经髋动力螺钉侧孔注入Ⅲ型丙烯酸树脂骨水泥强化固定轴向稳定性的测试

背景:髋动力螺钉系统仍旧是治疗高龄患者骨质疏松性转子间骨折最常用的器械,但是高龄患者往往由于股骨上端骨质疏松髋动力螺钉固定失败增高.目的:通过生物力学实验测试经髋动力螺钉侧孔注入骨水泥强化螺钉固定的效果.方法:在髋动力螺钉头端制作了4个侧孔,使骨水泥能够通过髋动力螺钉"中央孔→侧孔"注入股骨头的松质骨.成对的骨质疏松性股骨标本12根,复制股骨转子间不稳定型骨折模型后随机分入带侧孔髋动力螺钉固定加骨水泥强化组和标准髋动力螺钉固定组(标准髋动力螺钉固定组).分别进行轴向"加载-应变"和"载荷-位移"测试、抗扭转力学性能测试、拔出强度测试.结果与结论:带侧孔髋动力螺钉与标准髋动力螺钉的生物力学强度差异无显著性意义;轴向加载试验的"载荷-应变"的测试表明:骨水泥强化组张力侧的应变明显小于标准髋动力螺钉固定组(t=2.795,P<0.05),压力侧骨水泥强化组明显低于标准髋动力螺钉固定组(t=2.621,P<0.05).加载到600 N时,骨水泥强化组的下沉位移较标准髋动力螺钉固定组减少31%,横向位移减少29%,差异均有显著性意义(P<0.05).结果提示,通过髋动力螺钉中央孔和侧孔注入骨水泥的强化技术能够显著提高髋动力螺钉对股骨转子间骨折固定的生物力学强度.     

可灌注骨水泥动力髋螺钉内固定修复骨质疏松股骨转子间骨折的优势

背景：动力髋螺钉内固定系统被认为是治疗股骨转子间骨折的经典方法,但髋螺钉切割股骨头后位置偏移是目前常见的力学失败,需要进行二次手术。目的：在传统动力髋螺钉内固定系统的基础上,对髋螺钉部分进行改良,设计可灌注骨水泥动力髋螺钉内固定系统,探讨其治疗骨质疏松股骨转子间骨折的可行性及生物力学性能。方法：取24具新鲜完整湿润的人骨质疏松髋部标本,测量骨密度,按标准制成AO31-A1型股骨转子间骨折模型,每份骨质疏松髋部标本,其中一侧置入可灌注骨水泥动力髋螺钉内固定系统作为实验组,另一侧置入传统动力髋螺钉内固定系统作为对照组,进行轴向压缩、扭转度及失效载荷生物力学测试,比较两者生物力学性能。结果与结论：实验组应力强度、轴向刚度、水平剪切刚度高于对照组（P〈0.05）;当扭角为3°时,实验组扭矩高于对照组（P 〈0.05）;实验组失效载荷高于对照组（P 〈0.05）。表明可灌注骨水泥动力髋螺钉内固定系统治疗老年骨质疏松股骨转子间骨折,能有效增强髋螺钉的把持力,防止股骨头切割,其生物力学强度、刚度、抗疲劳性及稳定性均强于传统动力髋螺钉。     

动力髋螺钉与髓内钉治疗股骨转子间骨折疗效比较

目的通过比较分析动力髋螺钉（DUS）与股骨近端髓内钉（PFN）治疗股骨转子间骨折的手术效果,探讨这两种内固定手术方法的临床疗效。方法100例患者随机分为两组,各50例。分别给予DHS和PFN治疗,通过手术时间、X线暴露次数、术中出血量、术后引流量、骨折临床愈合时间、术后功能恢复程度等方面,比较两组间的结果。结果DHS组和PFN组在x线暴露次数、术中出血量、骨折临床愈合时间、术后功能恢复程度等方面比较均有差异,差异有统计学意义（P〈0．05）。PFN组与DHS组相比较,术中出血量少,骨折临床愈合时间短,术后功能恢复好,但X线暴露次数增加。结论PFN内固定治疗股骨转子间骨折手术创伤小、疗效好．是比较理想的内固定方法。     

动力髋螺钉联合防旋钉内固定治疗老年转子间骨折

股骨转子间骨折是一种常见病、多发病，多见于老年人，对于老年股骨转子间骨折的治疗，目前多主张采取早期手术治疗，动力髋螺钉（DHS）内固定是临床最常用的手术方式之一。我院自2002年2月至2007年10月采用动力髋螺钉联合防旋钉内固定治疗老年转子间骨折74例，取得良好效果，现报告如下。     

动力髋螺钉和股骨近端防旋髓内钉治疗股骨粗隆间骨折疗效比较

目的 比较动力髋螺钉(dynamic hip screw,DHS)和股骨近端防旋髓内钉(proximal femoral nail antirotation,PFNA)治疗股骨粗隆间骨折的效果。方法 103例股骨粗隆间骨折患者根据手术方法分为DHS组51例和PFNA组52例,比较2组手术时间、术中出血量、骨折愈合时间及相关并发症发生率,术后1a评定2组Harris功能评分。结果 PFNA组手术时间为(61.21±12.78)min,术中出血量为(187.12±88.12)mL,骨折愈合时间为(220.34±75.55)d,并发症发生率为3.85%;DHS组分别为(94.28±15.21)min、(330.87±112.22)mL、(269.21±88.12)d、17.65%,2组比较差异均有统计学意义(P<0.05);术后1aPFNA组Harris功能评分(88.98±5.45)分高于DHS组(84.71±4.98)分,但2组比较差异无统计学意义(P>0.05)。结论 PFNA治疗股骨粗隆间骨折可缩短手术及骨折愈合时间,降低并发症发生率。     

Gamma钉与动力髋螺钉治疗股骨转子间骨折的Mela分析

背景:股骨转子间骨折早期的内固定是一种积极有效的治疗手段,临床上老年人股骨转子问骨折的治疗方法较多,疗效不一,各有优缺点.目的:探讨Gamma钉与动力髋螺钉治疗股骨转子间骨折临床疗效方面的差异.方法:检索CENTRAL(the Cochrane central register of controlledtrials)、Medline、EMBASE、万方、中国生物医学文献数据库系统(CBM)、中国期刊全文数据库(CNKI)等,收集国内外公开发表的Gamma钉与动力髋螺钉治疗股骨转子间骨折的临床随机对照研究.根据Cochran手册提出的文献质量评价标准对纳入研究进行质量评价.应用统计软件Statal1.0进行数据分析.结果与结论:最终纳入分析的文章有12篇,Gamma钉组888例,动力髋螺钉组981例.Meta分析的结果显示接受Gamma钉治疗的患者与接受动力髋螺钉患者比较:置入后股骨干骨折风险增高、置入时间较短、置入中出血量较少,差异有显著性意义(P＜0.05).两组患者置入后感染风险、内固定优良率、住院时间方面差异无显著性意义(P＞0.05).说明与动力髋螺钉相比,接受Gamma钉治疗的患者内固定置入时间短,出血少但置入后股骨干骨折的风险增加.     

动力髋螺钉+空心钉内固定治疗股骨转子间骨折

2007年1月至2009年1月,采用动力髋螺钉(DHS)的基础上加用空心钉加强内固定治疗Evans Ⅱ型股骨转子间骨折15例,取得了良好的疗效.现报告如下.     

动力髋螺钉和股骨近端髓内钉治疗老年股骨转子间骨折的比较

目的 比较采用动力髋螺钉（DHS）和股骨近端髓内钉（PFN）治疗老年股骨转子间骨折的术中情况、术后并发症及疗效.方法 2004年1月至2009年10月,分别采用DHS（DHS组,32例）和PFN（PFN组,25例）治疗并随访老年股骨转子间骨折患者57例.比较两组患者手术情况、术后并发症及功能恢复情况.结果 PFN与DHS相比较在切口长度、手术时间、术中出血量、术后引流量及骨折临床愈合时间等方面比较差异有统计学意义（P均〈0.01）.与DHS组相比,PFN组手术切口小、手术时间短、术中出血量及术后引流量少、骨折临床愈合时间短.DHS组和PFN组的优良率分别为84.38%和88.00%,两组间疗效差异无统计学意义（P〉0.05）.结论 应用DHS和PFN治疗老年股骨转子间骨折,在疗效方面比较差异无统计学意义.PFN可缩短手术时间、减少术中出血量及术后并发症.     

动力髋螺钉与股骨近端抗旋髓内钉治疗转子间骨折的比较

背景：转子间骨折主要有两种固定方式,一是髓外固定的钉板系统,以动力髋螺钉为代表;另一种是髓内固定的髓内钉系统,以股骨近端抗旋髓内钉为代表。目的：比较动力髋螺钉与股骨近端抗旋髓内钉治疗老年股骨转子间骨折的疗效。方法：回顾性分析2008-01/2010-12山西省人民医院骨科收治的老年股骨转子间骨折患者58例。分别采用动力髋螺钉及股骨近端抗旋髓内钉两种内固定方式置入治疗。结果与结论：动力髋螺钉组平均随访13个月,股骨近端抗旋髓内钉组平均随访11个月。随访期内两组均达骨性愈合。置入内固定治疗后动力髋螺钉组完全负重时间、骨折愈合时间较股骨近端抗旋髓内钉组延长（P〈0.05）;末次随访时Parker-Palmer评分两组相比,差异无显著性意义（P〉0.05）。动力髋螺钉组主钉松动退出1例,钢板断裂1例;所有患者无伤口感染、内固定物切割、髋内翻等并发症出现,最终骨折愈合。提示两种内固定治疗转子间骨折均可达到良好的治疗效果。股骨近端抗旋髓内钉比动力髋螺钉内固定可更早负重,骨折愈合时间短。     

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.     

骨水泥强化正常骨质DHS固定的生物力学研究

背景:DHS是治疗股骨转子间骨折的标准内固定,对于伴有骨质疏松的骨折,容易发生拉力螺钉切割.国内外文献建议骨水泥强化DHS以达到坚强内固定,但是对于正常骨质,骨水泥强化是否有效还缺少报道.目的:选取正常骨密度的股骨转子间骨折标本,观察骨水泥强化对DHS固定的生物力学影响.设计、时间及地点:同一标本两侧对比观察实验,于2005-03/05在河北省骨科研究所生物力学实验室完成.材料:选取河北医科大学解剖教研室提供的成年男性防腐尸体双侧股骨上段标本.X射线证实无结核、畸形、肿瘤.方法:取成年男性防腐尸体双侧股骨上段标本24对48侧,制备A2型股骨转子间骨折模型.右侧标本行骨水泥强化DHS固定(在股骨头近端钉道用刮匙扩大.股骨头朝下,注入2mL低黏稠度骨水泥,拧入拉力螺钉,保持位置不变直至骨水泥凝固.置入套筒,拧紧尾钉适当加压,皮质骨螺钉固定钢板),为强化组;左侧行DHS常规固定,为对照组.两组标本进行弯曲强度试验及扭转强度试验.主要观察指标:两组标本的最大负荷及最大扭矩.结果:强化组最大负荷及最大扭矩与对照组比较,差异均无统计学意义[最大负荷分别为:(3852.1602±143.6031)N和(3702.9667±133.8601)N;最大扭矩分别为(15.5±2.6)N·m,(14.7±3.4)N·m, P>0.0⑤.结论:对于正常骨密度的股骨转子间骨折,骨水泥强化对DHS固定强度及骨折整体稳定性无显著的影响.     

Pullout strength for cannulated pedicle screws with bone cement augmentation in severely osteoporotic bone: Influences of radial hole and pilot hole tapping

Background

Pedicle screw fixation in a severely osteoporotic spine remains a challenge for orthopedic surgeons. The previous literature does not adequately address the effects of radial holes for cannulated screws with cement injection and pilot hole tapping on the bone/screw interfacial strength.

Methods

Specially designed cannulated pedicle screws, with or without radial holes, were installed in tapped and untapped pilot holes and then injected with cement. A uniform synthetic bone (test block) was used to provide a platform for each screw design. Specimens with inserted screws were then tested for axial pullout failure.

Findings

(1) Cannulated screws with cement augmentation significantly increased the pullout strength in comparison to solid screws. Additionally, the amount of cement exuded from the cannulated screws increased with an increasing number of radial holes, leading to an increase in the average ultimate pullout strength for cannulated screws with a large number of radial holes. (2) Radiological examination indicated that the cement was exuded from the most proximal holes at the very beginning of its flow path, whereas no cement exudation was found at the remaining distal holes. (3) Cement exudation from the holes of cannulated screws into the open cell of the test block led to a composite (cement/bone) structure at the area of cement exudation. Observations of the failed specimens indicated that failure occurred at the composite/bone interface, while the composite was well bonded to the screws. This implies that the screw/composite interfacial strength was much higher than the composite/bone interfacial strength. (4) Tapping pilot holes decreased the pullout strength of the screws. Generally, larger standard deviations were found for the tapped cases, implying that untapped cases results are more repeatable than tapped cases results.

Interpretation

Cannulated pedicle screws with radial holes combined with PMMA cement augmentation but without tapping may be a viable clinical option for achieving fixation in severely osteoporotic bone.     

动力髋关节螺钉内固定联合植骨治疗股骨粗隆间骨折

目的:探计动力髋关节螺钉(DHS)内固定治疗股骨粗隆间骨折(IFF)中植骨的临床作用.方法:2004-2007年对60例Evans Ⅰ～Ⅳ型IFF病例采用DHS治疗.不植骨组30例,术中采用常规实心三联扩孔器扩孔DHS内固定.植骨组30例,采用自行研制的DHS空心扩孔器扩孔、取骨、植骨,DHS内固定.术后对两组患者进行随访比较.结果:不植骨组30例中优14例,良9例,可4例,差3例,髋内翻7例,术后螺钉切割拔出2例,铜板、螺钉断裂2例,骨不连2例,优良率76.7%.植骨组30例中优18例,良9例,可2例,差1例,髋内翻3例,术后螺钉切割拔出1例,无钢板、螺钉断裂,无骨不连,优良率90.0%.结论:DHS内固定治疗IFF时,预防性植骨,可加速骨折愈合,迅速重建内侧支持结构,减少髋内翻及相关并发症.     

Biomechanical effects of insertion location and bone cement augmentation on the anchoring strength of iliac screw

Background

Iliac screw loosening has been a clinical problem in the lumbo-pelvic reconstruction. Although iliac screws are commonly inserted into either upper or lower iliac column, the biomechanical effects of the two fixations and their revision techniques with bone cement remain undetermined. The purpose of this study was to compare the anchoring strengths of the upper and lower iliac screws with and without cement augmentation.

Methods

5 pairs of formalin fixed cadaveric ilia with the bone mineral density values ranged from 0.82 to 0.97 g/cm² were adopted in this study. Using screws with 70-mm length and 7.5-mm diameter, 2 conventional iliac screw fixations and their revision techniques with cement augmentation were sequentially established and tested on the same ilium as follows: upper screw, upper cement screw, lower screw, and lower cement screw. Following 2000 cyclic compressive loading of − 300 N to −100 N to the screw on a material testing machine, the maximum pull-out strengths were measured and analyzed.

Findings

The average pull-out strengths of upper, upper cement, lower, and lower cement screws were 964 N, 1462 N, 1537 N, and 1964 N, respectively. The lower screw showed significantly higher pull-out strength than the upper one (P = 0.008). The cement augmentation notably increased the pull-out strengths of both upper and lower screws. The positive correlation between pull-out strength and bone mineral density value was obtained for the 4 fixations.

Interpretation

The lower iliac screw technique should be the preferred choice in lumbo-pelvic stabilization surgery; cement augmentation may serve as a useful salvage technique for iliac screw loosening; preoperative evaluation of bone quality is crucial for predicting fixation strength of iliac screw.     

动力髋螺钉治疗股骨粗隆间骨折的疗效评价

目的分析应用动力髋螺钉(DHS)内固定治疗股骨粗隆间骨折的疗效。方法对我院从2001年4月至2006年12月用DHS内固定治疗80例股骨粗隆间骨折的分类、手术方法、术后处理及疗效进行评价,平均随访1年3个月。结果所有病例术后全部随访,骨折愈合,无髓内翻、下肢外旋及短缩畸形,患髋关节功能优良率达89.6%,疗效肯定。结论DHS内固定是治疗股骨粗隆间骨折的理想方法。     

腰椎内固定中两种椎弓根钉加强技术与骨水泥的应用

背景：骨质疏松伴腰椎退行性病变行椎弓根钉固定骨质疏松的椎体后可能会出现螺钉的松动、脱落,使用固化材料强化椎弓根钉能提高治疗效果。目的：比较骨质疏松患者腰椎内固定中使用聚甲基丙烯酸甲酯骨水泥和可注射硫酸钙骨水泥加强椎弓根钉两种技巧的临床效果。方法：腰椎滑脱、腰椎失稳、严重腰椎管狭窄合并骨质疏松的患者共61例,根据治疗方式分为2组：传统聚甲基丙烯酸甲酯强化椎弓根钉组和可注射硫酸钙骨水泥强化椎弓根钉组。结果与结论：两组患者治疗操作时间、出血量、治疗前后目测类比评分、日本骨科协会评估治疗分数评分及改善率比较差异均无显著性意义（P〉0.05）。聚甲基丙烯酸甲酯组中2例患者出现了注入的骨水泥渗漏,随访未造成新的神经损伤。聚甲基丙烯酸甲酯组患者治疗后骨密度随着随访时间的延长未出现逐渐的增强趋势;硫酸钙骨水泥组患者治疗后骨密度出现渐进性的改善,与患者治疗后日本骨科协会评估治疗分数改善率呈线性相关。两组患者未出现螺钉松动、拔出及神经功能的异常。表明与聚甲基丙烯酸甲酯相似,硫酸钙骨水泥能增加椎弓根螺钉的稳定性。     

Comparison of bone screw holding strength in healthy bovine and osteoporotic human cancellous bone

Pushout tests were carried out on two different diameter, self-tapping, cancellous bone screws (4 mm and 6.4 mm) inserted in bovine cancellous bone sections taken perpendicular and at 45 degrees to the long axis of the bone. Comparison was made with the same type of screws inserted into sections taken from osteoporotic and/or osteoarthritic human femoral heads. The results showed no significant difference in the holding strength of different diameter screws in bovine bone sections of given orientation but significant differences when the trabecular orientation of the section was changed. By comparison, the holding strengths of the same screws in diseased femoral heads were found to be both significantly different from each other and significantly lower than for the same screws inserted in healthy bovine bone. The screw diameter, trabecular orientation, mineral content and the health of the bone all need to be considered in order to optimise the holding strength of the screws in cancellous bone.     

动力髋螺钉置入内固定治疗骨质疏松性转子间骨折110例

背景:动力髋螺钉置入内固定是治疗转子间骨折最常用手术方式,但对于骨质疏松患者易发生螺钉切出股骨头,导致手术失败.目的:回顾性分析导致骨质疏松性转子间骨折动力髋螺钉置入内固定失败的危险因素.方法:对127例接受切开复位,135°动力髋螺钉置入内固定,对病历资料完整110例股骨转子间骨折患者进行回顾性分析.采用Evans骨折分型,采用Singh分级评定骨的质量,采用尖项距评价拉力螺钉在股骨头的位置.选择年龄、骨质疏松程度、骨折类型、复位稳定性、内固定的植入位置作为分析变量,采用t检验及X2检验对危险因素进行分析.结果与结论:所有患者获得3～24个月随访,16例患者内固定失败.内固定失败者平均年龄77.5岁(63～88岁),较骨折愈合组者年长8.5岁(P=0.03).骨质疏松轻重程度以及尖顶距值大小间差异均存在显著性意义(P=0.01).骨折稳定与否对内固定成败有显著性意义(P＜0.05).良好复位与功能复位之间差异无显著性意义(P=0.31).结果提示,年龄、骨折类型、骨骼质量、螺钉置入内固定的置入位置(尖顶距)以及内侧骨皮质复位质量是导致螺钉置入内固定失败的危险因素.功能复位并不增加螺钉置入内固定失败的风险.对于高龄、严重骨质疏松的不稳定骨折不宜应用动力髋螺钉置入内固定.对于采用动力髋螺钉置入内固定的一般患者应力求使尖顶距值＜25 mm,功能复位即可,但应力求使后内侧骨皮质良好复位.     

Modification of the screw hole structures to improve the fatigue strength of locking plates

BackgroundThe fatigue fracture of locking plates can substantially threaten fracture treatment results. In the present study, three measures for modifying the screw hole structures of plates were implemented to improve their fatigue strength.MaterialsCustom-made identical titanium locking plates, except the screw hole configurations, were tested using four-point bending load. The three measures were partial removal of screw threads on the tension side of the plates, reduction of screw hole size, and modification of the thread radii. There were six types of plates: control (Type I), half of the threads removed (Type II) or one-third of the threads (Type III), smaller screw holes (Type IV), and increase of the thread root radii (Type V) or crest radii (Type VI).FindingsCompared with the control, Types II and III significantly improved the fatigue strength (14.5 and 10.1 times, respectively). Decreasing the size of the screw hole (Type IV) also yielded a higher fatigue strength (17.6%). Type VI significantly improved the fatigue strength (9.8 times). However, Type V decreased the fatigue strength (14%). For cyclic stiffness, Type IV was significantly higher than other types statistically. Failure analyses showed typical fatigue fracture in all plates and the cracks were always initiated at the thread crest.InterpretationsThe fatigue strength of titanium locking plates can be significantly improved by structural changes in the screw holes. Removing the threads of the plates and increasing the crest radii of the threads were more effective measures than decreasing the size of the screw holes.