Regional maps of rib cortical bone thickness and cross‐sectional geometry

Here we present detailed regional bone thickness and cross‐sectional measurements from full adult ribs using high resolution CT scans processed with a cortical bone mapping technique. Sixth ribs from 33 subjects ranging from 24 to 99 years of age were used to produce average cortical bone thickness maps and to provide average ± 1SD corridors for expected cross‐section properties (cross‐sectional areas and inertial moments) as a function of rib length. Results obtained from CT data were validated at specific rib locations using direct measurements from cut sections. Individual thickness measurements from CT had an accuracy (mean error) and precision (SD error) of ?0.013 ± 0.167 mm (R² coefficient of determination of 0.84). CT‐based measurement errors for rib cross‐sectional geometry were ?0.1 ± 13.1% (cortical bone cross‐sectional area) and 4.7 ± 1.8% (total cross‐sectional area). Rib cortical bone thickness maps show the expected regional variation across a typical rib's surface. The local mid‐rib maxima in cortical thickness along the pleural rib aspect ranged from range 0.9 to 2.6 mm across the study population with an average map maximum of 1.4 mm. Along the cutaneous aspect, rib cortical bone thickness ranged from 0.7 to 1.9 mm with an average map thickness of 0.9 mm. Average cross‐sectional properties show a steady reduction in total cortical bone area from 10% along the rib's length through to the sternal end, whereas overall cross‐sectional area remains relatively constant along the majority of the rib's length before rising steeply towards the sternal end. On average, male ribs contained more cortical bone within a given cross‐section than was seen for female ribs. Importantly, however, this difference was driven by male ribs having larger overall cross‐sectional areas, rather than by sex differences in the bone thickness observed at specific local cortex sites. The cortical bone thickness results here can be used directly to improve the accuracy of current human body and rib models. Furthermore, the measurement corridors obtained from adult subjects across a wide age range can be used to validate future measurements from more widely available image sources such as clinical CT where gold standard reference measures (e.g. such as direct measurements obtained from cut sections) are otherwise unobtainable.     

股骨近端防旋髓内钉治疗股骨转子下骨折

背景：髓内钉具有优良的力学承载性能,提高了骨与内固定的整体稳定性,减少了骨折畸形愈合和内固定失败的发生率。股骨转子下骨折的内固定治疗对内植物的要求较高,因此在内植物的选择上仍存在很多争议。 目的：评价股骨近端防旋髓内钉治疗股骨转子下骨折的临床疗效。 方法：回顾性分析苏州大学附属第一医院2006年6月至2011年11月采用股骨近端防旋髓内钉内固定治疗股骨转子下骨折患者17例的病例资料。其中股骨转子下骨折合并转子间骨折9例(Seinsheimer分型Ⅴ型),股骨转子下骨折(Seinsheimer分型ⅡB 2例,Ⅲ B 1例,Ⅳ 4例)累及股骨干骨折7例,Seinsheimer分型Ⅴ型同时累及同侧股骨干骨折1例。受伤原因：高能量损伤16例,低能量损伤1例。记录固定时间、固定时出血量、骨折愈合时间及患肢功能恢复情况。 结果与结论：固定后随访8-24个月,平均16.2个月。固定后X射线片示骨折愈合时间平均5.4个月。固定后X射线片示所有患者骨折复位良好,转子下骨折、转子间及股骨干骨折均愈合,未出现骨折移位、内固定松动及髋内翻畸形,固定时仅有1例患者出现插钉困难。固定后患者Harris髋关节功能评分优良率为88.2%。结果证实,股骨近端防旋髓内钉本身设计合理,其防旋刀片对骨折端具有抗旋转和成角稳定性,疗效较好,安全可靠,是治疗股骨转子下骨折较理想的内固定物。     

老年骨质疏松性转子间骨折PFNA内固定术后股骨近端几何结构的变化

目的　研究PFNA内固定治疗老年骨质疏松性股骨转子间骨折术后股骨近端几何结构参数值的变化。 方法　选取老年骨质疏松性股骨转子间骨折患者36 例,分别在术后即刻与术后1.5~2年的骨盆平片上测量股骨近端几何参数（包括顶高距、偏心距、近端长度、颈干角）,比较其术后即刻与骨折愈合后股骨近端形态学变化。 结果　患者术后即刻与骨折愈合后几何参数比较,术后1.5~2年所测量顶高距、偏心距、近端长度及颈干角均较术后即刻有不同程度的变小,其中顶高距变化值为(1.25±0.94)mm,偏心距的变化大小为(0.36±1.13)mm,近端长度变化大小为(3.25±3.06)mm,颈干角变化大小为(0.22±0.76)°,术后即刻与术后1.5-2年的资料比较,除顶高距、近端长度外（P＜0.05）,其余项目比较差异无显著性（P＞0.05）。 结论　应用PFNA治疗老年骨质疏松性股骨转子间骨折,在骨折愈合过程中,经股骨颈传导的应力作用导致近端受力解剖结构参数不同程度变小,可接受的几何结构变化值有助于维持内固定系统的整体稳定性,有利于骨折的愈合。     

The effects of body mass index and age on cross‐sectional properties of the femoral neck

Research on the relationship between body mass index (BMI) and cross‐sectional geometry of long bone diaphyses demonstrates that strength properties are significantly greater in obese versus normal BMI individuals. However, articular dimensions do not differ appreciably. If femoral head size remains constant, we hypothesize that the femoral neck remodels to accommodate greater loads associated with increased BMI. High‐resolution CT scans (n = 170 males) were divided into three BMI groups (normal, overweight, and obese) and two age groups (21–50 and >50). OsiriX software was used to obtain a cross‐sectional slice at the waist of the femoral neck. Cortical area (CA), total cross‐sectional area (TA), percent cortical area (%CA), circularity index (I_max/I_min), section modulus (Z_pol), and second moment of area (J) were measured with ImageJ software. The effects of age and BMI were evaluated statistically. Pairwise comparisons in the younger group only detected significant differences between normal and obese males in the circularity index (P = 0.022). The older cohort showed significant differences in CA (P < 0.001), %CA (P = 0.004), Z_pol (P = 0.007), and J (P < 0.001) between normal and obese groups. This study shows that the effects of obesity on the cross‐sectional geometry of the femoral neck are more pronounced in older males relative to younger males. Older males with increased BMI have greater cortical area and bone strength in the femoral neck relative to younger males, thus making the femoral neck less susceptible to fractures in obese individuals. Clin. Anat. 28:1048–1057, 2015. © 2015 Wiley Periodicals, Inc.     

65岁以下嵌插型股骨颈骨折初始畸形程度对颈缩短的影响

背景:非手术治疗嵌插型股骨颈骨折是目前很少使用的一种策略,空心螺钉内固定是嵌插型股骨颈骨折的主要治疗方式.目前为止对嵌插型股骨颈骨折的研究主要集中在治疗方式与影响内固定失败的危险因素上,但嵌插型股骨颈骨折初始的畸形程度对术后股骨颈短缩影响的相关研究未见报道.目的:分析65岁以下嵌插型股骨颈骨折患者空心螺钉固定后股骨颈的...     

Age‐related hypermineralization in the female proximal human femur

Hip fracture incidence increases exponentially with age in virtually every human population that has been studied. In spite of this, relatively few studies have examined age‐related changes in the metaphyseal cortex of the proximal femur. The present study investigates cortical aging changes in the female proximal femur, with particular reference to regions of hypermineralization. Thirty‐three femora from Caucasian females were obtained at autopsy and analyzed using backscattered electron imaging. Variations in hypermineralized tissue area, cortical bone area, and porosity were quantified with standard stereological methods. Cortical width was quantified with digital calipers. Gender differences were examined by statistical comparison with previously published results. Hypermineralized tissue volume was significantly (P < 0.001) greater in elderly individuals. Hypermineralized tissue preferentially appeared near ligamentous or tendinous insertion sites, suggesting the hypermineralized tissue may be a calcified fibrocartilage. Cortical width significantly (P < 0.001) decreased with age and porosity significantly (P < 0.001) increased with age, however the changes were site‐specific. The femoral neck and intertrochanteric cortices had a smaller change in cortical width and porosity with age than the diaphysis, but the femoral neck and intertrochanteric cortices had a larger increase in hypermineralized tissue. Comparison with previous data suggests that cortical aging in the proximal femur is similar between males and females and is unlikely to explain the higher incidence of fracture in females. However, the data strongly indicates that age‐related changes in the femoral diaphysis cannot be directly extrapolated to either the femoral neck or intertrochanteric cortices. Anat Rec 255:202–211, 1999. © 1999 Wiley‐Liss, Inc.     

Interpreting the three‐dimensional orientation of vascular canals and cross‐sectional geometry of cortical bone in birds and bats

Cortical bone porosity and specifically the orientation of vascular canals is an area of growing interest in biomedical research and comparative/paleontological anatomy. The potential to explain microstructural adaptation is of great interest. However, the determinants of the development of canal orientation remain unclear. Previous studies of birds have shown higher proportions of circumferential canals (called laminarity) in flight bones than in hindlimb bones, and interpreted this as a sign that circumferential canals are a feature for resistance to the torsional loading created by flight. We defined the laminarity index as the percentage of circumferential canal length out of the total canal length. In this study we examined the vascular canal network in the humerus and femur of a sample of 31 bird and 24 bat species using synchrotron micro‐computed tomography (micro‐CT) to look for a connection between canal orientation and functional loading. The use of micro‐CT provides a full three‐dimensional (3D) map of the vascular canal network and provides measurements of the 3D orientation of each canal in the whole cross‐section of the bone cortex. We measured several cross‐sectional geometric parameters and strength indices including principal and polar area moments of inertia, principal and polar section moduli, circularity, buckling ratio, and a weighted cortical thickness index. We found that bat cortices are relatively thicker and poorly vascularized, whereas those of birds are thinner and more highly vascularized, and that according to our cross‐sectional geometric parameters, bird bones have a greater resistance to torsional stress than the bats; in particular, the humerus in birds is more adapted to resist torsional stresses than the femur. Our results show that birds have a significantly (P = 0.031) higher laminarity index than bats, with birds having a mean laminarity index of 0.183 in the humerus and 0.232 in the femur, and bats having a mean laminarity index of 0.118 in the humerus and 0.119 in the femur. Counter to our expectation, the birds had a significantly higher laminarity index in the femur than in the humerus (P = 0.035). To evaluate whether this discrepancy was a consequence of methodology we conducted a comparison between our 3D method and an analogue to two‐dimensional (2D) histological measurements. This comparison revealed that 2D methods significantly underestimate (P < 0.001) the amount of longitudinal canals by an average of 20% and significantly overestimate (P < 0.001) the laminarity index by an average of 7.7%, systematically mis‐estimating indices of vascular canal orientations. In comparison with our 3D results, our approximated 2D measurement had the same results for comparisons between the birds and bats but found significant differences only in the longitudinal index between the humerus and the femur for both groups. The differences between our 3D and pseudo‐2D results indicate that differences between our findings and the literature may be partially based in methodology. Overall, our results do not support the hypothesis that the bones of flight are more laminar, suggesting a complex relation between functional loading and microstructural adaptation.     

Anatomic characterization of the femoral nutrient artery: Application to fracture and surgery of the femur

The localization of nutrient foramina and direction of nutrient canals have been studied. However, information about the origin and extraosseous course of nutrient arteries is lacking in some types of long tubular and irregular bones. Thus, we aimed to reexamine the origin and course of the femoral nutrient artery (FNA) through cadaveric dissection to clarify its anatomic characteristics. Sixty thighs were collected from 57 cadavers. To fix the cadavers and visualize the small arterial branches, 10% formalin was injected from the femoral artery, followed by an injection of acrylic ink. The arterial tree in the posterior part of the thigh was recorded by line drawings. The femur received single or double FNAs via the femoral nutrient foramina, which were on and along the linea aspera. In cases with single FNA (41 of the 60 thighs), it typically arose from the four parts of the profunda femoris system: profunda femoris artery between the origins of the third and fourth perforating arteries; second perforating artery; third perforating artery; and terminal branch. In cases with double FNAs (remaining 19 thighs), the superior FNA typically arose from the second perforating artery, and the inferior FNA arose from the terminal branch of the profunda femoris artery and popliteal system. FNAs are described as branches of the perforating arteries in Terminologia Anatomica and anatomy textbooks. However, we found that FNAs also frequently arose from the profunda femoris artery and popliteal system, in addition to the perforating arteries. Clin. Anat. 33:479–487, 2020. © 2019 Wiley Periodicals, Inc.     

Low cost continuous femoral nerve block for relief of acute severe cancer related pain due to pathological fracture femur

Pathological fractures in cancer patient cause severe pain that is difficult to control pharmacologically. Even with good pain relief at rest, breakthrough and incident pain can be unmanageable. Continuous regional nerve blocks have a definite role in controlling such intractable pain. We describe two such cases where severe pain was adequately relieved in the acute phase. Continuous femoral nerve block was used as an efficient, cheap and safe method of pain relief for two of our patients with pathological fracture femur. This method was proved to be quite efficient in decreasing the fracture-related pain and improving the level of well being.     

Evidence of a hypermineralised calcified fibrocartilage on the human femoral neck and lesser trochanter

Femoral neck fractures are a major cause of morbidity and mortality in elderly humans. In addition to the age‐related loss of cancellous bone, changes to the microstructure and morphology of the metaphyseal cortex may be a contributing factor in osteoporotic hip fractures. Recent investigations have identified a hypermineralised tissue on the neck of the femur and trochanteric region that increases in fractional area with advancing age in both males (Boyce & Bloebaum, 1993) and females (Vajda & Bloebaum, 1999). The aim of this study was to determine if the hypermineralised tissue previously observed on the proximal femur is calcified fibrocartilage. Regional variations in the fractional area of hypermineralised tissue, cortical bone, and porosity of the cortical bone along the neck of the femur and lesser trochanter were also quantified. Comparison of back scattered electron and light microscope images of the same area show that regions of hypermineralised tissue correlate with the regions of calcified fibrocartilage from tendon and capsular insertions. The hypermineralised tissue and calcified fibrocartilage had similar morphological features such as the interdigitations of the calcified fibrocartilage into the bone, lacunar spaces, and distinctly shaped pores adjacent to the 2 tissues. Regions of the neck that did not contain insertions were covered with periosteum. There were no regional differences (P > 0.05) on the superior and inferior femoral neck in terms of the percentage area of hypermineralised calcified fibrocartilage, cortical bone, or cortical bone porosity. The lesser trochanter exhibited regional differences in the fractional area of hypermineralised calcified fibrocartilage (P = 0.007) and cortical bone (P = 0.007) but not porosity of the cortical bone (P > 0.05). The effects of calcified fibrocartilage on femoral neck periosteal expansion, repair, and mechanics are unknown, but may play a role in osteoporotic fractures and intracapsular fracture healing.     

Evidence of age‐related responses to short‐term environmental variation: Time series analysis of cross‐sectional data from Taiwan, 1969 to 1990

Cross‐sectional heights and weights collected by Taiwan’s Ministry of Education since 1964, and reported separately for Taipei and rural townships from 1969 through 1990, were used to test the hypothesis that in Taiwan the degree to which increments of change in height and weight of urban or rural boys and girls tracked each other from year to year was a function of sex and age‐related capacities to respond to common environmental forces. Five testable implications follow from this hypothesis. Results were evaluated using detrended time series derived correlations of yearly or near yearly change in sex‐specific age group height or weight means within and across regions, cross‐sectionally estimated ages of maximum change of height and weight, and evidence of response to two recessions. The hypothesis was largely supported by the available evidence. The similarities in secular change from year to year, with only a few exceptions, suggested that socioeconomic trends indirectly affected the pace of growth of children in both urban and rural Taiwan measured in the spring of the following year. The strength and age‐related pattern of these correlations were consistent with sex and age‐related capacities to respond to shared environmental factors. Evidence of lags between height and weight, found both in cross‐sectionally estimated mean ages of maximum change in height and weight and in the pattern of within sex correlations also argued for the hypothesis. The evidence further suggested that when the economy faltered briefly in Taiwan following worldwide oil crises, children’s growth was rapidly affected in an age‐dependent manner. This study bolsters the view that secular changes in growth reflect environmental quality. It suggests as well that under some circumstances, environmental change may be rapidly reflected as mean changes in height or weight of certain age groups. The intensity of the response appears to be related to the degree of improvement or deprivation, the maturationally mediated pace of growth, and probably initial energy balance. Am. J. Hum. Biol. 14:61–73, 2002. © 2002 Wiley‐Liss, Inc.     

带旋股外动脉升支髂骨瓣加空心加压钉治疗股骨颈骨折

目的：报道旋股外侧动脉升支髂骨瓣加空心加压螺钉治疗青壮年股骨颈骨折的手术方法及临床效果。方法：在解剖学研究的基础上，设计并应用旋股外侧动脉升支髂骨瓣加空心加压螺钉治疗青壮年股骨颈骨折36例。结果：36例中，优22例，良11例，可2例，差1例。33例骨折完全愈合，3例出现股骨头坏死，优良率91．7％。结论：该术式骨瓣血供丰富，固定牢靠，操作简便，创伤小，是治疗青壮年股骨颈骨折的一种有效方法。     

Super‐osteons (remodeling clusters) in the cortex of the femoral shaft: Influence of age and gender

Previous studies of cortical remodeling in the fractured femoral neck indicated that the merging of spatially clustered remodeling osteons could result in the formation of deleteriously large cavities associated with femoral neck fracture. This study aimed to identify whether remodeling osteons in the femoral shaft were also clustered and to assess the influence of age and gender. Microradiographic images of femoral mid‐shaft cross‐sections from 66 subjects over 21 years of age were analyzed to determine the number, size and location of all Haversian canals. Those most recently remodeled were identified using an edge‐detection algorithm highlighting the most marked differential gradients in grey levels. Cluster analysis (JMP software) of these osteons identified the proportion of recently remodeled osteons that were within 0.75mm clusters. As in the femoral neck, remodeling osteons were significantly more clustered than could occur by chance (real, 59.4%; random, 39.4%; P < 0.0001). The density of these clusters (number/mm²) was not significantly associated with subject age or gender but was greatest near the periosteum and decreased toward the marrow cavity (periosteal 0.043 ± 0.004; mid‐cortex 0.028 ± 0.003; endosteal 0.017 ± 0.002). Cortical porosity increased with age. The presence of giant canals (diameter >385μm) was inversely related to the presence of clusters (R² = 0.237, P < 0.0001). This data suggest that remodeling osteons tend to be spatially colocalized in the shaft as they are in the neck of the femur and their presence is independent of age or gender. We propose that these remodeling clusters be termed super‐osteons. The negative relationship between super‐osteons and giant canals raises the intriguing possibility that loss of the control of remodeling depth results in the merging of osteonal systems to form deleteriously large cortical cavities with a marked reduction in bone strength. Anat Rec 264:378–386, 2001. © 2001 Wiley‐Liss, Inc.     

股骨头坏死动物模型的造模方法及特点

BACKGROUND: Osteonecrosis of the femoral head is a common and difficult disease in orthopedic department, with a high disability rate. At present, there is still no clear conclusion about its pathogenesis, as well as no ideal way to cure the disease. Therefore, it is necessary to use animal models to further study the etiology, pathogenesis and treatment of the disease. OBJECTIVE: To review some common animal models of osteonecrosis of the femoral head in recent years, summarize and analyze the corresponding clinical symptoms and the advantages and disadvantages of each animal model, so as to provide the basis for the follow-up research in this area. METHODS: The keywords of “femoral head necrosis” and “animal model” were used to search articles published between January 2000 to December 2019 in WanFang, VIP, CNKI, PubMed, Embase and Medline databases. Finally 42 eligible articles were included. RESULTS AND CONCLUSION: The animal model of osteonecrosis of the femoral head has been used for many years, which really improves the understanding and research of this kind of orthopedic disease. However, at present, the related research of such diseases still needs to be further explored, through the establishment of more ideal and perfect animal models to achieve a new breakthrough in this research field. © 2021, Journal of Clinical Rehabilitative Tissue Engineering Research. All rights reserved.     

Time‐dependent changes in bone healing capacity of scaphoid fractures and non‐unions

The scaphoid is the most frequently fractured carpal bone and prone to non‐union due to mechanical and biological factors. Whereas the importance of stability is well documented, the evaluation of biological activity is mostly limited to the assessment of vascularity. The purpose of this study was to select histological and immunocytochemical parameters that could be used to assess healing potential after scaphoid fractures and to correlate these findings with time intervals after fracture for the three parts of the scaphoid (distal, gap and proximal). Samples were taken during operative intervention in 33 patients with delayed or non‐union of the scaphoid. Haematoxylin and Eosin (HE ), Azan, Toluidine, von Kossa and Tartrate‐resistant acid phosphatase (TRAP ) staining were used to characterise the samples histologically. We determined distribution of collagen 1 and 2 by immunocytochemistry, and scanning electron microscopy (SEM ) was used to investigate the ultrastructure. To analyse the samples, parameters for biological healing status were defined and grouped according to healing capacity in parameters with high, partial and little biological activity. These findings allowed scoring of biological healing capacity, and the ensuing results were correlated with different time intervals after fracture. The results showed reduced healing capacity over time, but not all parts of the scaphoid were affected in the same way. For the distal fragment, regression analysis showed a statistically significant correlation between summarised healing activity scores and time from initial fracture (r  = ?0.427, P  = 0.026) and decreasing healing activity for the gap region (r  = ?0.339, P  = 0.090). In contrast, the analyses of the proximal parts for all patients did not show a correlation (r  = 0.008, P  = 0.969) or a decrease in healing capacity, with reduced healing capacity already at early stages. The histological and immunocytochemical characterisation of scaphoid non‐unions (SNU s) and the scoring of healing parameters make it possible to analyse the healing capacity of SNU s at certain time points. This information is important as it can assist the surgeon in the selection of the most appropriate SNU treatment.     

Genotype‐phenotype correlations of low‐frequency variants in the complement system in renal disease and age‐related macular degeneration

Genetic alterations in the complement system have been linked to a variety of diseases, including atypical hemolytic uremic syndrome (aHUS), C3 glomerulopathy (C3G), and age‐related macular degeneration (AMD). We performed sequence analysis of the complement genes complement factor H (CFH), complement factor I (CFI), and complement C3 (C3) in 866 aHUS/C3G and 697 AMD patients. In total, we identified 505 low‐frequency alleles, representing 121 unique variants, of which 51 are novel. CFH contained the largest number of unique low‐frequency variants (n = 64; 53%), followed by C3 (n = 32; 26%) and CFI (n = 25; 21%). A substantial number of variants were found in both patients groups (n = 48; 40%), while 41 (34%) variants were found only in aHUS/C3G and 32 (26%) variants were AMD specific. Genotype‐phenotype correlations between the disease groups identified a higher frequency of protein altering alleles in short consensus repeat 20 (SCR20) of factor H (FH), and in the serine protease domain of factor I (FI) in aHUS/C3G patients. In AMD, a higher frequency of protein‐altering alleles was observed in SCR3, SCR5, and SCR7 of FH, the SRCR domain of FI, and in the MG3 domain of C3. In conclusion, we observed a substantial overlap of variants between aHUS/C3G and AMD; however, there is a distinct clustering of variants within specific domains.     

Ageing of the somatosensory system at the periphery: age‐related changes in cutaneous mechanoreceptors

Decline of tactile sensation associated with ageing depends on modifications in skin and both central and peripheral nervous systems. At present, age‐related changes in the periphery of the somatosensory system, particularly concerning the effects on mechanoreceptors, remain unknown. Here we used immunohistochemistry to analyse the age‐dependent changes in Meissner's and Pacinian corpuscles as well as in Merkel cell‐neurite complexes. Moreover, variations in the neurotrophic TrkB‐BDNF system and the mechanoprotein Piezo2 (involved in maintenance of cutaneous mechanoreceptors and light touch, respectively) were evaluated. The number of Meissner's corpuscles and Merkel cells decreased progressively with ageing. Meissner's corpuscles were smaller, rounded in morphology and located deeper in the dermis, and signs of corpuscular denervation were found in the oldest subjects. Pacinian corpuscles generally showed no relevant age‐related alterations. Reduced expression of Piezo2 in the axon of Meissner's corpuscles and in Merkel cells was observed in old subjects, as well was a decline in the BDNF‐TrkB neurotrophic system. This study demonstrates that cutaneous Meissner's corpuscles and Merkel cell‐neurite complexes (and less evidently Pacinian corpuscles) undergo morphological and size changes during the ageing process, as well as a reduction in terms of density. Furthermore, the mechanoprotein Piezo2 and the neurotrophic TrkB‐BDNF system are reduced in aged corpuscles. Taken together, these alterations might explain part of the impairment of the somatosensory system associated with ageing.