组织隔离法与机械活动法在兔胫骨骨不连模型建立中的作用

目的 评价组织隔离法与机械活动法在建立兔胫骨萎缩型与肥大型骨不连模型中的作用方法将l2只体重为3～4．5kg的新西兰大白兔随机分成A、B两组，A组于胫骨中段截骨，两断端套接1cm硅胶管，单侧外固定器固定，保持两断端间距2mm，8周取出硅胶管，观察组织隔离法构建萎缩型骨不连模型的效果。B组于胫骨中段截骨后采用2枚1mm克氏针行髓内松动固定，被动活动断端200次／天，持续1个月，观察机械活动法构建肥大型骨不连模型的效果。结果 A组中所有动物在硅胶管取出后4周，无1例断端出现骨愈合表脱，X线片显示良好萎缩型骨不连的复制。B组中所有动物存6周内截骨端出现延迟愈合，部分伴有畸形．骨断端有人量肥大骨痂形成。结论 硅胶管组织隔离法是复制兔胫骨萎缩型骨不连模型的有效方法，而采用被动机械活动复制兔胫骨肥大型骨不连模型的方法尚需进一步研究。     

股骨粗隆间骨折滑动加压外固定器的设计及生物力学评价

目的设计制作股骨粗隆间骨折滑动加压外固定器，并对其生物力学性能进行评价。方法取5对成人新鲜股骨标本，造成AO分型A1．1型股骨粗隆间骨折模型。试验组用滑动加压外固定器固定，对照组用单侧成角外固定器固定。实验分为骨折端张开角度的测试、骨断端应力分布的测试、骨断端接触面积的计算。结果①张开角度：各载荷条件下试验组张开角度明显小于对照组；②骨断端的应力分布：试验组包括张力侧各点均为压应力，而对照组在外侧4个测试点为拉应力；③骨折端接触面积：相同载荷下骨折端接触面积试验组较对照组大47．1％。结论滑动加压外固定器的各项生物力学性能均优于普通外固定器。     

新型外固定器制作大鼠负重骨节段性骨缺损模型的实验研究

目的 为组织工程骨及细胞生物技术修复负重骨节段性骨缺损的研究建立一种新的动物模型. 方法选取24只健康雄性SD大鼠,随机分为2组:4 mm缺损组和6 mm缺损组,每组12只.分别于大鼠右侧股骨干截骨制备4 mm和6 mm骨缺损,然后采用自行研究设计的可调式单边外固定器固定.术后0、2、4、8、12周影像学观察股骨对位情况、外固定器的位置及骨缺损的愈合情况.术后12周取材行组织学观察新生骨的生成情况. 结果术后12周时大体观察见4 mm缺损组骨缺损区已形成坚实的骨痂,显示牢固的骨愈合;6 mm缺损组骨缺损区为软组织包裹,两截骨端略显粗大,无骨性连接.术后2、4、8、12周X线评分显示:随着时间延长,4 mm缺损组X线评分递增,12周时已有连续性骨痂桥接骨缺损区,骨缺损愈合;6 mm缺损组两骨端硬化、髓腔封闭,骨缺损不能愈合,不同时间点两组间评分比较差异均有统计学意义(P＜O.05).12周时组织学观察4 mm缺损组骨缺损区有大量的新生骨生成,连接骨缺损区;6 mm缺损组骨缺损区无骨性连接,由肉芽瘢痕充填. 结论本研究为骨组织工程及细胞生物技术的研究提供了一种可靠的动物负重骨节段性骨缺损模型.可调式单边外固定器可以为大鼠的股骨缺损模型提供足够的稳定.     

持续应力对松质骨骨折愈合影响的超微结构观察

目的 观察持续应力下松质骨骨折愈合的细胞超微结构变化,探讨持续应力对松质骨骨折愈合的影响.方法 取20只家犬两侧股骨转子部"L"型截骨,左侧以镍钛合金粗隆截骨固定器固定,右侧以钢丝贯穿环扎加压收紧固定.术后2、4、8、12周取材行透射电镜观察.结果 镍钛合金粗隆截骨固定器组内固定后骨折愈合时间早于钢丝固定组,且2种不同固定方式下骨折断端间成骨细胞、成软骨细胞及胶原纤维表型及形态均有明显不同,镍钛合金粗隆截骨固定器组细胞及胶原纤维排列表现出明显的同向性,与应力作用方向一致.细胞的增生及胶原的合成也较钢丝组旺盛.结论 在镍钛合金转子截骨固定器固定形成的骨折断端间持续应力作用下,松质骨骨折能够获得快速、有效地修复及愈合.     

股骨粗隆间骨折滑动加压外固定器的设计及生物力学评价

目的设计制作股骨粗隆间骨折滑动加压外固定器,并对其生物力学性能进行评价。方法取5对成人新鲜股骨标本,造成AO分型A1·1型股骨粗隆间骨折模型。试验组用滑动加压外固定器固定,对照组用单侧成角外固定器固定。实验分为骨折端张开角度的测试、骨断端应力分布的测试、骨断端接触面积的计算。结果①张开角度:各载荷条件下试验组张开角度明显小于对照组;②骨断端的应力分布:试验组包括张力侧各点均为压应力,而对照组在外侧4个测试点为拉应力;③骨折端接触面积:相同载荷下骨折端接触面积试验组较对照组大47·1%。结论滑动加压外固定器的各项生物力学性能均优于普通外固定器。     

介绍一种股骨粗隆下截骨延长新方法

利用组合式骨外固定器和股骨带锁髓内钉联合行股骨粗隆下截骨延长术 ,经随访疗效满意。1　手术方法术前测量好患肢股骨的长度及髓腔直径 ,准备好合适规格的带锁髓内钉及组合式骨外固定器一套 (半环式构形带延长杆 )。手术在硬膜外麻醉下进行。顺行打入带锁髓内钉后 ,于小粗隆下 1～ 2ｃｍ处横行截骨 ,截骨后缝合骨膜。通过体外定位装置沿近端 2个锁钉孔打入 2枚螺纹半钉 ,于两螺纹钉之间于股前方打入 1枚螺纹半钉 ,与上述 2枚螺纹钉相垂直。并经过髓内钉的内侧 ,用半环将 3枚螺纹钉连为一体。于股骨髁部在冠状面上打入 2枚 3ｍｍ骨圆针 ,2针…     

骨盆髋臼三维记忆内固定系统对犬骨盆弓状线部骨折力学性能的影响

目的:建立一种骨盆弓状线部骨折的动物模型,探讨骨盆髋臼三维记忆内固定系统(acetabular tri-dimen-sional memory fixation system,ATMFS)对骨折愈合及力学性能的影响。方法:选用10只成年杂种家犬,建立双侧髋臼臼顶上方1.5cm处的横形骨折动物模型,分别采用ATMFS前柱固定器和6孔重建钢板内固定,于术后1、2、4、8、12周各取2只动物,行X线检查、大体观察和生物力学测试。结果:动物术后12～24h开始站立行走,定期复查未发现骨折端移位及内固定断裂。ATMFS侧骨折端无凌乱骨痂,术后4周即可见连续性骨痂通过骨折线。生物力学测试发现术后第1、2周两侧生物力学强度差异无显著性统计学意义(P>0.05),第4、8周ATMFS侧骨折端生物力学强度明显高于钢板侧(P<0.05),术后第12周两侧生物力学强度差距缩小,但ATMFS侧仍大于钢板侧。结论:通过双侧髋臼臼顶上方的横形截骨能够建立可靠的骨盆弓状线部骨折动物模型,ATMFS的解剖位固定和其产生的持续顺应生理力线的压应力能够促进骨折愈合。     

外固定架辅助髓内钉技术治疗股骨畸形和股骨干骨折不愈合

目的 探讨外固定架辅助髓内钉(fixator assist nailing,FAN)技术治疗股骨畸形、股骨干骨折不愈合伴畸形和畸形愈合的疗效.方法 回顾性分析在2008年1月至2011年12月采用FAN技术治疗8例股骨干骨折不愈合伴畸形、3例维生素D抵抗性佝偻病性股骨畸形、2例股骨干骨折畸形愈合.男11例,女2例;年龄16～50岁,平均33岁.10例采用一期手术,3例采用二期手术.12例采用单边外固定架,1例采用环形外固定架.8例采用顺行髓内钉,5例采用逆行髓内钉.2例患者采用自体髂骨植骨,1例骨痂剪碎后植骨.结果 12例患者获得完整随访,随访时间12～48个月,平均21个月.7例股骨干骨折不愈合的患者骨折在术后3～6个月愈合,平均3.8个月.5例股骨畸形行截骨术的患者截骨端在术后3～5个月(平均3.5个月)愈合.根据Paley评分标准,9例为优,2例为良,1例为可.术前下肢不等长(48.2±23.0) mm,术后为(27.3±24.6) mm,肢体长度增加4.6～41.0 mm(平均23.3 mm).术前机械轴偏向(27.5±24.4) mm,术后(6.3±8.3) mm.未发生感染和神经、血管损伤.结论 FAN技术结合了外固定架安全、微创、便于调节,可准确矫正畸形优点和髓内钉固定患者依从性高特点,可有效地治疗代谢性骨病引起的股骨畸形、股骨干骨折不愈合伴畸形和畸形愈合.     

L型镶嵌式骨外固定器治疗胫腓骨开放骨折

目的评价L型镶嵌式骨外固定器治疗胫腓骨开放骨折的方法及临床疗效。方法 28例胫腓骨开放骨折患者急诊采用清创、骨折复位、L型镶嵌式骨外固定器固定治疗。结果患者均获随访,时间8～16个月。骨折愈合时间4～12个月。发生间隙性钉道感染3例9孔,经针对性治疗后治愈。无深部感染及螺纹钉松动。骨折无延迟愈合及畸形愈合。膝、踝关节活动良好。结论 L型镶嵌式骨外固定器治疗胫腓骨开放骨折具有操作简单、创伤小、固定可靠等优点,是一种良好的、符合生物力学原理的固定方法。患者功能恢复满意。     

穿针滑动固定家兔胫骨实验性骨折愈合过程断端位移测试

目的研究骨折愈合过程中断端微动.方法采用穿针滑动固定家兔胫骨实验性骨折治疗动物模型,手术截骨造成横断骨折,骨折线位于胫骨中部,采用自制滑动固定器4针固定,针径1.5mm;采用霍尔元件磁场传感器测量位移.结果术后1天断端最大位移278±122微米,2周时为190±91微米,3周时为70±35微米,4周时为54±25微米.结论所采用的骨折治疗模型具有对骨折断端生物力学环境的测控能力,骨折断端微动的大小能反映骨折愈合的早期进程.     

A new animal model for bone atrophic nonunion: Fixation by external fixator

A new small animal model of bone atrophic nonunion was established for investigating the process of bone regeneration by performing cauterization of the periosteum, removal of the local bone marrow, and stabilization with external fixation. The model allows the creation of an atrophic nonunion without the need for a critical size defect. Furthermore, it provides reproducible, well‐defined mechanical conditions and minimized physical interference of the implant with the biological processes in the healing zone. Eighty adult Sprague‐Dawley rats received an osteotomy of the left femur, stabilized with an external fixator. In half of the animals, the periosteum proximal and distal to the osteotomy was destroyed by cauterization and the adjacent bone marrow was removed (nonunion group). At 2 and 8 weeks after surgery, radiological, biomechanical, histological, and histomorphometrical analyses showed a typical physiological healing in the control group, while the nonunion group was characterized by resorption of the bone ends with some callus formation distant to the osteotomy. At both time points, the callus was composed of significantly less bone and significantly more connective tissue (p < 0.001). In addition, the torsional strength of the osteotomized femur was significantly less in the nonunion group than in the control group, which was comparable to that of the intact femur (p < 0.001). In conclusion, the present model allows the induction of an atrophic nonunion without the need of a critical size defect. It is reproducible, provides standardized biomechanical conditions, and allows minimized interaction of the implant with the healing zone. © 2008 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res     

Vascularity in a new model of atrophic nonunion

Our aim was to develop a clinically relevant model of atrophic nonunion in the rat to test the hypothesis that the vessel density of atrophic nonunion reaches that of normal healing bone, but at a later time-point. Atrophic nonunion is usually attributed to impaired blood supply and is poorly understood. We determined the number of blood vessels at the site of an osteotomy using immunolocalisation techniques in both normally healing bones and in atrophic nonunion. At one week after operation there were significantly fewer blood vessels in the nonunion group than in the healing group. By eight weeks, the number in the atrophic nonunion group had reached the same level as that in the healing group. Our findings suggest that the number of blood vessels in atrophic nonunion reaches the same level as that in healing bone, but at a later time-point. Diminished vascularity within the first three weeks, but not at a later time-point, may prevent fractures from uniting.     

组织工程骨联合外固定修复大鼠股骨节段性骨缺损

目的 观察以外固定器固定,骨髓间充质干细胞 (BMSCs) 联合双相磷酸钙(BCP)修复大鼠股骨节段性骨缺损的效果.方法 A组:BMSCs与BCP复合植入缺损区;B组:BCP植入缺损区;C组:空白组.定期摄X线片,术后12周取材.结果 A组随时间延长X线评分递增,12周时平均为4.17分,B组为1.18分,C组为1.08分,差异有统计学意义(P<0.05).组织学检查见A组缺损区有大量的新生骨生成,而B、C组无新生骨生成.A组的抗压刚度和扭转刚度分别为(8.09±2.42)N/mm、(1.89±0.72)Nmm/deg;B组为(1.75±0.90)N/mm、(0.40±0.21)Nmm/deg,差异有统计学意义(P<0.05).结论 组织工程骨联合外固定可以修复节段性骨缺损.

Abstract：

Objective To evaluate the efficacy of bone mesenchymal stem cells (BMSCs) combined with biphasic calcium phosphate (BCP) repair of segmental bone defect, which was stabilized with an adaptable external fixation system.Methods In group A, the femoral defect was filled with BCP combined with BMSCs; In group B, the femoral defect was filled with BCP, and in group C, defects were left empty. Animals were sacrificed 12 weeks post-operation.Results In group A, radiographic scores were average 4.17, significantly (P<0.05) greater than in group B (1.18) and group C (1.08). Histological evaluations displayed the bridging of the defect in group A, with remarkable new bone formation. In contrast, group B and group C showed no formation of new bone. The mechanical testing revealed that axial stiffness was (8.09±2.42) N/mm and torsional stiffness was (1.89±0.72) Nmm/deg in group A, and those in group B were (1.75±0.90) N/mm and (0.40±0.21) Nmm/deg respectively. There was significant difference in biomechanical tests between group A and group B (P<0.05).Conclusion External fixator combined with tissue engineered bone can repair segmental bone defect.     

高能量骨折延期手术促进骨愈合的实验研究

目的研究延期手术刺激旺盛的外骨痂生长在高能量骨折中的作用,探索提升骨折愈合能力的新途径。方法取成年狗20只,随机分为ABCD四组,各组均行股骨中段线锯截骨,电凝破坏周围骨膜,制造1 cm缺损,8孔钢板固定。A组截骨14 d后行内固定,B组即时内固定,C组即时内固定,但不用电凝破坏骨膜,D组14 d后行内固定,但固定时切除骨端周围已形成的肉芽。结果狗股骨破坏骨膜制造骨缺损后,早期手术固定组无外骨痂生长,几乎无内骨痂生长,引发了萎缩性骨不连;在同样破坏骨膜制造骨缺损的情况下延期手术固定组产生了旺盛的骨痂生长,产生了稳定固定下的骨痂愈合。结论高能量骨折早期手术固定抑制外骨痂生长,容易造成骨痂生长不良的低质量愈合现象。延期手术固定可以刺激良好的外骨痂生长,改善骨折愈合能力,预防骨不连的发生。     

Atrophic nonunion can be predicted with dual energy x-ray absorptiometry in a canine ostectomy model

This study demonstrated that dual energy x-ray absorptiometry can be used to distinguish between normal union and atrophic nonunion, with high sensitivity and high negative predictive value, by 8 weeks after surgery in a canine model. Eighteen adult mixed-breed dogs were divided into two equal groups: normal union and atrophic nonunion. In the normal union group, a 5 mm mid-diaphyseal transverse ostectomy was performed in the right tibia, and the bone was stabilized with a unilateral external fixator. In the atrophic nonunion group, a 5 mm mid-diaphyseal ostectomy was performed; the distal 1.5 cm of the bone ends, including the periosteum, were frozen twice to ?20°C using liquid nitrogen and thawed slowly twice; and the bone was stabilized with a unilateral external fixator. The members of the research team were blinded to the group assignments until after all dogs were killed and all data were acquired. Radiography and dual energy x-ray absorptiometry of both tibiae were performed at week 1, 2, 3, 4, 6, 8, 10, 12, 14, and 16 after surgery. All dogs were killed at 16 weeks, and the torsional stiffness and maximum torque of both tibiae of five dogs in each group were determined. Mechanically, the tibiae in the normal union group had significantly higher maximum torque (43-fold higher) and torsional stiffness (86-fold higher) than the tibiae in the atrophic nonunion group. The sensitivity and negative predictive value of dual energy x-ray absorptiometry for predicting nonunion were 100% by 8 weeks after surgery. The specificity and positive predictive value reached 78 and 82%, respectively, by 16 weeks. Radiographic scores were significantly higher for the union group than for the nonunion group beginning at 2 weeks after surgery. The earliest time after surgery that radiography classified an ostectomy as a nonunion was significantly later (4.6 ± 1.2 weeks) than for dual energy x-ray absorptiometry (2.6 ± 1.4 weeks). Before these results can be extrapolated to human applications, further animal studies must be performed to evaluate clinically or experimentally induced fractures, or both, rather than the well defined ostectomies that were performed in this study.     

Surgical treatment of the aseptic femoral shaft nonunion

Femoral shaft nonunions is difficult complication and a big challenge for the orthopaedic surgeons. These complications occur after open femoral fractures, comminuted fractures, segmental fractures, the infection, after the inadequate fixed osteosynthesis, the systemic disease, and smokers. The paper presents the results of treatment aseptic femoral shaft nonunion in 18 patients. They were primarily operated by the method of internal compresive plate fixation and external fixation (open fractures). For fixation we used dinamic internal fixator by Mitkovic. All nonunions treated by this method are healed. In patients with atrophic femoral shaft nonunions in addition to fixation was performed and bone grafting. This implant has proved successful in the treatment of femoral shaft nonunion. During the fixation no periostal and intramedullary vascularization damage, which is an important prerequisite for bone healing. Implant enables biological and mechanical conditions for nonunion healing.     

Temporary distraction and compression of a diaphyseal osteotomy accelerates bone healing

Mechanical strain during callus distraction is known to stimulate osteogenesis. It is unclear whether this stimulus could be used to enhance the healing of a normal fracture without lengthening the bone. This study tested the hypothesis that a slow temporary distraction and compression of a diaphyseal osteotomy accelerates fracture healing. Fourteen sheep underwent a middiaphyseal osteotomy of the right tibia, stabilized by external fixation. An external fixator allowed either a temporary axial distraction (TD group; n = 6) or a constant fixation (C group; n = 8). Distraction began 7 days postoperatively at a rate of 0.5 mm twice per day for 2 days with subsequent shortening of 1.0 mm twice on the third day. The procedure was repeated four times. Fluorochrome labeling was performed postoperatively. After 8 weeks the sheep were sacrificed and healing was evaluated using densitometric, biomechanical, and histological methods. Bending stiffness of the tibiae after 8 weeks was 58% higher in the TD group than in the C group. The volume of the periosteal callus was significantly (p = 0.05) higher in the TD group (3.9 cm³) than in the C group (2.7 cm³). There was 20% more bone in the fracture gap of the TD group than the C group. There was a significantly higher bone formation rate in the TD group than in the C group. This study demonstrated the feasibility of fracture healing stimulation by the temporary application of distraction and compression. © 2008 Orthopaedic Society. Published by Wiley Periodicals, Inc. J Orthop Res 26:772–777, 2008     

股骨干骨折术后内固定失效原因分析

目的探讨股骨干骨折术后内固定失效的原因,以利于更好地指导临床治疗。方法股骨干骨折内固定失效后均出现骨不连,其中肥大型骨不连12例,萎缩型骨不连4例,感染性骨不连2例。1例取出内固定,选择单髋石膏外固定;2例感染性骨不连采用AO外固定架固定;15例更换髓内钉固定。结果本组手术时间60~160 min,平均90 min;术中输红细胞400~600 ml,平均440 ml。18例均获得随访14~26个月,平均18个月。末次随访时采用膝关节功能HSS评分评定疗效：优10例,良6例,可1例,差1例。疗效差的1例因反复感染,骨折仍未愈合。结论股骨干骨折术后内固定失效的原因：1内固定选择失误或钢板未放置张力侧;2骨折合并骨缺损,未一期植骨;3骨折部位血液循环损伤严重导致骨折愈合时间延长,进而内固定疲劳失效;4术后早期负重或不恰当的功能锻炼。     

Effects of high-frequency, low-magnitude mechanical stimulus on bone healing

Recent studies have shown osteogenic effects of high-frequency mechanical stimuli. The purpose of this study was whether externally applied, high-frequency, low-magnitude interfragmentary movements affect the process of bone healing. In 12 sheep, a transverse osteotomy with a 3 mm gap was created in the right metatarsus and externally stabilized by a rigid circular fixator. External stimulation was performed in six sheep with the use of ground-based vibration. The sheep were standing with their hind limbs on a platform that produced vertical movements resulting in interfragmentary movements of approximately 0.02 mm magnitude at 20 Hz frequency. The other six sheep remained rigidly stabilized by external fixation during the 8-week study and served as a control group. Healing was assessed postmortem by densitometric and mechanical examinations. No significant differences were found between the two groups, although callus formation was slightly enhanced (11%) in the stimulated group compared with the control group. Mechanical stimuli attributable to weightbearing in the control group were sufficient enough to initiate callus formation even under rigid, external fixation. Thus, external mechanical stimulation with the stimulation design described in the current study might not be indicated for improvement of bone healing.