股骨近端主张力骨小梁生物力学特性

目的 研究股骨近端主张力骨小梁的生物力学性能,为解释股骨颈骨折后股骨头坏死的发生原因提供实验依据.方法 取8个正常国人(45 ～60岁)尸体股骨,排除畸形、骨折等病变.将近端主张力骨小梁系统从外侧到内侧分成3个区,在每个区内沿主张力小梁方向及与其垂直方向切取骨小梁试件,并分别在EnduraTEC ELF3200生物力学...     

动力髋联合空心钉与动力髋联合内侧板治疗PauwelsⅢ型股骨颈骨折的有限元分析比较

目的探究动力髋螺钉(DHS)的两种手术方式(DHS联合空心钉和DHS联合股骨颈内侧板)治疗PauwelsⅢ型股骨颈骨折的生物力学优缺点。方法建立采用3种内固定方法治疗PauwelsⅢ型股骨颈骨折的有限元模型。分别为单独使用DHS内固定、DHS联合空心钉固定、DHS联合股骨颈内侧板固定,并建立正常股骨模型用于与前3个模型对比分析。在相同边界及载荷条件下比较以下结果:4个模型的股骨颈内侧(股骨头下缘至股骨距到小转子的位置)的等效应力分布;3个内固定模型的内固定物的最大等效应力值;4个模型股骨头断端最大位移。结果股骨颈内侧等效应力分布最接近正常股骨的模型是DHS联合股骨颈内侧板,单纯DHS固定的模型和DHS联合空心钉固定的模型在股骨颈内侧的等效应力集中值大于正常股骨模型,分别为53.57 MPa和26.72 MPa。股骨头骨折断端总位移:单纯DHS固定模型的位移是4.01 mm,DHS联合空心钉固定模型的位移是1.73 mm,DHS联合股骨颈内侧板固定模型的位移是1.68 mm。DHS内固定物最大等效应力由大到小分别是:单独DHS固定为101.07 MPa,DHS联合空心钉固定为38.19 MPa,DHS联合股骨颈内侧板固定为22.69 MPa。结论DHS联合空心钉与DHS联合内侧板手术方式都优于单独DHS固定的手术方式。DHS联合空心钉固定能在股骨头位移相对较小的情况下维持较高的股骨颈应力,适合于股骨颈内侧相对完整及未出现粉碎骨折的患者;DHS联合内侧板可以更好地重建股骨力线,更适合于股骨颈内侧皮质处有粉碎骨折的患者。     

利用有限元分析股骨颈骨折内固定术后前倾角变化对股骨近端力学的影响

目的探讨股骨颈骨折闭合复位空心螺钉内固定术后不同股骨颈前倾角对股骨近端力学分布的影响,为临床中内固定术解剖复位的重要性提供生物力学依据。方法采用16层螺旋CT扫描正常成人髋关节数据,基于三维重建软件和CAD软件,分别建立Pauwells角为70°的股骨颈骨折空心螺钉内固定术后前倾角为0°、5°、10°、15°、20°的股骨近端三维有限元分析模型,对所有模型施加人体缓慢行走时的载荷和约束,观察不同模型间股骨近端结构应力分布的变化。结果当前倾角未改变时(10°模型),股骨所受应力、产生的位移及发生的等效应变最小,股骨近端最大应力值为1.7 MPa,产生的位移为1.1 mm。随着前倾角的增大或减小,股骨近端所承受的有效应力及产生位移呈逐渐增大趋势。当前倾角为20°时,股骨近端及螺钉所受应力最大;当前倾角为0°时,股骨近端产生的位移及发生的等效应变值最大。股骨近端应力集中的部位由股骨距区域转移至头颈交界处的外上方。3枚空心螺钉承受的应力较周围骨组织高,最下方螺钉承受的应力较上方两枚螺钉明显增高。结论股骨颈骨折闭合复位空心螺钉内固定术中恢复前倾角达到解剖复位至关重要;股骨颈骨折术后生物力学因素的改变可能在术后股骨头坏死中起一定作用。     

股骨近端骨缺损在内固定术后的生物力学特征分析

目的 探讨股骨头近端骨缺损在内固定术后的生物力学情况.方法 选择正常志愿者1例以及股骨近端骨缺损内固定术后患者1例进行股骨近端有限元模型的建构.在Mimics软件中输入DICOM数据进行截骨模拟,建立70°Pauwells角且骨缺损体积不等的股骨颈骨折模型.在模型与空心钉完成装配之后,于ABAQUS软件中进行导入,执行约束与加载操作.结果 股骨颈外上方和下方的最大应力是18.9 MPa和24.2 MPa,应力集中分布在股骨颈中段.股骨头的应力峰值最大,股骨颈上方次之,而下方空心钉所受到的应力峰值最低.随着股骨颈下后方骨缺损体积的增大,股骨颈上方两枚空心螺钉所承受的最大拉伸应力值变大,该最大拉伸应力出现于骨折断端位置,且股骨头最大应力范围向外移动,非主要负重区出现高压强区.结论 股骨颈近端骨缺损固定术中,在股骨颈下方置钉的固定方式螺钉变形断裂概率最小,对股骨颈下后方骨缺损体积患者来说倒三角置钉固定方式可为骨折处提供良好的力学环境.     

应用角度钢板治疗发育性髋关节脱位的临床研究

目的探讨应用角度钢板治疗儿童发育性髋关节脱位（DDH）的临床疗效。方法回顾分析本组48例（52髋）采用角度钢板行开放复位,股骨短缩内翻去旋转截骨术加Salter或Pemberton截骨术式治疗的DDH患儿临床资料。其中男6例,女42例;左侧26例,右侧18例,双侧4例。患儿手术年龄为2～9岁,平均3.5岁。按Tonnis系统分级：Ⅲ度10例,Ⅳ度38例。结果患儿随访1～4年,平均2.4年,股骨颈前倾角术前测量30°～50°,术中皆矫正至20°左右。股骨颈干角术前140°～160°,术后矫正至125°左右。术前髋臼指数35°～55°,术后矫正至18°～35°。术中行短缩截骨长度0.8～3.0 cm,平均2.0 cm。McKay评分,优35例,良13例。结论角度钢板应用于治疗儿童发育性髋关节脱位临床疗效良好,值得推广应用。     

复杂受力下股骨应力分析

目的对人体在行走时身体发生扭曲、跌倒等情况下股骨可能发生在弯矩和压力复合荷载作用下的受力问题进行研究,为人工股骨头置换的设计和手术提供指导。方法应用大型通用有限元软件ANSYS进行受力分析,根据人体股骨的实际尺寸,采用plate42单元建立平面模型,将股骨头传递的关节力的作用点向外偏移为0mm、5mm、10mm、15mm,模拟股骨头受弯矩作用的情况下股骨应力分布。结果得出了在弯压复合荷载下股骨的变形、应力云图、股骨颈和股骨干上端的截面应力。结论股骨颈存在较大的应力集中现象,股骨颈外侧承受较大的拉应力,股骨颈内侧承受较大的压应力,股骨干在垂直方向上外侧为拉应力,内侧为压应力。随着弯矩的增加股骨的应力有明显增加。     

儿童股骨颈前倾角的数字化三维重建与解剖测量

目的探讨发育性髋关节脱位患儿股骨颈前倾角的数字化测量方法,为股骨近端截骨手术提供解剖学依据。方法收集单侧发育性髋关节脱位儿20例,其中男10例,女10例,应用Mimics15.0软件,利用数字化三维重建技术重建股骨,标定相关解剖标志测量患侧及健侧股骨颈前倾角,并与在断层CT上测量的股骨颈前倾角相比较。结果重建的股骨数字化虚拟可视模型能够从多角度、多平面进行观察及测量,二维CT测量健侧和患侧股骨颈前倾角分别为(25.54±7.17)°和(42.98±10.36)°,数字化三维重建测量健侧和患侧股骨颈前倾角分别为(24.29±3.46)°和(40.36±5.42)°。数字化三维重建股骨颈前倾角与二维CT测量的数值差异有统计学意义(P0.05)。结论基于三维CT扫描的股骨数字化三维重建图像具有良好的形态和清晰的边界,可精确识别出股骨前倾角的解剖数据,为完成个体化的股骨截骨术提供了新的方法。     

先天性髋关节发育不良股骨近端髓腔内径曲线形态

目的测量并分析国内先天性髋关节发育不良(developmental dysplasia of the hip,DDH)患者股骨近端形态参数与髓腔内径曲线,为DDH股骨柄设计提供参考依据。方法进行股骨三维重建后,测量并比较分析30名正常人(30髋,男21名,女9名,平均年龄29.4岁)和64名DDH患者(74髋,男12名,女52名,平均年龄45.3岁)股骨近端形态参数和多个高度上髓腔内外径、前后径,建立不同人群的髓腔内径曲线并进行比较分析。结果 DDH患者与正常人群相比,前倾角(26.39°±14.74°vs 15.68°±7.95°)显著较大(P=0.001),颈干角(125.65°±5.73°vs 129.19°±5.80°)、峡部高度[(99.14±14.62) mm vs (110.13±11.73) mm]、髓腔开大指数[(3.63±0.77) vs (4.45±0.79)]、股骨头直径[(44.01±5.75)mm vs (47.26±3.94)mm]和偏心距[(31.80±3.82)mm vs (36.42±4.84)mm]则显著较小(P0.05)。结合测量所得的髓腔前后径、内外径与所拟合的内径曲线,DDH近端髓腔呈现的特点为内外径变狭窄、前后径向前偏移。在不同分型DDH中,股骨的变形程度随着分型增大愈发严重,CroweⅣ型DDH患者与其他分型间的股骨髓腔形态存在较大差异。结论 DDH患者的平均股骨近端曲线与正常人群存在较大差异,且DDH的不同分型间也存在形态差异。研究结果有助于定量了解DDH患者的股骨近端形态特征,为设计适用于DDH患者的新型股骨柄提供参考依据。     

股骨近侧端动脉的分布与吻合

通过动脉灌注,对100侧不同年龄(新生儿～67岁)尸体的股骨近侧端的血液供应进行了研究。囊外动脉环围绕股骨颈基部,由旋股内、外侧动脉组成,完整者占71％;囊内动脉环位于关节软骨缘滑膜下,由内侧、后、外侧和前颈升动脉组成,多见此环前部、后部和前、后部合并缺损,占74％。外骺动脉向关节软骨发出多级动脉弓,分布于股骨头的上、内、中央和外侧区。内侧颈升动脉分布于股骨头下后区。内骺动脉分布于有限的股骨头凹下区。关节软骨游离面由接近关节软骨缘和股骨头凹周缘的滑膜血管网及滑液营养,它的深部近骨—软骨接合处,由骺毛细管襻供给营养。上干骺部动脉分布于股骨颈外2/3,内侧颈升动脉和前、后颈升动脉短支分布于股骨颈相应区。在骺软骨骨化过程中,骺动脉与内侧颈升动脉在骨骺中建立一定的吻合弓。骺软骨板在成年骨化后消失,干骺部动脉穿入骨骺,与骺动脉建立广泛吻合。本文对股骨近侧端动脉的形态、行经、分布及其与临床的意义进行了讨论。     

Delbet Ⅱ型儿童股骨颈骨折不同内固定方式的有限元分析

背景：儿童DelbetⅡ型股骨颈骨折后股骨头坏死率较高,有限元法已广泛应用于研究成人股骨颈骨折内固定后的稳定性,但儿童股骨颈骨折的相关分析较少。目的：研究3种不同内固定方式治疗DelbetⅡ型儿童股骨颈骨折的生物力学性能。方法：选择1例8岁儿童健康志愿者为研究对象。CT扫描患儿股骨近端影像数据导入Mimics 17.0,在Geomagic 14.0,Cero 3.0,Hyper Works13.0中建立3种内固定方式治疗DelbetⅡ型儿童股骨颈骨折的有限元模型,分别为空心钉模型（CS模型）、空心钉联合克氏针模型（CS+K模型）、锁定钢板模型（LP模型）,观察3种模型的内固定应力、骨骺应力及骨折断端相对位移。结果与结论：（1）CS+K模型骨折端和股骨头内的应力显著大于CS模型、LP模型（P <0.001）;LP模型的股骨侧应力显著大于CS+K模型、CS模型（P<0.001）;（2）CS模型的相对位移量显著大于CS+K模型和LP模型（P<0.001）;（3）LP模型的骺板平均应力显著大于CS+K模型、CS模型（P<0.001）;（4）结果表明,空心钉联合克氏针固定...     

Mechanobiological Predictions of Femoral Anteversion in Cerebral Palsy

Many morphological changes occur during development of the proximal femur. The anteversion angle is a measure of the rotation of the neck of the femur around the diaphysis. In normal development anteversion is 30 degrees at birth and decreases to 15 degrees by skeletal maturity. In children with cerebral palsy (CP) anteversion often increases slightly and remains high throughout development. Previous models have proposed that cyclic hydrostatic stress decreases the growth rate while cyclic octahedral shear stress increases the growth rate. In this study we also examine changes in the growth direction caused by deformation of the developing cartilage. Using these mechanobiological principles we considered the influence of mechanical loads on the formation of the anteversion angle in normal and CP development. Loads were applied to a three-dimensional finite element model of the proximal femur. From the resulting stresses and deformations at the growth front we calculated the growth rate and growth direction and simulated the progression of the growth front over 6 months. The model predicted a decrease in anteversion angle (-2 degrees over 6 months) under normal-loading conditions, and an increase in anteversion (+ 1 degrees over 6 months) under CP-loading conditions. These results compare well with observations during skeletalgenesis, in which the anteversion angle decreases rapidly in the first few years of normal growth and may increase in children with CP.     

髋关节发育不良伴股骨前倾角异常增大成人患者联合截骨术的疗效

目的 对比年龄≥30岁伴股骨前倾角异常增大（>40°）髋关节发育不良患者（developmental dysplasia of the hip, DDH）接受髋臼周围截骨术（periacetabular osteotomy, PAO）联合股骨近端去旋转截骨术（derotational osteotomy, PFDO）与单纯PAO的手术效果。方法 选取2012年1月至2020年1月在解放军总医院第四医学中心骨科医学部接受PAO联合PFDO的年龄≥30岁伴股骨前倾角异常增大（>40°）的DDH患者,共计55例,按照接受手术方式不同,分为联合手术组（n=29）和PAO组（n=26）。联合手术组接受PAO联合PFDO治疗,PAO组仅接受PAO治疗。比较两组患者的LCEA、ACEA、T?nnis角术前及术后1年的差异,比较两组患者术前、术后6个月、术后1年及末次随访（>2年）的改良Harris评分和iHot-12评分。结果 共计随访55例患者,随访时间为2年1个月～9年11个月。术后6个月,联合手术组与PAO组的改良Harris评分和iHot-12评分相近（P>0.05）...     

双侧股骨近端对称性及解剖形态的三维重建研究

目的建立正常成人双侧股骨近端的三维模型,分析双侧股骨近端形态并测量解剖形态的相关参数,研究双侧股骨近端的对称性及解剖形态。方法选取50例正常成人双侧股骨近端CT扫描数据,其中男性27例,女性23例;年龄20～65岁,平均年龄44.52岁。扫描参数:扫描层厚0.625 mm,扫描电压120 kV,扫描电流100 mA。扫描范围:自双侧股骨头上10 mm至小转子中点平面下50 mm。将双侧股骨近端CT薄层扫描数据利用Mimics 10.01软件进行三维重建,将左侧股骨与右侧股骨镜像模型相配准,对配准后模型进行三维测量,并测量左右股骨近端的形态参数,使用SPSS 16.0软件对测量结果进行统计分析。结果股骨近端形态和髓腔内部结构有明显的个体差异性,双侧股骨近端形态及内部结构具有高度对称性。股骨头直径为(45.71±4.08)mm,股骨头高度为(53.61±5.43)mm,偏心距为(39.91±5.07)mm,股骨颈中央直径为(36.71±3.75)mm,颈干角为(127.88±6.28)°,股骨颈长度(46.61±4.74)mm,小粗隆中点所在平面的髓腔内径为(26.21±4.59)mm,其中偏心距、颈干角与白种人形态参数相比,差异有显著统计学意义(P<0.01);提供了一种验证双侧股骨对称性的新方法。结论正常成人双侧股骨内外部形态存在一定的对称性,变异较小,为股骨形态的测量提供理论依据;三维重建更利于对股骨近端形态参数的测量;新配准方法的提出对于临床中股骨近端骨折的诊治具有重大意义。     

步态周期中髋关节软骨应力分布对弧形髋臼周围截骨手术的影响

目的 研究在完整步态周期受力环境下髋关节周围软骨的应力分布情况,探求弧形髋臼周围截骨术（curved periacetabular osteotomy, CPO）术中所截骨块的最佳矫正角度,为临床手术提供理论依据。方法 利用CT扫描获取1名髋关节发育不良（development dysplasia of hip, DDH）患者和1名健康志愿者骨盆及股骨近端DICOM数据,构建三维有限元模型。采用划分蒙罩的方法区分皮质骨和松质骨,并为有限元模型赋予材料属性。对DDH模型模拟CPO,调整外侧中心边缘角（lateral center edge angle, LCEA）和前方中心边缘角（anterior center edge angle, ACEA）,共得到100个不同的术后模型。根据完整步态周期中的髋关节受力情况为模型分别施加载荷,分析对比术前、术后和正常髋臼软骨的受力变化。结果 DDH模型模拟术后髋臼软骨在完整步态周期中脚跟落地相、开始单腿支撑相、单腿支撑中期相、单腿支撑结束相、双腿支撑相的最小接触应力峰值分别为5.273、6.128、7.463、6.347、6.582 MPa,分别比术前减少了2.159、2.724、2.249、2.164、2.119 MPa;术后头臼接触面积较术前明显增加,但仍小于正常志愿者。结论 利用有限元方法可以得到LCEA和ACEA的最佳矫正角度,对不同患者模拟CPO手术对提高手术精准度和手术效率具有重要意义。     

髋臼及股骨上端畸形致人工髋关节置换术后脱位原因及对策

目的：分析髋臼及股骨上端畸形致人工髋关节置换(THR)术后脱位的原因，探讨防治对策。方法：本组行全髋置换术172例后发生脱位5例(2．9％)，其中后脱位4例，前脱位1例。发生时间最早在术毕搬动时，最迟在术后第20天。脱位原因分析，4例存在先天性髋臼发育不良，前倾角过小，术中未能调整；1例为股骨上端畸形，假体头臼对合不良。结果：复位后牵引6周1例、髋人字石膏固定6周1例，手术调整前倾角2例、调整股骨假体柄1例，均未发生再脱位。结论：为避免发生脱位，术前CT平扫了解髋臼前倾角和股骨头包容程度，做好特殊假体准备；术中加大加深髋臼以增加臼杯的包容度，并调整股骨头、颈角度来配合对应关系。术中人工髋试活动稳定性良好是减少术后脱位保证。     

A new classification for idiopathic genu vara

PURPOSE: Past classification for the treatment of idiopathic genu vara depended simply on the measurement of distance between the knees, without attention to the rotational profile of the lower extremity. We retrospectively analyzed anatomical causes of idiopathic genu vara. PATIENTS AND METHODS: Twenty eight patients with idiopathic genu vara were included in this study. All patients were surgically treated. To evaluate the angular deformity, a standing orthoroentgenogram was taken and the lateral distal femoral angle and the medial proximal tibial angle were measured. In order to assess any accompanying torsional deformity, both femoral anteversion and tibial external rotation were measured using computerized tomographic scans. A derotational osteotomy was performed at the femur or tibia to correct rotational deformity, and a correctional osteotomy was performed at the tibia to correct angular deformity. RESULTS: Satisfactory functional results were obtained in all cases. Genu vara was divided into 3 groups according to the nature of the deformity; group 1 (6 patients) with increased femoral anteversion, group 2 (10 patients) with proximal tibial varus deformity alone, and group 3 (12 patients) with proximal tibial varus deformity accompanied by increased external tibial rotation. CONCLUSION: The success seen in our cases highlights the importance of an accurate preoperative analysis that accounts for both rotational and angular deformities that may underlie idiopathic genu vara.     

Knee joint changes in patients with neglected developmental hip dysplasia: A prospective case–control study

BackgroundFew reports are available describing knee changes in neglected developmental dysplasia of the hip (DDH). The purpose of this study was to assess the radiographic morphology of knee joints in adults with neglected DDH.MethodsThirty-seven patients (35 females and two males) with neglected DDH were prospectively recruited with an average age of 32.6 years. Twenty-three patients had unilateral and 14 patients had bilateral neglected DDH. Thirty-seven healthy individuals were recruited to form a matched control group. Three groups of knee joints were examined: affected knees (on the same side of the neglected DDH), unaffected knees (contralateral to the neglected DDH in patients with unilateral involvement), and control knees. A series of radiographic parameters of the knee joint were measured in the coronal and sagittal plane, and they were compared between patients and normal controls.ResultsIn the coronal plane, the affected knees had increased valgus angulation related to increased height of the medial femoral condyle, decreased height of the lateral femoral condyle and decreased lateral distal femoral angle compared to control knees. In the sagittal plane, both distal femoral and proximal tibial joints of the affected knees developed a decrease in posterior angles. Additionally, the unaffected knees also developed radiographic changes compared to control knees.ConclusionsPatients with neglected DDH may develop changes in both knee joints. These changes should be considered during surgery to the hip, femur and knee to prevent potential complications.Level of evidenceLevel 2.     

3D femoral neck anteversion measurements based on the posterior femoral plane in ORTHODOC® system

This study provides a robust measuring method of the femoral neck anteversion angle for use in a total hip replacement pre-planning program. The femora of 24 patients (69.3 +/- 6.3 years old) were CT-scanned and converted into three-dimensionally volume-rendered models in ORTHODOC (ISS Inc., CA, USA) which is the pre-planning software for ROBODOC surgery. The Mod.ISS method (the modified ISS method), designed by authors, measures the anteversion angle of the proximal-most femoral neck confluence on the plane perpendicular to the femoral mechanical axis. 3D FNC method proposed by the authors of the present study involves measurement of the anteversion angle of three-dimensional femoral neck center on a plane perpendicular to the posterior femoral plane and parallel to the posterior condylar axis. Here, we found that interobserver reproducibility was 1.8 degrees (SD = 1.3) for the Mod.ISS method and 2.4 (SD = 1.9) for the proposed 3D FNC method. The anteversion angle of the local femoral neck axis was measured as theta = 25.3(L/D) + [corrected] 5.4 in L/D = 0.1-0.6, where L/D is distance (L) from the proximal-most neck confluence along the femoral mechanical axis, normalized with respect to the diameter of the femoral head (D). At L/D = 0.5, the anteversion angle of the femoral neck axis was coincident with the average femoral neck anteversion determined by the 3D FNC method. We conclude that the 3D FNC method is a gold standard for measuring the femoral neck anteversion applicable during both pre-operative and post-operative stages, because its femoral neck center can be determined in three-dimensional space during both stages.     

髋部骨折的发生与股骨近端三维几何解剖形态的相关性研究

目的运用计算机辅助设计(computer aided design,CAD)及三维重建技术测量髋部几何解剖形态学参数,探究骨折人群股骨近端解剖形态与正常组人群(未骨折人群)的差异,分析其对髋部骨折发生率和发生类型的影响。方法通过髋部骨折患者正常侧下肢CT扫描图像,运用Mimics 10.01软件建立三维解剖形态模型,并测量股骨颈前倾角(femoral neck anteversion angle,FNAA)、颈干角(neck-shaft angle,NSA)、股骨头直径(femoral head diam-eter,FHD)及股骨颈轴长(length of femoral neck axis,LFNA)等正常股骨近端三维几何解剖形态学参数。结果股骨颈骨折组中FNAA、NSA、FHD、LFNA平均值为分别为(7.9±4.6)°、(128.6±4.6)°、(46.0±4.6)mm、(47.1±5.1)mm。股骨粗隆间骨折组中FNAA、NSA、FHD、LFNA平均值分别为(15.5±6.8)°、(134.7±6.9)°、(45.3±3.6)mm、(46.7±3.4)mm。股骨粗隆间骨折组FNAA及NSA无论男性还是女性都显著大于股骨颈骨折组(P<0.01),股骨颈骨折组、股骨粗隆间骨折组FNAA和NSA均与正常对照组有非常显著的差异性。结论中国人群FNAA较正常值大越容易发生股骨粗隆间骨折,较正常值小越容易发生股骨颈骨折。髋部骨折患者NSA较正常值大,其中NSA越大越容易发生股骨粗隆间骨折。骨折组人群的股骨近端解剖结构与正常人存在一定的差异,以角度解剖学参数影响为主。年龄越大越容易发生股骨粗隆间骨折,年龄越小越容易发生股骨颈骨折。