动力髁螺钉(DCS)治疗股骨髁上骨不连16例报告

目的观察动力髁螺钉(DCS)治疗股骨髁上骨不连的临床疗效。方法16例股骨髁上骨不连均采用断端修整、自体髂骨植骨及DCS内固定治疗，5例伴有膝关节粘连者同时行膝关节松解术。结果所有病例获得随访，时间12～48个月，平均18个月。在4～9个月内均获骨性愈合。合并膝关节粘连者功能也获得明显改善。参照Shelbourne疗效评定标准，优8例，良5例，功能优良率达81．3％。结论应用DCS固定 自体髂骨植骨后，骨折端可获得坚强内固定及持久的压应力，有利于早期进行膝关节功能锻炼，是治疗股骨髁上骨不连的有效方法。     

影响冠状动脉旁路移植术手术死亡的危险因素分析

目的探讨影响我国冠状动脉旁路移植术(coronary artery bypass grafting,CABG)手术死亡的危险因素。方法选择北京阜外心血管病医院2002年1月1日至2003年12月31日(以手术日期为准)行CABG的冠心病患者2251例,确定潜在危险因素后,根据潜在危险因素从其临床资料中收集数据,对影响手术死亡的潜在危险因素进行单因素分析和logistic多因素回归分析,最终确立影响我国CABG手术死亡的危险因素,并对分析结果的校准度和分辨能力进行检验。结果全组手术死亡率为1.87%(42/2251),手术时年龄60.3±9.3岁,女性436例(19.4%)。logistic多因素回归分析结果:心源性休克、心律失常、左主干病变>50%、左心室射血分数(LVEF)、二尖瓣反流、肺动脉瓣反流、术前最后一次肌酐值、手术状态(非择期手术)、合并主动脉瘤手术等9个因素是本组CABG手术死亡的独立危险因素。受试者工作特征(Receiver-Operating Characteristic,ROC)曲线检验结果:曲线下面积为0.842。结论通过logistic多因素回归分析得出,心源性休克、心律失常、左主干病变>50%、LVEF、二尖瓣反流、肺动脉瓣反流、术前最后一次肌酐值、手术状态(非择期手术)、合并主动脉瘤手术等9个影响我国患者CABG手术死亡的危险因素。分析结果具有良好的校准度和分辨能力。     

A journey through growth plates: tracking differences in morphology and regulation between the spine and the long bones in a pig model

Background Context

The process of linear growth is driven by axial elongation of both long bones and vertebral bodies and is accomplished by enchondral ossification. Differences in regulation between the two skeletal sites are mirrored clinically by the age course in body proportions. Whereas long bone growth plates (GPs) can easily be discriminated, vertebral GPs are part of the cartilaginous end plate, which typically shows important species differences.

生长因子促进转基因小鼠坐骨神经体外预变性的实验研究

目的 探索一种简便高效的小鼠坐骨神经体外预变性的方法,以便在短期内获取大量高活性的雪旺细胞.方法　选用绿色荧光蛋白(GFP)转基因的小鼠24只,随机分为A、B、C和D四组.A、B、C组切取双侧坐骨神经,分别置于DMEM、DMEM+10％FBS及含生长因子的雪旺细胞培养液中体外预变性1周,D组切断一侧坐骨神经体内预变性1周.1周后取材,行免疫组织学和细胞学方面的检测,比较各组获取的雪旺细胞量和纯度.结果　C组获得的雪旺细胞量及纯度较高,与D组的雪旺细胞相似.结论　生长因子能促进小鼠坐骨神经的体外预变性,具有与体内预变性相似的效果,能在短期能获得大量雪旺细胞.     

Heterogeneity of Trabecular Bone Structure in the Calcaneus Using Magnetic Resonance Imaging

The purpose of this study was to quantify the heterogeneity in the trabecular bone structure in the calcaneus. Magnetic resonance (MR) images of the calcaneus were obtained in the sagittal plane at an inplane resolution of 195 μm and a slice thickness of 1000 μm in 12 young normal subjects. Regions of interest (ROI) were selected to cover the calcaneus using a grid of square boxes (10 mm per side). A thresholding technique based on the regional intensity histogram was used to segment the images into trabecular bone and marrow phases and to calculate measures such as apparent trabecular bone area fraction, apparent trabecular spacing, apparent trabecular thickness and apparent trabecular number. Bone mineral density (BMD) of the calcaneus was assessed using dual-energy X-ray absorptiometry (DXA). Histological sections of three calcanei were also analyzed using transmission light illumination, and the results used to calibrate our computational software. For a relatively narrow inter-subject variation in posterior BMD, a significant inter-subject variation was seen in MRI-derived structural parameters. Furthermore, the spatial heterogeneity of the structural parameters in the posterior region was as high as 40%. Thus, the posterior tuberosity of the calcaneus, a typical site for BMD and single-point ultrasound assessments, can demonstrate significant regional variation in trabecular bone structure.     

Improved Performance of Hip DXA Using a Novel Region of Interest in the Upper Part of the Femoral Neck: In Vitro Study Using Bone Strength as a Standard of Reference

We tested the hypothesis that bone mineral density (BMD) and bone mineral content (BMC) in proximal human femur specimens in the upper neck region of interest (ROI) and femoral neck axis length (FNAL) provide a significantly better prediction of femoral bone strength than standard ROIs in vitro. BMD and BMC were measured in 110 proximal femur specimens using a standard dual-energy X-ray absorptiometry (DXA) scanner. The analysis included a new ROI in the upper neck as well as the standard ROIs. FNAL was obtained from the scan images. The specimens' failure-load was measured in a mechanical loading device, simulating a fall on the greater trochanter. For the standard ROIs, correlations between failure-load and BMD ranged from R2 = 0.64 (shaft ROI) to R2 = 0.70, p < 0.001 (femoral neck). Prediction of strength by BMD did not significantly differ from those of BMC (R2 ranging from 0.65 to 0.75, p < 0.001). In the upper neck ROI, for both BMD and BMC correlations with failure-load were higher (R2 = 0.76 and 0.81, respectively; p < 0.001). A lower, yet still significant, correlation was found between FNAL and bone strength (R2 = 0.23, p < 0.001). Normalization of failure-load with respect to FNAL did not significantly increase the correlations with densitometric measures. This study provides in vitro evidence indicating that among the ROIs of the proximal femur the newly defined upper neck ROI provides the best prediction of bone strength. Only a weak association was observed between failure load and FNAL.     

Quantitative Radiographic Assessment of Cancellous Bone Changes in the Proximal Tibia After Total Knee Arthroplasty: a 3-year Follow-up Study

The objective of this study was to determine whether fractal signature analysis (FSA) of digitized macroradiographs of knees with prosthetic implants quantifies alterations in tibial trabecular structure surrounding the implant over a 3-year period. Nineteen knees (16 patients) with arthroplasty had macroradiographs (×4) at baseline and annually for 3 years. The regions of interest (ROIs) were located in the medial and lateral plateau, midstem, and apical sites. FSA of horizontal and vertical trabecular organization was measured at each ROI, and the changes at the yearly visits were compared to the baseline values. Compared to the baseline values, FSA of the first-year radiographs detected a significant (P < 0.05) decrease in the number of vertical trabeculae in the medial compartment, and vertical, and horizontal trabeculae in the lateral compartment. During the second year, bone remodeling led to an increase in the number of horizontal trabeculae in the medial compartment, and vertical, and horizontal trabeculae in the lateral compartment. During the third year, there was a significant increase (P < 0.05) in the number of vertical and some horizontal trabeculae in both the medial and lateral compartments. Overall trabecular changes were significantly greater in the lateral than in the medial compartment. Following total knee arthroplasty, the response of bone showed that the first year was characterized by trabecular loss in response to posttraumatic osteopenia following surgery. By the third year, this process had reversed, with a significant increase in mainly vertical and some horizontal trabeculae in both the medial and lateral compartments, with only the lateral compartment showing an overall loss in small- and medium-sized trabeculae by the end of the study period.     

Effect of bone marrow stromal cells in combination with biomaterials in early phases of distraction osteogenesis: An experimental study in a rabbit femur model

Acceleration of the consolidation of the distracted bone is a relevant medical need. As a platform to improve in vivo bone engineering, we developed a novel distraction osteogenesis (DO) model in a rabbit large bone (femur) and tested if the application of cultured bone marrow stromal cells (BMSCs) immediately after the osteotomy promotes the formation of bone. This report consists of two components, an animal study to evaluate the quality of the regenerate following different treatments and an in vitro study to evaluate osteogenic potential of BMSC cultures. To illuminate the mechanism of action of injected cells, we tested stem cell cultures enriched in osteogenic-BMSCs (O-BMSCs) as compared with cultures enriched in non-osteogenic BMSCs (NO-BMSCs). Finally, we included a group of animals treated with biomaterials (fibrin and ground cortical bone) in addition to cells. Injection of O-BMSCs promoted the maturity of distracted callus and decreased fibrosis. When combined with biomaterials, O-BMSCs modified the ossification pattern from endochondral to intramembranous type. The use of NO-BMSCs not only did not increase the maturity but also increased porosity of the bone. These preclinical results indicate that the BMSC cultures must be tested in vitro prior to clinical use, since a number of factors may influence their outcome in bone formation. We hypothesize that the use of osteogenic BMSCs and biomaterials could be clinically beneficial to shorten the consolidation period of the distraction and the total period of bone lengthening.     

Predicting the effects of estrogen replacement therapy on lumbar bone mineral density in oophorectomized women: analysis of a 10-year longitudinal study

The purpose of this study was to investigate whether it is possible to predict the long-term effects of estrogen replacement therapy (ERT) on lumbar bone mineral density (BMD) of oophorectomized women based on changes in BMD. In this study, we retrospectively investigated the changes in lumbar BMD of 70 oophorectomized women under ERT for more than 10 years, and examined whether it was possible in the early stage of ERT to predict the amount of lumbar BMD based on various parameters. Seventy oophorectomized Japanese women (56.8±3.9 years old) treated with conjugated equine estrogen (oral) at a dosage of 0.625 mg/day for 10 years were enrolled. Lumbar (L2–L4) BMD was measured annually by dual-energy X-ray absorptiometry (DXA; CV<1.0%). The correlation between changes in BMD after 10 years on ERT (BMD10) and several clinical factors was examined using a stepwise multiple regression model. The change in BMD after 1 year on ERT (%BMD1) was the only independent factor that correlated with changes in BMD after 10 years on ERT; the coefficient of correlation was R ²=0.557 (R=0.750, P<0.001). Based on the %BMD1, the 70 women were divided into two groups: women with a positive change in the 1st year (%BMD10%) in group A (n=40) and those with a negative value in the first year ( %BMD1<0%) in group B (n=30). We investigated the sensitivity and specificity in the coincidence of %BMD1 changes in BMD after 10 years on ERT. The %BMD1 coincided with changes in BMD after 10 years on ERT; the sensitivity was 92.5% and specificity was 70.0%. In conclusion, changes in lumbar BMD on ERT can be predicted from the changes in lumbar BMD at the end of the 1st year.     

手法复位联合微创手术治疗骨质疏松性椎体压缩骨折疗效的Meta分析

目的:应用Meta分析评价手法复位在联合经皮椎体成形术(percutaneous vertebroplasty,PVP)或经皮椎体后凸成形术(percutaneous kyphoplasty,PKP)治疗骨质疏松性椎体压缩骨折(osteoporotic vertebral compression fracture,OVCF)中的有效性,为临床治疗提供参考。方法:检索中国学术期刊网、万方数据库、Web of Science 和PubMed,获得1987年1月至2014年4月期间有关手法复位和PVP及PKP治疗骨质疏松性椎体压缩骨折的临床对照研究文献,对入选的文献进行质量评价,选择疼痛(VAS评分)缓解、后凸角(Cobb角)改善、椎体前缘高度恢复等作为Meta分析的评价指标。结果:共纳入文献7篇,包含5篇随机对照研究,2篇非随机对照研究。2篇研究为手法复位联合PVP与单纯PVP治疗OVCF的效果,5篇研究为手法复位联合PKP与单纯PKP治疗OVCF的效果。所有研究均来自中国,共纳入410例研究对象(465个病椎).与单纯PVP比较,手法复位联合PVP能更好地改善Cobb角(WMD=-7.35;95%CI:-12.15,-2.54)和椎体前缘高度(p<0.01),但两组在VAS评分改善方面差异无统计学意义(WMD=-0.01;95%CI:-0.45,0.42);与单纯PKP比较,手法复位联合PKP治疗在VAS评分改善、Cobb角改善、椎体前缘高度恢复方面差异均无统计学意义(p>0.05).结论:与单纯PVP及PKP治疗OVCF相比,手法复位联合PVP能更好地改善Cobb角和椎体前缘高度,而手法复位联合PKP在疼痛缓解、Cobb角改善、椎体前缘高度恢复方面均无明显优势。研究纳入的文献数量较少,有必要进一步开展大样本、高质量的随机对照研究予以证实。     

Assessment of the Stratos, a New Pencil-Beam Bone Densitometer: Dosimetry, Precision, and Cross Calibration

The goal of this study was to assess a new pencil-beam densitometer, the Stratos (Diagnostic Medical Systems, Pérols, France). Evaluation of the dosimetry and precision were done together with an in vivo cross-calibration study performed with the fan beam densitometer Discovery A (Hologic, Bedford, MA). The results indicated that the Stratos performed bone mineral density (BMD) measurements with a good precision, low radiation dose, and good agreement with the Discovery A. The air dose, measured by an ionization chamber, was 40 μGy. The effective dose was assessed using an anthropomorphic phantom and thermoluminescent detectors resulting in 1.96 and 0.31 μSv for a lumbar spine and proximal femur scan, respectively. The average scattered dose rate at a distance of 1 m from the device was 1.06 and 1.21 μSv.h⁻¹ in the lumbar spine and left proximal femur scan mode, respectively. For the precision evaluation, 30 patients underwent 2 lumbar spine and 2 proximal femur scans with repositioning after each scan. The percentage root-mean-square coefficient of variation was 1.22%, 1.38%, 2.11%, and 0.86% for the lumbar spine (L1–L4), lumbar spine (L2–L4), femoral neck, and total hip, respectively. The cross-calibration studies were done on 57 patients (60 ± 9 yr). Lumbar spine, left neck, and left total hip mean BMD were 3.10% lower and 11.94% and 8.83% higher, respectively, with the Stratos compared with the Discovery A. Cross-calibration equations were calculated with a correlation coefficient of 98% (p < 0.01) for the lumbar spine (L2–L4), 94% (p < 0.01) for the left neck, and 92% (p < 0.01) for the left total hip. After standardizing the Stratos measures using the cross-calibration equations, LIN’s concordance correlation coefficient was 0.98, 0.93, and 0.92 for the lumbar spine (L2–L4), left neck, and total hip, respectively.