下颈椎椎弓根入口内壁探测法行根钉置入的可行性研究

目的：评价椎弓根入口内壁探测法行新鲜下颈椎椎弓根钉置入的可行性。方法：采用6具新鲜成人尸体下颈椎的60侧椎弓根。在下关节突下缘的外1／4处咬除后方骨皮质，形成大小约5mm开口；刮勺内倾50°刮除开口内侧松质骨达椎板前皮质，转向外探明椎弓根入口，用直径3mm探针以椎弓根内壁为参照钻孔。DR拍片、CT扫描观察钉道准确性。结果：DR片可满意观察钉道矢状面。CT示54侧钉道完全在髓腔内（90％），3侧椎弓根外皮质部分胀开，2侧外皮质胀破并移位，1侧髓腔闭塞，钉道进入横突孔。结论：入口内壁探测法行下颈椎椎弓根钉置入效果满意。     

自体浓缩骨髓移植促进腱骨愈合

背景：前交叉韧带断裂后应用自体腘绳肌腱移植进行重建应用较多,腱-骨愈合的时间较长,限制了患者交叉韧带重建后早期的功能活动。 目的：用浓缩自体骨髓植于前交叉韧带重建腱-骨界面,观察其界面愈合情况。 方法：32只新西兰大白兔行双侧膝关节半腱肌肌腱前交叉韧带重建,随机选取一侧膝关节作为实验组,胫骨侧腱骨界面植入自体浓缩骨髓,对侧不植入作为对照组。 结果与结论：组织学显示,前交叉韧带重建后2周对照组移植肌腱与骨隧道的界面由肉芽组织填充,连接组织松散,有成骨活动;实验组移植肌腱与骨隧道界面肉芽组织连接亦不紧密,骨隧道侧成骨活动较活跃。前交叉韧带重建后12周对照组腱骨结合部组织界面变模糊,可见胶原纤维-纤维软骨-钙化的软骨组织-骨组织的移行带改变;实验组显示明显的胶原纤维-纤维软骨-钙化的软骨组织-骨组织的移行带改变,潮线清晰。前交叉韧带重建后4,8,12周,实验组最大抗拉脱强度数值显著大于对照组(P < 0.05)。提示自体浓缩骨髓可以增强腱骨界面的抗拉伸强度,有利于腱-骨界的组织愈合。     

单髁膝关节置换胫骨元件不同固定柱形状的有限元分析

目的针对单髁膝关节置换后胫骨前内侧疼痛、胫骨元件松动以及对侧关节炎恶化的问题,通过有限元方法比较分析胫骨元件固定柱的不同几何形状对胫骨应力分布的影响。方法建立有效的单髁膝关节置换有限元模型,对胫骨元件固定柱的形状进行设计。在相同的加载条件下,分别对双柱形、单脊形、双脊形和十字星形胫骨元件进行有限元分析,并与完整膝关节模型进行对比,评估胫骨元件固定柱不同形状设计对胫骨前内侧皮质骨应力、胫骨截骨面松质骨应力、胫骨对侧软骨应力的影响。结果单髁置换后胫骨前内侧皮质骨应力峰值均增大。与完整膝关节相比,在双柱形、单脊形、双脊形和十字星形胫骨元件固定柱的模型中,胫骨前内侧皮质骨应力峰值分别增加56.1%、55.9%、54.5%和68.4%。单脊形和双脊形胫骨元件松质骨截骨面应力峰值比完整胫骨分别减小8.1%和15.6%,而双柱形和十字星形则分别增大67.9%和121.5%,超过松质骨的疲劳屈服应力。双柱形、单脊形、双脊形和十字星形胫骨固定柱对应的胫骨对侧软骨应力峰值相比于完整胫骨分别减小42.1%、26.6%、24.2%和28.5%。结论单髁膝关节置换改变了胫骨内外侧的载荷分布,使置换侧承受更大的载荷。单脊形和双脊形胫骨元件在降低胫骨前内侧皮质骨和截骨面松质骨应力方面效果更好,其中单脊形胫骨元件更接近完整膝关节胫骨的应力分布。研究结果可为设计更符合膝关节力学性能的单髁膝关节假体提供理论依据。     

锁定加压钢板置入内固定治疗胫骨骨折的力学分析

背景：锁定加压钢板结合了传统钢板和支架原理,即头部有锁定螺纹的螺钉和钢板锁钉孔构成的内固定支架锁定单元,又有传统螺钉和动力加压孔构成的内固定支架加压单元,在骨折的内固定治疗方面具有很多优势。 目的：分析锁定加压钢板置入内固定治疗胫骨骨折的生物力学特点,以及在胫骨骨折治疗中的疗效。 方法：锁定加压钢板是依靠钢板与螺钉的成角稳定性和螺钉与骨之间的把持力来实现骨折内固定的。骨髓腔细小时应避免螺钉尖端损伤近端皮质的骨螺纹,应更换为双皮质自攻螺钉至少在对侧骨皮质获得把持力。骨质疏松植入螺钉,由于单皮质骨螺钉产生的工作长度减少,在所有骨折块均使用双皮质自攻螺钉,以提高螺钉工作长度。当长骨轴线与钢板对线不良时,要么打入长自攻螺钉,要么改变角度打入标准螺钉。锁定加压钢板应选择适宜的长度,钢板的长度取决钢板跨越比和钢板螺钉密度,钢板与螺钉间的应力还受螺钉数量和位置的影响。 结果与结论：锁定加压钢板置入内固定可应用于骨干或干骺端的简单骨折、粉碎性骨折、关节内及关节周围骨折、骨折延迟愈合、闭合或开放截骨术和不适合髓内钉固定的骨干骨折,对于骨质疏松骨折和假体周围骨折的内固定有很好的成角稳定性和把持力。锁定加压钢板置入内固定治疗胫骨骨干骨折均取得满意的疗效,符合生物力学固定原理。需要术者熟练掌握锁定加压钢板的内固定技术,避免由于失误导致内固定的失败。     

胫后血管肌间隙支胫骨内侧骨膜瓣移位术的应用解剖

目的：为胫后血管肌间隙支胫骨内侧骨膜瓣修复胫骨中、下段骨折、骨不连提供解剖学基础。方法：４０侧经动脉内灌注红色乳胶的成人下肢标本，观测胫骨内侧面骨膜血管来源、走行、分支分布及其吻合。结果：胫后动脉发肌间隙支２～７支，平均每侧２．２支，外径１．１±０．２ｍｍ。肌间隙主分出升支、降支，分布胫骨内侧中、下段骨膜，形成骨膜动脉网。结论：以胫后血管肌间隙支为蒂设计胫骨内侧骨膜瓣，可修复胚骨中、下段骨不连，已应用于临床。     

小儿胫骨皮质的血液供应

本文采用血管灌注、显微镜观察骨切片的方法,研究了40侧小儿胫骨皮质的血液供应。骨皮质血管主要由毛细血管和静脉窦组成。二者粗细不等,相互吻合成网。滋养动脉是骨皮质的主要血供来源,供应骨皮质深层的3/4左右。骨皮质浅层由骨膜动脉供应。两组血供来源在骨皮质内有广泛吻合。小儿胫骨皮质血管由骨干中部向两侧干骺端呈放射状分布。骨皮质的静脉血主要经皮质窦回流到骨髓静脉内。     

体力载荷对废用性兔胫骨超微结构和力量性能的影响

成年健康家兔26只,雌雄各半,单侧后肢用石膏管型固定六周.去固定后分四组.废用组兔胫骨皮质出现骨质疏松,骨胶原受累,暴露了骨单位的轮廓.去固定后四周,骨皮质代谢活跃,积极重建;在此基础上兔接受低强慢跑八周,骨髓腔壁有一厚层纤维骨板及类骨质,骨小梁数量少,线应变值未恢复.成年兔胫骨在体力活动影响下,以骨内膜成骨为主要方式.     

跟骨内侧定位载距突螺钉导向器的研制与初步评价

目的　探讨从跟骨内侧定位、经载距突置入导向针后,由跟骨外侧壁置入载距突螺钉的可行性及精确度,为临床手术方案设计及导向器械的研发改进提供参考依据。 方法　选取10具20侧成人尸体标本,在跟骨外侧做“L”形延长切口,暴露跟骨外侧结构及距下关节,采用自主研发的“跟骨内侧定位载距突螺钉导向器”辅助载距突螺钉置入。首先,从内侧将“定位针”置入距下中关节,将导向器“内侧臂”的“定位孔”套牢定位针,调整“内侧臂”使“导向通道”位于载距突中心,安装“外侧臂”与“手柄”固定。调整“外侧臂”位置,经“导向通道”从内向外穿入跟骨一枚“导向针”,C臂透视提示“导向针”位置理想后,自跟骨外侧壁沿“导向针”用空心钻钻孔,测深后拧入合适的载距突螺钉。最后行CT扫描,利用CT图像评估置入螺钉的精确度。过程中采集相关数据,评估导向器的功能。 结果　肉眼观察标本,所有的导向针位于载距突内,其中65%位于载距突中心,25%偏下方,10%偏后方。在内侧,75%的导向针穿过胫后肌腱,15%位于胫后肌和趾长屈肌腱之间,10%穿经趾长屈肌腱上1/3。在外侧,导向针出针点与跟骰关节的距离为（38.03±5.60）mm,与后关节面的距离为（15.01±3.38）mm,螺钉平均长度为（44.80±3.59）mm。CT扫描图像可见,所有螺钉位于载距突内,有2例穿透上方骨皮质,无螺钉穿出载距突下方、前方及后方骨皮质。 结论　采用跟骨内侧定位法,在自主设计的导向器引导下,可提高载距突螺钉置入的准确性,降低螺钉进入关节、跟骨内侧皮质等并发症。     

跟骨内侧定位载距突螺钉导向器的研制与初步评价

目的　探讨从跟骨内侧定位、经载距突置入导向针后,由跟骨外侧壁置入载距突螺钉的可行性及精确度,为临床手术方案设计及导向器械的研发改进提供参考依据。 方法　选取10具20侧成人尸体标本,在跟骨外侧做“L”形延长切口,暴露跟骨外侧结构及距下关节,采用自主研发的“跟骨内侧定位载距突螺钉导向器”辅助载距突螺钉置入。首先,从内侧将“定位针”置入距下中关节,将导向器“内侧臂”的“定位孔”套牢定位针,调整“内侧臂”使“导向通道”位于载距突中心,安装“外侧臂”与“手柄”固定。调整“外侧臂”位置,经“导向通道”从内向外穿入跟骨一枚“导向针”,C臂透视提示“导向针”位置理想后,自跟骨外侧壁沿“导向针”用空心钻钻孔,测深后拧入合适的载距突螺钉。最后行CT扫描,利用CT图像评估置入螺钉的精确度。过程中采集相关数据,评估导向器的功能。 结果　肉眼观察标本,所有的导向针位于载距突内,其中65%位于载距突中心,25%偏下方,10%偏后方。在内侧,75%的导向针穿过胫后肌腱,15%位于胫后肌和趾长屈肌腱之间,10%穿经趾长屈肌腱上1/3。在外侧,导向针出针点与跟骰关节的距离为（38.03±5.60）mm,与后关节面的距离为（15.01±3.38）mm,螺钉平均长度为（44.80±3.59）mm。CT扫描图像可见,所有螺钉位于载距突内,有2例穿透上方骨皮质,无螺钉穿出载距突下方、前方及后方骨皮质。 结论　采用跟骨内侧定位法,在自主设计的导向器引导下,可提高载距突螺钉置入的准确性,降低螺钉进入关节、跟骨内侧皮质等并发症。     

杜仲醇提取物对兔下颌牵张成骨的影响

背景：目前牵张成骨由于治疗周期长、并发症较多成为临床广泛运用的瓶颈,不能满足临床推广需要。 目的：以兔下颌骨牵张动物模型为实验平台,观察全身运用杜仲醇提取物对牵张新骨再生的影响。 方法：24只新西兰大白兔随机均分为对照组及实验组,建立兔下颌单侧牵张模型,牵张速率为每12 h 1 mm。在牵张期2次/d,实验组及对照组分别予以灌胃杜仲醇提取物及等量生理盐水,牵张结束后6周处死动物收集标本行成骨检测。 结果与结论：两组动物牵张间隙内均可观察到新骨生成。牵张成骨结束后6周下颌骨CT图像显示实验组兔牵张间隙舌侧骨皮质生成良好,颊侧骨皮质连续,牵张间隙可见均匀骨质生成桥接;下颌骨核素扫描显示实验组兔下颌骨牵张间隙表现为核浓集,强度明显强于对照组;X射线显示实验组牵张间隙完全桥接,新生成骨质密度均匀,可见上下侧骨皮质形成良好;Micro-CT图像显示实验组骨皮质部分形成较好,骨小梁分布较为均匀,骨小梁明显较对照组粗壮,对照组部分区域仍有囊性变;Micro-CT微结构参数检测显示实验组骨体积分数、骨小梁厚度、骨小梁数量和连接密度均显著高于对照组;组织学观察显示与对照组比较,实验组牵张间隙中有较为成熟的束状骨,骨小梁方向较为规律。实验结果显示全身运用杜仲醇提取物可有效促进兔下颌快速骨牵张的新骨再生。     

冷冻、冻干、辐照对用于脊柱融合的胫骨皮质骨力学性能的影响

目的研究冷冻、冻干及辐照处理方法对胫骨皮质骨抗压强度和硬度的影响,探讨适合的胫骨皮质骨处理方法。方法收取外伤截肢的胫骨干中段皮质骨,将其加工成大小约10 mm×10 mm×5 mm的皮质骨板,并随机平均分为7组:正常组(A组)、深冻组(B组)、冻干组(C组)、冷冻+~(60)Co辐照(25 J/g)组(D组)、冷冻+~(60)Co辐照(50 J/g)组(E组)、冻干+~(60)Co辐照(25 J/g)(F组)、冻干+~(60)Co辐照(50 J/g)组(G组)。应用生物材料试验机分别对不同处理方法的同种皮质骨进行抗压强度和硬度测试。结果胫骨皮质骨的最大抗压强度为6.089~9.089 k N。与A组比较,B、C、D、F组胫骨皮质骨的抗压强度无明显区别(P0.05),B、C组硬度无明显区别(P0.05),但D、F组硬度分别减少9.6%(P0.05)和8.7%(P0.05);E、G组与A组比较,抗压强度分别减少29.6%(P0.05)和33.1%(P0.05),硬度分别减少16.7%(P0.05)和14.8%(P0.05)。结论对胫骨皮质骨进行冷冻、冻干处理时,抗压强度及硬度较无处理组无明显变化。与无处理组比较,冷冻后或冻干后接受小剂量60Co辐照时胫骨皮质骨的抗压强度无明显变化,但硬度有一定降低;大剂量60Co辐照时,抗压强度及硬度均有明显降低。在应用同种皮质骨融合支架行椎间融合时,辐照灭菌剂量应控制在15~25 J/g。     

Structural analysis of the human tibia by tomographic (pQCT) serial scans

This study analyses the evaluation of tomographic indicators of tibia structure, assuming that the usual loading pattern shifts from uniaxial compression close to the heel to a combined compression, torsion and bending scheme towards the knee. To this end, pQCT scans were obtained at 5% intervals of the tibia length (S5–S95 sites from heel to knee) in healthy men and women (10/10) aged 20–40 years. Indicators of bone mass [cortical area, cortical/total bone mineral content (BMC)], diaphyseal design (peri/endosteal perimeters, cortical thickness, circularity, bending/torsion moments of inertia – CSMIs), and material quality [(cortical vBMD (bone mineral density)] were determined. The longitudinal patterns of variation of these measures were similar between genders, but male values were always higher except for cortical vBMD. Expression of BMC data as percentages of the minimal values obtained along the bone eliminated those differences. The correlative variations in cortical area, BMC and thickness, periosteal perimeter and CSMIs along the bone showed that cortical bone mass was predominantly associated with cortical thickness toward the mid‐diaphysis, and with bone diameter and CSMIs moving more proximally. Positive relationships between CSMIs (y) and total BMC (x) showed men’s values shifting to the upper‐right region of the graph and women’s values shifting to the lower‐left region. Total BMC decayed about 33% from S5 to S15 (where minimum total BMC and CSMI values and variances and maximum circularity were observed) and increased until S45, reaching the original S5 value at S40. The observed gender‐related differences reflected the natural allometric relationships. However, the data also suggested that men distribute their available cortical mass more efficiently than women. The minimum amount and variance of mass indicators and CSMIs, and the largest circularity observed at S15 reflected the assumed adaptation to compression pattern at that level. The increase in CSMIs (successively for torsion, A–P bending, and lateral bending), the decrease in circularity values and the changes in cortical thickness and periosteal perimeter toward the knee described the progressive adaptation to increasing torsion and bending stresses. In agreement with the biomechanical background, the described relationships: (i) identify the sites at which some changes in tibial stresses and diaphyseal structure take place, possibly associated with fracture incidence; (ii) allow prediction of mass indicators at any site from single determinations; (iii) establish the proportionality between the total bone mass at regions with highly predominant trabecular and cortical bone of the same individual, suitable for a specific evaluation of changes in trabecular mass; and (iv) evaluate the ability of bone tissue to self‐distribute the available cortical bone according to specific stress patterns, avoiding many anthropometric and gender‐derived influences.     

Low amplitude, high frequency strains imposed by electrically stimulated skeletal muscle retards the development of osteopenia in the tibiae of hindlimb suspended rats

The purpose of this study was to determine the extent to which high frequency, low amplitude skeletal muscle contractions, induced using electrical stimulation, could prevent or retard disuse osteopenia. Ten minutes of 30 Hz electrical stimulation was delivered, 5 days a week, during a 4 week rat-hindlimb suspension protocol. Each pulse generated a peak compressive dynamic strain on the tibia of approximately 200 microepsilon. We hypothesized that the electrical stimulation protocol would significantly reduce the loss of tibial bone mineral density compared to the contralateral control tibia that did not receive electrical stimulation. Compared to the contralateral control limb, the tibia of the stimulated limb had significantly higher bone mineral density and enhanced newly formed bone in the tibial diaphysis. The diaphysis, specifically the posterior bone cortex, of the tibia of the limb receiving the stimulation also demonstrated substantially larger mineral-binding fluorochrome biomarker within the osteocyte lacunae and canalicular volumes. Although the protocol did not prevent disuse osteopenia the evidence suggests that it was effective at reducing the extent of the osteopenia. One possibility for this outcome may be the insensitivity of bone to static, compared to dynamic compressive loads. In the present study there was a considerable static component to the compressive loads that accounted for a large component of the peak load generated by the stimulated skeletal muscle. Nevertheless, the results provide impetus for further development of the methods by which muscle contraction-induced loading of bone can be clinically exploited.     

Neuromuscular performance and bone structural characteristics in young healthy men and women

Muscle mass and strength have been shown to be important factors in bone strength. Low muscular force predisposes to falling especially among elderly. Regular exercise helps to prevent falls and resulting bone fractures. Better understanding of muscle function and its importance on bone properties may thus add information to fracture prevention. Therefore the purpose of this study was to examine the relationship between bone strength and muscular force production. Twenty-young men [24 (2) years] and 20 [24 (3) years] women served as subjects. Bone compressive (BSI_d) and bending strength indices (50 Imax) were measured with peripheral quantitative computed tomography (pQCT) at tibial mid-shaft and at distal tibia. Ankle plantarflexor muscle volume (MV) was estimated from muscle thickness measured with ultrasonography. Neuromuscular performance was evaluated from the measurements of maximal ground reaction force (GRF) in bilateral jumping and of eccentric maximal voluntary ankle plantarflexor torque (MVC). Specific tension (ST) of the plantarflexors was calculated by dividing the MVC with the muscle volume. Activation level (AL) was measured with superimposed twitch method. Distal tibia BSI_d and tibial mid-shaft 50 Imax correlated positively with GRF, MVC and MV in men (r = 0.45–0.67, P < 0.05). Tibial mid-shaft 50 Imax and neuromuscular performance variables were correlated in women (r = 0.46–0.59, P < 0.05), whereas no correlation was seen in distal tibia. In the regression analysis, MV and ST could explain 64% of the variance in tibial mid-shaft bone strength and 41% of the variation in distal tibia bone strength. The study emphasizes that tibial strength is related to maximal neuromuscular performance. In addition, tibial mid-shaft seems to be more dependent on the neuromuscular performance, than distal tibia. In young adults, the association between bone adaptation and neuromuscular performance seems to be moderate and also site and loading specific.     

Morphological profile of atypical femoral fractures: age‐related changes to the cross‐sectional geometry of the diaphysis

The use of bisphosphonates for osteoporosis patients has markedly decreased the incidence of femoral neck or trochanteric fractures. However, anti‐osteoporosis drugs have been reported to increase the incidence of atypical femoral fractures, which involve stress fractures in the subtrochanteric region or the proximal diaphysis. In this study, the morphological characteristics of the cortical bone in human femoral diaphysis samples were analyzed from individuals who lived before bisphosphonate drugs were available in Japan. A total of 90 right femoral bones were arbitrarily selected (46 males and 44 females) from modern Japanese skeletal specimens. Full‐length images of these femurs were acquired using a computed tomography scanner. An image processing method for binarization was used to calculate the threshold values of individual bones for determining their contours. The range between the lower end of the lesser trochanter and the adductor tubercle of each femur was divided at regular intervals to obtain 10 planes. The mean value of cortical bone thickness, periosteal border length, and the cortical cross‐sectional area was evaluated for all planes. Moreover, the ratio of the area of the cortical bone to the total area of cross‐section at the mid‐diaphysis was calculated. A comparison between males and females demonstrated that most females had lower cortical bone area ratios at the mid‐diaphysis. The femoral outer shape did not differ markedly according to age or sex; however, substantial individual differences were observed in the shape of the inner surface of the cortical bone. The cortical bone thickness and the cross‐sectional area decreased with age in the femoral diaphysis; furthermore, in females, the decrease was higher for the former than for the latter. This may be due to a compensatory increase in the circumference of the femoral diaphysis. In addition, in about half of the subjects there was a discrepancy between the region with maximal value of the cortical bone thickness and that of the total cross‐sectional area. Biological responses to mechanical stresses to the femoral diaphysis are thought not to be uniform. Bisphosphonates inhibit bone resorption and may promote non‐physiological bone remodeling. Thus, a nonhomogeneous decrease in cortical thickness may be related to the fracture occurrence in the femoral diaphysis in some cases. Thus, long‐term administration of bisphosphonates in patients with morphological vulnerability in the femoral cortical bones may increase the occurrence of atypical femoral fractures.     

Bone modeling controlled by a nickel-titanium shape memory alloy intramedullary nail

Nitinol (NiTi) shape memory metal alloy makes it possible to prepare functional implants that apply a continuous bending force to the bone. The purpose of this study was to find out if bone modeling can be controlled with a functional intramedullary NiTi nail. Pre-shaped intramedullary NiTi nails (length 26 mm, thickness 1.0-1.4 mm) with a curvature radius of 25-37 mm were implanted in the cooled martensite form in the medullary cavity of the right femur in eight rats, where they restored their austenite form, causing a bending force. After 12 weeks, the operated femurs were compared with their non-operated contralateral counterpairs. Anteroposterior radiographs demonstrated significant bowing, as indicated by the angle between the distal articular surface and the long axis of the femur (p = 0.003). Significant retardation of longitudinal growth and thickening of operated femurs were also seen. Quantitative densitometry showed a significant increase in the average cross-sectional cortical area (p = 0.001) and cortical thickness (p = 0.002), which were most obvious in the mid-diaphyseal area. Cortical bone mineral density increased in the proximal part of the bone and decreased in the distal part. Polarized light microscopy of the histological samples revealed that the new bone induced by the functional intramedullary nail was mainly woven bone. In conclusion, this study showed that bone modeling can be controlled with a functional intramedullary nail made of nickel-titanium shape memory alloy.     

Histomorphological study on pattern of fluid movement in cortical bone in goats.

Streaming potential is considered one of the most important mechanisms to moderate the function of osteoblasts and osteocytes in bone growth, remodeling and fracture repair. The present study was designed to demonstrate the fluid flow pattern in the cortical bone matrix in an animal model using undecalcified histological techniques. Immediately after injection of ferritin into the tibia nutrient artery of four adult goats, the animals were euthanized. Undecalcified transverse and longitudinal blocks of cortical bone obtained from the tibial diaphysis were immersed in Perl's reagent and embedded in methyl methacrylate. Sections were cut and ground to 30-50 microm thickness for histomorphological evaluation at different magnifications and focusing levels. A serial grinding technique was used to validate the observations made at different focusing levels. As expected, ferritin was observed in the interstitial compartment in both transverse and longitudinal sections. In osteons sectioned transversely, the pattern of centrifugal movement of ferritin marker was demonstrated as single or multiple halos around the Haversian canal. The most apparent halo in osteons with multiple halos was the one found closest to the Haversian canal. The total number of identifiable single or multiple halos increased or was altered when counting was made with higher magnification or at different focusing levels, respectively. Irregular and incomplete ferritin halos indicated structural complexity of the osteons. Overall, the pattern of ferritin movement was consistent with bulk interstitial fluid flow influenced by both hydrostatic pressure and transudation. This study demonstrated for the first time multiple concentric halos of the fluid flow marker ferritin around Haversian canals in the cortical interstitial compartment. The results suggest that the undecalcified technique might be a useful method for qualitative and quantitative studies on cortical fluid flow.     

Histomorphological study on pattern of fluid movement in cortical bone in goats

Streaming potential is considered one of the most important mechanisms to moderate the function of osteoblasts and osteocytes in bone growth, remodeling and fracture repair. The present study was designed to demonstrate the fluid flow pattern in the cortical bone matrix in an animal model using undecalcified histological techniques. Immediately after injection of ferritin into the tibia nutrient artery of four adult goats, the animals were euthanized. Undecalcified transverse and longitudinal blocks of cortical bone obtained from the tibial diaphysis were immersed in Perl's reagent and embedded in methyl methacrylate. Sections were cut and ground to 30–50 μm thickness for histomorphological evaluation at different magnifications and focusing levels. A serial grinding technique was used to validate the observations made at different focusing levels. As expected, ferritin was observed in the interstitial compartment in both transverse and longitudinal sections. In osteons sectioned transversely, the pattern of centrifugal movement of ferritin marker was demonstrated as single or multiple halos around the Haversian canal. The most apparent halo in osteons with multiple halos was the one found closest to the Haversian canal. The total number of identifiable single or multiple halos increased or was altered when counting was made with higher magnification or at different focusing levels, respectively. Irregular and incomplete ferritin halos indicated structural complexity of the osteons. Overall, the pattern of ferritin movement was consistent with bulk interstitial fluid flow influenced by both hydrostatic pressure and transudation. This study demonstrated for the first time multiple concentric halos of the fluid flow marker ferritin around Haversian canals in the cortical interstitial compartment. The results suggest that the undecalcified technique might be a useful method for qualitative and quantitative studies on cortical fluid flow. Anat Rec 255:380–387, 1999. © 1999 Wiley‐Liss, Inc.     

Development of Cortical Bone Geometry in the Human Femoral and Tibial Diaphysis

Ontogenetic growth processes in human long bones are key elements, determining the variability of adult bone structure. This study seeks to identify and describe the interaction between ontogenetic growth periods and changes in femoral and tibial diaphyseal shape. Femora and tibiae (n = 46) ranging developmentally from neonate to skeletally mature were obtained from the Norris Farms No. 36 archeological skeletal series. High‐resolution X‐ray computed tomography scans were collected. Whole‐diaphysis cortical bone drift patterns and relative bone envelope modeling activity across ages were assessed in five cross‐sections per bone (total bone length: 20%, 35%, 50%, 65%, and 80%) by measuring the distance from the section centroid to the endosteal and periosteal margins in eight sectors using ImageJ. Pearson correlations were performed to document and interpret the relationship between the cross‐sectional shape (I_max/I_min), total subperiosteal area, cortical area, and medullary cavity area for each slice location and age for both the femur and the tibia. Differences in cross‐sectional shape between age groups at each cross‐sectional position were assessed using nonparametric Mann‐Whitney U tests. The data reveal that the femoral and tibial midshaft shape are relatively conserved throughout growth; yet, conversely, the proximal and distal femoral diaphysis and proximal tibial diaphysis appear more sensitive to developmentally induced changes in mechanical loading. Two time periods of accelerated change are identified: early childhood and prepuberty/adolescence. Anat Rec, 296:774–787, 2013. © 2013 Wiley Periodicals, Inc.