Bone histological heterogeneity in postmenopausal osteoporosis: A sequential histomorphometric study

We studied sequential bone biopsies performed at 6 to 24 month intervals from 14 untreated osteoporotic women (64 ± 7). Subgroups were defined, respectively, by increased osteoclastic resorption surfaces and decreased osteoblastic surfaces ± 2 S.D. Normal values were obtained from bone biopsy of 23 normal women (61 ± 8). When patients were divided into subgroups according to the above criteria the first biopsy showed that 3 out of the 14 patients had high resorption surfaces and 6 had low osteoblastic surfaces. Eight patients spontaneously changed during the study. In 2 patients there was a change in resorption surfaces, in 3 in osteoblastic surfaces and in 3 a change in both osteoblastic and resorption surfaces was observed. Considering the first or second bone biopsy results the patient variance was higher than the control subject's variance; however the variance between the first and second bone biopsy of one patient was not different from the variance inside the group of patients. The average intraindividual variation of the parameters on sequential biopsies was of the same order as the one we previously observed on simultaneous bone biopsies of normal and hemodialyzed patients. We concluded that if osteoporosis is a heterogeneous disorder, subgroups cannot be definitively defined on the basis of cellular parameters of bone remodelling assessed on bone biopsies.     

Glucocorticoid-induced inhibition of osteoblastic bone formation in ewes: A biochemical and histomorphometric study

The mechanisms underlying glucocorticoid-induced osteoporosis in humans are a defect in bone formation associated with increased bone resorption. The latter may be due to elevated parathyroid hormone (PTH) levels induced by the impairment of intestinal calcium absorption caused by corticosteroids. In this study we analysed the effects of corticosteroids in old ewes, a potential model for the study of human bone turnover. Two groups of seven 9-year-old female sheep were selected. The first group was injected intramuscularly with a daily dose of 30 mg methylprednisone (MP) during the first 2 months and 15 mg during the last month. After 2 and 3 months of treatment, blood samples were taken. At the end of the experiment the animals were slaughtered and the iliac crest kept for bone histomorphometry. Serum osteocalcin (sOC) rapidly and markedly decreased in the MP-treated group compared with controls (–77%;p<0.01). In contrast, at the end of the experiment serum calcium and PTH levels were similar in both groups. Histomorphometric analysis showed a significant reduction in the wall width of trabecular packets. Dynamic parameters reflecting bone formation at the tissue and cell levels were significantly lower in the MP-treated group than in controls, with a highly significant decrease in the mineralization rate (MAR: –63%,p<0.05) and double-labeled perimeter (dLPm/B.Pm: –92%p<0.05). The bone formation rate (BFR/B.Pm) also decreased by 84% and the adjusted apposition rate (Aj.AR) by 80%. The increase in the total formation period was mainly due to an increase in the inactive period. Significant correlations were found between sOC and MAR, dLPm/B.Pm and BFR/B.Pm (withr respectively 0.67, 0.76 and 0.51). In conclusion, the effects of corticosteroid on ewe bone remodeling are essentially characterized by a major bone formation defect without evidence of secondary hyperparathyroidism, although this cannot be totally excluded by our results. Ewes treated with glucocorticoids could represent a good model for evaluating the effects of drugs candidates for all bone conditions characterized by reduced bone formation resulting from osteoblastic depression.     

Feasibility study on posterior laminar screw fixation techniques in the axis

Objective： To get morphologic parameters of Chinese adults through observation and measurement on axial laminas, to evaluate the feasibility of placing axial laminar screws and to introduce the technique. Methods： Relative parameters of 28 sets of fresh Chinese adults＇ axial specimens, including distance from the superior and inferior entry points of axial laminar screws to the superior margins of axial laminas, superior, middle, inferior thickness and height of the axial laminas, length and angle of the axial laminar screw trajectories, distance from the entry points of axial laminar screws to the transverse foramen and central points of the inferior articular process, were measured with a digital caliper and a goniometer. Data were statistically analyzed. Results： Averagely, distance from the superior and inferior entry points of axial laminar screws to the superior margins of axial laminas was 5 mm and 9 mm, superior, middle, inferior thickness and the height of the axial laminas were 3.2 mm, 6.7 mm, 5.5 mm and 12.8 mm respectively, and the length of the superior and inferior axial laminar screw trajectories was 26.2 mm and 25.5 ram, respectively. Conclusions： It is feasible and reliable to apply posterior laminar screw fixation techniques to the axes of Chinese adults. Also the C2 laminar screw fixation technique can be taken as a supplementary to conventional posterior screw fixations of C2.     

Dose effects on ewe bone remodeling of short-term sodium fluoride administration — A histomorphometric and biochemical study

The early effects of two doses of sodium fluoride (NaF) on bone remodeling was studied in 14 ewes divided into two groups. Group I received orally 1 mg NaF/kg/day and group II received a five-fold greater dose. No calcium supplement was given. Transiliac bone biopsies and blood samples were taken before treatment (T₀) and after 45 (T₄₅) days of treatment. Bone fluoride content significantly increased in group II. In both groups, a significant decrease of serum calcium and phosphorus, and a slight but nonsignificant augmentation in serum parathyroid hormone were noted. Osteoid perimeter and area were significantly increased. The osteoid width significantly increased in both groups, but was twice higher in group II than I. At T₄₅, the osteoblast perimeter increased in both groups. Osteoid perimeter was significantly correlated with serum osteocalcin values (r = 0.74; p < 0.001) and bone fluoride content (r = 0.64; p < 0.01). The bone formation rate at tissue level tended to increase in both groups. Concerning the apposition rate, a decrease was noted which was 1.5-fold higher in group II than in I. The increased formation period resulted from a prolonged inactive period in group II. These results point out a stimulatory effect of fluoride on the birth rate of osteoblasts. However, fluoride prolonged the lifespan of osteoblasts that had reduced activity.     

Tibial epiphyseal development: a cross-sectional histologic and histomorphometric study in the New Zealand white rabbit

Sequential histomorphometric studies on the developing rabbit tibia from birth to skeletal maturity demonstrate that growth plate height lessens as longitudinal growth diminishes. Differing rates of development proximally and distally are documented. Distally, growth plate height, width, and area and total epiphyseal area peak or reach near maximum values by 3 weeks, whereas proximally, they do so by 8 weeks (except for height, which also peaks at 3 weeks). The distal growth plate is being obliterated by 16 weeks, at which time the proximal growth plate remains well structured and open. The distal tibia and fibula develop as one tissue mass. The articular cartilage and epiphyseal cartilage are continuous from birth, whereas a single ossification center and a single growth plate are present by 8 weeks. The data point to the presence of intrinsic growth plate, as well as systemic, control mechanisms affecting skeletal growth. Knowledge of temporal and quantitative features of epiphyseal and growth plate development will greatly aid in the elucidation of the underlying controls.     

维氏显微压痕技术测量人体枢椎硬度

目的 :探讨成人新鲜尸体枢椎的显微压痕骨硬度的分布特征及生理意义。方法 :取3具新鲜尸体标本(62岁男性,45岁女性,58岁男性)的枢椎,通过X线和定量CT检查除外影响骨量的疾病,将其分为齿状突椎体区和附件区2个测量部位,每个区域使用高精慢速锯精确切取1片厚约3mm的标本,3块枢椎共计6片。齿状突椎体区选取上侧、下侧、前侧和后侧四个部位的皮质骨区域以及中部松质骨区;附件区选取椎弓根、横突、椎板和侧块皮质骨区域以及中部侧块松质区。每块枢椎选取10个区域,合计30个区域。标本固定于纯平玻片上,应用维氏显微硬度测量仪测量标本表面硬度,每个区域随机选取5个有效硬度值,合计获得150个有效压痕硬度值。记录并分析枢椎的显微硬度分布规律。结果:枢椎整体硬度变化范围为17.70～40.60HV,其中皮质骨硬度范围17.70～40.60HV,平均硬度30.10±4.96HV;松质骨硬度范围20.40～37.40HV,平均硬度29.06±4.42HV;齿状突椎体区皮质骨平均硬度30.25±5.06HV,松质骨平均硬度28.78±4.17HV;附件区皮质骨平均硬度29.95±4.90HV,松质骨平均硬度29.33±4.79HV;同一部位的皮质骨硬度值均高于该部位的松质骨硬度值。附件区硬度值最高为椎弓根皮质(32.92±4.06HV),组间比较差异具有统计学意义(F=3.5832,P=0.014)。齿状突椎体区硬度值最高为后侧皮质(33.23±4.80HV),组间比较差异具体统计学意义(F=3.363,P=0.025)。结论:齿状突椎体区的后侧皮质硬度值与附件区椎弓根皮质硬度值均较高,可能与枢椎后侧皮质区域和椎弓根区域较其他部位承受着更大的应力有关。     

Electromagnetic stimulation of bone repair: a histomorphometric study

The effect of pulsing electromagnetic fields (PEMFs) on bone repair was studied in principal metacarpal bones of eight adult male horses: Six horses were treated with PEMFs, and two horses were untreated. In treated horses, Helmholtz coils were applied during a 60-day period to the left metacarpal bones, bored with eight holes of equal diameter and depth, from the middiaphysis toward the distal metaphysis. Eight equal holes bored in the right metacarpal, surrounded by unactivated Helmholtz coils, were taken as controls. The two untreated horses were taken as additional control. The results of computer-assisted histomorphometric analysis indicate that (a) in diaphyseal levels, the amount of bone formed during 60 days is significantly greater (p less than 0.01) in PEMF-treated holes than in contralateral ones and those in control horses; (b) in metaphyseal levels, PEMF-treated holes are sometimes more closed, sometimes less, as compared with contralateral holes and those in control horses; in any case the statistical analysis indicates that the symmetry in the rate of hole repair, found between the two antimeres of control horses, is not appreciable at metaphyseal levels also; (c) there was no statistically significant difference between untreated holes in PEMF-treated horses and holes in control horses, neither at diaphyseal nor at metaphyseal levels. These preliminary findings indicate that PEMFs at low frequency influence the process of bone repair on both diaphysis and metaphysis, and seem to improve the process of bone repair in skeletal regions normally having a lower osteogenetic activity, i.e., in diaphyses as against metaphyses.     

Pattern of bone loss of the proximal femur: a radiologic, densitometric, and histomorphometric study

The pattern of bone loss in the proximal femur was studied in 141 cadaveric femora from 36 women and 39 men ranging from 27 to 89 years of age. Bone mineral density (BMD) of the femoral neck, greater trochanter, Ward's triangle, and tensile and compressive stress regions were measured by dual photon absorptiometry. Radiographs were graded by Singh's method. Histomorphometry of tensile and compressive trabecular areas was performed on ground midsection of the methylmethacrylate-embedded whole proximal femur. Although Singh index had some correlation with BMD of the femoral neck, the various BMD measurements showed that all regions lost bone to the same extent; in particular, no selective bone loss was found at low stress regions (tensile trabeculae or Ward's triangle). Histomorphometry revealed that most of the trabecular bone loss of the proximal femur is attributable to a decrease in thickness of individual trabeculae.     

Paget disease of the spine: an evaluation of 101 patients with a histomorphometric analysis of 29 cases

Introduction  

Paget’s disease of bone (PDB) is the second most frequent metabolic bone disease with the spine being a common site of manifestation. Still, neither the disease’s etiology nor reasons for its manifestation at preferred skeletal sites are understood. The aim of the current study was therefore to perform a histologic and histomorphometric analysis of PBD biopsies of the spine to achieve a more detailed understanding concerning PDB activity and characteristics.     

Risk factors for non-union in the non-operative management of type II dens fractures

Background: Despite the publication of numerous studies, there remains controversy regarding the non‐operative treatment of type II dens fractures. The halo‐thoracic vest (HTV) and rigid cervical collar are the most commonly used. We sought to compare the outcomes of patients managed with these devices in terms of risk factors for non‐union and complication rates. Methods: This study was a retrospective review of adult patients with type II dens fractures treated non‐operatively at a Level 1 Trauma Centre between 2001 and 2007. Patient medical records and imaging studies were reviewed. Union was defined as stable fibrous union or bony union at 3 months. Results: Sixty‐seven patients were included – 35 treated using a HTV and 32 with a collar. Non‐union was associated with increased time in HTV or collar (P= 0.011), a mechanism of injury involving a low fall (P= 0.008), or low velocity injuries (P= 0.04). The proportion of patients with stable union at 3 months was 60% for the HTV group versus 35% for the cervical collar group (P= 0.10). There were trends to support increased risk of non‐union with age ≥65 years (P= 0.13) or with fracture displacement ≥2 mm (P= 0.17) at the time of presentation. Clinically significant complications of the HTV were more common than those experienced with collar. Of HTV patients, 60% suffered one or more complications compared with 6% for collar. Conclusions: We were unable to demonstrate any statistically significant advantage or disadvantage of either device. Further investigation of mortality and morbidity would be beneficial.     

Effect of a five-week swimming program on rat bone: A histomorphometric study

Summary To specify the exercise-induced changes on different skeletal sites, the effect of a 5-week endurance swin training was studied in rats. Eighteen Lyon strain (Sprague-Dawley) 5-week old female rats were divided into nine sedentary and nine swimming rats. Each swim training session was increased by 15 minutes from 2–6 hours per day. A histomorphometric study was performed at the primary and secondary spongiosa of the distal femur and at the secondary spongiosa of lumbar and thoracic vertebral bodies. After training, bone loss was observed in the secondary spongiosa of lumbar vertebral bodies (24.7%) and in the primary spongiosa of distal femur (15.2%). A tendency to bone loss was also detected in the secondary spongiosa of distal femur (10.8%), whereas no change was detected in thoracic vertebral bodies. In secondary spongiosa, bone loss was accompanied with a thinning of trabeculae. Total eroded surfaces and osteoid surfaces were significantly decreased in the three studied skeletal sites, suggesting a decreased bone turnover. The decreased thickness of osteoid seams in both lumbar vertebrae and distal femur could mean that the osteoblastic activity has also been altered at the cell level, leading to thinning of trabeculae. Five-week swim training with such duration and intensity of exercise appears unable to increase bone volume in rats and, therefore, causes adverse effects. The three studied bones seemed to adapt differently to experimental conditions. The lack of ground reaction forces induced by water immersion might have contributed to the observed bone loss. Normal gravity would be an important cofactor in the osteogenic effects of exercise.     

Bone microarchitecture of the calcaneus and its changes in aging: a histomorphometric analysis of 60 human specimens.

Bone structure and quality are an important parameter in the propensity of bone to fracture. Although the calcaneus is used as diagnostic reference site for osteoporosis by ultrasound, its structure has never been analyzed in detail. The purpose of this study was therefore to histomorphometrically analyze the trabecular microarchitecture of the calcaneus, and to determine whether the calcaneal bone structure is changing with age. Sixty complete human calcanei were harvested from thirty age- and gender-matched patients at autopsy. Each of the three different age groups (group I: 20 to 40, group II: 41 to 60, group III: 61 to 80 years of age) was represented by 20 specimens. The specimens were subjected to radiographic, microCT, and histologic analysis. Bone structure and bone mass of the calcaneus were quantified for three different regions of interest: the anterior ROI, the superior ROI (the subtalar region under the posterior facet), and the posterior ROI. An iliac crest biopsy was obtained from all patients to exclude any metabolic bone disease. Histomorphometric analysis revealed significant differences in bone volume within the calcaneus with highest values in the superior ROI: age group I: 31.3% (27.8-34.8%); II: 25.5% (22.1-28.9%); III: 18.9% (16.6-21.2%) and lowest bone volumes in the anterior ROI; age group I: 6.2% (4.8-7.6%); II: 3.6% (2.1-5.1%); III: 3.9% (2.9-4.9%). There was a significant age-related decrease in bone volume (BV/TV) in aging. Interestingly, this bone loss was most prominent in the superior ROI, with a 39% decrease in BV/TV between age group I and III (p < 0.001). Qualitative and structural analysis of trabecular number, thickness, and spacing demonstrated that the bone loss in the thalamic portion of the calcaneus was due to the transition of plate-like trabecular elements into a rod-like structure. In conclusion, our study demonstrated that the calcaneus displayed age-related changes in its microarchitecture that are known to reduce the biomechanical stability of trabecular bone, and that the age-related bone loss was most prominent in the region adjacent to the posterior facet (superior ROI). These results suggest that bone mass and structure are risk factors in respect to the occurrence and severity of calcaneal fractures, and indicate that calcaneal fractures are at least in part osteoporotic fractures.     

Diabetes mellitus and the risk of non-vertebral fractures: the Tromsø study

We wanted to determine the risk of non-vertebral fracture associated with type and duration of diabetes mellitus, adjusting for other known risk factors. This is a population-based 6-year follow-up of 27,159 subjects from the municipality of Tromsø, followed from 1994 until 2001. The age range was 25–98 years. Self-reported diabetes cases were validated by review of the medical records. All non-vertebral fractures were registered by computerized search in radiographic archives. A total of 1,249 non-vertebral fractures was registered, and 455 validated cases of diabetes were identified. Men with type I diabetes had an increased risk of all non-vertebral [relative risk (RR) 3.1 (95% CI 1.3–7.4)] and hip fractures [RR 17.8 (95% CI 5.6–56.8)]. Diabetic women, regardless of type of diabetes, had significantly increased hip fracture risk [RR 8.9 (95% CI 1.2–64.4) and RR 2.0 (95% CI 1.2–3.6)] for type I and type II diabetes, respectively. Diabetic men and women using insulin had increased hip fracture risk. Duration of disease did not alter hip fracture risk. An increased risk of all non-vertebral fractures and, especially, hip fractures was associated with diabetes mellitus, especially type I. Type II diabetes was associated with increased hip fracture risk in women only.     

枢椎椎板螺钉固定的解剖可行性研究

目的:评价对国人进行枢椎椎板螺钉固定的可行性,探讨进钉技术。方法:用电子游标卡尺和量角器在30例干燥枢椎标本上测量与进钉技术相关的解剖学数据,包括枢椎椎板的厚度,棘突根部、椎板和下关节突的高度。设定枢椎椎板螺钉的进钉点位于枢椎棘突中线两侧5mm,上位螺钉距椎板上缘5mm,对侧的下位螺钉距椎板上缘9mm,螺钉在棘突根部上下交叉进入对侧椎板,并于下关节突中心点出钉,测量上位和下位椎板螺钉的钉道长度和进钉角度。结果:枢椎椎板上缘、中部、下缘的厚度分别是3.02mm、5.91mm和5.59mm;枢椎棘突根部、椎板和下关节突中部的高度分别是12.40mm、12.95mm、14.03mm;上位和下位椎板螺钉的平均长度分别是25.41mm和27.39mm;上位螺钉前斜26.4°,下斜7.6°;下位螺钉前斜30.1°,上斜1.4°。结论:对国人进行枢椎椎板螺钉固定在解剖学上是可行的,该方法可作为传统枢椎后路螺钉固定技术的补充。     

新型一体化人工枢椎力学性能的有限元分析

目的:通过有限元方法分析新型一体化人工枢椎的力学性能。方法:通过薄层CT扫描l名健康21岁男性志愿者颅颈椎(颅前窝至C7)获取其骨性结构信息。将信息导入医学三维重建软件,模拟手术完整切除C2并在此基础上建立新型一体化人工枢椎和异形钛网两套内固定系统三维有限元模型。通过Ansys 14.5有限元软件调整上颈椎的3D模型,使其与Panjabi尸体标本实验数据基本一致,以验证模型的有效性。然后在有限元软件Ansys 14.5中对模型枕骨髁部施加40N的压力模拟头颅重力,同时施加1.5N·m的力矩,使模型产生前屈、后伸、侧屈及旋转运动,分别测量两套内固定系统中假体的最大应力和最大位移,以及C3上终板的最大应力。结果:在后伸、前屈、侧屈及旋转4种工况下,一体化人工枢椎和异形钛网的最大应力值分别为199.79MPa、472.52MPa、239.96MPa、403.45MPa以及820.47MPa、848.98MPa、492.24MPa、804.12MPa;最大位移值分别为1.8734mm、1.8887mm、0.8121mm、2.6758mm以及2.4268mm、2.5195mm、0.9731mm、3.2075mm;C3椎体上终板的最大应力值分别4.5104MPa、5.8427MPa、4.0497MPa、12.7230Mpa以及4.8444Mpa、5.7976Mpa、6.4343Mpa、14.0820Mpa。结论:新型一体化人工枢椎假体在上颈椎前路重建手术方面可提供足够的固定强度和稳定性,与异形钛网相比,具有更好的稳定性和更少的应力集中等优势。     

Effect of low-power GaAlAs laser (660 nm) on bone structure and cell activity: an experimental animal study

Low-level laser therapy (LLLT) is increasingly being used in the regeneration of soft tissue. In the regeneration of hard tissue, it has already been shown that the biomodulation effect of lasers repairs bones more quickly. We studied the activity in bone cells after LLLT close to the site of the bone injury. The femurs of 48 rats were perforated (24 in the irradiated group and 24 in the control group) and the irradiated group was treated with a GaAlAs laser of 660 nm, 10J/cm² of radiant exposure on the 2nd, 4th, 6th and 8th days after surgery (DAS). We carried out histomorphometry analysis of the bone. We found that activity was higher in the irradiated group than in the control group: (a) bone volume at5 DAS (p=0.035); (b) osteoblast surface at 15 DAS (p=0.0002); (c) mineral apposition rate at 15 and 25 DAS (p=0.0008 and 0.006); (d) osteoclast surface at 5 DAS and 25 DAS (p=0.049 and p=0.0028); and (e) eroded surface (p=0.0032). We concluded that LLLT increases the activity in bone cells (resorption and formation) around the site of the repair without changing the bone structure.