Role of collagen enzymatic and glycation induced cross-links as a determinant of bone quality in spontaneously diabetic WBN/Kob rats

Introduction Diabetes is associated with an increased risk of fracture, although type 2 diabetes is often characterized by normal bone mineral density (BMD). Enzymatic and glycation-induced non-enzymatic cross-links play important roles in the expression of bone strength. The serum vitamin B6 concentration is lower in patients with diabetes than in healthy controls. The aim our study was to see if spontaneously diabetic WBN/Kob rats in the pre- and post-onset of diabetes would serve as a suitable model for studying the pathogenesis of the susceptibility to fracture in diabetes without the reduction of bone mineral density. Seventy male WBN/Kob rats were obtained at the ages of 1 to 18 months.Methods Seventy normal male Wistar rats were used as the non-diabetic, age-matched control. The contents of enzymatic cross-links (dihydroxylysinonorleucine, hydroxylysinonorleucine, lysinonorleucine, pyridinoline and deoxypyridinoline) and non-enzymatic cross-links (pentosidine) were determined in femoral bone. We also analyzed the serum concentration of vitamin B6 (pyridoxal and pyridoxamine), femoral BMD and a three-point bending test of the femur.Results A low level of serum vitamin B6 was associated with a decrease in enzymatic crosslinking in bone during the subclinical diabetes stage. After the onset of diabetes, there was a steady decrease in enzymatic cross-links and a steep increase in pentosidine. Furthermore, impaired bone mechanical properties in the WBN/Kob rats despite the lack of reduction in BMD coincided with impaired enzymatic cross-link formation and increases in glycation-induced pentosidine.Conclusions These results indicate that the alteration of enzymatic and non-enzymatic crosslinking in bone could be important for explaining the variation of fracture susceptibility in diabetes.     

双膦酸盐的长期治疗增加了骨单位的矿化程度

目的评估双膦酸盐的长期应用对骨单位的次级矿化程度的影响。方法30只1岁龄猎犬按体重随机分成三组(每组雌雄各5只):对照组犬每天口服乳糖,低剂量组和高剂量组犬分别每天口服因卡膦酸钠incadronate0.3mgkg和0.6mgkg。所有犬持续给药3a。处死前进行四环素双标,处死后取左侧第9肋骨进行组织形态计测和次级矿化程度评估。结果组织形态计测表明两个双膦酸盐治疗组的骨激活频率(Ac.f)都明显低于对照组,分别降低了40%和82%。矿化程度的测定表明,低剂量和高剂量双膦酸盐组骨单位内的平均矿化程度(MDMB)都明显高于对照组,分别增加了22%和30%。双膦酸盐组MDMB分布曲线与对照组保持了相同的峰值,并且随治疗剂量的增大逐渐向高矿化端漂移。结论双膦酸盐长期应用明显抑制了骨转换,增加了骨单位的矿化程度。     

Patterns of osteocytic endothelial nitric oxide synthase expression in the femoral neck cortex: differences between cases of intracapsular hip fracture and controls

Evidence indicates that extensive amalgamation of adjacent resorbing osteons is responsible for destroying the microstructural integrity of the femoral neck’s inferior cortex in osteoporotic hip fracture. Such osteonal amalgamation is likely to involve a failure to limit excessive resorption, but its mechanistic basis remains enigmatic. Nitric oxide (NO) inhibits osteoclastic bone destruction, and in normal bone cells its generation by endothelial nitric oxide synthase (eNOS, the predominant bone isoform) is enhanced by mechanical stimuli and estrogen, which both protect against fracture. To determine whether eNOS expression in osteocytes reflects their proposed role in regulating remodeling, we have examined patterns of osteocyte eNOS immunolabeling in the femoral neck cortex of seven cases of hip fracture and seven controls (females aged 68–96 years). The density of eNOS⁺ cells (mm⁻²) was 53% lower in the inferior cortex of the fracture cases (p < 0.0004), but was similar in the superior cortex. eNOS⁺ osteocytes were, on average, 22% further from their nearest blood supply, than osteocytes in general (p < 0.0001) and the nearest eNOS⁺ osteocyte was 57% further from its nearest canal surface (p < 0.0001). This differential distribution of eNOS⁺ osteocytes was significantly more pronounced in the cortices of fracture cases (p < 0.0001). We conclude that the normal regional and osteonal pattern of eNOS expression by osteocytes is disrupted in hip fracture, particularly at sites that are loaded most by physical activity. These results suggest that eNOS⁺ osteocytes may normally act as sentinels confining resorption within single osteons. A reduction in their number, coupled to an increase in their remoteness from canal surfaces, may thus permit the irreversible merging of resorbing osteons, and thus contribute to the marked increase in the fragility of osteoporotic bone.     

The compositional and physicochemical homogeneity of male femoral cortex increases after the sixth decade

The temporal and spatial fluctuations in the dynamics of secondary osteonal remodeling impart heterogeneity to the compositional quality of bone. Bone mineral density (BMD) fails to reflect this heterogeneity as being a single score, and thus it cannot resolve the overlap between healthy individuals and those who experience fractures. Such information on tissue heterogeneity is lacking in the literature. In the current study, specimens were prepared from mid-diaphyseal portions of human femora (N = 16, age range 52–85 years old) and grouped based on the anatomical location (anterior, lateral, medial and posterior quadrants). Raman microscopy was used to obtain multiple measurements from each specimen which allowed the construction of histograms of mineralization, crystallinity and carbonation. The coefficient of variation (COV) and skewness were extracted from histograms as measures of heterogeneity. Results demonstrated that average mineralization of the medial quadrant and the data pooled over quadrants significantly increased with age. The mean carbonation increased within the observed age range for the pooled data. The variations of values about the mean became tighter for mineralization, crystallinity and type-B carbonation with age, indicating an overall reduction in compositional heterogeneity of aging femoral cortex. Skewness values indicated that the distributions of histograms were not Gaussian. We conclude that age-related changes in mean tissue composition are confounded with changes in the variation of tissue make-up about the mean. Future studies will establish as to whether compositional heterogeneity correlates with the mechanical strength of bone.     

压力侧和张力侧股骨颈皮质粉碎是股骨颈骨折术后无菌性坏死的独立危险因素

目的:探讨股骨颈骨折闭合复位内固定术后发生股骨头无菌性坏死的相关影响因素.方法:2009年1月至2016年1月,采用闭合复位3枚中空拉力螺钉内固定治疗236例股骨颈骨折患者,男111例,女125例;年龄19～89(50.17±12.88)岁.根据随访结果分析其发生股骨头无菌性坏死的相关性.对年龄、性别、损伤侧、体重、损...     

Degree of Mineralization-related Collagen Crosslinking in the Femoral Neck Cancellous Bone in Cases of Hip Fracture and Controls

Based on the present definition of osteoporosis, both bone density and quality are important factors in the determination of bone strength. Collagen crosslinking is a determinant of bone quality. Cross-links can form enzymatically by the action of lysyl oxidase or non-enzymatically, resulting in advanced glycation end products. Collagen crosslinking is affected by tissue maturation as well as the degree of mineralization. Homocysteine and vitamin B6 (pyridoxal) are also regulatory factors of collagen crosslinking. We elucidate the relationship between the degree of mineralization and collagen cross-links in cancellous bone from hip fracture cases. We also determined plasma levels of homocysteine and pyridoxal. Twenty-five female intracapsular hip fracture cases (78 ± 6 years) and 25 age-matched postmortem controls (77 ± 6 years) were included in this study. Collagen crosslinking was analyzed after each bone specimen was fractionated into low (1.7–2.0 g/ml) and high (>2.0 g/ml) density fractions. The content of enzymatic (immature reducible and mature nonreducible cross-links) and nonenzymatic cross-link (pentosidine) were determined. In the controls, there was no difference in total enzymatic cross-links between low and high density bone, while pentosidine content was significantly higher in high density bone. In the fracture cases, not only reduced enzymatic cross-links in high density bone and increased pentosidine in both low and high density bone, but also higher plasma homocysteine and lower pyridoxal levels were evident compared with the controls. These results indicate that detrimental crosslinking in both low and high mineralized bone result in impaired bone quality in osteoporotic patients. All authors have no Conflict of interest policy.     

Clinical usefulness of a bone mineral measurement method on the femoral shaft

Summary An improved version of a previously described photon absorptiometry method for measuring the bone mineral content of the femoral shaft is presented. The study included 267 healthy persons, who served as control subjects, and 31 osteoporotic and 3 osteomalacic female patients. A monoenergetic source of²⁴¹Am was used and a fully automatic apparatus designed. The examinations were recorded with an independent microcomputer and secondarily processed by the nuclear unit central computer. The guidelines of Cameron and West were used to perform various calculations from the initial absorption curve, and the clinical usefulness of these was tested. On the one hand, cortical bone density (CBD) and bone linear attenuation coefficient (BLAC) were found adequately to differentiate between osteoporotics and controls, but we defined a discriminative function (F) which allowed even better separation between the two groups. On the other hand, bone index (BI) was found to be the best parameter to follow an individual patient during therapy. These results underline the usefulness of these calculations for detecting and monitoring the progress of pathological states.     

老年骨质疏松症股骨颈骨折术后抗骨质疏松治疗的初步观察

目的探讨老年人骨质疏松症股骨颈骨折术后应用（密盖息＋钙＋维生素D3）方案抗骨质疏松治疗的效果。方法随机选择诊断为“原发性骨质疏松症＋股骨颈病理性骨折”的老年患者56例,人工关节置换术后除髋关节康复锻炼外,应用（密盖息＋钙＋维生素D3）方案治疗3个月,比较治疗前后临床症状和空腹血钙、磷、甲状旁腺激素、碱性磷酸酶、24h尿钙、磷以及定量CT腰椎骨密度值变化。结果周身疼痛症状改善有效率为50％;治疗3个月前、后空腹血钙、磷、甲状旁腺激素、碱性磷酸酶、24h尿钙、磷变化间的差异无统计学意义（P〉0．05）;腰椎骨密度值间的差异有统计学意义（P〈0．01）。结论老年人股骨颈骨折术后应用（密盖息＋钙＋维生素D3）方案抗骨质疏松治疗能有效增加骨密度,改善疼痛,从而预防再次骨折。     

球囊扩张骨水泥加强内固定术治疗老年骨质疏松性股骨颈骨折的临床初步报告

目的 探讨一种治疗老年骨质疏松性股骨颈骨折的简单、微创、安全、有效的方法。方法 自2001年7月-2003年9月，采用球囊扩张骨水泥加强内固定术治疗23例骨质疏松性股骨颈骨折，男9例，女14例，平均85岁。结果 所有患者术后1-10d疼痛减轻，均下地免负重活动，无严重并发症发生。结论 球囊扩张骨水泥加强内固定术是一种治疗骨质疏松性股骨颈骨折简单、有效、安全的新方法，能早期去除疼痛，尽快使患者下床，减少卧床所致并发症，尤其适用于严重骨质疏松不能耐受人工髋关节置换术的病人。     

Time-dependent changes of collagen cross-links and their precursors in the culture of osteogenic cells

Summary The early stage of cross-link formation in bone collagen was studied in a cell culture system. An osteogenic cell line that produces and accumulates a remarkably high amount of collagen, and that eventually forms bone-like structures, was used in this study for its time-dependent development of reducible cross-links. It was found that precursors of the cross-link, dehydro-dihydroxynorleucine and dehydro-hydroxynorleucine became detectable as soon as the cells attained a confluent state. They showed maximal amounts at day 3–5 after confluence, but substantially disappeared at day 10 after confluence. In contrast, two characteristic cross-links of bone collagen, dehydrodihydroxylysinonorleucine dehydro-DHLNL and dehydrohydroxylysinonorleucine (dehydro-HLNL), which were present in trace amounts at the stage of cell confluence, gradually increased in amount and reached a plateau at day 10, just when their precursors disappeared. Thus, it was found that there was a time lag of about a week between the maximal formations of precursors and cross-links of bone collagen in this system. The significance of this time lag was interpreted in terms of the minimum essential accumulation of collagen for the precursor-product transition. The ratio of dehydro-DHLNL to dehydro-HLNL was as low as 0.7 at day 3 after confluency, increased to 4.2 at day 20, the period just before mineralization began, and decreased thereafter, suggesting a qualitative change in bone collagen associated with mineralization.     

Effect of dynamic hip screw on the treatment of femoral neck fracture in the elderly

[Abstract] Objective： To discuss the indications, surgical procedures, and curative effect of dynamic hip screw （DHS） in the treatment of femoral neck fracture in the elderly. Methods： A retrospective study was conducted to analyse the clinical data of 42 elderly patients who had been treated for femoral neck fracture with DHS in our department between June 2009 and November 2011. There were 21 males and 21 females with a mean age of 68.5 years （range 60-75 years）. According to the Garden Classification, there were 19 cases of type II, 21 cases of type III and 2 cases of type IV fractures. By the Singh In- dex Classification, there were 3 cases of level 2, 19 cases of level 3 and 20 cases of level 4 fractures. The Harris cri- terion, complications and function recovery after operation were analysed. Results： The average hospitalization time in 42 patients was 11.2 days （range 7-21 days）. All patients were followed up for 12-26 months （mean 18 months）. No lung infection, deep venous thrombosis or other complications occurred. Partial backing-out of the screws was found in 2 cases. The internal fixation device was with- drawn after fracture healing. Internal fixation cutting was found in 1 case, and he had a good recovery after total hip arthroplasty. The time for fracture healing ranged from 3-6 months （average 4.5 months）. According to Harris criteri- on, 15 cases were rated as excellent, 24 good, 2 fair and 1 poor. The Harris scale was significantly improved from 30.52＋2.71 preoperatively to 86.61＋2.53 at 6 months post- operatively （P〈0.05）. Conclusion： DHS, being minimal invasive, al- lowing early activity and weight-bearing, is advisable for treatment of elderly patients with femoral neck fracture. In addition, it can avoid complications seen in artificial joint replacement. It is especially suitable for patients with mild osteoporosis.     

Bone mineral content of the femoral neck and shaft: Relation between cortical and trabecular bone

Summary Bone mineral content (BMC) of the femoral neck and shaft was determined with dual photon absorptiometry, using¹⁵³Gd. Comparison of BMC with the amount of hydroxyapatite (HA) ofin vitro specimen showed correlation coefficients of 0.992 and 0.996 for the femoral neck and shaft respectively. In the femoral neck the amount of cortical bone in a bone section varies from 16% ash weight in the proximal part of 71% in the distal part. Corresponding to the site of BMC measurements, the cortical bone constitutes 57% in the femoral neck and 95% in the femoral shaft. The precision error of measurements of BMCin vivo, expressed as the coefficient of variation for repeated determinations, was 1.4% for the femoral neck and 1.3% for the femoral shaft. In the femoral neck it is possible to distinguish between structures consisting mainly of cortical bone and structures containing mostly trabecular bone. While the cortical bone value decreases only slowly with age in normal women, corresponding to BMC of the femoral shaft, the trabecular bone value decreases rapidly even compared with BMC of the femoral neck. Despite the significant correlation between the values for cortical and trabecular bone a distinction seems essential from a clinical point of view.     

Cortical and trabecular bone in the femoral neck both contribute to proximal femur failure load prediction

Summary  We examined the contributions of femoral neck cortical and trabecular bone to proximal femur failure load. We found that trabecular bone mineral density explained a significant proportion of variance in failure load after accounting for total bone size and cortical bone mineral content or cortical area. Introduction  The relative contribution of femoral neck trabecular and cortical bone to proximal femur failure load is unclear. Objectives  Our primary objective was to determine whether trabecular bone mineral density (TbBMD) contributes to proximal femur failure load after accounting for total bone size and cortical bone content. Our secondary objective was to describe regional differences in the relationship among cortical bone, trabecular bone, and failure load within a cross-section of the femoral neck. Materials and methods  We imaged 36 human cadaveric proximal femora using quantitative computed tomography (QCT). We report total bone area (ToA), cortical area (CoA), cortical bone mineral content (CoBMC), and TbBMD measured in the femoral neck cross-section and eight 45° regions. The femora were loaded to failure. Results and observations  Trabecular bone mineral density explained a significant proportion of variance in failure load after accounting for ToA and then either CoBMC or CoA respectively. CoBMC contributed significantly to failure load in all regions of the femoral neck except the posterior region. TbBMD contributed significantly to failure load in all regions of the femoral neck except the inferoanterior, superoposterior, and the posterior regions. Conclusion  Both cortical and trabecular bone make significant contributions to failure load in ex vivo measures of bone strength.

Trabecular microfracture and the influence of pyridinium and non-enzymatic glycation-mediated collagen cross-links

The propensity of individual trabeculae to fracture (microfracture) may be important clinically since it could be indicative of bone fragility. Whether or not an overloaded trabecula fractures is determined in part by its structural ductility, a mechanical property that describes how much deformation a trabecula can sustain. The overall goal of this study was to determine the structural ductility of individual trabeculae and the degree to which it is influenced by pyridinium and non-enzymatic collagen cross-links. Vertically oriented rodlike trabeculae were taken from the thoracic vertebral bodies of 32 cadavers (16 male and 16 female, 54–94 years of age). A total of 221 trabeculae (4–9 per donor) were tested to failure in tension using a micro-tensile loading device. A subset of 76 samples was analyzed to determine the concentration of hydroxylysyl–pyridinoline (HP) and lysyl–pyridinoline (LP) cross-links as well as pentosidine, a marker of non-enzymatic glycation. Structural ductility (defined as the ultimate strain of the whole trabecula) ranged from 1.8% to 20.2% strain (8.8 ± 3.7%, mean ± SD) and did not depend on age (P = 0.39), sex (P = 0.57), or thickness of the sample at the point of failure (P = 0.36). Pentosidine was the only marker of collagen cross-linking measured that was found to be correlated with structural ductility (P = 0.01) and explained about 9% of the observed variance. We conclude that the ductility of individual trabeculae varies tremendously, can be substantial, and is weakly influenced by non-enzymatic glycation.     

Preferential low bone mineral density of the femoral neck in patients with a recent fracture of the proximal femur

Bone mass is an important determinant of resistance to fractures. Whether bone mineral density (BMD) in subjects with a fracture of the proximal femur (hip fracture) is different from that of age-matched controls is still debated. We measured BMD of the femoral neck (FN) on the opposite side to the fracture, as well as femoral shaft (FS) and lumbar spine (LS) BMD by dual-photon absorptiometry in 68 patients (57 women and 11 men, mean age 78.8±1.0) 12.4±0.8 days after hip fracture following a moderate trauma. These values were compared with BMD of 93 non-fractured elderly control subjects (82 women and 11 men), measured during the same period. As compared with the controls, FN BMD was significantly lower in fractured women (0.592±0.013 v. 0.728±0.014 g/cm²,P<0.001) and in fractured men (0.697±0.029 v. 0.840±0.052,P<0.05). Expressed as standard deviations above or below the mean BMD of age and sex-matched normal subjects (Z-score), the difference in FN BMD between fractured women and controls was highly significant (–0.6±0.1 v. +0.1±0.1,P<0.001). As compared with mean BMD of young normal subjects, BMD was decreased by 36.9±1.4 and 22.4±1.5% (P<0.001) in fractured and control women, respectively. There was no significant difference between FN BMD of 33 women with cervical and 24 with trochanteric hip fractures (0.603±0.017 v. 0.577±0.020). FN BMD was lower than 0.705 g/cm² in 90% of fractured women. The prevalence of fracture increased with decreasing FN BMD, reaching 100% with values below 0.500 g/cm². FS and LS BMD were significantly lower in women with hip fracture than in controls (1.388±0.036 v. 1.580±0.030,P<0.001, for FS, and 0.886±0.027 v. 0.985±0.023,P<0.01, for LS), but these differences were not significant when expressed as a Z-score. In men with a recent hip fracture, FS BMD was significantly lower than in controls (1.729±0.096 v. 2.069±0.062,P<0.01), but the difference at the LS level did not reach statistical significance. These results indicate that both women and men with a recent hip fracture had decreased bone mineral density of the femoral neck, femoral shaft and lumbar spine. However, the difference appeared to be of higher magnitude for the femoral neck suggesting a preferential bone loss at this site.     

绝经后股骨颈骨折股骨头骨铁含量、血清铁蛋白与骨密度相关性研究

 目的 探讨女性绝经后股骨颈骨折股骨头骨铁含量、血清铁蛋白与髋部骨密度的相关性。方法 2010年6月至2013年3月,收集156例股骨颈骨折行髋关节置换的绝经后女性患者资料,年龄56~92岁,平均(72.40±8.97)岁;按每10岁年龄段分组,共分5组,即≤ 60岁组、61~70岁组、71~80岁组、81~90岁组、≥91岁组。患者入院后第2天留空腹血清标本测定血清铁蛋白和骨代谢指标;对髋关节置换术后留取的股骨头组织行骨铁含量检测和骨铁染色,术后第10天行髋部和腰椎骨密度(DXA)检测。结果 5组之间骨铁、血清铁蛋白、转铁蛋白、总铁结合力、Ⅰ型原胶原氨基端延长肽、Ⅰ型胶 原C端肽β降解产物、髋部和L1~4骨密度存在组间差异。髋部和L1~4骨密度随年龄增加而下降,骨铁和血清铁蛋白随年龄增 加而升高,骨铁和血清铁蛋白检测值均在81~90岁年龄组达到峰值,156例患者的平均骨铁量为96.81 μg/g,平均血清铁蛋白为235.66 μg/L。156例患者中,血清铁蛋白＞200 μg/L的患者为100例(100/156,64.1%)。骨铁、血清铁蛋白、年龄、体重指数可进入髋部骨密度回归模型,股骨颈R2=0.443,Wards三角R2=0.397,大转子R2=0.322,全股骨R2=0.379;控制年龄、体重、体重指数等因素,骨铁和血清铁蛋白与髋部骨密度呈负相关,与腰椎骨密度无明显相关性。结论 发生股骨颈脆性骨折的绝经后女性患者体内存在铁蓄积,股骨头骨铁含量随年龄增加而升高,骨铁增加和血清铁蛋白升高可能是髋部骨密度下降的独立危险因素,铁蓄积与绝经后骨质疏松症存在相关性。     

Correlation of bone mineral density and femoral neck hardness in bovine and human samples

Bone mineral density (BMD) was measured in 353 healthy white women using dual-energy X-ray absorptiometry (DXA). Measurements were made of both the posterior-anterior (PA) and lateral spine, as well as the proximal femur (neck and Ward's triangle). From age 50 to 80 years, the BMD of the PA spine and femur neck BMD had an 18% diminution (0.6%/year), and BMD of the lateral spine showed about a 35–40% decline (1.4%/year). The Ward's triangle region of the femur was not quite as decreased (30% or 1.1%/year). The BMD decrease associated with aging did not differ as much among sites when expressed relative to the intrapopulation variation rather than as a percentage. The Z-score for PA spine and femur neck BMD (-1.1) was significantly different than that for lateral spine BMD (-1.6); Ward's triangle was intermediate (-1.3), i.e., the lateral spine still showed the highest sensitivity to aging. However, the ability to detect age changes in an individual subject can be increased only if the precision error for lateral spine BMD is not increased to a greater extent than the sensitivity.Deceased     

桡骨骨密度与股骨颈及腰椎骨密度的比较分析

通过分析桡骨骨密度与股骨颈及腰椎骨密度，了解它们之间的相关性，为选择预测骨折的最佳部位提供依据。选取健康人群１００例，其中男性５３例，女性４７例；骨质疏松患者１１例。采用日本ＡＬＯＫＡ公司生产的ＤＣＳ－６００ＥＸ型双能Ｘ线骨密度仪和美国ＬＵＮＡＲ公司生产的ＤＰＸ－Ｌ型骨密度仪对比测量，选择的部位为前臂、股骨颈及腰椎。两种仪器的前臂１／１０点与腰椎骨的密度值相关性非常好（ｒ＝０．６６１），而１／３点相关性则较差（ｒ＝０．３３２），说明在前臂桡骨骨远端，松质骨比重较大，代谢较快，骨矿物含量变化最为敏感，此部位能代替腰椎骨作为骨质疏松的诊断指标。另外，两种仪器的前臂１／１０点与髋部骨密度值相关性也非常好（ｒ＝０．７９２）。表明在桡骨骨远端骨矿物含量的结果中，可以了解髋部骨量变化的信息。就前臂同一部位两种仪器的测量结果看ＤＣＳ－６００ＥＸ型的１／３点和１／１０点与ＤＰＸ－Ｌ型的１／３点和１／１０点的测定值相关性都非常好，绝对值基本上均在误差范围之内，说明骨矿含量的变化程度在两种仪器上的测量显示相同的结果。     

Prediction of the strength and fracture location of the femoral neck by CT-based finite-element method: a preliminary study on patients with hip fracture

The purpose of this study was to predict fracture load and fracture location of the femora by means of the originally developed CT-based finite-element method (FEM). The femora of ten patients with contralateral hip fracture were analyzed to estimate fracture strength and to investigate whether the predicted fracture locations were similar to those of contralateral hip fractures. FEM has been utilized to determine the stress or strain distribution in bones under a certain load. FEM analyses of the strength of the femora in cadavers and patients have been reported, but those of hip fracture patients have not been analyzed. The femora of ten patients with contralateral hip fracture and those of three volunteers were analyzed based on the axial CT images of the whole femora. Prediction of hip fracture load and failure locations was made using CT-based finite-element analysis software. The predicted strength of the patients was less than half that of volunteers, and the predicted fracture lines existed at the proximal femur in all patients. It can be concluded that the FEM analyses adopted in this study are able to predict the fracture locations and load of the femora in patients with hip fracture.     

青壮年移位性股骨颈骨折的治疗——附55例病例长期随访

目的 评价股方肌肌骨瓣移植治疗青壮年移位性股骨颈骨折的长期疗效.方法 55例26～57岁股骨颈移位性骨折(GardenⅢ-Ⅳ型)患者,采用带股方肌肌蒂骨瓣移植和螺纹钉内固定术治疗.结果 本组55例均获随访,随访时间为4年6个月～10年8个月.所有患者的股骨颈骨折均在6～9个月内愈合,5例发生股骨头坏死.结论 带股方肌肌蒂骨瓣移植治疗青壮年移位性股骨颈骨折是一种疗效确切、创伤较小、操作方便的有效方法.