青年与老年股骨距的显微结构特征及其临床意义

目的 观察青年、老年股骨距的显微结构。方法 取１８～３０岁青年男性及６０岁以上老年（性别不详）冷藏尸体股骨上段各６根,ＣＴ扫描后,由股骨距起点开始向远端做连续三层股骨截片,每层厚５ｍｍ,对股骨截片先做Ｘ线摄片,然后分别对其中的股骨距进行光镜和扫描电镜观察。结果 在横截面上股骨距分为三个区域：股骨距近端为皮质骨,附着于股骨内侧皮质,主要功能是加强股骨颈根部;中部为疏松皮质骨;而到远端则为松质骨。中远     

股骨距

股骨距（calcar femorale）是位于小转子深部股骨颈、体连接部的内后方的致密骨板，是股骨体后内侧皮质向松质内的延伸。有人把他描述为“真正的股骨颈”。向外放射达臀肌粗隆。为连续性螺旋状板层状结构，是股骨上端偏心性受载的着力点，相当与起重机基梁的基础。直立时承受巨大的压引力。其下极与小转子下方的股骨体后内侧骨皮质融合，沿小转子前外侧垂直向上，上极与股骨颈的后侧皮质融合。     

PFN与DCS治疗股骨转子下骨折的生物力学研究

目的比较PFN和DCS固定股骨转子下骨折的生物力学性能。方法成年男性新鲜尸体股骨6对,每对标本随机分成PFN和DCS固定组,先后模拟SeinsheimerⅠ型骨折、ⅢA型骨折恢复内侧皮质完整、ⅢA型骨折移除内侧皮质。在生物力学实验机上予垂直载荷,测定抗压载荷及股骨近端应变分布情况。结果PFN对股骨的正常生理应力分布的干扰较DCS明显。两组刚度差异不明显,仅在ⅢA型骨折移除内侧皮质标本PFN的刚度明显高于DCS(P<0.05)。两者均能提供较强的极限载荷,PFN组高于DCS组(P<0.05)。结论对于SeinsheimerⅠ型骨折,PFN与DCS均可作为较好的内固定物选择。在ⅢA型骨折,PFN生物力学特性要明显优于DCS,尤其是内侧皮质复位不佳者。术后功能锻炼时,两者均要采取保护性的功能锻炼方法。     

股骨转子间骨折治疗中前内侧皮质正性支撑复位的研究进展

目的介绍股骨转子间骨折内固定治疗中的前内侧皮质支撑复位理念,总结其历史、特征、生物力学及临床应用研究进展,提出存在的问题并展望研究方向。方法查阅近年来国内外针对股骨转子间骨折正性皮质支撑复位的相关研究,结合临床应用经验进行归纳总结。结果股骨转子间骨折的前内侧皮质正性支撑复位,作为一种稳定的非解剖骨折复位技术,具有力学结构支撑和生物学促进愈合的双重效果。皮质支撑复位对医生来说并不增加手术操作难度,对患者而言股骨颈长度丢失少,颈干角内翻发生率低,骨盆的正常力学结构得以维持,术后器械相关并发症发生率低,肢体功能评分高。内侧皮质支撑的力学性能高于前侧皮质支撑,当两者均达到正性对位时骨折稳定性最佳。结论前内侧皮质支撑复位能分担内固定器械的力学载荷,提高股骨转子间骨折内固定术后稳定性,作为一种功能复位形式,可作为解剖复位之外的次选。     

股骨干骨折并内侧皮质缺损重建的生物力学研究

目的 采用同种异体骨板重建股骨干内侧皮质缺损并进行生物力学评价。方法 6具新鲜股骨标本,在内侧造成皮质缺损后,测定正常股骨组(对照组),钢板固定组(实验组1),钢板加骨板固定组(实验组2),钢板加骨板加内侧骨块复位组(实验组3)的垂直压缩,三点弯曲及抗扭转能力,比较不同内固定方法在相同载荷下的位移。结果 本实验三项指标间,对照组和实验组3间的垂直压缩、三点弯曲间无显著性差异(P>0.05),与实验组1、2间有显著性差异(P<0.05),旋转角度间均有显著性差异(P<0.05)。压力侧骨缺损单纯用钢板内固定效果最差,而用异体骨板加钢板固定强度明显优于单纯钢板固定,骨块复位加骨板、钢板固定优于单纯骨板及钢板固定。结论 应用异体骨板重建股骨干内侧皮质缺损,可较好的恢复股骨干内侧皮质的完整性,增加钢板内固定的成功率,值得在临床上推广应用。     

动力髋螺钉固定股骨转子间骨折的有限元分析

目的研究后内侧骨折块对股骨转子间骨折动力髋螺钉(DHS)固定后的生物力学影响。方法利用股骨CT数据建立一组股骨近端的三维有限元模型,在此基础上制作股骨转子间骨折累及小转子和内侧骨皮质的骨折模型,对骨折模型进行DHS固定,并对DHS固定模型进行有限元分析。结果股骨转子间骨折累及单纯小转子骨折后,股骨内侧皮质应力和外侧DHS钢板所承受的应力大小无明显变化。当累及1/2内侧皮质时,内侧应力升高约28%,外侧DHS钢板所承受的应力升高约9%;当内侧皮质完全累及时,前内侧皮质的交界处应力升高约125%,外侧DHS钢板所承受的应力升高约96%。结论股骨转子间骨折伴单纯小转子骨折可以不予固定;而当内侧皮质累及时,无论是累及1/2还是累及全部内侧骨皮质,均需复位固定后内侧骨皮质。     

有限元法分析后内侧骨折对近端股骨的力学影响

[目的]研究后内侧骨折对近端股骨的生物力学影响。[方法]利用CT扫描图像建立高度仿真的完整近端股骨的三维有限元模型,并在此基础上建立累及小粗隆和内侧皮质的后内侧骨折模型,并对模型进行有限元分析。[结果]后内侧骨折后股骨最大应力出现在骨折缺损的前内侧。单独小粗隆骨折后股骨颈上下、内外侧皮质应力无明显变化;骨折累及1/2内侧皮质后,内侧皮质最大等效应力显著升高约47%,外侧皮质应力升高约12%;内侧皮质完全累及时,内侧皮质应力升高约247%,外侧升高约66%。[结论]不同大小的后内侧骨折块对近端股骨的应力大小及分布影响不同。从力学角度考虑,用动力髋螺钉治疗粗隆间骨折时,可根据后内侧骨折块大小作适当处理。     

腓肠肌内侧头动力重建后交叉韧带3例报告

我院自1988年5月以来,利用腓肠肌内侧头对3例陈旧性后交叉韧带断裂患者进行动力重建,效果满意,报告如下.手术方法在气囊止血带下操作,患侧膝关节呈半屈并外旋,做膝后内侧切口:(1)牵开股内侧肌、半膜半腱肌、显露腓肠肌内侧头并游离至股骨内髁后附着部,将内侧头纵向劈开内外两部分,于附着部切取外侧部分,向远端游离约4cm.(2)切开后关节囊,将骨膜剥离器安放于股骨内髁之髁间凹外侧面,以保护腘血管及神经不受损伤,自股骨内髁内侧面偏后距关节面0.5cm外垂直向外侧面(即后交叉韧带附着处)钻一较粗隧道(直径约0.6cm)并于内口旁钻一小孔与隧     

膝内侧隐血管为蒂的胫骨中上段骨膜瓣移位修复股骨髁上骨不连

目的 报道膝内侧隐血管为蒂的胫骨中、上段骨膜瓣修复股骨髁上骨不连的疗效和方法.方法对 于7例股骨倒打髓内钉及2例解剖钢板螺钉、2例DCS内固定的股骨髁上骨折手术后并发骨不连病例,保留原内固定采用同侧膝内侧隐血管为蒂的胫骨中上段内侧骨膜瓣移位包绕修复骨不连部.其中3例同时携带部分胫骨嵌入骨缺损部. 结果 11例骨不连2～4个月骨性愈合,平均3个月,术后膝关节伸0°-屈120°～ 135°. 结论 膝内侧隐血管为蒂的胫骨骨膜瓣解剖恒定,血运可靠,切取方便,成骨效果好,是修复股骨髁上骨不连的有效方法,且由于不必重新内固定故治疗费用低廉.     

丝线环扎致儿童股骨再骨折一例报告

患儿女,１０岁,身高１２０ｃｍ,体重２１ｋｇ。于１９９７年１月２５日不慎摔伤左下肢,Ｘ线检查显示左股骨干粉碎性骨折图１。于１９９７年１月２８日在当地医院行梅花形髓内钉内固定术,并以双７号丝线环行捆扎螺旋形骨折的远侧和内侧骨折块,术中对局部骨膜特别是内侧骨膜未给予环行剥离。术后切口一期愈合。伤后３个月,Ｘ线片复查显示,骨折线模糊,但其远侧即丝线环扎处外侧皮质骨上可见小凹陷。伤后８个月,股骨外侧皮质凹陷加深,可达骨皮质的１／５。至伤后１２个月,Ｘ线片显示骨折线消失,但股骨外侧皮质凹陷更加明显深度近骨…     

Proximal strain distribution in the loaded femur. An in vitro comparison of the distributions in the intact femur and after insertion of different hip-replacement femoral components

The distribution of strain in the proximal part of loaded cadaver femora was measured in vitro using strain gauges applied to the cortex. The loading conditions simulated single-limb stance and the strains were recorded first with the femora intact and then with the femoral components of six different designs inserted. Each femur served as its own control. After insertion of a femoral component, the pattern of strain in the proximal part of the femur was reversed compared with that in the intact femur, in that the maximum strain occurred around the tip of the prosthesis rather than at the calcar femorale. A massive decrease in stress in the region of the calcar femorale was found when the implants were in place, and it was concluded that this decrease could contribute substantially to the calcar femorale resorption sometimes observed in patients after total hip replacement. Transfer of load directly to the calcar femorale through a larger collar in direct contact with the cortical bone restored 30 to 40 per cent of the normal strain to the calcar femorale and shifted the strain pattern toward normal. Compared with the less stiff stems tested, the larger, stiffer stems, which provide more protection against fatigue failure, did not affect the strain pattern adversely.     

The role of the calcar femorale in stress distribution in the proximal femur

Objective: To investigate the role of the calcar femorale in stress distribution in the proximal femur. Methods: Twenty‐five specimens of proximal femurs were fixed to simulate single‐limb stance. Strain gauges were applied to record the strain under different loads. Strain values of 27 selected sites in the proximal femur were recorded and analyzed at the level of 100 N, 200 N, 300 N, 400 N, 500 N, 600 N and 700 N, respectively before and after disruption of the calcar femorale. Results: When a normal load was being borne, strain values measured in the posterior and medial aspects of the proximal femur were greater than those measured in the anterior and lateral aspects, no matter whether the calcar femorale was disrupted or not. However after disruption of the calcar femorale, strain values in the posterior and medial aspects of the proximal femur increased significantly, whereas those of the anterior and lateral aspects decreased significantly. Conclusion: The calcar femorale redistributes stress in the proximal femur by decreasing the load in the posterior and medial aspects and increasing the load in the anterior and lateral aspects.     

The calcar femorale in cemented stem fixation in total hip arthroplasty

The calcar femorale is a vertical plate of bone lying deep to the lesser trochanter and is formed as a result of traction of the iliopsoas which separates the femoral cortex into two distinct layers, the calcar femorale and the medial femoral cortex. They fuse together proximally to form the medial femoral neck. A stem placed centrally will abut against the calcar femorale with little or no space for cement. Clearing of the calcar will offer space for a cement layer, which will support the stem proximally on the posterior aspect. We compared two consecutive groups of Charnley low-friction arthroplasties, with and without clearing of the calcar. In 330 patients who had an arthroplasty without clearing the calcar, there were ten revisions for aseptic loosening of the stem and six other stems were considered 'definitely loose', giving a rate of failure of 4.8%. In 111 patients in whom the calcar was cleared there was only one revision for aseptic loosening and no stems were classed as 'definitely loose', giving a rate of failure of 0.9%. Survivorship analysis has again shown the need for long-term follow-up; the differences became clear after ten years but because of the relatively small numbers, statistical analysis is not yet applicable. We now clear the calcar femorale routinely and advocate optimal access to the medullary canal and insertion of the stem in the area of the piriform fossa.     

Morphological analysis of the proximal femur using quantitative computed tomography

The anatomy of the proximal femur was studied in 35 specimens using quantitative computed tomography (QCT) and compared with anatomical sections studied by plane radiography and gross dissection. We found the primary supporting structure of the femoral head to be the primary compressive strut, which is a dense column of trabecular bone projecting from the pressure buttress of the medial femoral neck to the epiphyseal scar. Trabecular bone mushroomed from the epiphyseal scar and terminated at right angles to the cortex of the femoral head. We believe the primary compressive strut is the predominant load-bearing structure connecting the femoral head to the femoral neck, as many specimens lacked continuity of the head cortex to the femoral neck. Based on the CT number, the primary compressive strut had similar bone density to cortical structures such as the lesser trochanter, calcar femorale and posterior lateral femoral cortex. Ward's triangle lacked structural integrity in many cases, and we doubt the significance of tensile trabculae for sharing load. Surgical techniques such as femoral fracture fixation, resurfacing hip arthroplasty and allograft transplantation may benefit from this knowledge.     

Anatomically adapted endoprosthesis of the proximal end of the femur

The marrow-cavities of several human femora were cleaned and filled with plastics; the femoral component design was developed based on these moulds. Different sizes of the stem were obtained by scaling down the biggest mould in steps of 10%. The stem has an oval cross-section and is twisted similar to the form of the marrow-cavity; therefore different designs for the left and right femur are necessary. As the marrow-cavity of the femur tapers down to the middle of the shaft the length of the prosthetic stem cannot be selected arbitrarily. The stem must end above the narrowest site of the cavity. Data are presented. To avoid disadvantageous frictional stresses between the collar of the prosthesis and the plane of resection of the femoral neck both must be aligned perpendicular to the most common direction of the load of the hip joint. Therefore a step-like osteotomy of the femoral neck becomes necessary without disturbing the calcar femorale instead of an inclined osteotomy. A firm contact between the femoral wall and the collar, which forms an angle of 64 degrees with the axis of the femoral shaft, guarantees that only small frictional stresses occur between collar and femoral cortex if the load of the hip joint varies within the physiological range. A set of ceramic femoral heads with three different conical borings yield different lengths of the neck of the prosthesis. Independent of which femoral head and which size of prosthesis are chosen the direction of the maximum hip load in any case thrusts the contact area between collar and femoral wall. Thus dangerous tilting moments round the medial calcar femorale do not occur, the incidence of a fracture of the prosthesis shaft is therefore reduced. After implantation of the anatomically designed femoral component both remodeling and resorption of the calcar femorale are observed. This reaction is independent of the kind of fixation, i.e. if a smooth stem was fixed with cement or a stem with a porous, cancellous bone-like metallic surface was implanted without cement fixation.(ABSTRACT TRUNCATED AT 250 WORDS)     

Ideal screw positions for multiple screw fixation in femoral neck fractures – Study of proximal femur morphology in a Japanese population

Background

Despite the fact that multiple screw fixation is a common option of surgical treatment for femoral neck fractures, there is a paucity of precise morphological study of the femoral neck. To identify appropriate positions and spacing of hip screws for multiple-screw femoral neck fracture fixation, proximal femur morphology in Japanese patients was studied.

Bone Mass and Structure at the Hip in Men and Women over the Age of 60 Years

Bone mass and structure at the proximal femur are important predictors of hip fracture. The aims of this study were to compare in a large sample of elderly men and women the precision of measurements of bone mass and structure at multiple sites at the proximal femur, to examine their interrelationships, to establish their relationships with age and body size, and to examine criteria for defining geometric and architectural variables in bone structure. Women (n= 336) and men (n= 141) over the age of 60 years were studied cross-sectionally. Bone mineral density (BMD) and content (BMC) at the proximal femur were measured in duplicate by dual-energy X-ray absorptiometry (DXA). Shaft and total upper femur (hip) sites in addition to femoral neck, Ward's triangle and trochanter were measured. Structural variables, measured from radiographs and from DXA images, including cortical thickness at calcar femorale, lateral cortex and mid-femur, width of the femur and medulla, Singh grade, hip and femoral axis length, femoral head and neck width and the center of mass of the femoral neck. BMD and BMC had high reproducibility and there were significant differences in reproducibility across sites. Among sites, total upper femur and shaft had the highest reproducibility. Duplicate measurements substantially improved reliability of the measurement and are recommended when the value is close to a diagnostic level or when it will be used to establish rates of change. Reproducibility of structural variables was also high except for the lateral cortex, center of mass and Singh grade. Variance due to measurement error did not change with either age or gender. Women were significantly different from men, after controlling for differences in body size, in all variables except Singh grade and medulla width. BMD and BMC were negatively related to age and positively to body size. Structural variables examined in relation to age and body size fell into two categories. The first comprised variables that were not age-related but were body-size-related, suggesting that they could be classified as geometric variables. The second comprised variables that were both body-size-related and age-related, suggesting that they could be classified as architectural variables. Using these criteria, calcar and lateral cortex were architectural variables, whereas shaft width, hip and femoral axis length, femoral head and neck width, and center of mass were geometric in both men and women. In women, shaft cortex width and medulla width were age-related, whereas in men they were not. Singh grade showed no consistent pattern with age or body size in women and men. Received: 7 January 1997 / Accepted: 7 November 1997     

全髋关节置换前后股骨应力变化的有限元分析

目的:研究Chamley Elite骨水泥型和Summit近端多孔非骨水泥型股骨假体置换后股骨总体应力以及假体周围骨质区应力分布的变化。方法:根据Charnley Elite骨水泥柄和Summit非骨水泥柄假体形态建立三维有限元模型，并加载关节合力以及相关肌肉的肌力负荷，分析假体植入前后股骨总体应力模式并对股骨近端假体周围区域骨质应力分布进行分区量化研究。结果:两种假体植入后没有改变股骨总体的应力模式，应力峰值区域均位于全长股骨的中下段，但股骨应力峰值有所下降。股骨近端假体周围骨质等效应力水平出现了显著下降，下降最严重的区域为近段内侧象限即股骨距区，应力遮挡率分别达90．8％和95．3％；向假体远端应力水平逐渐增大，直至假体远段和末段水平应力值逐渐恢复并接近生理水平。就该两种不同固定方式的假体比较而言，引起的应力遮挡区域分布基本一致，应力下降程度Summit近端多孔非骨水泥型假体要高于Charnley Elite骨水泥型假体。结论:两种假体植入后均在股骨近端形成显著的应力遮挡，假体周围骨质应力大小和分布的改变是引起术后骨量丢失和假体松动的原因之一，也是术后股骨骨折发生的类型以术后肢体疼痛发生的力学基础。两种固定方式的假体均需通过进一步改进以减少应力遮挡。     

Computerized tomography of proximal femoral trabecular patterns

A comprehensive imaging and pathologic investigation utilizing patients and cadaver material was performed in order to identify the normal trabecular pattern of the proximal femur and to assess alterations in this pattern in various disorders. Patients and specimens were studied with computed tomography (CT), including three-dimensional CT image reconstruction in selected cases and plain film radiography. The CT imaging of the proximal femur provides insight into the dynamic state of bone in this region. Despite limited resolution, three-dimensional CT image reconstruction is capable of portraying the concentration and orientation of major trabeculae in the proximal femur. Increased trabecular spacing occurs in osteoporosis and is well depicted by CT. Proliferation and thickening of the most superior subchondral primary compressive trabeculae is an early sign of osteoarthritis. In the region of the calcar femorale, crossing trabeculae, similar to the appearance of an enchondroma or bone infarct, have been described in osteoporosis and osteoarthritis and probably represent unmasking of normally present reinforcing trabeculae. In ischemic necrosis, CT should be considered a useful modality for detection of early or mild alterations and may be valuable in treatment planning.