自制微创股骨近端接骨板与普通动力髋螺钉治疗稳定型股骨转子间骨折的 生物力学对比

背景：研制一种新型植入物用于固定稳定型股骨转子间骨折。 目的：比较自制微创股骨近端系列接骨板与动力髋螺钉固定稳定型股骨转子间骨折后的生物力学性能。 方法：采集干燥股骨标本,模拟AO分型 A1.3型稳定型股骨转子间骨折模型,分别采用自制微创股骨近端系列接骨板和动力髋螺钉内固定,然后在股骨近端内外侧皮质布置6枚电阻片,检测固定后的抗压、抗弯、抗剪和抗扭能力。 结果与结论：股骨转子间骨折采用自制微创股骨近端系列接骨板固定后,股骨内、外侧强度比动力髋螺钉组固定强度高13%,内侧强度高16%,扭转强度高18%,扭转刚度高31%,差异有显著性意义(P < 0.05)。可见自制微创股骨近端系列接骨板整体生物力学性能优于常规用动力髋螺钉,前者能十分有效对抗股骨抗拉、抗压、抗旋和内翻能力。     

锁定钢板与伽马钉三代修复股骨转子间骨折:生物力学稳定性比较

背景:老年人股骨转子间骨折使用伽马钉三代(Gamma3)治疗时,可能使骨折块分离,难于固定小转子使稳定性差,易出现髋内翻畸形,则较难支撑及满意复位。目的:比较股骨近端锁定钢板与Gamma3治疗稳定型股骨转子间骨折后的效果及稳定性。方法:1纳入64例股骨转子间骨折患者,分别采用Gamma3内固定(n=32)和股骨近端锁定钢板内固定(n=32)进行治疗,通过X射线正、侧位片评估骨折复位及愈合情况,并对股骨转子内翻角、股骨转子内侧后倾角进行生物力学测试。2选取形态、大小近似的8对股骨标本,随机分为Gamma3组和股骨近端锁定钢板组(n=4),分别采用Gamma3内固定和股骨近端锁定钢板内固定,轴向压缩试验和破坏试验后描绘载荷-位移曲线,采用扭转试验计算最大屈服载荷值。结果与结论:股骨近端锁定加压钢板内固定组患者手术时间、术中出血量多于Gamma3内固定组(P0.05)。股骨近端锁定加压钢板内固定组患者骨折复位质量评定结果优于Gamma3内固定组(P0.05)。股骨近端锁定加压钢板组股骨标本轴向刚度及各扭转角相应扭矩均小于Gamma3组(P0.05)。说明在固定合并大转子骨折的股骨转子间骨折中,股骨近端锁定钢板更具有生物力学上的稳定性。     

自制加锁梅花针治疗股骨中下段骨折的生物力学测试

目的对自行研制的用于治疗股骨中下段骨折加锁梅花针进行生物力学测试,为临床应用提供生物力学基础。方法用6例新鲜成人股骨标本,制作股骨中上段骨折模型两种,梅花针固定;然后制作股骨下段骨折模型两种,加锁梅花针固定;最后利用股骨下段骨折模型交锁钉固定,每次作下一骨折模型前,用钢片张力带固定前一次的骨折线。依次对正常股骨标本、梅花针固定后的标本、加锁梅花针固定的标本、交锁钉固定的标本进行扭转测试、垂直压缩试验、4点弯曲试验,分析4组试验的实验数据。结果梅花针固定股骨中上段骨折、加锁梅花针固定股骨下段骨折和交锁钉固定的股骨下段骨折抗扭转测试中,均可以达到4Nm抗旋转刚度;轴向压缩试验中最大应变正常组和梅花针组、加锁梅花针组无明显差异,4点弯曲试验中梅花针与加锁梅花针和正常标本的弯曲刚度相近,交锁钉的抗弯曲刚度明显高于其他3者。结论加锁梅花针冶疗股骨中下段骨折,具有良好的生物力学性能,固定效果可靠。     

股骨近端防旋髓内钉联合前外侧重建钢板修复不稳定型股骨转子间骨折的有限元分析

背景：股骨转子间骨折后如何重建外侧壁目前尚无统一方法,在股骨转子前外侧放置重建钢板是目前较为常用的方式,但其生物力学、临床适用如何目前鲜有研究。目的：探讨股骨近端防旋髓内钉联合前外侧重建钢板用于不同类型不稳定型股骨转子间骨折的生物力学参数变化。方法：CT扫描1名男性志愿者下肢骨,通过有限元建立股骨三维模型,根据骨折线涉及内侧壁、外侧壁与内外侧壁以及其在侧壁上是否获得稳定支撑,对模型进行分割,建立对应的骨折模型：外侧壁不稳定、内侧壁稳定模型;外侧壁稳定、内侧壁不稳定模型;内外侧壁均不稳定模型,同时进行装配股骨近端防旋髓内钉、前外侧重建钢板,应用普通钉或锁定钉固定,由abaqus进行计算,比较多组模型骨折块、内固定的应力及位移等变化。结果与结论：(1)在3种不稳定型股骨转子模型中,前外侧重建钢板可以提升股骨近端的稳定性,并且在一定程度上恢复股骨近端失衡杠杆。在外侧壁不稳定型、内侧壁不稳定型中,锁定钉优于普通钉;在内外侧壁均不稳定型中,锁定钉与普通钉差异性未能探知。(2)结果说明,前外侧重建钢板的放置可以显著提升不稳定股骨转子间骨折的稳定性,减少退钉以及内固定物的失效可能,并且对恢复股骨近端...     

骨骺生长滑动钢板的设计及生物力学研究

目的:通过生物力学试验对骨骺部生长滑动钢板生物力学性能进行评估,检测其避免产生骨骼纵向生长抑制的特殊结构是否影响其力学性能。方法:根据青少年股骨髁部的解剖特点设计出适用于青少年儿童股骨髁部骨折的内固定滑动钢板,并选用7具新鲜人体尸体股骨标本并制作骨折模型,行左右侧对比,左侧行滑动钢板固定,右侧行普通钢板固定,用MTS实验机进行三点弯曲、轴向压缩、扭转试验测试比较两种钢板力学性能。结果:力学试验显示轴向刚度(N/mm):滑动钢板数值为1766.88±106.30,普通钢板数值为1831.74±62.80,P=0.877>0.05;三点弯曲(跨距:8cmN/mm):滑动钢板数值为752.17±31.44,普通钢板数值为793.84±24.52,P=0.838>0.05;抗扭转(Nm/度):滑动钢板数值为3.29±0.26,普通钢板数值为3.62±0.15,t=-0.544,P=0.606>0.05。三项指标滑动钢板和普通钢板之间差异均无显著性。结论:可滑动钢板具有一定的力学强度,能够为骨折愈合提供可靠的固定强度。     

重建钢板前置和上置固定锁骨中段斜形骨折的有限元分析

目的　通过三维有限元法对重建钢板前置和上置固定锁骨中段斜行骨折的生物力学稳定性进行比较,为临床应用提供理论参考。 方法　建立锁骨中段斜行骨折分别予以重建钢板前置位固定和上置位固定的三维有限元模型,相同的加载和约束条件下模拟轴向压缩、顺时针扭转、逆时针扭转和三点弯曲4种工况,评价不同内固定的最大等效应力、骨折块的最大综合位移和骨折断端的最大等效应力。 结果 ⑴压缩工况下前置位和上置位各评价指标无差异;⑵在顺时针扭转和弯曲时,前置位内固定装置的最大应力明显大于上置位,但骨折块的最大综合位移和骨折断端的最大应力差别不大;⑶在逆时针扭转工况下,上置位固定的各个指标数值虽大于前置位,但基本接近。 结论　对于重建钢板固定锁骨中段斜行骨折,前置位固定比上置位更容易出现应力集中,提示上置位固定的生物力学稳定性优于前置位。     

股骨近端解剖型钢板在股骨转子间骨折中应用

目的:报告股骨近端解剖型钢板治疗股骨转子间骨折的疗效。方法:应用股骨近端解剖钢板治疗19例股骨转子间骨折,评价治疗结果。结果:19例病人中4个月全部骨性愈合,髋关节屈伸活动恢复95%以上,旋转活动恢复85%,2例轻度髋内翻。结论:股骨近端解剖型钢板治疗转子间骨折具有手术简单,有效,符合生物力学要求,效果满意。     

波形钢板固定股骨骨折的生物力学实验研究与临床应用

本文采用7具人尸股骨标本骨折后采用波形钢板和普通钢板加以固定，对照比较了两种不同固定方式下轴向压缩、三点弯曲、扭转试验下的生物力学性能。结果表明：波形钢板的强度比普通钢板的强度大32％，刚度高33％，两者是显著性差异（P＜0．01）。同时试验证明：波形钢板固定的应力遮挡率小于普通钢板32．5％，有利于骨重建应力环境的改善，能加速食痂生长。两种钢板本身的强度和刚度也显示了前者优于后者。证明采用波形钢板是符合生物力学原则的，临床应用波形钢板治疗股骨干骨折20例，经5～16个月随访，优良率达94．7％。表明波形钢板是治疗股骨干骨折较好的内固定方法，值得推广应用。     

三种不同内植物固定治疗老年股骨转子间骨折

背景：治疗高龄患者股骨转子间骨折的内植物有传统的动力髋螺钉、防旋型股骨近端髓内钉、股骨近端解剖型锁定钢板,然而目前哪种内植物治疗方法较好仍存在争议。 目的：分析动力髋螺钉、防旋型股骨近端髓内钉、股骨近端解剖型锁定钢板3种内植物治疗老年股骨转子间骨折的临床疗效。 方法：回顾性分析159例老年股骨转子间骨折患者的临床资料,比较动力髋螺钉、防旋型股骨近端髓内钉、股骨近端解剖型锁定钢板治疗转子间骨折的差别。 结果与结论：①置入后1周、6个月、1年髋关节功能Harris评分：防旋型股骨近端髓内钉组优于股骨近端解剖型锁定钢板组(P < 0.05),股骨近端解剖型锁定钢板组优于动力髋螺钉组(P < 0.05)。②置入后3,6,12个月X射线片显示骨折愈合情况：防旋型股骨近端髓内钉组优于股骨近端解剖型锁定钢板组(P < 0.05),股骨近端解剖型锁定钢板优于动力髋螺钉组(P < 0.05)。提示防旋型股骨近端髓内钉置入治疗老年转子间骨折具有创伤小、固定牢靠、操作简单、骨折愈合率高、愈合时间短、术后髋关节功能恢复好等优点,对于老年股骨转子间骨折患者应优先选择。     

胫骨远端后内侧解剖钢板的设计与生物力学研究*

目的测试自制胫骨远端后内侧解剖钢板的力学性能，为临床应用提供科学依据。方法根据胫骨远端后内侧解剖特征设计出后内侧解剖钢板，新鲜胫骨各6具造成相同的胫骨远端骨折，分别行后内侧解剖钢板和外侧钢板内固定后，通过轴向压缩试验，三点弯曲试验，扭转力学性能试验来进行两种固定方法的生物力学研究，数据采用SPSS13．0分析。结果后内侧解剖钢板在三点弯曲、轴向压缩、扭转力学试验与外侧钢板之间均无差异（P〉0．05）。结论胫骨远端后内侧解剖钢板能够为治疗胫骨远端骨折提供一种新型的内固定材料，来弥补外侧解剖钢板在临床应用的局限性。     

不同植入物内固定修复股骨颈合并同侧转子下骨折：生物力学性能比较

BACKGROUND: Choosing internal fixator implants with good strength and stiffness is the key to repair femoral neck combined with ipsilateral subtrochanteric fractures. OBJECTIVE: To compare the biomechanical properties of different implant fixation for femoral neck combined with ipsilateral subtrochanteric fractures. METHODS: Totally 24 adult antiseptic cadaver specimens were used to produce fracture models with femoral neck fracture combined with 5 cm of ipsilateral subtrochanteri medical cortical defect, and were divided into femoral proximal locking plate group, lengthening proximal femur anti-rotation intramedullary nail group and lengthening proximal femoral nail group according to the random number table method. The results of axial compression test, torsion test and axial compression failure rest in three groups were compared. RESULTS AND CONCLUSION: The axial compressive stiffness and failure load in lengthening proximal femur anti-rotation intramedullary nail group were significantly greater than those in femoral proximal locking plate group and lengthening proximal femoral nail group, and those in lengthening proximal femoral nail group were significantly greater than those in femoral proximal locking plate group (P < 0.05). The torsional stiffness in femoral proximal locking plate group was significantly greater than that in lengthening proximal femur anti-rotation intramedullary nail group and lengthening proximal femoral nail group, and that in lengthening proximal femur anti-rotation intramedullary nail group was significantly greater than that in lengthening proximal femoral nail group (P < 0.05). The indexes of biomechanical properties of specimens at the 4th and 8th weeks after fixation in three groups were slightly increased compared with those in 0 week after surgery, but the difference was no statistically significant (P > 0.05). These results demonstrate that to a certain extent, compared with the femoral proximal locking plate and lengthening lengthening proximal femoral nail, lengthening proximal femur anti-rotation intramedullary nail fixation for repair of femoral neck combined with ipsilateral subtrochanteric fractures has more biomechanical advantages.       

锁定加压接骨板固定股骨近端假体周围骨折的生物力学分析

目的评价锁定加压接骨板(locking compression plate,LCP)固定股骨近端假体周围骨折(periprosthetic proximal femur fracture,PPFF)的生物力学强度。方法采用LCP和倒置股骨远端微创锁定接骨板(less invasive stabilization system,LISS)分别固定8对左、右配对的Vancouver B1型成人尸体PPFF标本,假体柄对应长度的股骨分别采用4枚双层皮质锁定螺钉固定(LCP组)和4枚单层皮质锁定螺钉固定(LISS组),骨折远端均采用4枚双层皮质锁定螺钉固定,两种接骨板使用锁定螺钉的螺孔距骨折端的距离相等。通过4点弯曲试验和扭转试验,对比分析两组的最大弯曲载荷、最大弯曲位移、抗弯刚度、最大扭矩、最大扭转角度和抗扭转刚度。结果 LCP组最大弯曲载荷、最大弯曲位移和抗弯刚度均大于LISS组,但差异无统计学意义(P>0.05)。LCP组最大扭矩、最大扭转角度和抗扭转刚度均大于LISS组,差异具有统计学意义(P<0.05)。结论 LCP抗扭转刚度明显优于LISS,对PPFF固定的力学稳定性更好。     

骨质疏松股骨转子间不稳定型骨折人工股骨头置换的三维有限元应力分析

BACKGROUND: Artificial femoral head replacement provides a new idea for the repair of unstable intertrochanteric fracture. Artificial prosthesis replacement may affect original femoral biomechanical stability and lead to a variety of adverse consequences.  OBJECTIVE: To analyze the stress distribution of femoral head replacement in the treatment of unstable femoral intertrochanteric fractures with three-dimensional finite element analysis. METHODS: One male old volunteer was randomly selected from population who underwent health examination. The left femur was scanned with spiral CT, and the three-dimensional finite element models of the human femur and prosthesis were established. The three-dimensional finite element model was used to simulate the actual working conditions of human climbing stairs, and the stress distribution of the bone channels around the surface of the femur and the prosthesis was analyzed with three-dimensional finite element analysis. RESULTS AND CONCLUSION: Under normal condition, the stress of the human femur was in a consistent state. Stress changed gradually from the proximal end to the distal end. The stress of the prosthesis was concentrated in the middle section. The prosthesis of inner stress distribution was analyzed to obtain stress distribution of prosthesis and femur cancellous bone interface. The analysis found that stress change trend was consistent. The results suggest that artificial femoral head replacement does not have a significant effect on the overall stress distribution of the human femur, and the overall stress distribution does not change, and the maximum stress region is located in the middle of the whole femur. After the reconstruction, the stress concentration of the femur is not observed.        

Mechanical Evaluation of Large-Size Fourth-Generation Composite Femur and Tibia Models

Composite analogue bone models provide consistent geometric and structural properties that represent a valuable asset in a range of biomechanical analyses and testing procedures. The objective of this study was to evaluate the diaphyseal structural properties of the large-size Fourth-Generation composite analogue femur and tibia models concentrated on mechanical behaviors under axial compression, bending and torsion. Thirty of each large-size composite analogue models (femora and tibiae) were tested under medial-lateral four-point bending, anterior-posterior four-point bending, axial compression and external rotational torque to evaluate flexural rigidity, axial stiffness, torsional rigidity and ultimate failure strength. The composite femur was tested under torsion at both the femoral neck and the mid-diaphyseal areas. Large-size Fourth-Generation composite replicate bones exhibited intra-specimen variations under 10% for all cases and was also found to perform within the biological range of healthy adult bones (age: <80 years old) range with respect to flexural rigidity (<8%) and torsional rigidity (<12%). The failure modes of these composite models were close to published findings for human bones (four-point bending: butterfly fragment fracture; torsional: spiral fracture; and compression: transverse fracture). The large-size composite analogue femur and tibia are close to ideal replicas for standardization in biomechanical analyses. One advantage of these analogue models is that their variability is significantly lower than that of cadaveric specimens for all loading regimens. Published results vary widely in cadaveric studies, which is likely due to the high anatomic variability among cadaveric specimens. This study evaluated and advanced our overall understanding of the capacity of composite analogue bone models mimic the structural properties of average healthy adult human bones.     

不同手术方法治疗老年股骨粗隆间骨折效果及其生物力学研究

目的分析股骨近端锁定钢板(locking proximal femoral plate,LPFP)和股骨近端抗旋髓内钉(proximal femoral nail anti-rotation,PFNA)内固定术治疗老年股骨粗隆间骨折的疗效及生物力学性能。方法 106例老年股骨粗隆间骨折患者随机分为LPFP治疗组53例和PFNA治疗组53例,于治疗干预后分别统计两组患者的手术时间、术中出血量、负重时间、骨折愈合时间及术后9个月Harris髋关节功能评分,统计两组患者术后并发症的发生率。取新鲜老年股骨标本10具制备老年股骨粗隆间骨折模型,并将其随机分为PFNA组和LPFP组各5具,于治疗干预后采用力学试验机进行轴向压缩实验、破坏载荷实验和扭转刚度实验,记录生物力学性能指标。结果 PFNA组平均手术时间、负重时间及骨折愈合时间均短于LPFP组(P 0.05),平均术中出血量少于LPFP组(P 0.05),平均Harris评分高于LPFP组(P 0.05)。PFNA组、LPFP组术后并发症总发生率分别为7.56%、18.87%,差异有统计学意义(P 0.05)。骨折模型治疗干预后,PFNA组平均轴向压缩、破坏载荷、扭转刚度均高于LPFP组(P 0.05)。结论 PFNA治疗老年股骨粗隆间骨折创伤小,其良好的生物力学性能可有效促进骨折愈合和髋关节功能的恢复,并显著减少髋内翻和螺钉松动与切割并发症的发生率。     

A new approach to the design of internal fixation plates

Mathematical analysis by finite element modeling methods was used in conjunction with laboratory bench experiments in selecting appropriate stiffness parameters for internal fixation plate designs. Bench experiments performed included tests of an idealized plated magnesium tube and of a plated canine femur. Finite element modeling of the plate-tube and plate-bone structures was also performed, and the computed results were compared with those obtained experimentally. Three types of internal fixation plates--one "rigid" control plate and two less rigid experimental plates--were examined using both the finite element and experimental models. These plates were further examined by finite element modeling of a plated human femur during single stance loading. In all cases, the "rigid" control plate was found to shield the underlying bone from stress, while both experimental plates were found to have significantly less bone stress shielding. Our findings suggest that an improved plate design should have a low axial stiffness but moderate bending and torsional stiffnesses to facilitate fracture healing and bone remodeling without causing osteopenia.     

旋转臂自锁式髓内钉固定股骨干骨折的生物力学研究

将14根成人股骨标本分成两组,制成股骨中段粉碎性骨折模型,将自研的旋转臂自锁式髓内钉作为实验组和国产带锁髓内钉作为对照组,分别对骨折模型进行固定,在M TS试验机上对髓内钉及髓内钉固定骨折模型依次进行旋转、四点弯曲及压缩试验,比较旋转臂自锁式髓内钉与国产交锁髓内钉的力学性能。为旋转臂自锁式髓内钉设计的改进、临床应用及推广提供理论依据。结果显示:(1)实验组钉骨试件的抗扭转钢度为0.89 Nm/度,对照组钉骨试件的抗扭转刚度为1.18 Nm/度,实验组钉骨试件的抗扭转刚度小于对照组,为对照组的75.4%;实验组钉骨试件在扭角为16°时的扭矩为14.44 Nm,对照组钉骨试件为22.44 Nm,实验组钉骨试件的扭矩小于对照组,约为对照组的64.3%。(2)试验组钉骨试件的抗弯刚度为1 535 N cm/mm,对照组钉骨试件的抗弯刚度为1 737N cm/mm,对照组大于试验组,但无统计学意义(P>0.05)。(3)实验组最大轴向载荷为1 339 N,试件变形为3.5mm;对照组为1 910 N,试件变形为5.2 mm。对照组的最大载荷大于实验组(P<0.05)。在2倍体重时,实验组的位移为2.1 mm,对照组为3.0 mm,实验组小于对照组(P<0.05),实验组的抗短缩刚度大于对照组。(4)实验组髓内钉的力学指标比对照组小,髓内钉的各项力学指标均大于髓内钉股骨试件。因此,旋转臂自锁式髓内钉能够满足固定股骨干粉碎性骨折的生物力学要求和临床内固定的需要。     

股骨颈内固定系统固定股骨颈基底部旋转截骨的有限元分析

目的 采用有限元分析法比较股骨颈内固定系统（FNS）和空心螺钉作为治疗股骨头坏死的旋转截骨术中内固定装置的生物力学特性。方法 采用虚拟有限元建立中日友好医院分型L2型股骨头坏死模型,模拟前旋90°和后旋180°的旋转截骨术,分别模拟植入FNS（FNS组）及空心螺钉（空心螺钉组）,分析股骨近端截骨块、内固定装置、坏死区的应力分布及位移和股骨的位移。结果 前旋90°和后旋180°模型中,FNS组股骨近端截骨块、坏死区的应力和股骨近端截骨块、内固定装置、坏死区、股骨的位移均小于空心螺钉组。FNS组股骨近端截骨块和坏死区的应力峰值比空心螺钉组减少明显,近端截骨块应力峰值减小47.45%和13.64%,坏死区应力峰值减少44.96%和35.52%。结论 与空心螺钉相比,无论截骨后向前旋90°还是向后旋180°,FNS提供了更好的生物力学稳定性。