椎椎弓峡部内上壁为解剖标志,确立最内侧进钉点A和最外侧进钉点B,减去螺钉半径1.75mm,A、B点至枢椎椎弓峡部内上壁的距离分别为(L1-L2+1.75mm)、(D1-L2-1.75mm),寰椎后弓上置钉时螺钉允许的最大内倾角与最大外倾角大致相等时的点为最佳进钉点(M点),记录M点至枢椎椎弓峡部内上壁水平间距。自2004年3月～2009年3月对29例患者采用以枢椎椎弓峡部为标志实施后路寰枢椎椎弓根螺钉内固定手术,其中陈旧性齿状突骨折24例,横韧带损伤并寰椎前脱位5例。观察手术过程中与寰椎椎弓根螺钉置钉相关的并发症,术后三维CT重建观察螺钉的位置。结果:0°内倾角置钉时,CT测量最内侧进钉点A、最外侧进钉点B、最佳进钉点M至枢椎椎弓根峡部内上壁的水平间距分别为4.22±0.54mm、8.66±0.73mm、5.79±0.63mm。临床共置入寰椎椎弓根螺钉58枚,术中枢椎椎弓峡部内上壁均得到良好显露,未出现椎动脉、静脉丛损伤出血及脊髓、C2神经根损伤等并发症。术后三维CT复查显示所有寰椎椎弓根螺钉均未误入椎管或椎动脉孔,测量寰椎椎弓根螺钉进钉点与枢椎椎弓峡部内上壁水平间距为5.45±0.82mm,与术前M点测量值相比较无显著性差异。结论:在纠正寰椎旋转移位后,以枢椎椎弓峡部内上壁作为解剖参照,寰椎椎弓根存在一定的置钉安全区间,利用该解剖标志行寰椎椎弓根置钉是安全可行的。     

标杆型3D打印导板辅助寰枢椎椎弓根置钉准确度分析

目的探讨标杆型3D打印导板辅助寰枢椎椎弓根置钉的可行性,并进行置钉准确度分析。方法 2014年6月—2015年8月,本院收治寰枢椎脱位患者21例,男12例,女9例;年龄12~54岁,平均42.6岁。术前使用Mimics 17.0软件和3-matic 9.0软件为每例患者制作标杆型3D打印导板,术中使用标杆型3D打印导板辅助寰枢椎椎弓根置钉,术后患者行颈椎CT平扫。在Mimics 17.0软件中,将手术前后的寰枢椎模型及螺钉配对拟合,调整空间坐标轴,测量并比较术前预设钉道与术后实际钉道的内倾角、头倾角、进钉点坐标。结果 21例患者手术顺利,手术时间(193±51)min,术中出血量(384±127)m L。共置入寰椎椎弓根螺钉30枚,枢椎椎弓根螺钉42枚。除2枚寰椎椎弓根螺钉侵入椎管≤2 mm外,其他螺钉均位于椎弓根骨皮质内。寰椎左右侧预设最佳钉道内倾角度分别为9.4°±1.8°、9.8°±1.6°,实际钉道内倾角度分别为8.7°±1.6°、10.6°±2.2°;左右侧预设最佳钉道头倾角度分别为8.9°±2.5°、8.8°±2.3°,实际钉道头倾角度分别为9.3°±2.9°、9.4°±3.5°。枢椎左右侧预设最佳钉道内倾角度分别为21.9°±6.6°、22.4°±6.9°,左右侧实际钉道内倾角度分别为24.1°±6.3°、20.8°±6.4°;左右侧预设最佳钉道头倾角度分别为23.7°±7.3°、24.2°±7.2°,左右侧实际钉道头倾角度分别为22.1°±7.9°、22.3°±7.6°。寰枢椎术后实际钉道与术前预设最佳钉道的内倾角、头倾角、进钉点坐标差异均无统计学意义(P0.05)。结论标杆型3D打印导板辅助寰枢椎椎弓根置钉方向可调整性好,置钉准确度较高,为临床寰枢椎置钉提供了一种新的方法。     

多平面CT重建下个体化改良寰椎椎弓根进钉路径的测量

目的:通过对寰椎椎弓根轴位、矢状位多平面CT重建,测量个体化改良椎弓根进钉路径数据,以期提高寰椎椎弓根置钉准确率。方法:20具成人颈椎标本,男11具,女9具,年龄不详。进行螺旋CT薄层扫描多平面重建,在寰椎椎弓根轴位像上建立改良的椎弓根进钉路径,即经椎管外缘和齿突孔外缘划切线L1线,经椎动脉孔内缘画L2线平行于L1线,经L1、L2线之间中点画A线平行于L1、L2线,A线即为改良的寰椎椎弓根进钉路径。根据A线确定并测量椎弓根进钉点、进钉方向等个体化置钉参数,根据测量的置钉参数在标本的寰椎椎弓根置入直径3.5mm皮质骨螺钉。置钉后行螺旋CT扫描,按Ludwing椎弓根置钉安全标准统计椎弓根螺钉误置率。结果:多平面CT重建后影像学测量表明,改良寰椎椎弓根进钉路径的进钉点距寰椎后结节:右侧25.8±1.9mm,左侧25.7±1.8mm,比传统的进钉点(距寰椎后结节18~20mm)更偏外;进钉内倾角度:右侧21.1°±4.6°,左侧20.0°±4.9°,比传统的内倾角(0~10°)更大。20具颈椎标本共置钉40枚,按照Ludwing椎弓根置钉安全标准:0级36枚(90%),1级4枚(10%)。结论:寰椎椎弓根多平面CT重建下建立的改良椎弓根进钉路径,能够获取进钉点、进钉角度的个体化置钉参数。该路径比传统的方法进钉点更偏外,内倾角更大,能够提高寰椎椎弓根置钉准确率。     

不同内倾角置入寰椎后路侧块螺钉的安全性比较

目的:将寰椎后路侧块螺钉上倾角固定在15°的情况下,比较不同内倾角度置钉相对应的寰椎侧块有效宽度和进钉深度,以确定寰椎后路侧块螺钉在横断面上的最佳内倾角度。方法:募集颈椎结构正常的健康成年国人64名,男32名,女32名;年龄32.7±7.8岁(18~60岁),进行颈椎CT平扫,通过Mimics软件对志愿者的颈椎CT数据进行测量,在寰椎后路侧块螺钉上倾角为15°的情况下,分别测量内倾角度为0°、5°、10°、15°、20°、25°、30°和理想内倾角(β角)时的寰椎侧块有效宽度和寰椎后路侧块螺钉的进钉深度;测量正中矢状面与寰椎后弓最后缘的交点与进钉点之间的距离和进钉点处的后弓下缘侧块高度;并进行统计学数据分析。结果:寰椎后路侧块螺钉的β角男性为20.01°±2.97°,女性为21.89°±3.14°。寰椎后路侧块螺钉内倾角度为0°、5°、10°、15°、20°、25°、30°和β角时的寰椎侧块有效宽度男性分别为8.95±1.18、9.51±1.14、10.00±1.17、10.42±1.20、10.39±1.29、9.41±1.25、8.04±1.21、11.02±0.96mm,女性分别为7.64±1.01、8.31±1.11、8.88±1.10、9.32±1.11、9.51±1.09、8.90±1.02、7.62±1.07、9.97±0.98mm;进钉深度男性分别为19.03±1.34、19.60±1.39、20.28±1.47、21.20±1.48、22.11±1.54、23.06±1.63、24.19±1.97、22.37±1.52mm,女性分别为17.47±1.68、17.90±1.64、18.50±1.79、19.31±1.93、20.47±2.03、21.67±2.18、22.89±2.38、21.26±1.99mm。相较于其他内倾角,β角对应的寰椎侧块有效宽度最大且差异有统计学意义(P0.01)。寰椎后路侧块螺钉内倾角为β时,寰椎后路侧块螺钉进钉点距离正中矢状面与寰椎后弓最后缘的交点距离男性为28.35±1.75mm,女性为26.70±1.60mm;进钉点处的后弓下缘侧块高度男性为4.38±0.85mm,女性为4.13±0.80mm。结论:寰椎后路侧块螺钉上倾15°时,以所对应的寰椎侧块有效宽度最大的内倾角β角进钉,理论上损伤椎动脉、脊髓等结构的几率最低。     

以枢椎椎弓峡部内上壁为解剖标志行枢椎椎弓根置钉的CT测量及临床应用

目的:探讨以枢椎椎弓根峡部内上壁为解剖标志的枢椎椎弓根螺钉置钉的可行性及安全性。方法:57例成人枢椎行三维CT重建,在三维重建图像上测量枢椎左右侧椎弓根的中部宽度L1和高度L2;以枢椎椎弓峡部内上壁为标志横断面确立左右侧的最外侧模拟进钉点B和最内侧模拟进钉点A到峡部距离;测量最佳进钉点S(经过枢椎椎弓根中部宽度连线的中垂线与峡部后侧皮质交点)到峡部内壁距离,分别测量A、B、S点横断面进钉角度最大置钉角度区间;冠状面上测量S点距离峡部内上壁距离;测量S点进钉最佳内倾角及上倾角。选择2007年10月～2011年7月收治的33例患者采用枢椎椎弓根峡部内上壁为标志实施枢椎椎弓根螺钉内固定术,其中新鲜齿状突骨折13例,陈旧性齿状突骨折10例,横韧带损伤伴寰枢椎脱位7例,寰椎骨折3例。观察手术中与枢椎椎弓根螺钉置钉相关的并发症,术后三维CT重建观察螺钉的位置。结果:CT横断面测量进钉点A、B、S到峡部的距离为1.75mm、9.01±0.62mm、5.77±0.53mm,S点置钉角度区间与A、B点置钉角度区间比较有显著性差异(P<0.05)。冠状面上S点距离峡部内上壁距离为4.30±0.49mm;S点进钉内倾角为30°、上倾角为26°时为最佳进钉角度。临床共置入枢椎椎弓根螺钉66枚,术中显露良好,未出现椎动脉、静脉丛损伤出血及脊髓、神经根损伤等并发症。术后三维CT复查显示所有枢椎椎弓根螺钉均未误入椎管或椎动脉孔,术中测量枢椎椎弓根螺钉进钉点横断面上与枢椎椎弓峡部内壁水平间距为5.44±0.72mm,冠状面上距离峡部内上壁为4.50±0.52mm,与术前S点测量值相比较均无显著性差异。结论:枢椎椎弓根与峡部存在恒定位置关系,以枢椎椎弓峡部内上壁为解剖参照行枢椎椎弓根置钉是安全可行的。     

寰椎椎弓根显露置钉技术的影像学测量研究

目的 :利用CT三维重建对椎动脉沟后弓高度4 mm的寰椎进行置钉通道相关参数测量,探讨椎弓根显露置钉技术的意义。方法:回顾性分析2015年4月至2015年6月行颈椎CT三维重建检查且排除上颈椎畸形、手术的患者90例,其中单侧或双侧椎动脉沟后弓高度4 mm的51例,共84侧。利用其图像数据行寰椎三维数字化重建,并分别测量置钉通道相关数据。结果:51例患者中,椎动脉沟处后弓最低高度为(3.28±0.51)mm,侧块高度、宽度、与后弓移行处高度均可容纳3.5 mm直径螺钉置入。0°~15°(0°、5°、10°、15°)理想椎弓根螺钉钉道长度依次为(27.36±1.81)、(27.01±1.68)、(27.07±1.75)、(27.48±1.72)mm,椎弓根显露置钉技术钉道长度依次为(23.44±1.79)、(23.87±1.84)、(24.58±1.89)、(25.56±2.01)mm,侧块螺钉钉道长度为(20.78±2.05)mm。螺钉通道5个截面的CT值均值分别为椎弓根螺钉(701.89±141.48)HU、侧块螺钉(599.11±137.33)HU。0°~15°理想椎弓根螺钉通道长度之间差异无统计学意义(P0.05),0°~15°椎弓根显露置钉法钉道长度随内倾角增加而增长(P0.05),且均比侧块螺钉钉道长(P0.05),椎弓根螺钉通道穿过骨质CT值均值高于侧块螺钉通道(P0.01)。结论:利用椎弓根显露置钉技术可完成椎动脉沟处后弓高度4 mm的寰椎置钉,且钉道长度损失不多,穿行骨量较大,预期把持力良好。     

寰椎椎弓根与枢椎侧块关系的解剖与临床研究

目的研究寰椎椎弓根与枢椎侧块的位置关系,建立以枢椎侧块为解剖标志的寰椎椎弓根螺钉进钉定位技术,并通过临床应用评价其可靠性。方法取50套干燥寰枢椎标本,测量寰椎椎弓根和枢椎侧块的内缘、中点(内、外缘中点)、外缘与正中矢状线的垂直距离,计算寰椎椎弓根与枢椎侧块的内缘间距、中点间距和外缘间距,建立寰椎椎弓根螺钉进钉定位技术。临床应用该定位技术进行后路寰椎椎弓根螺钉固定治疗寰枢椎不稳患者6例,男5例,女1例;平均年龄41岁。其中游离齿突1例,齿突发育不良3例,齿突陈旧性骨折2例。结果寰椎椎弓根的内缘、中点、外缘分别在枢椎侧块的内缘、中点、外缘的内侧(1.37±0.51)mm、(1.60±0.61)mm、(2.15±0.60)mm处。确定寰椎椎弓根螺钉的进钉点为:经枢椎侧块内、外缘的中点作纵垂线,与寰椎后弓上缘交点的正下方3.0mm处。6例患者共放置寰椎椎弓根螺钉12枚,术中无脊髓和椎动脉损伤等并发症,术后X线及CT扫描显示螺钉位置均良好。结论枢椎侧块与寰椎椎弓根间存在较恒定的解剖位置关系,枢椎侧块可作为术中确定寰椎后弓显露范围和判断寰椎椎弓根螺钉进钉点的解剖学标志,可简化术中繁琐的定位操作。     

寰椎椎弓根进钉通道的数字解剖学研究

目的:探讨寰椎椎弓根进钉通道在矢状面角(SSA)为0°时不同水平面角(TSA)方向投影的变化规律。方法:将20例健康成年志愿者(男12例,女8例;年龄24~68岁,平均45岁)的寰椎CT连续断层扫描数据导入Mimics 10.01软件,三维重建寰椎数字解剖模型,将重建的结果以.stl格式保存,再将寰椎数字模型导入UG Imageware 12.0,建立寰椎椎弓根进钉通道数字化分析方法,确定三维参考平面,分析在SSA为0°时左右椎弓根TSA分别从0°～30°,均匀间隔5°,观察280个寰椎椎弓根进钉通道的长度和内切圆半径的变化规律。结果:280个寰椎椎弓根进钉通道的长度为20.54～33.21mm,其中11个通道长度小于最短椎弓根螺钉长度(22mm);TSA为0°进钉时左右通道长度均最大,左右侧比较无显著性差异(P0.05),5°～30°进钉时同一进钉角度左右侧比较有显著性差异(P0.05);同侧不同进钉角度比较无显著性差异(P0.05)。280个寰椎椎弓根螺钉通道的内切圆半径为1.38～2.51mm,其中有42个内切圆半径小于最小椎弓根螺钉半径(1.75mm);同一进钉角度右侧内切圆半径与左侧比较及同侧不同进钉角度比较均无显著性差异(P0.05)。结论:不同个体甚至同一个体的左右两侧椎弓根形态之间有较大差异。部分寰椎椎弓根进钉通道长度和内切圆半径小于椎弓根螺钉最小长度和最小半径,椎弓根进钉通道内切圆半径小于最小椎弓根螺钉半径时置钉会穿破椎弓根的皮质骨,不适合采用经寰椎椎弓根螺钉内固定技术。术前用数字化技术测量寰椎椎弓根进钉通道可以实现个体化置钉。     

采用椎弓根螺钉内固定治疗寰枢椎骨折脱位

[目的]探讨寰枢椎椎弓根螺钉技术治疗创伤性寰枢椎不稳的临床效果。[方法]2009年9月~2017年3月,对6例创伤性寰枢椎不稳患者采用颈椎后路寰枢椎椎弓根螺钉固定技术治疗。术前均常规行颅骨牵引,椎弓根进钉点位于寰椎椎弓两侧距后结节20 mm、后弓下缘2 mm,内倾5°~10°、头倾10°~15°,置入直径3.5 mm、长22~26 mm螺钉。枢椎螺钉的进钉点位于侧块内上象限,内倾约25°,头倾约25°置入直径3.5 mm、长24~28 mm螺钉。[结果]术中无血管及神经损伤。术后随访6~36个月,患者临床症状得到明显改善。术后检查显示螺钉位置良好,无内置物松动、断裂。术后12个月JOA评分为11.00~17.00分。[结论]寰枢椎椎弓根螺钉固定治疗创伤性寰枢椎不稳疗效满意。     

前路枢椎椎弓根螺钉固定通道的CT测量及临床应用

目的:探讨CT扫描测量指导前路枢椎椎弓根螺钉置人的临床应用价值.方法:对20具干燥枢椎标本行椎弓根螺钉置入,然后应用CT测量进针的角度、钉道长度以确定最佳进钉点,并根据测量数据和术前影像学检查对10例难复性寰枢椎脱位患者行前路寰枢椎复位椎弓根螺钉固定植骨融合术,观察寰枢椎复位及螺钉位置情况.结果:枢椎椎弓根的平均长度为25mm,进针点距离枢椎正中线6.6mm,安全进钉的角度向外倾斜21°±2°,下倾10°±2°.10例患者寰枢椎均完全复位,枢椎椎弓根螺钉均位于椎弓根钉道内.结论:前路寰枢椎椎弓根螺钉固定有较高的安全性,术前行CT扫描对于前路寰枢椎内固定手术有重要的指导意义.     

Development and validation of a quantitative method to assess pedicle screw loosening in posterior spine instrumentation on plain radiographs

Purpose

Currently, the diagnosis of pedicle screw (PS) loosening is based on a subjectively assessed halo sign, that is, a radiolucent line around the implant wider than 1 mm in plain radiographs. We aimed at development and validation of a quantitative method to diagnose PS loosening on radiographs.

Methods

Between 11/2004 and 1/2010 36 consecutive patients treated with thoraco-lumbar spine fusion with PS instrumentation without PS loosening were compared with 37 other patients who developed a clinically manifesting PS loosening. Three different angles were measured and compared regarding their capability to discriminate the loosened PS over the postoperative course. The inter-observer invariance was tested and a receiver operating characteristics curve analysis was performed.

Results

The angle measured between the PS axis and the cranial endplate was significantly different between the early and all later postoperative images. The Spearman correlation coefficient for the measurements of two observers at each postoperative time point ranged between 0.89 at 2 weeks to 0.94 at 2 months and 1 year postoperative. The angle change of 1.9° between immediate postoperative and 6-month postoperative was 75 % sensitive and 89 % specific for the identification of loosened screws (AUC = 0.82).

Discussion

The angle between the PS axis and the cranial endplate showed good ability to change in PS loosening. A change of this angle of at least 2° had a relatively high sensitivity and specificity to diagnose screw loosening.     

枢椎后路3种螺钉固定技术生物力学测试的对比研究

目的：评价单皮质和双皮质枢椎椎弓根螺钉、枢椎侧块螺钉和枢椎椎板螺钉的固定强度,为临床选择后路螺钉的固定方式提供生物力学依据。方法：利用30具新鲜尸体枢椎标本,进行单皮质和双皮质的枢椎椎弓根螺钉、枢椎侧块螺钉、枢椎椎板螺钉固定,测试比较其螺钉拔出强度。结果：双皮质枢椎椎弓根螺钉的拔出力量最大,为（1255.8±381.9）N;单皮质枢椎椎弓根螺钉[（901.8±373.3）N]、双皮质枢椎侧块螺钉[（776.1±306.8）N]和双皮质枢椎椎板螺钉[（640.8±302.9）N]之间差异无统计学意义。结论：枢椎后路螺钉固定宜首选椎弓根螺钉,枢椎侧块螺钉和枢椎椎板螺钉可作为枢椎后路补充固定技术,且以双皮质骨固定为宜。     

Safe corridor for iliosacral and trans-sacral screw placement in Indian population: A preliminary CT based anatomical study

ObjectivesNonsurgical management of unstable pelvic ring injuries is associated with poor outcomes. Posterior pelvic ring injuries include sacroiliac joint disruption and sacral fractures or a combination of the two. Morbidity is high in non-operatively managed patients. Screw fixation is being increasingly used to manage unstable posterior pelvic injuries. Limitations include a steep learning curve and potential for neurovascular injury. This is the first study in Indian population to describe the safe corridor for screw placement and check the feasibility of screw in both upper and lower sacral segments.MethodsThis study involved retrospective analysis of 105 pelvic CT scans of patients admitted to the emergency department of a Level 1 trauma centre. Vertical height at the level of constriction (vestibule) of S1 and S2 was measured in coronal sections and anteroposterior width of constrictions was measured in axial sections. We created a trajectory for 7.3 mm cylinder keeping additional 2 mm free bony corridor around it and confirmed that bony limits were not breached in axial, coronal and sagittal sections. Whenever there was breach in bony limit we checked applicability of 6.5 mm screw.ResultsThe vertical height and anteroposterior width of vestibule/constriction of S1 was significantly higher in males, whereas S2 vestibule height and width were similar in males and females. Both male and female pelves were amenable to S1 Trans-sacral and S1 Iliosacral screw fixation with a 7.3 mm screw when a safe corridor of 2 mm was kept on all sides. However, when S2 segment was analysed, only 42.9% of male pelves and 25.7% of female pelves were amenable to insertion of trans-sacral 7.3 mm screw.ConclusionAn individualized approach is necessary and each patient’s CT must be carefully studied before embarking on sacroiliac screw fixation in Indian population.     

O型臂联合CT三维导航系统辅助颈椎椎弓根螺钉置入的准确性研究

目的:探讨O型臂联合CT三维导航系统辅助颈椎椎弓根螺钉置钉的准确性,并与侧块螺钉置钉进行比较.方法:回顾性分析2017年3月～2021年2月在我院分别使用O型臂联合CT三维导航系统辅助置入椎弓根螺钉与徒手置入侧块螺钉行颈椎后路内固定术的54例患者,其中男44例,女10例,年龄42～79岁(58.3±9.3岁).根据置钉...     

A novel technique for accurate Poller (blocking) screw placement

Achieving good results with intramedullary nailing of oblique long bone fractures at the metaphyseal–diaphyseal junction can be difficult. There is a strong tendency for axial displacement and an association with characteristic malalignment of the short fragment. Poller or blocking screws have been shown to be effective in aiding fracture reduction. While several papers describe methods for screw placement, these are confusing to understand, difficult to follow in clinical practice and not always applicable. Here we describe a new, simple, reproducible and easy to use method for ensuring accurate Poller screw placement, in order to maximise the benefits of their use and achieve good overall results.     

Comparison of standard versus reconstruction proximal interlocking screw configurations for antegrade intramedullary nail fixation of femoral shaft fractures

BackgroundThe standard proximal interlocking screw (SS) configuration for antegrade intramedullary nail (IMN) fixation of femoral shaft fractures is lateral to medial or from the greater to less trochanter. Some authors argue for the routine use of the reconstruction screw (RS) configuration (oriented up the femoral neck) instead to prevent femoral neck complications. The purpose of this study was to compare a matched cohort of patients receiving these screw configurations and subsequent complications.MethodsA retrospective review of two urban level-one trauma centers identified adults with isolated femoral shaft fractures undergoing antegrade IMN. Patients with RS and SS configurations were matched 1:1 by age, sex, fracture location, and AO classification in order to compare complications.Results130 patients with femoral shaft fractures were identified. SS and RS configurations were used in 83 (64%) and 47 (36%) patients. 30 patients from each group were able to be matched for analysis. The RS and SS group did not differ in age, fracture location, AO classification, operative time, or number of distal interlocking screws. The RS group had fewer open fractures and were more likely to have two proximal screws. There were 7 complications, including 5 nonunions and 2 delayed unions, with no detectable difference between RS vs. SS groups (10% vs 13%, Proportional difference −3%, 95% confidence interval (CI) −30 to 14%, p = 0.1). There were no femoral neck complications in the entire cohort of 130 patients. On multivariate analysis none of the variables analyzed were independently associated with the development of complications.ConclusionsIn this matched cohort of patients with femoral shaft fractures undergoing antegrade IMN fixation, RS and SS configurations were associated with a similar number of complications and no femoral neck complications. The SS configuration remains the standard for antegrade IMN femoral shaft fixation.Level of evidenceLevel III, Retrospective cohort study.     

基于影像归档和通信系统的下颈椎椎管旁螺钉相关参数三维测量及可行性研究

目的 应用影像归档和通信系统测量下颈椎椎管旁螺钉（paravertebral foramen screw, PVFS）相关参数并探讨其可行性。方法 按时间先后选取2016年12月至2017年12月因颈椎退变或外伤于我院行颈椎手术的病人100例,收集上传至PACS的颈椎三维CT数据,分别测量C₃~C₆侧块螺钉和椎管旁螺钉的钉道长度,并进行比较分析。结果 C₃~C₆椎管旁螺钉10°和15°误差范围内的安全钉道长度分别为（12.54±1.16） mm、（11.76±1.11） mm,而侧块螺钉的钉道长度和有效钉道长度分别为（14.58±1.20） mm、（12.83±1.21） mm。对于C₃~C₆椎体,椎管旁螺钉10°、15°误差范围内的钉道长度与侧块螺钉的钉道长度相比,差异均有统计学意义（P均＜0.05）,但是与侧块螺钉的有效钉道长度是接近的。结论 下颈椎椎管旁螺钉安全固定长度可等同于侧块螺钉固定有效长度,且其方法安全合理,基于影像学角度探究而言,下颈椎椎管旁螺钉具有临床应用的可行性。     

Evaluation of Two Types of Intramedullary Jones Fracture Fixation in a Cyclic and Ultimate Load Model

Implant choice is a matter of concern in athletes and active patients who sustain a Jones fracture because they are prone to failure including non-union, screw failure, and refracture. The aim of this study was to compare the biomechanical behavior of a Jones fracture-specific screw (JFXS) with a cannulated headless compression screw (HCS) in a simulated partial weight-bearing and ultimate load Jones fracture fixation model. Ten matched pairs of human anatomical specimens underwent Jones fracture creation and consecutive intramedullary stabilization with a solid JFXS or a cannulated HCS. The bone mineral density was assessed prior to testing. Cyclic plantar to dorsal loading was applied for 1000 cycles, followed by load to failure testing. Angulation was measured by an opto-electronic motion capture system and mode of failure classification was determined by video analysis. Paired analysis showed no statistically significant difference between both screw constructs. Ultimate load reached 236.9 ± 107.8 N in the JFXS group compared with 210.8 ± 150.7 N in the HCS group (p = 0.429). The bone mineral density correlated positive with the pooled ultimate load (R = 0.580, p = 0.007) for all constructs and negatively with angulation (R = −0.680, p = 0.002) throughout cyclic loading. Solid fracture-specific and cannulated headless compression screws provide equal ultimate loads and stiffness for Jones fracture fixation. A low bone mineral density significantly impairs the construct stability and the ultimate load of both intramedullary screw constructs. © 2019 The Authors. Journal of Orthopaedic Research ® published by Wiley Periodicals, Inc. on behalf of Orthopaedic Research Society J Orthop Res 38:911-917, 2020     

经后路C2、3融合固定术选择性治疗Hangman骨折

目的探讨经后路C2、3固定融合术选择性治疗Hangman骨折的适应证并评价其临床应用价值。方法笔者共收治Hang，man骨折24例。所有患者人院后均给予颅骨牵引，然后行后路G椎弓根螺钉结合C3侧块螺钉植骨融合内固定术。结果术后神经功能恢复按Frankel分级：C级2例，其中1例恢复至E级、1例恢复至D级；D级12例，其中11例恢复至E级、1例神经症状无变化；10例E级无变化。3～6个月时复查X线片骨折均愈合，无稚动脉损伤及其他并发症。结论后路G稚弓根螺钉结合巴侧块螺钉植骨融合内固定术选择性治疗Hangman骨折，安全、有效，可以最大程度上保留上颈椎的生理功能。