The comparison of Nice knots and traditional methods as an auxiliary reduction-fixation technique in pre-contoured locking plate fixation for comminuted Robinson type 2B clavicle fracture: A retrospective study

Open reduction and pre-contoured locking plate fixation is a popular treatment option for displaced midshaft clavicle fracture. Lag screw and cerclage are 2 main intraoperative techniques to reduce and fix fragments. However, both lag screw and metallic cerclage have disadvantages. The doubled-suture Nice knot has been reported in many areas of orthopedic surgery for its effectiveness. This study aims to compare the outcomes of comminuted mid-shaft clavicle fractures reduced by Nice knots vs traditional techniques (lag screw or/and metallic cerclage) when bridged with pre-contoured locking plates.We retrospectively reviewed 101 patients (65 females and 36 males) diagnosed with midshaft clavicle fractures with at least one wedge fragment reduced by either Nice knots or traditional methods and bridged with pre-contoured locking plates between December 2016 and April 2019. Operation time, functional outcomes, pain, patient satisfaction, fracture healing, and complications were assessed at a follow-up of 12 to 40 months.The mean age of all the patients was 50.8 years. There were 52 and 49 patients in the Nice knot group and traditional group respectively, and no differences between 2 groups were found in general patient characteristics, fracture type, follow up and injury-to-surgery duration. The Nice knot group had significant less operation time (P < .01) than the traditional group (mean and standard deviation [SD], 78.6 ± 19.0 compared with 94.4 ± 29.9 minutes, respectively). For healing time, functional score, pain, satisfaction and complications, there were no significant differences between groups, despite the Nice knot group had slightly better results.Both Nice knots and traditional methods treated for comminuted Robinson type 2B clavicle fractures were effective and safe. And the Nice knots seemed to be superior with significant less operation time.     

Anatomical study of the ideal cortical bone trajectory in the lumbar spine

Background:To explore the ideal trajectory of lumbar cortical bone trajectory screws and provide the optimal placement scheme in clinical applications.Methods:Lumbar computed tomography (CT) data of 40 patients in our hospital were selected, and the cortical vertebral bone contour model was reconstructed in three dimensions (3D). Depending on the different regions of the screw through the entrance and exit of the pedicle, 9 trajectories were obtained through combinational design: T-Aa, T-Ab, T-Ac, T-Ba, T-Bb, T-Bc, T-Ca, T-Cb, and T-Cc. Cortical bone trajectory (CBT) screws with appropriate diameters were selected to simulate screw placement and measure the parameters corresponding to each trajectory (screw path diameter, screw trajectory length, cephalad angle, and lateral angle), and then determine the optimal screw according to the screw parameters and screw safety. Then, 23 patients in our hospital were selected, and the navigation template was designed based on the ideal trajectory before operation, CBT screws were placed during the operation to further verify the safety and feasibility of the ideal trajectory.Results:T-Bc and T-Bb are the ideal screw trajectories for L1–L2 and L3–L5, respectively. The screw placement point is located at the intersection of the inner 1/3 vertical line of the superior facet joint and the bottom 1/3 horizontal line of the outer crest of the vertebral lamina (i.e., 2–4 mm inward at the bottom 1/3 of the outer crest of the vertebral lamina). CBT screws were successfully placed based on the ideal screw trajectory in clinical practice. During the operation or the follow-up period, there were no adverse events.Conclusion:CBT screw placement based on the ideal screw trajectory is a safe and reliable method for achieving effective fixation and satisfactory postoperative effects.     

关节镜辅助下无头加压螺钉固定治疗髌骨横型骨折?

目的：探讨关节镜下采用无头加压螺钉(HCS)固定治疗髌骨横型骨折的临床疗效。方法选择髌骨橫型骨折患者19例,采用关节镜辅助下无头加压螺钉固定治疗,术后复查并随访。结果术后3~5周行 X 线片骨折线模糊或消失,髌骨关节面平整无位移,术后骨折愈合时间平均8周;患侧膝末次膝关节活动范围[(135.42±5.82)°]与健侧活动范围[(139.38±6.55)°]差异无统计学意义(P >0.05)。末次随访膝关节 Lysholm 评分86~100分,平均(93.7±4.14)分,显著高于术前评分65.7分(P <0.05);随访期内无骨折移位,内固定物脱落、断裂等并发症。结论关节镜辅助下 HCS 固定治疗髌骨横行骨折,关节功能恢复快,且术后并发症少,是治疗髌骨橫型骨折的有效方法之一。     

Shell-core bi-layered scaffolds for engineering of vascularized osteon-like structures

Bottom-up assembly of osteon-like structures into large tissue constructs represents a promising and practical strategy toward the formation of hierarchical cortical bone. Here, a unique two-step approach, i.e., the combination of electrospinning and twin screw extrusion (TSE) techniques was used to fabricate a microfilament/nanofiber shell–core scaffold that could precisely control the spatial distribution of different types of cells to form vascularized osteon-like structures. The scaffold contained a helical outer shell consisting of porous microfilament coils of polycaprolactone (PCL) and biphasic calcium phosphates (BCP) that wound around a hollow electrospun PCL nanofibrous tube (the core). The porous helical shell supported the formation of bone-like tissues, while the luminal surface of nanofibrous core enabled endothelialization to mimic the function of Haversian canal. Culture of mouse pre-osteoblasts (POBs, MC 3T3-E1) onto the coil shells revealed that coils with pitch sizes greater than 135 μm, in the presence of BCP, favored the proliferation and osteogenic differentiation of POBs. The luminal surface of PCL nanofibrous core supported the adhesion and spreading of mouse endothelial cells (ECs, MS-1) to form a continuous endothelial lining with the function similar to blood vessels. Taken together, the shell–core bi-layered scaffolds with porous, coil-like shell and nanofibrous tubular cores represent a new scaffolding technology base for the creation of osteon analogs.     

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.     

四孔螺钉肋骨接骨板治疗多发性肋骨骨折的力学分析

目的分析自主设计开发的新型四孔螺钉肋骨接骨板在治疗多发性肋骨骨折中的力学特性并验证其临床疗效。方法使用有限元方法,分析四孔螺钉肋骨接骨板固定后断骨的最大位移与骨折断面间隙,并与目前临床常用的六爪肋骨接骨板的固定效果进行对比,最后回顾临床数据验证其治疗多发性肋骨骨折的临床疗效。结果有限元分析结果表明,使用四孔螺钉肋骨接骨板固定后,断骨的最大位移降低,断面间隙缩小,固定效果优于六爪肋骨接骨板。但螺钉孔处存在应力集中,可能会损伤皮质骨。回顾分析复旦大学附属浦东医院30例使用四孔螺钉肋骨接骨板治疗多发性肋骨骨折的临床资料,术后患者胸痛症状明显减轻,呼吸恢复顺畅,术后CT显示骨折复位良好,验证了四孔螺钉肋骨接骨板的临床疗效。结论四孔螺钉肋骨接骨板对断骨固定良好,且对于大曲率肋骨的骨折情形适用性强,适用于治疗多发性肋骨骨折。     

关节镜下克氏针联合界面螺钉固定治疗Schatzker Ⅲ型胫骨平台骨折的疗效分析

目的 研究关节镜辅助下经皮克氏针联合界面螺钉固定治疗Schatzker Ⅲ型胫骨平台骨折的可行性和疗效分析。方法 自2008年5月至2018年1月,中国人民解放军联勤保障部队第910医院骨科采用克氏针联合界面螺钉固定治疗Schatzker Ⅲ型胫骨平台骨折20例。所有病例均采用关节镜辅助,结合骨折微创复位技术进行复位,采用多根克氏针联合界面螺钉固定并结合异体骨植骨。手术后采用HSS评分标准对膝关节功能进行评估。结果 本组20例患者均获随访,术后随访2 ～ 10年,平均（6.7±2.2）年。术后患者切口均Ⅰ期愈合,骨折均达骨性愈合,愈合时间为2.5 ～ 6个月,平均3.1个月,膝关节活动度为0° ～ 130°。末次随访时膝关节功能HSS评分： 优18例,良1例,可1例,优良率95.0%。所有患者均未出现下肢深静脉血栓、切口感染、膝关节僵硬。结论 关节镜辅助下经皮克氏针联合界面螺钉固定治疗Schatzker Ⅲ型骨折具有直视下精确复位、损伤小、愈合快,可一期处理关节腔内其他损伤,有利于功能快速康复,并发症少等优点。     

生物型空心松质骨螺钉的力学强度研究

目的 研发生物型空心螺钉并评价其力学性能,为今后经螺钉尾部注射富集骨髓干细胞并经螺钉扩散治疗骨折,特别是促进股骨颈骨折术后骨愈合、预防股骨头坏死提供理论基础。方法 对用于股骨颈骨折治疗的内固定TC4钛合金空心松质骨螺钉（直径7.3 mm）进行改良,设计研制封堵尾帽,并在长900 mm的空心松质骨螺钉的螺杆上设计侧孔,侧孔沿螺钉轴线排列,第1侧孔距钉尖20 mm,以后每个侧孔间距10 mm,依次为侧孔0~6个不等。侧孔为0的螺钉作为对照,其余分成平行于孔加力A组和垂直于孔加力B组,应用Instron材料试验机对螺钉进行3点弯曲测试,统计分析侧孔的数量及加压方向与螺钉力学强度的关系。结果（1） 平行于孔加力A组,即当螺钉侧孔方向面对受力方向,侧孔数量为0、1、2个时,螺钉受压应变达到3 mm,最大载荷和弹性模量均没有统计学差异;而当侧孔数量增加至3个以上时,最大载荷和弹性模量均出现明显下降,有统计学意义（P<0.05）。（2） 垂直于孔加力B组,即当螺钉侧孔方向垂直于受力方向,侧孔数量为0、1、2个时,螺钉受压应变达到3 mm,最大载荷间没有统计学差异（P>0.05）,侧孔数量为0、1、2、3个时,螺钉的弹性模量间没有统计学差异（P>0.05）;而当侧孔数量增加时,最大载荷（≧3个侧孔）、弹性模量（≧4个侧孔）均出现明显下降,有统计学意义（P<0.05）。（3） 当侧孔数≧3个时,垂直于孔加力组螺钉所能承受的最大载荷和弹性模量均高于同等侧孔数目螺钉受到平行于孔加力时的结果（P<0.05）。结论（1） 直径7.3 mm钛合金空心松质骨螺钉的侧孔数目控制在2个以内,对螺钉的力学性能无明显影响;（2） 若螺钉侧孔数≧3个,螺钉侧孔方向垂直于载荷方向较平行于载荷方向,能提供更强的力学性能。本研究为今后生物型空心螺钉的临床开发和使用提供了理论依据和支持。     

骶髂关节螺钉手术导航机器人系统设计及实验研究

目的 针对骶髂关节螺钉手术设计手术导航机器人系统,完成空间定位和路径导航,开展精度测试实验,检测系统定位的位置误差和角度误差.方法 本文开发手术导航机器人系统,利用基于透视视觉的双平面定位算法完成空间定位,利用串并混联结构的机器人完成路径导航.使用模型骨和尸体骨共完成模拟手术实验16例,通过术前规划与术后结果图片的重叠来评价手术导航机器人的系统精度.结果 本机器人系统最终测得的位置误差为(1.91±1.15)mm,角度误差为1.88°±0.915°.结论 本文开发的手术导航机器人可提高手术精度和手术安全性,并减少术中透视的使用.系统的平均误差能够满足骶髂关节手术的要求,但误差的标准差较大,需在后续研究中通过算法和系统优化来改善.