Biomechanical comparison of three internal fixation configurations for low transcondylar fractures of the distal humerus

BackgroundWe aimed to evaluate the biomechanical stiffness and strength of different internal fixation configurations and find suitable treatment strategies for low transcondylar fractures of the distal humerus.Methods and materialsThirty 4^th generation composite humeri were used to create low transcondylar fracture models that were fixed by orthogonal and parallel double plates as well as posterolateral plate and medial screw (PPMS) configurations (n=10 in each group) using an anatomical locking compression plate-screw system and fully threaded medial cortical screws. Posterior bending (maximum 50 N), axial loading (maximum 200 N) and internal rotation (maximum 10 N·m) were tested, in that order, for each specimen. Stiffness under different biomechanical settings among different configurations were compared. Another 18 sets of fracture models were created using these three configurations (n=6 in each group) and the load to failure under axial loading among different configurations was compared.ResultsUnder posterior bending, the stiffness of parallel group was higher than orthogonal group (P<0.001), and orthogonal group was higher than PPMS group (P<0.001). Under axial loading, the stiffness of parallel group was higher than orthogonal group (P=0.001) and PPMS group (P<0.001); however, the difference between orthogonal and PPMS group was not statistically significant (P>0.05). Under internal rotation, the stiffness of parallel group was higher than orthogonal group (P=0.044), and orthogonal group was higher than PPMS group (P=0.029). In failure test under axial loading, the load to failure in the orthogonal group was lower than parallel group (P=0.009) and PPMS group (P=0.021), but the difference between parallel group and PPMS group was not statistically significant (P>0.05). All specimens in orthogonal group demonstrated “distal medial failure”; most specimens had “distal medial and trochlear failure” in the parallel group; most specimens exhibited “contact failure” in the PPMS group.ConclusionFor treating low transcondylar fractures, the overall stiffness and strength of the parallel configuration were superior to those of the orthogonal and PPMS configurations. Nevertheless, the PPMS configuration can provide adequate stability and stiffness comparable to double-plate configurations under axial loading. Therefore, the PPMS construct may have certain clinical value.     

双平面骨科机器人系统辅助骶髂关节螺钉置入的实验研究

目的本研究应用双平面骨科机器人系统进行尸体骨骨盆骶髂关节螺钉置入的实验研究,评估该系统的安全性和有效性。方法双平面骨科机器人系统是由北京航空航天大学和北京积水潭医院联合开发的一种基于术中X线图像的手术导航系统。在该系统辅助下对4具尸体骨骨盆进行骶髂关节螺钉置入,共12枚空心钉,均置入S1。作为对比,由同一位医生操作,应用传统方法在C型臂透视控制下对模型骨盆进行骶髂关节螺钉置入,同样为12枚空心钉。记录从采集图像到置入空心钉导针所需透视的次数、透视累计时间及操作时间,并进行统计学分析。置入骶髂关节螺钉后,通过目测、透视和锯开骶骨直接测量的方法检查螺钉的位置。结果在机器人导航辅助下,置入一枚导针的平均透视次数是2.5次,平均透视累计时间为1.5s,平均操作时间为253s;12枚骶髂关节螺钉均在安全区内。在透视控制下徒手操作,置入每枚导针的平均透视次数是20.3次,平均透视累计时间为13.7s,平均操作时间为246s;12枚骶髂关节螺钉中,两枚螺钉误置。应用双平面骨科机器人系统辅助操作的透视次数和透视累计时间少于徒手操作,二者差异有显著性意义(P<0.05)。而操作时间二者差异无显著性意义(P>0.05)。结论双平面骨科机器人系统为骶髂关节螺钉置入提供精准的空间定位和稳定的路径导航,而这一切都在短短的数分钟之内完成,具备极好的安全性和高效性,并使患者和医生受到的X线照射量显著减少。目前的应用结果鼓舞我们进一步的临床实验应用。     

计算机辅助带锁髓内钉固定胫骨骨折全程规划手术系统的实验研究

目的评价计算机辅助带锁髓内钉固定胫骨骨折全程手术规划系统的有效性及临床可行性。方法在分析系统结构和操作流程的基础上,利用塑料胫骨模型(9根)和尸体胫骨(12具下肢肢体)进行基于C型臂透视图像的术中骨折肢体图像拼接、骨折闭合复位及髓内钉置入仿真测量实验；利用胫骨模型及尸体胫骨进行图像拼接精度分析,以验证图像拼接与规划模块的正确性。利用尸体胫骨进行计算机辅助骨折闭合复位试验,分析骨折复位机构模块的操作可行性。结果图像拼接模块只需术中采集7～10张有效的C型臂图像即可拼接出下肢长骨的全景图像,为采集图像所需的术中透视时间为(19．75±0．61)s；计算机进行X线透视图像采集和拼接总时间为(4．17±0．86)min；塑料模型拼接精度达(1．26±0．76)mm。结论该系统实现了基于C型臂拼接图像的计算机辅助胫骨骨折髓内钉内固定全程手术规划,术中可完成骨折复位图像分析、手术规划、虚拟仿真,髓内钉型号选择以及骨折复位等关键操作,为计算机辅助骨科手术系统治疗长骨骨折搭建了精确、安全、稳定的软硬件技术平台。     

带锁髓内钉治疗新鲜四肢长骨干骨折1224例疗效分析

目的总结带锁髓内钉治疗肱骨干、股骨干、股骨髁上、胫骨干和转子间骨折的疗效。方法自1996年10月至2004年6月间使用带锁髓内钉治疗的有完整资料的新鲜四肢骨折1224例,男778例,女446例;平均年龄39岁(16￣92岁)。骨折位于肱骨干92例,股骨转子间210例,股骨干488例,股骨髁上92例,胫骨342例。闭合骨折按AO分型:A型642例;B型364例;C型218例。开放骨折15例(GustiloⅠ型8例,GustiloⅡ型7例)。受伤至手术时间平均为8d(3h￣33d)。闭合复位1203例,切开复位23例;扩髓409例,非扩髓815例。结果平均随访时间为24个月(6￣70个月)。1204例骨折愈合,愈合率为98.2%,平均愈合时间为5个月(3￣12个月)。骨折不愈合22例,其中肱骨4例,股骨8例,股骨髁上4例,胫骨6例,总不愈合率为1.8%。术后无急性感染发生,3例发生晚期深部感染,总感染率为0.2%。术中16例发生严重骨折劈裂,4例为肱骨逆行髓内钉固定,4例Gamma钉固定,9例为股骨逆行髓内钉固定,占1.3%。6例发生医原性神经损伤,占0.4%。股骨髓内钉主钉断裂1例,锁钉断裂9例(0.6%)。晚期髓内钉末端骨折3例,占0.2%。53例主诉髓内钉尾端部位不适,占4.3%。结论闭合复位带锁髓内钉治疗骨干骨折在骨折愈合率、感染率、出血量、功能恢复情况和早期活动方面均较满意,是治疗骨干骨折较好的方法,但     

医用机器人辅助股骨带锁髓内针远端锁钉瞄准系统的实验研究

目的研制在骨折治疗中精确定位的机器人辅助远端锁钉瞄准系统。方法在以股骨髓内针远端锁钉植入手术中,采用模块化、小型化的并联机器人结构设计,应用机械臂空间定位技术,双目视觉、6自由度的机器人辅助髓内针远端锁钉瞄准系统。结合C型臂定位并实施导航控制进行远端锁钉植入。髓内针被分别置入塑料股骨(Swiss Sybone,5根,35孔)、人类干股骨标本(2根,12孔)、新鲜人尸体大腿(1具,6孔)。非扩髓型髓内针的尺寸范围从9/310到12/340。应用机器人辅助瞄准系统对上述髓内针进行远端锁钉植入,术中C型臂透视确认螺钉准确置入,记录锁钉植入过程的X线透视时间。结果所有远端锁孔被成功地锁定。在53个锁孔中,6例(11.1%)钻头触到锁定孔道,仍顺利穿过锁孔,没有对髓内针造成损伤。螺钉植入过程中需要的术中X线透视时间为1.8s±0.3s。结论医用机器人使仅应用两幅计算机校准的X线图像,不需要额外的术中X线透视来导航器械,手术过程中总的X线透射时间显著减少。人机交互功能操作易于掌握,可作为机器人辅助长骨治疗中精确定位和稳定操作的技术平台。     

创伤性肘关节僵硬致病原因分析

一、概述肘部主要功能是连接上臂与前臂,维持手部在空间的位置,从而发挥上肢功能。文献报道约5%~15%的肘部创伤后会出现肘僵硬,是人体最容易出现僵硬的关节。既往曾将伸肘受限>30°、屈肘<130°考虑为手术松解的指征,然而由于现代生活中对肘部活动范围的要求越来越高,当其不能满足生活、工作需要时即可诊断为肘僵硬。     

老年髋部骨折患者跌倒的现状研究

目的探讨跌倒所致髋部骨折患者的流行病学情况。方法收集2015年5月至2017年12月住院的年龄≥65岁脆性髋部骨折患者(A组),其中男性179例,女性456例;并以同期老年科住院的年龄≥65岁无髋部骨折病史患者作为对照(B组),其中男性29例,女性52例;应用SPSS 19统计学软件,采用二元Logistic回归分析危险因素。结果①635例髋部骨折老年患者,平均年龄(79.69±7.64)岁;有45.2%的跌倒是发生在家中,在家中的高发地点是卧室、起居室(占家中跌倒的72.1%),跌倒高发时间为入睡时间段,22:00～7:00占33.6%;有54.8%的跌倒是发生在户外,老人因使用非机动车产生的相关非暴力伤占到户外跌倒的28.2%。②发生跌倒后髋部骨折与老人行走时是否使用助行器(P=0.000)、步态(P=0.000)、优势手握力(P=0.000)、内科合并症CCI(P=0.006)有关;其中,行走时需要双手支撑辅助的老年患者比独立行走的老年患者发生髋部骨折的风险高4.7倍(95%CI:2.7,8.0)。③反复发生跌倒,即跌倒超高危老人与行走时是否使用助行器(P=0.000)、优势手握力(P=0.027)、内科合并症指数(P=0.027)相关。结论老年人需尽可能的改善肌力及掌控平衡,居家出门少的老人需要注意卧室和起居室的布置,使用非机动车来助行的老人在上下车时及行驶时需要尽可能的缓慢来预防跌倒。随着人口老龄化程度的加剧,需要更多的社会力量来开展跌倒预防及跌倒损伤发生后的复健工作。     

Disease distribution and medical resoureces during the Beijing 2008 Olympic and Paralympic Games

Background Appropriate planning and staffing for medical services at large-scale athletic events is essential to provide for a safe and successful competition. There are few well-documented accounts describing the demand for such services.The present study provided the data from the Beijing 2008 Olympics and Paralympics,with a view to provide the guidance for planning future events.Methods A total of 22 029 and 8046 patients,who received medical care from a physician at an Olympic or Paralympic medical station,were included. The patient proportion among different personnel,various disease proportions at different kinds of venues,and the disease spectrum at specified venues at the Olympics and Paralympics were analyzed.Results At both games,the patient proportion varied by accreditation status. The staff accounted for the largest number of visits at the Olympics (44.83%) and Paralympics (36.95%),with respiratory diseases the most common. Various disease spectrums were discovered at the different kinds of venues. Surgical diseases were the most frequently listed reason for visits,both at competition and non-competition venues,especially during the Paralympics. The sport-related injuries accounted for a majority of the surgical cases during both games. At training venues,ear nose and throat diseases accounted for the greatest number of visits during both games.Conclusions During both games,people contracted different diseases at different venues. Adequate surgeons should be designated to offer assistance mostly in trauma situations. Appropriate numbers of physicians in respiratory diseases and otorhinolaryngology is of great importance.     

Essex-Lopresti损伤的诊断与治疗

目的探讨Essex-Lopresti损伤的诊断和治疗特点。方法对5例病人在确诊后行手术治疗,恢复或重建桡骨长度,同时复位并稳定下尺桡关节,并在术后对这5例病人进行了随访。结果术后所有病人的肘关节活动度均无严重受限,均无肘关节不稳定,除开放损伤的1例外其他均无疼痛和明显力量减弱。Morry肘关节评分平均为86．8分（75．5～95．5分）,其中优1例,良4例,可1例。病人的腕关节活动受限轻微,均没有明显的疼痛,1例病人在从事原来的重体力工作时略有力不从心,其他病人均能很好地恢复原来的工作。改良的Green＆O’Brien腕关节临床评分平均为87分（80—90分）,其中优3例,良2例。结论对于Essex—lopresti损伤,早期诊断非常重要。主要的治疗原则是恢复或重建桡骨长度的同时复位、稳定下尺桡关节。首要的是恢复或重建桡骨长度,在可能的情况下应尽量早期对桡骨头骨折进行切开复位内固定（ORIF）,如桡骨头骨折粉碎严重不能进行内固定,则可考虑一期进行人工金属桡骨头假体置换。对下尺桡关节损伤的处理应早期进行复位并对其进行一定的固定。     

计算机辅助带锁髓内钉远端锁定瞄准系统的设计与实验研究

目的　测试计算机辅助带锁髓内钉远端锁定瞄准系统应用于下肢模型骨及尸体骨固定中的准确性及安全性。方法　采用 10根塑料模型胫骨 ,2 0根塑料模型股骨 (SynboneAG ,Malans,Switzerland) ,6具青年男性新鲜尸体的双下肢标本 ,随机平均分为两组 ,行胫骨、股骨带锁髓内钉内固定术 (Orthofix带锁髓内钉 ,每根针远端有 2孔 )。在远端锁钉时 ,实验组采用计算机辅助带锁髓内钉远端锁定瞄准系统 ;对照组采用Orthofix带锁髓内钉机械锁定瞄准器。两组以远端锁钉锁定的手术操作时间、在C型臂X线下暴露时间、锁定的成功率三项指标进行比较。结果　实验组锁钉锁定的手术时间、X线下暴露时间、锁定成功率分别为 (4 4 4± 2 99)min、(1 16± 0 38)min ,(10 0± 0 ) % ;对照组手术时间、X线下暴露时间、锁定成功率分别为 (10 4 2± 4 18)min ,(4 71± 3 86 )min ,(94 4 4±0 36 ) % ,两组手术与X线下暴露时间显著减少 (P <0 0 5 )。结论　计算机辅助带锁髓内钉远端瞄准系统设计合理、定位准确、操作简便、成功率高、缩短了手术时间 ,特别是在手术中对C型臂X线的依赖程度降低 ,在X线下暴露时间短 ,减少了医患人员的放射损伤。该系统能够通用于各种类型的髓内针 ,便于推广、普及。