Does a trochanteric lag screw improve fixation of vertically oriented femoral neck fractures? A biomechanical analysis in cadaveric bone

Background

We assessed the biomechanical performances of a trochanteric lag screw construct and a traditional inverted triangle construct in the treatment of simulated Pauwels type 3 femoral neck fractures.

Methods

An inverted triangle construct (three 7.3-mm cannulated screws placed in inverted triangle orientation) and a trochanteric lag screw construct (two 7.3-mm cannulated screws placed across the superior portion of the femoral neck and one 4.5-mm lag screw placed perpendicular to the fracture in superolateral to inferomedial orientation) were tested in nine matched pairs of non-osteoporotic human cadaveric femora. We used a previously described vertically oriented femoral neck fracture model and testing protocol that incrementally loaded the constructs along the mechanical axis of the femur to 1400 N. Specimens that survived incremental loading underwent cyclic loading. Apparent construct stiffness, force at 3 mm of displacement, and survival of incremental loading were recorded.

Findings

The trochanteric lag screw group had a 70% increase in stiffness (261 N/mm [29 standard deviation] versus 153 N/mm [16 standard deviation]; P = 0.026) and a 43% increase in force required for displacement (620 N versus 435 N; P = 0.018) compared with the inverted triangle group. One trochanteric lag screw and no inverted triangle specimen survived incremental loading.

Interpretation

A trochanteric lag screw construct applied to vertically oriented femoral neck fractures provides marked improvement in mechanical performance compared with the inverted triangle construct.     

髓内与髓外固定股骨转子间骨折的预后比较

背景：目前股骨转子间骨折临床多采用早期内固定治疗,随着现代医学及内固定器材等相关科学的发展,股骨转子间骨折的修复方式较多。然而股骨转子间骨折内固定方式及内固定类型的选择临床上存在较多争议。目的：对股骨转子间骨折髓内与髓外固定的临床预后进行对比分析。方法：选取2009年7月至2013年7月宣城中心医院收治的股骨转子间骨折患者146例,根据内固定方式不同分为3组,其中锁定加压钢板组者31例,动力髋螺钉组者66例,股骨近端抗旋髓内钉组者49例。动力髋螺钉组和锁定加压钢板均属于髓外固定系统,股骨近端抗旋髓内钉属于髓内固定系统。通过对比各组患者的手术时间、术中失血量、切口长度及临床疗效,探讨不同内固定方式对股骨转子间骨折预后的指导意义。结果与结论：所有患者均获得术后随访,随访时间为4个月-3年。与锁定加压钢板组及动力髋螺钉组比较,股骨近端抗旋髓内钉组的手术时间及术中出血量较少,差异有显著性意义（P〈0.05）;其中锁定加压钢板组的手术时间显著低于动力髋螺钉组（P〈0.05）。股骨近端抗旋髓内钉组的疗效优良率（94%）显著高于锁定加压钢板组（81%）及动力髋螺钉组（83%）,差异有显著性意义（P〈0.05）。提示应用髓内及髓外固定系统股骨转子间骨折患者均可取得良好的修复效果,但髓内固定系统较髓外固定系统在手术时间、失血量及患者内固定后疗效上更具优势。     

防旋髓内钉与动力髋螺钉内固定治疗股骨转子间骨折

背景：防旋髓内钉与动力髋螺钉已被广泛应用于股骨转子间骨折的置入内固定治疗。目的：评估与比较防旋髓内钉与动力髋螺钉置入内固定治疗股骨转子间骨折的效果。方法：对股骨转子间骨折的临床患者进行随访观察,通过评估患者骨折的愈合情况、并发症发生情况以及关节功能评分综合分析防旋髓内钉与动力髋螺钉内固定治疗股骨转子间骨折的临床效果,并对两种内固定治疗效果进行对比。结果与结论：防旋髓内钉与动力髋螺钉置入内固定治疗股骨转子间骨折均可以获得较好的治疗效果,但是防旋髓内钉置入内固定治疗股骨转子间骨折置入内固定操作时间更短,出血量更少,并发症的发生率更低,骨折愈合时间更短,髋关节功能优良率更高,是股骨转子间骨折首选置入内固定治疗的方法之一。     

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。     

Locking plate constructs benefit from interfragmentary lag screw fixation with decreased shear movements and more predictable fracture gap motion in simple fracture patterns

BackgroundA mechanical characterisation of lag screw fixation plus locking plate – although clinically widely used as either “mixed fixation concept” or absolutely stable fixation – is so far missing. This study aimed to evaluate the influence of an interfragmentary lag screw on the resulting motion at the fracture site of locking plate constructs using a simple fracture at the distal femur.MethodsHuman cadaver femora were in vitro loaded in torsion and axial bending-compression with and without lag screw fixation next to a locking plate fixation. In addition, two plate working lengths were tested. Interfragmentary movement was measured optically.FindingsAxial interfragmentary movement is reduced with lag screw (102 mm plate working length, 1000 N, mean): 0.28 mm versus 0.82 mm. With lag screw, the fracture gap stays closed with mean normal interfragmentary movement ≤0.03 mm. Fracture gap tends to open without lag screw: normal interfragmentary movement up to −0.29 mm. Reduction of shear interfragmentary movement was observed throughout all tested loads and groups. Mean true shear remains generally low with lag screw (≤0.42 mm) compared to without lag screw (≤1.46 mm). We also found that interfragmentary movement variance decreases with lag screw, especially for longer plate working length.InterpretationAn interfragmentary lag screw next to locking bridge plating reduces fragment motion in vitro for a simple fracture pattern and provides a sufficient tool to decrease detrimental shear movements. Prospective clinical trials with interfragmentary lag screw fixation should prove these findings in wide clinical use to treat simple fracture patterns.     

经皮空心钉固定治疗小儿股骨颈骨折的疗效观察

目的:观察C型臂引导下闭合复位空心钉固定治疗小儿股骨颈骨折的疗效.方法:回顾性分析本院2000年1月～2003年12月股骨颈骨折11例的临床资料.对3例骨折移位不明显者采用原位1枚空心钉固定;对8例明显移位成角者采用2枚空心钉固定3例,采用1枚空心钉 克氏针固定5例.结果:全部病例骨折处愈合良好,无1例发生股骨头髓板早闭及髋内翻,仅1例股骨头轻度坏死.结论:空心钉固定治疗小儿股骨颈骨折疗效好,操作方法简单,损伤小,并发症少,建议推广应用.     

动力髋螺钉与防旋阻挡钉联合修复不稳定型股骨转子间骨折

背景：严重的股骨转子间骨折,其抗旋转能力差,单单动力髋螺钉内固定容易失败.如内固定后出现股骨头塌陷、股骨颈短缩、小转子内侧失稳髋内翻、头颈旋转、头颈切割穿钉、钢板拨钉及钢板断裂等现象.故对于不稳定型股骨转子间骨折,动力髋螺钉内固定有一定的局限性.目的：探讨动力髋螺钉联合防旋阻挡钉置入内固定对不稳定型股骨转子间骨折的修复效果.方法：选取96例不稳定型股骨转子间骨折患者,分别实施内固定治疗,其中采用动力髋螺钉组48例,动力髋螺钉联合防旋阻挡钉组48例.从手术时间、术中出血量、X射线暴露次数、骨折愈合时间、内固定后Harris髋关节评分及内固定后并发症等方面进行对比评估.结果与结论：内固定后随访时间为18-36个月.动力髋螺钉组和动力髋螺钉联合防旋阻挡钉组在手术时间、术中出血量、X射线暴露次数、骨折愈合时间方面比较差异无显著性意义（P＞0.05）.动力髋螺钉联合防旋阻挡钉组内固定后髋关节评分（Harris评分）高于动力髋螺钉组（P＜0.05）.动力髋螺钉组内固定后并发症发生率（14％）显著高于动力髋螺钉联合防旋阻挡钉组（4％,P＜ 0.05）.提示单纯动力髋螺钉置入内固定修复不稳定型股骨转子间骨折并发症较多,失败率较高;而动力髋螺钉联合防旋阻挡钉能重建股骨后内侧结构,弥补动力髋螺钉的缺点和不足,对不稳定型股骨转子间骨折的修复有重要价值.     

新型儿童股骨颈螺钉设计中的生物力学因素

背景：由于骺板在股骨的生长发育过程中有重要的作用,内固定的设计要求尽量避免对骺板的损伤,因此对儿童股骨骺板的定位显得尤其重要。 目的：探讨新型儿童股骨颈螺钉固定儿童股骨颈骨折的生物力学性能。 方法：由南华大学解剖室提供的6具儿童尸体上取下股骨12根,X射线排除骨病后,分别采用3枚新型儿童股骨颈螺钉固定;3枚2.0 mm克氏针固定。分别进行生物力学实验,测试其轴向压缩、扭转刚度。 结果与结论：轴向压缩刚度及最大3 N·m 的扭转力矩下扭转刚度,儿童股骨颈螺钉分别为（190.74±20.88） N/mm、（0.18±0.045） N·m/（°）,克氏针为（138.95±15.19） N/mm、（0.120±0.036） N·m/（°）,两者比较差异均有显著性意义（P〈0.05）;显示儿童股骨颈螺钉的抗压能力和抗扭能力上明显强于克氏针。实验说明儿童股骨颈螺钉是一种符合儿童股骨近端解剖学特点,能够满足儿童股骨颈骨折需要的新型内固定器械,具有良好的生物力学性能。     

人工股骨头置换术与全髋关节置换术治疗老年股骨颈骨折临床效果比较

目的比较人工股骨头置换术和全髋关节置换术治疗老年股骨颈骨折的临床效果。方法选择2010年4月—2012年6月本院骨科收治的老年股骨颈骨折患者120例,随机将其均分为3组,每组40例,分别行传统空心加压螺钉内固定术(D组)、人工股骨头置换术(G1组)、全髋关节置换术(G2组)。比较各组患者的平均手术时间、失血量、住院时间以及PSQI评分,各组患者术后2年髋关节功能Harris评分和SF-36生活质量评分。结果 G1组和G2组的手术出血量、手术时间以及住院时间,显著高于D组(P<0.05);G2组和G1组2年后髋关节Harris评分优良率分别为82.5%和72.5%,2组优良率均显著高于D组(P<0.05);G1组和G2组生活质量总评分和PSQI评分分别为(72.72±5.27)、(77.31±5.14)分,(6.25±2.64)、(10.11±2.93)分,均显著高于D组(P<0.05);G1组和G2组再次手术率、肺部感染以及股骨头坏死等并发症率显著低于D组(P<0.05)。结论人工股骨头置换术和全髋关节置换术与传统空心加压螺钉内固定术,在治疗老年股骨颈骨折各有优缺点,应根据股骨颈骨折的具体情况选择相应的手术方法。     

微创防旋髓内钉治疗股骨干骨折并同侧股骨近端骨折

目的探讨长型股骨近端防旋髓内钉（PFNA）治疗股骨干骨折并同侧股骨近端骨折（包括股骨颈或转子间骨折）的临床疗效。方法对32例股骨干骨折并同侧股骨近端骨折患者应用长型PFNA固定治疗。结果 32例患者均获得随访,随访时间6～24个月,平均13个月,均骨性愈合,无股骨头坏死、骨不愈及内固定断裂松动。根据Harris髋关节评分及膝关节KSS评分,32例髋关节功能恢复良好,除了1例（伴同侧髌骨粉碎骨折）膝关节活动度欠佳外,其余31例膝关节功能恢复良好。髋关节功能优良率达100.0%,膝关节优良率达96.9%。结论长型PFNA使股骨干骨折并同侧股骨近端骨折通过一次手术完成,具有创伤小、失血少、固定牢固、防切割、防旋转等优点,是治疗股骨干骨折并同侧股骨近端骨折理想的内固定物。     

A biomechanical study comparing cortical onlay allograft struts and plates in the treatment of periprosthetic femoral fractures

BACKGROUND: Periprosthetic femoral fractures with well-fixed femoral components can be difficult to manage and internal fixation is usually necessary. This study was designed to determine the effect of cable plate, strut allograft and combined plate and strut allograft fixations of periprosthetic femoral fractures. METHODS: A transverse fracture at the level of the tip of the femoral stem was simulated in six cadaveric femurs. The fracture was fixed with a plate-strut graft construct with and without proximal screws, a plate only construct with and without proximal screws and with both anterior and lateral struts grafts of 12 cm or 20 cm in length. The intact femur and the six constructs were tested using anteroposterior and axial loads to simulate the forces at the hip during gait. The interfragmentary motions were measured with an optoelectronic camera system. FINDINGS: The highest median interfragmentary translations were observed with the plate only construct without proximal screws. No significant differences in median translations were found between the combined plate-strut and the strut-graft alone constructs. Median interfragmentary rotations were largest with the plate only construct and lowest with the plate-strut constructs. INTERPRETATION: The best fracture fixation was achieved with the combined plate and strut graft constructs particularly in combination with the two unicortical screws above the fracture. The plate only constructs may not provide sufficient fixation stability in rotation for the simulated transverse fracture. The within-construct interfragmentary motions were not significantly different except for the plate only constructs. This suggests that the fixation construct type is the determining factor of interfragmentary motion.     

股骨颈骨折空心钉内固定数字化模板的建立

背景：按照骨折治疗的 AO 原则,目前治疗股骨颈骨折的趋势是尽早切开关节囊,清除血肿,解剖复位,加强内固定,不必缝合关节囊,可降低股骨头缺血性坏死的发生率。股骨颈骨折空心钉的安放位置是维持稳定构型的关键,但置钉准确性受个体差异,置钉定位影像设备二维性及术者经验等主观因素影响较大,临床上急需一种实用性强花费较小且易于推广使用的辅助置钉方法。目的：构建骨颈骨折中空加压螺钉立体模型,通过3D生物打印技术精确建立导航模板并验证。方法：18例志愿者知情同意后,连续螺旋CT进行双侧股骨上端加密扫描。将Dicom数据导入Amira3.1（TGS）软件,三维重建骨折模型,导入Imageware12.1软件,数字化设计最佳穿刺通道,三维重建股骨颈螺钉三维立体模型。提取解剖学形态,建立反向模板,3D生物打印实物模板,进行手术模拟验证。结果与结论：成功地建立了股骨颈三维模型及空心钉内固定模型,设计出了数字通道及螺钉最佳穿刺途径,制作出导航模板。模拟手术中置钉位置全部在最佳钉位。生成的三维模型与导航模板体外贴附良好,成功穿刺后断层证明穿刺通道位置较准确。提示成功构建了数字仿真股骨颈骨折内固定三维模型,逆向工程及3D生物打印导航模板技术能够提高手术操作精确性,为临床提供理论依据和技术支持。     

股方肌骨瓣转移联合多枚加压空心螺纹钉与AO多枚加压空心螺纹钉置入内固定修复中青年股骨颈骨折

背景：股骨颈骨折临床上还没有统一的治疗标准,股方肌骨瓣转移移植联合多枚加压空心螺纹钉内固定法与AO多枚加压空心螺纹钉内固定均为股骨颈骨折常用治疗方法,但两者均有优缺点.目的：探讨股方肌骨瓣转移移植联合多枚加压空心螺纹钉内固定法与AO多枚加压空心螺纹钉内固定治疗中青年股骨颈骨折GardenⅢ,Ⅳ型效果及并发症发生率.方法：将60例中青年股骨颈骨折患者根据治疗方法的不同分为观察组和对照组,观察组应用开放复位股方肌骨瓣转移移植联合多枚加压空心螺纹钉内固定法,对照组应用闭合复位AO多枚加压空心螺纹钉内固定,比较两组患者骨折愈合时间、愈合率、功能优良率、股骨头坏死率及远期塌陷率.结果与结论：①观察组患者骨折愈合时间明显少于对照组,骨折愈合率及功能优良率明显高于对照组（P＜0.05）.②观察组患者骨折愈合时间明显少于对照组,骨折愈合率及功能优良率明显高于对照组（P＜0.05）.说明应用股方肌骨瓣转移移植联合多枚加压空心螺纹钉内固定法治疗中青年股骨颈骨折GardenⅢ,Ⅳ型效果良好.     

Open reduction and Herbert screw fixation of Pipkin type IV femoral head fracture in an adolescent: A case report

BACKGROUNDFemoral head fracture is extremely rare in children. This may be the youngest patient with femoral head fracture ever reported in the literature. There are few pediatric studies that focus on cases treated with open reduction via the modified Hardinge approach.CASE SUMMARYA 14-year-old female adolescent suffered a serious traffic accident when she was sitting on the back seat of a motorcycle. A pelvic radiograph and computed tomography revealed a proximal femoral fracture and slight acetabular rim fracture. This was diagnosed as a Pipkin type IV femoral head fracture. An open reduction and Herbert screw fixation was performed via a modified Hardinge approach. After 1-year follow-up, the patient could walk without aid and participate in physical activities. The X-ray results showed that the fractures healed well with no evidence of complications.CONCLUSIONOpen reduction and Herbert screw fixation is an available therapy to treat Pipkin type IV femoral head fractures in children.     

Minimally invasive removal of a deep-positioned cannulated screw from the femoral neck: A case report

BACKGROUNDClinical femoral neck fracture is common. Based on patient age and fracture type, different surgical methods can be selected, including cannulated screw fixation of the femoral neck and artificial total hip joint or semi-hip joint replacement. When patients with femoral neck fracture are treated with cannulated screw fixation, a cannulated screw may be positioned too deep. The excessively deep-placed screw is difficult to remove and causes major trauma to the patient.CASE SUMMARYA patient with poliomyelitis and femoral neck fracture was treated with a cannulated screw that was placed too deep. A self-made auxiliary tool (made of a steel sternal wire) was used to remove the cannulated screw near the pelvic cavity.CONCLUSIONThe depth of the cannulated screw can be estimated before screw placement using an improved hollow screwdriver with a scale mark, thus improving the safety of screw placement and facilitating clinical use.     

四种金属植入物内固定修复老年股骨转子间骨折的比较

背景：对于老年股骨转子间骨折如何选择金属植入物,应根据不同患者的年龄、骨质疏松程度、围手术期状态、骨折类型等多因素进行考虑,制定个性化的治疗方案。目的：比较4种不同金属植入物内固定修复老年股骨转子间骨折的疗效。方法：回顾2009年9月至2012年9月收治的180例老年股骨转子间骨折患者,采用4种不同金属植入物内固定进行骨折修复,动力髋螺钉组、防旋型股骨近端髓内钉组、Gamma 钉组和解剖型髋动力带锁钢板组各45例。比较各组手术时间、出血量、住院时间、内固定后Harris评分、骨折愈合时间和并发症发生情况。结果与结论：解剖型髋动力带锁钢板组和防旋型股骨近端髓内钉组手术时间、出血量及住院时间均短于动力髋螺钉组和Gamma钉组（P 〈0.05）,内固定后Harris评分优良率均高于动力髋螺钉组和Gamma 钉组（P 〈0.05）,而前两组间差异无显著性意义（P〉0.05）。解剖型髋动力带锁钢板组和防旋型股骨近端髓内钉组内固定后并发症发生率明显低于Gamma组和动力髋螺钉组（P〈0.05）。提示解剖型髋动力带锁钢板和防旋型股骨近端髓内钉治疗老年转子间骨折内固定可靠、内固定后并发症少,是老年股骨转子间骨折植入物内固定治疗较为理想的选择。     

Imaging observation of percutaneous compression plate use in promoting femoral neck fracture healing

ObjectiveTo examine the imaging evidence of the use of percutaneous compression plate (PCCP) in promoting femoral neck fracture healing compared with cannulated screws (CS).MethodsThis retrospective study enrolled patients with femoral neck fractures undergoing internal fixation procedures. The patients were divided into a PCCP group and a CS group with imaging as the primary outcome and Harris hip score (HHS) as the secondary outcome.ResultsThis study included 162 patients: 80 in the PCCP group and 82  in the CS group. There were no significant differences between the patients in their preoperative baseline characteristics. Patient follow-up ranged from 24–56 months (mean 30.7 months). Differences in reduction quality, screw slipping, neck shortening and avascular necrosis (AVN) were not significant between the two groups. There were significant differences between the treatment groups in bone absorption, nonunion, healing time, screw withdrawal and fixation failure in favour of the PCCP group. Postoperative HHS at 6 and 12 months were significantly better for the PCCP group than the CS group, but the differences were not significant at 24 months and last follow-up.ConclusionStable internal fixation with dynamic compression was the key to PCCP promoting femoral neck fracture healing.     

改良撬拨闭合复位内固定修复复杂股骨颈骨折及内固定植入物的选择

背景：股骨颈骨折后常用闭合复位内固定进行手术治疗,但仍有一部分患者常规手法闭合复位失败。目的：观察复杂股骨颈骨折运用改良撬拨闭合复位内固定的临床疗效。 方法：收集2011年12月至2013年10月期间上海交通大学附属第六人民医院骨科复杂股骨颈骨折住院患者36例,经过常规手法复位失败一两次后,采用改良的撬拨闭合复位空心加压螺钉内固定。根据年龄、骨折类型、骨密度状况选择动力髋螺钉加1枚空心螺钉（n=17）或3枚空心螺钉（n=19）内固定。内固定后随访采用Harris评分评价临床疗效。 结果与结论：所有36例患者均得到随访,随访时间6个月-2年,平均15.5个月。发生股骨头坏死患者3例,骨折延迟愈合2例。Garden复位质量评价：Ⅰ级23例,Ⅱ级11例,Ⅲ级2例,Ⅳ级0例,Ⅰ级、Ⅱ级占患者总数的94.4%。Harris评分情况：优22例,良7例,中3例,差4例,优良率80.56%。且采用动力髋螺钉加空心螺钉或3枚空心螺钉进行内固定的患者的髋关节Harris评分接近（P〉0.05）。因此,对于常规复位失败的复杂股骨颈骨折,建议尝试改良的撬拨闭合复位法,内固定采用动力髋螺钉或空心螺钉对疗效无明显影响。     

两种构型空心加压螺钉固定头颈型股骨颈骨折的生物力学特征

背景:股骨颈骨折后缺血性坏死及骨不愈合的发生率与内固定器械的生物力学性能密切相关,压缩应力可促进骨折愈合,张应力可推迟骨折愈合,剪切应力可阻止骨折愈合。如何消除剪切应力,扩大压缩应力具有重要的理论和临床意义。目的:比较两种构型空心加压螺钉固定头颈型股骨颈骨折的股骨标本的生物力学特征,为临床治疗股骨颈骨折提供生物力学依据。设计:观察对比实验。单位:解放军第二五一医院骨科,河北医科大学第三医院骨科。对象:实验于2002-11/2003-03在河北骨科研究所完成。选取河北医科大学解剖教研室提供的骨密度值相近的标本5具,男性4具,女性1具,经X射线摄片证实无风湿、结核、肿瘤、骨折、畸形变异。方法:将10根股骨随机分成倒等腰三角形组和正等腰三角形组,每组5根。倒、正等腰三角形构型的三枚空心加压螺钉固定头颈型股骨颈骨折的股骨标本,用生物力学机(长春市实验机研究所产CSS-44020生物力学仪,河北骨科研究所提供)测试、比较两种空间构型抗压、抗扭性能及最大垂直载荷。主要观察指标:①抗压实验中在600N和750N时股骨头下沉的位移。②抗扭转实验中扭转2°和4°时的力矩。③最大垂直负荷实验中至内固定失败的负荷。结果:①600N和750N垂直载负下,倒等腰三角形组股骨头下沉位移小于正等腰三角形组[(0.933±0.135),(1.556±0.235)mm;(1.310±0.217),(1.975±0.250)mm,P均<0.05]。②倒等腰三角形组和正等腰三角形组在扭转2°和4°时所需力矩相近,差异无显著性[(3.148±0.765),(2.847±1.130)N·m;(6.658±2.021),(5.392±1.601)N·m,P均>0.05]。③倒等腰三角形组最大垂直载荷大于正等腰三角形组[(2069.97±200.864),(1614.57±80.567)N,P<0.05]。结论:对头颈型股骨颈骨折,应用倒等腰三角形构型的空心加压螺钉比正等腰三角形构型的空心加压螺钉固定股骨标本,可获得更好的抗压和体现其最大垂直载荷性能的生物力学效果。     

股骨颈骨折中空钉置钉方式对股骨头缺血坏死的影响

目的探讨中空钉治疗股骨颈骨折中置钉位置对股骨头缺血坏死发生情况的影响。方法本研究始于2006年1月止于2009年7月,将明确诊断的260例股骨颈骨折按数字随机法分为两组,各130例,1组采用三枚中空钉正三角形固定方式(正三角形置钉组);另1组采用倒三角形固定方式(倒三角形置钉组)。术后随访18个月,比较两组股骨头坏死率。结果 260例均获得完整随访,正三角形置钉组股骨头坏死率4.62%,倒三角形置钉组股骨头坏死率14.62%,两组比较差异有统计学意义(χ2=7.48,P<0.05)。结论中空钉正三角置钉位置符合解剖学入钉要求,对股骨头血循环破坏小,股骨头坏死发生率低,属于临床固定应采取的最佳置钉方式。