Isolation and characterization of microsatellite markers in the new world screw‐worm Cochliomyia hominivorax (Diptera: Calliphoridae)

The new world screw‐worm, Cochliomyia hominivorax, is one of the most important parasitic insect pests. This species causes myiasis and, consequently, significant losses to livestock industries in neotropical regions. As part of an investigation into the genetic variability and population structure of the new world screw‐worm, a set of 10 polymorphic microsatellite markers was isolated from an AC‐enriched genomic library. Amplification of the reported loci in 30 screw‐worms revealed an average of 6.9 alleles per locus with expected heterozygosities ranging from 0.3831 to 0.8022. Cross‐species amplifications suggested that these loci may be useful in other Calliphoridae species.     

"F"型置钉与FNS固定术对成人创伤性Pauwels III型股骨颈骨折患者疗效、骨折愈合状况及髋关节功能的影响

摘要 目的：探讨"F"型置钉与新型股骨颈内固定系统（FNS）固定术对成人创伤性Pauwels III型股骨颈骨折疗效、骨折愈合状况及髋关节功能的影响。方法：选取2019年1月-2021年12月我院收治的78例成人创伤性Pauwels III型股骨颈骨折患者作为研究对象,采用随机数字表法将患者分为对照组及研究组,各36例。对照组采用FNS进行治疗,观察组采用"F"型置钉内固定术进行治疗。观察并比较两组患者治疗疗效、术后情况、骨折愈合情况、髋关节功能、骨折复位质量及并发症发生情况。结果：观察组治疗总有效率80.56%高于对照组52.78%（P<0.05）。观察组住院时间、下地行走时间及完全负重时间均短于对照组（P<0.05）。观察组骨折愈合状况优于对照组（P<0.05）。两组患者Harris评分随时间发展而逐渐升高,且观察组术后1个月、术后3个月及术后6个月评分均高于对照组（P<0.05）。观察组骨折复位率77.78%高于对照组41.67%（P<0.05）。观察组并发症发生率低于对照组（P<0.05）。结论："F"型置钉及FNS固定术均可以治疗成人创伤性Pauwels III型股骨颈骨折患者,但"F"型置钉治疗疗效更好,并且力学稳定性能更好,术后并发症较少,利于患者术后恢复,值得在临床治疗中推广使用。     

Muscle moment-arms: a key element in muscle-force estimation

A clear and rigorous definition of muscle moment-arms in the context of musculoskeletal systems modelling is presented, using classical mechanics and screw theory. The definition provides an alternative to the tendon excursion method, which can lead to incorrect moment-arms if used inappropriately due to its dependency on the choice of joint coordinates. The definition of moment-arms, and the presented construction method, apply to musculoskeletal models in which the bones are modelled as rigid bodies, the joints are modelled as ideal mechanical joints and the muscles are modelled as massless, frictionless cables wrapping over the bony protrusions, approximated using geometric surfaces. In this context, the definition is independent of any coordinate choice. It is then used to solve a muscle-force estimation problem for a simple 2D conceptual model and compared with an incorrect application of the tendon excursion method. The relative errors between the two solutions vary between 0% and 100%.     

齿状突骨折手术方式的选择及治疗效果分析

目的:通过回顾性分析齿状突骨折不同术式的疗效,从而指导后期临床治疗。方法:回顾分析齿状突骨折26例,对比观察前、后路手术时间、出血量、平均住院时间及术后疼痛数字评分、颈椎功能障碍指数评分(NDI)等指标。结果:前路齿状突螺钉内固定手术时间105.7±35.3 min、出血量62.1±18.5 mL、平均住院时间7.0±1.9天、疼痛数字评分3.6±1.7分、NDI 24.3%±11.7%,后路寰枢椎融合手术时间148.2±36.2 min、出血量338.4±143.3 mL、平均住院时间11.2±2.1天、疼痛数字评分5.1±1.4分、NDI33.6%±13.4%。结论:前路齿状突螺钉内固定术具有手术时间短、出血少、平均住院时间短、疼痛数字评分低、对颈椎活动功能影响小等优势,而后路寰枢椎融合术具有手术适应范围广、手术操作难度小等优势,而其对颈椎活动功能影响较大。     

伤椎置钉与不置钉短节段内固定对胸腰椎爆裂骨折患者临床疗效及血清炎症损伤介质的影响

目的:探讨伤椎置钉与不置钉短节段内固定对胸腰椎爆裂骨折患者临床疗效及血清炎症损伤介质的影响。方法:回顾性分析2017年3月~2018年7月期间内蒙古医科大学第三附属医院骨科收治的269例胸腰椎爆裂骨折患者的临床资料,根据手术方式的不同分为A组(n=131,给予短节段内固定治疗)和B组(n=138,给予伤椎置钉联合短节段内固定治疗),比较两组患者围术期指标、影像学指标、血清炎症损伤介质及并发症。结果:两组术后1周、术后半年、术后1年伤椎椎体前缘高度呈先升高后降低趋势,且B组术后半年、术后1年伤椎椎体前缘高度均低于A组(P<0.05);两组术后1周、术后半年、术后1年Cobb'S角呈先降低后升高趋势,且B组术后半年、术后1年Cobb'S角均大于A组(P<0.05)。两组患者手术时间、术中出血量、住院时间及并发症发生率比较无差异(P>0.05)。两组术后3d血清白细胞介素-6(IL-6)、白细胞介素-8(IL-8)、白细胞介素-1β(IL-1β)、肿瘤坏死因子-α(TNF-α)、髓过氧化物酶(MPO)水平均升高(P<0.05),但两组术后3d血清炎症损伤介质比较差异无统计学意义(P>0.05)。结论:伤椎置钉与不置钉短节段内固定治疗胸腰椎爆裂骨折患者,可获得相似的临床疗效,且对患者损伤程度基本一致,但伤椎置钉在恢复伤椎椎体前缘高度、Cobb'S角方面更优,临床应用价值较高。     

An informational framework to predict reaction of constraints using a reciprocally connected knee model

Researchers have used screw theory to describe the motion of the knee in terms of instantaneous axes of the knee (IAK). However, how geometric change to the dynamic alignment of IAK may affect stance phase of foot loading has not yet been fully explained. We have tested our informational framework through readily accessible benchmark data (Fregly et al. 2012): muscle contraction and ground reaction force are compounded into a wrench that is reciprocal to the IAK and resolved into component wrenches belonging to the reciprocal screw system. This revealed the special screw system that defines the freedom available to the knee and more precisely revealed how to measure this first order of freedom. After this step, we determined the reciprocal screw system, which involves the theory of equilibrium. Hence, a screw system of the first order will have a screw system of the fifth order as its reciprocal. We established a framework the estimation of reaction of constraints about the knee using a process that is simplified by the judicious generation of IAK for the first order of freedom in equilibrium.     

Biomechanical differences of Coflex-F and pedicle screw fixation combined with TLIF or ALIF – a finite element study

Lumbar interbody fusion is a common procedure for treating lower back pain related to degenerative disc diseases. The Coflex-F is a recently developed interspinous spacer, the makers of which claim that it can provide stabilisation similar to pedicle screw fixation. Therefore, this study compares the biomechanical behaviour of the Coflex-F device and pedicle screw fixation with transforaminal lumbar interbody fusion (TLIF) or anterior lumbar interbody fusion (ALIF) surgeries by using finite element analysis. The results show that the Coflex-F device combined with ALIF surgery can provide stability similar to the pedicle screw fixation combined with TLIF or ALIF surgery. Also, the posterior instrumentations (Coflex-F and pedicle screw fixation) combined with TLIF surgery had lower stability than when combined with ALIF surgery.     

非刚性内固定治疗踝关节骨折合并下胫腓联合损伤患者术后踝关节功能和生活质量的影响

摘要 目的：探讨非刚性内固定治疗踝关节骨折合并下胫腓联合损伤的临床疗效及对术后踝关节功能和生活质量的影响。方法：回顾性分析2015年1月至2020年6月我院收治的60例踝关节骨折合并下胫腓联合损伤患者的诊治资料。根据内固定方法的不同,将患者分为非刚性组（n=30,采用非刚性内固定治疗下胫腓联合损伤）和传统螺钉组（n=30,采用传统螺钉内固定治疗下胫腓联合损伤）。比较两组的围术期指标和完全负重所需时间、手术前后的下胫腓重叠距离（TBOL）和下胫腓间隙（TBCS）;以美国足踝外科协会（AOFAS）踝-后足评分评估两组的术后踝关节功能,以世界卫生组织生活质量测定简表（WHOQOL-BREF）评估两组的生活质量,并比较两组的术后并发症情况。结果：非刚性组的完全负重所需时间短于传统螺钉组,操作角度大于传统螺钉组（均P<0.05）。两组患者术后6周、12周和6个月的TBOL均大于术前,TBCS均小于术前（均P<0.05）,但两组术后6周、12周和6个月的TBOL和TBCS相比无明显差异（P>0.05）。非刚性组术后12周的AOFAS评分高于传统螺钉组（P<0.05）;两组术后6个月的AOFAS评分均较术后12周升高（P<0.05）,但组间比较无明显差异（P>0.05）。术后6个月,非刚性组的WHOQOL-BREF各项评分及总分均高于传统螺钉组（P<0.05）。两组并发症发生率比较无明显差异（P>0.05）。结论：非刚性与传统螺钉内固定治疗踝关节骨折合并下胫腓联合损伤的临床疗效及康复效果相当,但非刚性固定的操作更加便利,术后恢复较快,患者术后生活质量更高,可较早完全负重。     

生物活性玻璃提高骨质疏松绵羊椎弓根螺钉稳定性的体内实验研究

目的：研究生物活性玻璃（Bioactive Glass,BG）在骨质疏松绵羊体内强化椎弓根螺钉固定的力学效果,并观察钉道界面及材料吸收等情况。方法：4只成年雌性小尾寒羊,采用去势联合激素注射方法建立骨质疏松绵羊模型。选择绵羊L2至L5双侧椎弓根,随机化选取一侧直接拧入椎弓根螺钉（空白组）,对侧采用BG强化钉道后拧入椎弓根螺钉（实验组）。术后3月随机选取6个椎体（12枚椎弓根螺钉）,对螺钉骨质界面行显微CT分析和组织学观察。对剩余10个椎体（20枚椎弓根螺钉）行轴向拔出实验,分析螺钉固定强度。结果：术前绵羊腰椎BMD为0.818±0.0310 g/cm2,建模完成后为1.000±0.0316 g/cm2,BMD平均值下降22.38%,差异有统计学意义（P〈0.05）。实验组螺钉骨质界面的Tb.Th、Tb.N组较对照组分别增加143.60%和33.56%,差异有统计学意义（P〈0.05）。实验组钉道周围材料绝大部分已经降解吸收,大量新生骨组织紧密包裹螺钉;对照组钉道周围骨量较少,钉骨结合不紧密,实验组螺钉骨质界面结合优于对照组。实验组的最大轴向拔出力为1083.04±86.37N,空白组为871.76±79.03N,前者较后者提高25.26%,差异有统计学意义（P〈0.05）。结论：生物活性玻璃能显著改善骨质疏松情况下螺钉骨质界面的骨微观结构,进而提高椎弓根螺钉的把持力。