Proximal Femur Bionic Nail (PFBN): A Panacea for Unstable Intertrochanteric Femur Fracture

With the aging population,intertrochanteric femur fracture in the elderly has become one of the most serious public health issues and a hot topic of research in trauma orthopedics.Due to the limitations of internal fixation techniques and the insufficient mechanical design of nails,the occurrence of complications delays patient recovery after surgical treatment.Design of a proximal femur bionic nail(PFBN)based on Zhang’s N triangle theory provides triangular supporting fixation,which dramatically decreases the occurrence of complications and has been widely used for clinical treatment of unstable intertrochanteric femur fracture worldwide.In this work,we developed an equivalent biomechanical model to analyze improvement in bone remodeling of unstable intertrochanteric femur fracture through PFBN use.The results show that compared with proximal femoral nail antirotation(PFNA)and InterTan,PFBN can dramatically decrease the maximum strain in the proximal femur.Based on Frost’s mechanostat theory,the local mechanical environment in the proximal femur can be regulated into the medium overload region by using a PFBN,which may render the proximal femur in a state of physiological overload,favoring post-operative recovery of intertrochanteric femur fracture in the elderly.This work shows that PFBN may constitute a panacea for unstable intertrochanteric femur fracture and provides insights into improving methods of internal fixation.

Conversion hip arthroplasty for failed nailing of intertrochanteric fracture: Reflections on some important aspects

In this editorial,I present my comments on the article by Solarino et al.Conversion hip arthroplasty,which is an optional salvage procedure performed following unsuccessful fixation of intertrochanteric femur fractures in elderly pati-ents,entails more complex processes and higher rates of operative complications than primary arthroplasty.Hence,it is important to consider the appropriateness of the primary treatment choice,as well as the adequacy of nailing fixation for intertrochanteric fractures.This article briefly analyzes the possible factors contributing to the nailing failure of intertrochanteric fractures and attempts to find corresponding countermeasures to prevent fixation failures.It also analyzes the choice of treatment between nailing fixation and primary arthroplasty for intertrochanteric fractures.

Does proximal femoral nail antirotation achieve better outcome than previous-generation proximal femoral nail?

BACKGROUND There are few studies in the literature comparing the clinical outcomes and radiographic results of proximal femoral nail(PFN)and proximal femoral nail antirotation(PFNA)for pertrochanteric femoral fracture(PFF)in elderly patients.AIM To evaluate both clinical and radiographic outcomes after fixation with PFN and PFNA in an elderly patient population.METHODS One hundred fifty-eight patients older than 65 years with PFF who underwent fixation with either PFN or PFNA were included.Seventy-three patients underwent fixation with PFN,whereas 85 were fixed with PFNA.The mean follow-up was 2.4 years(range,1-7 years).Clinical outcome was measured in terms of operation time,postoperative function at each follow-up visit,and mortality within one year.Radiographic evaluation included reduction quality after surgery,Cleveland Index,tip-apex distance(TAD),union rate,time to union,and sliding distance of the screw or blade.Complications including nonunion,screw cutout,infection,osteonecrosis of the femoral head,and implant breakage were also investigated.RESULTS Postoperative function was more satisfactory in patients who underwent PFNA than in those who underwent PFN(P=0.033).Radiologically,the sliding difference was greater in PFN than in PFNA patients(6.1 and 3.2 mm,respectively,P=0.036).The rate of screw cutout was higher in the PFN group;eight for PFN(11.0%)and two for PFNA patients(2.4%,P=0.027).There were no differences between the two groups in terms of operation time,mortality rate at one year after the operation,adequacy of reduction,Cleveland Index,TAD,union rate,time to union,nonunion,infection,osteonecrosis,or implant breakage.CONCLUSION Elderly patients with PFF who underwent PFNA using a helical blade demonstrated better clinical and radiographic outcomes as measured by clinical score and sliding distance compared with patients who underwent PFN.

Comparison of Clinical Effect of PFNA and Internal Fixation with Anatomical Locking Plate of Proximal Femur in Treatment of Intertrochanteric Fracture of Femur

Purpose:To investigate the clinical value of proximal femoral nail antirotation and anatomical locking plate of proximal femur in the treatment of intertrochanteric fracture of femur.Methods:The study group is treated with PFNA internal fixation.The control group is treated by internal fixation with anatomical locking plate of proximal femur.Results:The time of operation,the amount of intraoperative bleeding and the time of fracture healing in the study group are significantly less than those in the control group.The incidence rate of complication in the study group(3.23%)is significantly lower than that in the control group(17.2%).Data comparison shows P<0.05.Conclusion:The curative effect and prognosis for patients with intertrochanteric fracture of femur treated by PFNA internal fixation are more ideal.

Comparison of Clinical Effect of PFNA and Internal Fixation with Anatomical Locking Plate of Proximal Femur in Treatment of Intertrochanteric Fracture of Femur

Purpose To investigate the clinical value of proximal femoral nail antirotation and anatomical locking plate of proximal femur in the treatment of intertrochanteric fracture of femur.Methods The study group is treated with PFNA internal fixation.The control group is treated by internal fixation with anatomical locking plate of proximal femur.Results The time of operation,the amount of intraoperative bleeding and the time of fracture healing in the study group are significantly less than those in the control group.The incidence rate of complication in the study group(3.23%)is significantly lower than that in the control group(17.2%).Data comparison shows P<0.05.Conclusion The curative effect and prognosis for patients with intertrochanteric fracture of femur treated by PFNA internal fixation are more ideal.

PFNA2 versus 95 Degree Condylar Blade Plate in the Management of Unstable Trochanteric Fractures

Purpose: The proximal femoral nail anti-rotation (PFNA) is known to have advantages in enhancing the anchorage ability of internal fixation in elderly unstable osteoporotic intertrochanteric fracture patients. However whether it is superior to condylar blade fixation is not clear. This study aimed to determine which treatment has better clinical outcomes in older patients. Materials and Methods: A total of 86 patients over the age of 60 with unstable trochanteric fractures within the past 3 weeks, were included in this prospective study conducted from June 1, 2018, to May 31, 2021. All the intertrochanteric fractures were classified according to AO/OTA classification. Among them, 44 cases were treated with the Proximal Femoral Nail (PFNA2) with or without an augmentation screw, and 42 cases were treated with the Condylar Blade Plate. In addition, the operative time, intraoperative blood loss, intraoperative and postoperative blood transfusion, postoperative weight-bearing time, hospitalization time, Harris score of hip function, Kyle’s criteria and postoperative complications were compared between the two groups. Results: The mean duration of surgery for the PFN group was 66.8 minutes (on average), whereas for the condylar blade plate group, it was 99.30 minutes (on average). The PFNA2 group experienced less blood loss (average of 80 mL) compared to the condylar blade plate group (average of 120 mL). Union and partial weight-bearing occurred earlier in the PFNA2 group (14.1 weeks and 10.6 weeks, respectively) compared to the Condylar blade plate group (18.7 weeks and 15.8 weeks). In two patients from the PFNA2 group, screw backing out and varus collapse complications were encountered;however, these patients remained asymptomatic and did not require revision surgery. In two other patients, screw cut out and breakage of the nail at the helical screw hole leading to non-union of the proximal femur were observed during the nine-month follow-up, necessitating revision surgery with prosthetic replacement. Among the condylar blade plate group, three patients experienced complications, including blade breakage at the blade and plate junction. In two cases, the fracture united in varus, and in one case, the blade cut through, resulting in non-union of the femoral head, which required revision surgery. According to the Harris hip score and Kyle’s criteria, a good-excellent outcome was observed in 92.85% of cases in the PFNA2 group and 90.90% of cases in the condylar blade plate group. Conclusion: Both the Proximal Femoral Nail A2 and Condylar blade plate are effective implants for the treatment of unstable trochanteric fractures. The intramedullary implant promotes biological healing and allows for early ambulation with minimal complications. Similarly satisfactory restoration of anatomy and favorable radiological and functional results can be achieved with the biological fixation provided by the 95-degree condylar blade plate. However, the use of PFNA2 internal fixation technique has the advantage of less trauma in elderly patients than the 95-degree condylar blade plate.

Risk Assessment of Retrograde Intramedullary Nailing for Proximal Humeral Fracture

In proximal humeral fracture except AO classification 11A1, fixations with a locking plate and nails are recommended. We performed mechanical tests to investigate whether retrograde intramedullary nailing has fixation stability comparable to those of anterograde intramedullary nailing and locking plate which achieve clinically favorable outcomes. In retrograde intramedullary nailing, a nail entry point is made in the diaphysis, for which reduction of stiffness of the humerus is of concern. Thus, we investigated the influence of a nail entry point made in the diaphysis on humeral strength. Retrograde intramedullary nailing had fixation stability against bending and a force loaded in the rotation direction comparable to those of anterograde intramedullary nail and locking plate. Displacement by the main external force loaded on the humerus, compressive load, was less than half in the bone fixed by retrograde intramedullary nailing compared with that in the bone fixed with a locking plate, showing favorable fixation stability. It was clarified that stiffness of the humerus against rotation and a load in the compression direction is not reduced by a nail entry point made by retrograde intramedullary nailing.

股骨近端防旋髓内钉-Ⅱ治疗31-A3型股骨转子间骨折扩髓与否的有限元分析

背景:针对股骨转子间骨折是否需要扩髓的问题尚有争议,一些人认为不扩髓缩短手术时间、减少出血、降低高龄患者术中风险,但此举是否会降低髓内钉支撑效果,尚无依据。另一些人认为扩髓可选择直径更粗的髓内钉,获得更好的力学支撑,但基础研究显示此方法存在脂肪栓塞、破坏骨质(尤其高龄骨质疏松患者)等风险。目的:通过有限元分析股骨近端防旋髓内钉-Ⅱ治疗31-A3型股骨转子间骨折时扩髓与不扩髓的力学分布特点。方法:纳入一名健康志愿者,CT扫描其股骨获取DICOM格式文件,顺序导入Mimics、Geomagic Wrap、SolidWorks、Hypermesh、Ansys软件处理文件,得到A3.1型、A3.2型及A3.3型股骨转子间骨折模型,分别与9,11 mm直径、170 mm长度的股骨近端防旋髓内钉-Ⅱ进行装配,赋予材料属性,设定各接触面相互作用关系及定义载荷及边界条件,之后进行求解。观察不同模型中股骨应力分布、内固定应力分布、股骨位移及内固定位移情况。结果与结论:①各型骨折采用扩髓髓内钉固定时股骨应力均小于非扩髓髓内钉固定,A3.3型骨折股骨最大应力值大于A3.1型和A3.2型;②各型骨折采用扩髓髓内钉固定时内固定应力均大于非扩髓髓内钉固定,A3.3型骨折内固定最大应力值大于A3.1型;③扩髓与非扩髓对股骨及内固定位移影响较小,应力影响较大;④提示采用扩髓髓内钉固定可使股骨应力减小,内固定整体承担应力增大,远端锁钉承担应力减小;与非扩髓髓内钉固定相比,采用扩髓髓内钉固定可能会提供更好的治疗效果。

延长氨甲环酸使用时间有助于减少老年股骨转子间骨折围术期隐性失血

背景:股骨转子间骨折好发于老年人,手术后会出现大量的隐性失血,减少隐性失血可以降低并发症和住院时间。目的:评估延长氨甲环酸的使用时间对股骨近端防旋髓内钉治疗转子间骨折围术期隐性失血的影响。方法:选择2022年1月至2023年5月自贡市第四人民医院经急诊收治入院的老年股骨转子间骨折患者共62例,均在牵引床上闭合牵引复位后置入股骨近端防旋髓内钉治疗。根据氨甲环酸的使用时间分为2组,对照组38例在切开皮肤前15-30 min给予氨甲环酸1 g静脉滴注,3 h后追加1 g;试验组24例在对照组的基础上,术后第1天再追加氨甲环酸1 g静脉滴注每12 h一次。术前、术后当天、术后第1,3,5天均复查血常规,统计血红蛋白量和红细胞压积,理论总失血量采用Gross方程计算,同时记录两组患者并发症发生情况。结果与结论:①通过统计学分析,两组患者术中显性出血量相差较小,差异无显著性意义(P>0.05);②试验组围术期血红蛋白下降量、总失血量、隐性失血量低于对照组,差异有显著性意义(P<0.05);③试验组术后第3天的血红蛋白值、术后第1,3天的红细胞压积值高于对照组,差异有显著性意义(P<0.05);④两组术后血红蛋白和血小板计数呈下降趋势,第3天的血红蛋白值为最低值,术后第1天的血小板值为最低值,然后开始回升;⑤两组患者术后并发症发生率相比差异无显著性意义(P>0.05);⑥结果表明,术后延迟氨甲环酸的使用时间,可能有助于减少股骨近端防旋髓内钉治疗股骨转子间骨折的隐性失血量,并不会增加并发症风险。

髋关节囊周围神经阻滞与髂筋膜间隙阻滞对老年股骨粗隆间骨折患者镇痛效果的对比研究

目的 探讨髋关节囊周围神经(pericapsular nerve group, PENG)阻滞与髂筋膜间隙阻滞(fascia iliaca compartment block, FICB)对老年股骨粗隆间骨折(intertrochanteric femur fracture, IFF)患者股骨近端防旋髓内钉(proximal femoral nail anti-rotation, PFNA)内固定术的镇痛效果。方法 选取2022年1—12月首都医科大学附属北京积水潭医院老年IFF患者60例,随机分为P组和F组,每组各30例。P组采用PENG阻滞,F组采用FICB。两组患者均接受椎管内麻醉进行手术,术后均给予患者静脉自控镇痛(patient controlled intravenous analgesia, PCIA)。比较两组患者不同时点(T1,神经阻滞前;T2,神经阻滞后30 min;T3,术后6 h;T4,术后24 h;T5,术后48 h)静息和运动时的视觉模拟评分(visual analogue score, VAS)、术后补救镇痛率、镇痛满意度评分、住院时间、PCIA按压次数及不良反应发生率。结果 60例患者中,男23例,女37例,年龄65~85岁,平均(70.6±6.0)岁。两组T2~T5时点静息和运动时VAS均低于T1时点,差异均有统计学意义(P <0.05);两组静息和运动时所有时点VAS、术后补救镇痛率、镇痛满意度评分、住院时间、PCIA按压次数及不良反应发生率的比较,差异均无统计学意义(P>0.05)。结论 PENG阻滞与FICB均可缓解老年IFF患者PFNA内固定术的镇痛,且镇痛效果相当。

基于加速康复外科理念的骨水泥强化型防旋股骨近端髓内钉治疗在老年骨质疏松性股骨转子间骨折中的应用效果

目的探讨基于加速康复外科(ERAS)理念的骨水泥强化型防旋股骨近端髓内钉(PFNA)治疗在老年骨质疏松性股骨转子间骨折中的应用效果。方法选取东台市人民医院2021年1月至2022年10月收治的40例老年骨质疏松性股骨转子间骨折患者为研究对象,采用随机数字表法分为对照组(20例)和观察组(20例)。对照组采用ERAS理念联合PFNA治疗,观察组采用ERAS理念联合骨水泥强化型PFNA治疗,并对两组进行为期6个月的随访。比较两组髋关节Harris评分优良率、髋关节活动角度、手术及恢复情况、生活质量及并发症。结果观察组术后6个月髋关节Harris评分优良率高于对照组,观察组住院时间、骨折愈合时间、术后下地行走时间、负重练习时间均短于对照组,总并发症发生率低于对照组,差异有统计学意义(P<0.05);两组的手术时间、术中出血量的比较,差异无统计学意义(P>0.05);观察组术后6个月的欧洲五维健康量表(ED-5Q)各项评分低于对照组,髋关节活动角度大于对照组,差异有统计学意义(P<0.05)。结论ERAS理念下的骨水泥强化型PFNA治疗老年骨质疏松性股骨转子间骨折患者能提高治疗优良率,提高患者生活质量,增加髋关节活动角度,且并发症发生率低。

老年股骨近端骨折围手术期处理流程的研究

目的研究老年股骨近端骨折围手术期处理流程,比较新旧流程体系的合理性以及治疗结果的有效性,不断改进,制定规范、合理的临床围手术期处置流程。方法本研究选取2016年1月—2019年7月包头医学院第三附属医院骨科使用旧有流程的老年髋部骨折患者102例,纳入旧流程组;2019年8月—2022年7月包头医学院第三附属医院骨科使用新流程患者118例,纳入新流程组。同时整理并收集新旧流程实施过程中的患者年龄、性别比例、入院诊断、平均手术等待时间、术中出血量、围手术期输血量,术后髋关节功能评定结果、手术并发症发生例数、平均医疗费用、平均住院时间、并发症加重情况等,通过收集数据进行组间比较,明确新旧流程实施结果。结果新流程组围手术期平均输血量为(257.63±77.24)mL,24 h内完成手术27例,平均住院医疗费用为(41602.6±11878.49)元,优于旧流程组的(333.33±135.22)mL、5例(、51790.49±15744.51)元,差异有统计学意义(P<0.05)。结论新流程的实施可以有效缩短手术等待时间,缩短该类患者的平均住院日,有效降低围手术期用血量,降低住院期间医疗支出,提高24 h内手术完成率,是行之有效的围手术期处置流程。

加长型股骨近端防旋髓内钉治疗股骨干合并同侧股骨转子间骨折

目的探讨加长型股骨近端防旋髓内钉(PFNA)治疗股骨干合并同侧股骨转子间骨折的疗效。方法采用加长型PFNA治疗30例股骨干合并同侧股骨转子间骨折患者。记录骨折愈合情况、患者下地行走情况、髋及膝关节活动度、并发症发生情况。采用Sanders评分评价髋关节功能。结果患者均获得随访,时间12~40个月。术后1个月股骨转子间骨折线开始模糊,骨折愈合时间3~6个月;术后3个月股骨干骨折端周围均骨痂丰富,包裹断端,骨折愈合时间4~9个月。术后均未发生血管损伤、脂肪栓塞、下肢深静脉血栓、骨折再移位、内固定松动等并发症。末次随访时,髋关节屈曲110°~120°、后伸5°~10°,膝关节屈曲110°~115°、伸直0°。患者均可弃拐行走,其中24例步态正常,5例轻度跛行,1例跛行明显;采用Sanders评分评价髋关节功能:优24例,良5例,差1例,优良率29/30。结论加长型PFNA治疗股骨干合并同侧股骨转子间骨折创伤小,安全性高,患者功能恢复快,疗效满意。

基于倾向性评分匹配法探讨血府逐瘀汤对老年股骨粗隆间骨折患者PFNA术后康复的影响

目的:基于倾向性评分匹配法探讨血府逐瘀汤对老年股骨粗隆间骨折患者PFNA术后康复的影响。方法:回顾性分析140例行防旋股骨近端髓内钉(proximal femoral nail antirotation,PFNA)手术治疗的股骨粗隆间骨折患者,使用SPSS 22.0进行倾向性匹配评分匹配分为观察组(血府逐瘀汤治疗)和对照组(常规支持治疗)各50例,比较两组术后相关康复治疗指标,并对两组用药安全性进行评价分析。结果:观察组证候积分,术后第5、7天患肢肿胀程度,VAS评分,术后第3、7天血清白细胞及C反应蛋白水平均明显低于对照组(P<0.05),而术后第7天血清血红蛋白、红细胞压积水平和术后1个月Harris评分均显著高于对照组(P<0.05);两组不良反应发生率比较,差异无统计学意义(P>0.05)。结论:PFNA联合血府逐瘀汤内服治疗对老年股骨粗隆间骨折术后康复恢复效果确切,可显著减轻患肢肿胀程度,在更短时间内缓解患者局部疼痛,减少术后隐性失血,提升Harris评分,快速恢复髋关节功能,且不增加患者用药安全性风险。

两种内固定术式治疗高龄无移位型股骨颈骨折的疗效

目的比较股骨近端锁定接骨板与空心螺钉内固定治疗高龄无移位型股骨颈骨折的疗效。方法根据内固定不同将66例高龄无移位型股骨颈骨折患者分为接骨板组(32例,采用股骨近端锁定接骨板内固定治疗)和螺钉组(34例,采用空心螺钉内固定治疗)。记录两组手术情况、骨折愈合时间、髋关节Harris评分、术后并发症发生情况。结果患者均获得随访,时间6~95个月。手术时间、切口长度、术中出血量、术后血红蛋白下降量两组比较差异均无统计学意义(P>0.05),下床部分负重锻炼时间接骨板组早于螺钉组(P<0.05)。接骨板组骨折均顺利愈合,时间3.5~8.0(4.63±1.04)个月;螺钉组中出现1例骨折不愈合,其余33例骨折愈合时间为3.0~7.5(5.03±1.04)个月;骨折愈合时间两组比较差异无统计学意义(P>0.05)。术后6个月髋关节Harris评分两组比较差异无统计学意义(P>0.05);但髋关节Harris评分优良率接骨板组高于螺钉组(P<0.05)。术后早期并发症发生率两组比较差异无统计学意义(P>0.05),中远期并发症发生率螺钉组高于接骨板组(P<0.05)。结论股骨近端锁定接骨板与空心螺钉内固定治疗高龄无移位型股骨颈骨折均可获得满意疗效,与空心螺钉相比,股骨近端锁定接骨板治疗早期髋关节功能恢复更好,中远期并发症更少。

两种方法治疗老年股骨转子间骨折的疗效比较

目的比较股骨近端防旋髓内钉(PFNA)与半髋关节置换(HA)治疗老年股骨转子间骨折的临床疗效。方法将106例老年股骨转子间骨折患者根据治疗方法不同分为PFNA组(采用PFNA治疗,64例)和HA组(采用HA治疗,42例)。记录手术时间、术中出血量、术中透视次数、住院时间、住院费用、部分负重时间及并发症发生情况,采用Harris评分评价髋关节功能。结果患者均获得随访,时间12~24个月。手术时间、术中出血量、住院费用PFNA组短(少)于HA组(P<0.05)。术中透视次数PFNA组多于HA组(P<0.05)。部分负重时间HA组早于PFNA组(P<0.05)。住院时间两组比较差异无统计学意义(P>0.05)。髋关节功能Harris评分术后1、3、6个月HA组均高于PFNA组(P<0.05);术后12个月两组比较差异无统计学意义(P>0.05)。并发症发生率HA组低于PFNA组(P<0.05)。结论与PFNA相比,HA治疗老年股骨转子间骨折在早期髋关节功能改善和减少术后并发症方面更有优势,但存在手术时间长、术中出血量大、住院费用高等缺点。

机器人导航辅助下股骨近端防旋髓内钉治疗股骨粗隆间骨折的随机对照研究

目的 探讨机器人导航辅助下股骨近端防旋髓内钉(PFNA)与C型臂X射线机透视下PFNA治疗股骨粗隆间骨折(IFOF)的疗效。方法 选择我院单侧IFOF患者100例为研究对象,按照随机数字表法分为对照组(50例)和机器人辅助组(50例),对照组在C型臂X射线机透视下行PFNA内固定治疗,机器人辅助组在机器人导航辅助下行PFNA内固定治疗。比较2患者组手术指标、骨折复位及骨折愈合情况、应激反应指标、髋关节功能、生活质量评分以及手术相关并发症发生率。结果 机器人辅助组患者手术时间、总透视时间、置钉时间、骨折愈合时间短于对照组(P<0.05),术中出血量、导针调整次数、透视次数少于对照组(P<0.05)。机器人辅助组患者骨折复位情况、骨折愈合情况均优于对照组(P<0.05)。术后2 d,2组患者血清去甲肾上腺素(NE)、血管紧张素Ⅱ(Ang Ⅱ)、超氧化物歧化酶(SOD)水平均高于术前(P<0.05);机器人辅助组术后2 d血清NE、Ang Ⅱ、SOD水平均低于对照组(P<0.05)。2组患者术后7 d、术后3个月Harris评分及健康状况调查量表(SF-36)评分高于术前(P<0.05),且术后3个月上述评分高于术后7 d(P<0.05);术后7 d、术后3个月,机器人辅助组患者Harris评分、SF-36评分均高于对照组(P<0.05)。机器人辅助组患者并发症发生率低于对照组(P<0.05)。结论 与C型臂X射线机透视相比,机器人导航辅助下PFNA治疗IFOF能进一步缩短手术时间、减小手术创伤及降低并发症发生率,骨折复位、愈合效果更佳,机体应激更小,更能改善患者髋关节功能及生活质量。

Comparative biomechanical study of reversed less invasive stabilization system and proximal femoral nail antirotation for unstable intertrochanteric fractures

Objective Unstable intertrochanteric fractures （ITFs） are mostly treated by proximal femoral nail antirotation （PFNA）,Inter-Tan,Asian Hip,and other new internal fixation devices.But for complex unstable fractures,such as crushed lateral wall of the greater trochanter,the loss of fixation point on lateral wall slightly reduces the fixing effect.This study aimed to compare the biomechanical strengths between reversed less invasive stabilization system （LISS） and PFNA for treatment of unstable ITFs.Methods Forty synthetic femurs were used to simulate unstable ITFs in vitro and were fixed using the reversed LISS or PFNA.These fractures were divided into two groups depending on whether the lateral wall of the greater trochanter is intact or not （AO classification：31-A2.3 and 31-A3.3,respectively）.The load-displacement of femur,stiffness,ultimate load,and cyclic fatigue resistance were detected using an incremental load test and a dynamic fatigue test through an MTS 858 test system.Results For both 31-A2.3 and 31-A3.3,the vertical sinking displacement （VSD） of the femoral head under 500 N load was insignificantly smaller after treatment with reversed LISS than with PFNA,and when the displacement was 5 mm,the femoral head bore insignificantly greater load.The fixation with reversed LISS resulted in greater axial stiffness of the femur but smaller ultimate load.During the same cycle in the dynamic fatigue test,the VSD was insignificantly smaller with the fixation of reversed LISS.Conclusion Reversed LISS and PFNA have similar biomechanical strength for unstable ITFs.This conclusion should be supported by additional large-size research on basic biomechanics and clinical application.This is the first comparative biomechanical study comparing reversed LISS and PFNA for unstable ITFs.

股骨近端防旋髓内钉治疗外侧壁完整型和外侧壁危险型股骨转子间骨折

背景:对于老年创伤性髋部骨折患者而言,预后的相关因素非常复杂,股骨外侧壁的完整与否是影响因素之一,了解外侧壁损伤对股骨转子间骨折预后的影响具有重要的临床价值。目的:评估外侧壁完整性与股骨转子间骨折患者髋关节功能恢复及其预后之间的关系。方法:筛选股骨转子间骨折患者82例,所有患者均接受股骨近端防旋髓内钉固定治疗。依据外侧壁厚度将患者分为2组,外侧壁完整组(n=31)及外侧壁危险组(n=51)。比较两组患者围术期指标、负重时间、骨折愈合时间、髋关节功能及活动度、术后疼痛及并发症发生情况。结果与结论:(1)外侧壁完整组患者的住院时间、术中透视次数明显低于外侧壁危险组(P<0.05),其余围术期指标的差异无显著性意义;(2)术后两组患者均能早期下地和最终完全负重,但外侧壁危险组患者骨折愈合时间更长,完全负重时间明显延迟,末次随访的Harris评分更低,患侧髋伸屈活动度及颈干角更小(P<0.05);(3)两组患者各种并发症发生率比较差异无显著性意义,但总体并发症发生率外侧壁完整组明显更低(P<0.05);(4)综上,接受股骨近端防旋髓内钉内固定治疗后,与外侧壁危险组患者相比,外侧壁完整组患者具有相对更好的预后。

Treatment of subtrochanteric femoral fracture with long proximal femoral nail antirotation

Objective： Subtrochanteric femoral fractures are severe injuries. Although many treatment methods have been developed, controversy exists regarding the optimal management of these fractures. This study evaluated the clinical outcome of subtrochanteric femoral fractures fixed with long proximal femoral nail antirotation （PFNA-Iong）. Methods： Between October 2006 and February 2008, 25 patients with traumatic subtrochanteric fractures of the femur were treated with PFNA-long. Closed reduction and fixation were performed in 20 cases. In the remaining 5 cases, closed reduction was difficult, so limited open reduction was performed, with bone grafting in 4 cases and circumfer-ential wiring in 4 cases. Results： The average follow-up time was 16.1 months. All subtrochanteric femoral fractures healed uneventfully except one case of delayed union. The mean union time was 26.2 weeks. Technical difficulties with nail insertion were encountered in 3 cases. No implant failure was observed. Conclusion： PFNA-long is effective in treatment of subtrochanteric femoral fractures, with a high rate of bone union, minor soft tissue damage, early return to functional exercise and few implant-related complications.