Growth in width of the metacarpals--an investigation in human fetuses.

The process of growth in width of the human hand during fetal life has never been described. Do metacarpals grow concentrically and separation between the bones occurs through expansion of soft tissues? Or is growth eccentric, a process termed drift by Enlow, a relocation in space of organs? Hands of 10 spontaneously aborted fetuses (age range: between 14.5 and 24 weeks of gestation) were examined paying special attention to the bone bark. A thicker bone bark was taken as an indication of growth in that direction. The thickness of the bone bark was measured at the radial and ulnar sides at the level of the proximal and of the distal physes of the second to fifth metacarpals. A ratio of radial over ulnar bone bark thickness (R/U ratio) was calculated. The third metacarpal grew almost concentrically (R/U ratio 1.12 ± 0.06). The second metacarpal grew in a radial direction (R/U ratio 3.29 ± 0.19) and the fourth and more so the fifth metacarpal grew in an ulnar direction (R/U ratio 0.70 ± 0.04 and 0.42 ± 0.02, respectively). The differences in R/U ratios between every metacarpal were statistically significant for all comparisons P ≤ 0.001. Fetal growth in width of the human metacarpals is eccentric and not concentric. It is concluded that during growth in width the metacarpals move away from the midline of the hand and that growth occurs through eccentric bone apposition rather than through soft tissue expansion. © 2001 Orthopaedic Research Society. Published by Elsevier Science Ltd. All rights reserved.     

Spleen's relative growth in human fetuses.

The growth of the spleen weight was studied by bivariate allometry. It was correlated to fetal parameters of development as gestational age (in weeks), crown-rump length (mm) and weight (gm). Thirty human fetuses ranging from 16 to 36 weeks were studied. These were analysed in second and third trimesters separately and together. The growth of the spleen weight presents statistically significant positive allometry relative to age, C-R length and fetal weight. In second trimester the allometric coefficient, analysing spleen's weight and fetus' weight, calculated by reduced major axis method (RMA) was 1.21. In the third one the RMA was 1.73. Considering fetuses together the RMA = 1.65. This study presents growth curves of the spleen weight useful in medical branches such as anatomy, forensic medicine, medical imagery, fetophatology, obstetrics and pediatrics.     

Low width of tubular bones is associated with increased risk of fragility fracture in elderly men--the MINOS study

The risk of fragility fractures in elderly men is only partly explained by areal bone mineral density (aBMD) measured by dual X-ray absorptiometry (DXA). Several studies suggest the importance of bone morphology for the risk of fracture. The aim of this study was to assess the value of bone size and estimated structural parameters for the prediction of incident fractures in a large cohort of men. This study was made in 759 men aged 50-85 from the MINOS cohort. During a 90-month follow-up, 74 men sustained incident vertebral and peripheral fractures. Areal BMD was measured by DXA at femoral neck, distal radius and distal ulna. Estimates of structural bone parameters and volumetric BMD (vBMD) were derived from aBMD measured by DXA. Given the limited number of fractures, the predictive value of investigated parameters was assessed for peripheral and vertebral fractures jointly by using logistic regression. Men who sustained the fractures had, at baseline, lower aBMD (3.5-6.5%), lower bone mineral content (BMC 5.4-8.7%) and lower cortical thickness (3.5-6.9%) compared with the men without fracture. At all the three skeletal sites, aBMD, BMC, width, cortical area and thickness, cross-sectional moment of inertia (CSMI), and section modulus predicted incident fractures (O.R. = 1.28-1.92 per 1 SD decrease, P < 0.05-0.0001). Fracture risk was weakly associated with vBMD for ulna (O.R. = 1.25 per 1 SD decrease, P < 0.05) but not for femoral neck or radius. After adjustment for aBMD, bone width remained a significant predictor of fractures (O.R. = 1.37-1.48 per 1 SD decrease, P < 0.02-0.01). Men with osteopenia (BMD T score < -1) and low bone width (T score < -1) had the fracture incidence similar to that observed in men with BMD T score < -2. Bone width and aBMD of the femoral neck and radius were predictive of fractures in 49 men with the incident peripheral fractures, whereas their O.R. did not attain the level of statistical significance in 25 men with the incident vertebral fractures. Men, who had both low aBMD and low CSMI ( both T scores < -1), had the fracture risk 3.8 to 4.2 higher than the reference group (both T scores >or= -1). Men, who had both low aBMD and low section modulus (both T scores < -1), had the fracture risk 2.1 to 4.1 higher than the reference group (both T scores >or= -1). In conclusion, men who sustained a fragility fracture during a 90-month follow-up had, at baseline, lower BMC because they had narrower bones but not necessarily less dense. In elderly men, small bone width, low BMC and poor resistance to bending may increase bone fragility. Low bone width seems to be associated with an increased fracture risk in elderly men regardless of aBMD.     

Localization of estrogen receptors in long bones and vertebrae of human fetuses

Summary In order to investigate the possible role of estrogen in the development of cartilage and bone we studied by immunofluorescence immunohistochemistry and autoradiography 26 human embryos and fetuses 7–22 weeks in gestational age associated with pregnancy interrupted for nonmedical reasons. In order to demonstrate the presence of estrogen receptors (ERs) in human fetal cartilage, cryostat sections of long bones and lumbar and thoracic vertebrae were prepared for (1) fluorescent immunocytochemistry using an antiidiotypic monoclonal antibody to antiestradiol receptor monoclonal Ab labeled with fluorescein isothiocyanate (FITC), (2) immunohistochemistry using monoclonal antihuman estradiol receptor antibody, labeled with strept. A-B immunoperoxidose, and (3) autoradiographic localization of estradiol using labeled (3 H) l7 estradiol. In fetuses aged 10 weeks or older, intranuclear and perinuclear localization of ER was demonstrated by all methods, mainly amongst chondrocytes of the proliferating and higher hypertrophic zones of the epiphyses and in the cartilage of vertebral bodies. These data suggest that estrogen acts directly on chondrocytes of human fetuses through an ER-mediated mechanism.     

60例四肢长管骨骨不连的原因分析

[目的]探讨骨不连发生的原因。[方法]对60例骨不连病人的骨折类型、手术方式、内固定材料等因素进行综合分析，研究导致骨不连的原因。[结果]因为患者自身因素导致骨不连的占8．3％；由于选用内固定器械不当或操作失误占81．6％；术后功能锻炼不当占10％。[结论]作者认为正确的使用内固定器械，熟练的运用手术技巧和术后科学的功能锻炼是防止骨不连的重要因素。     

Comparison of whole calvarial bones and long bones during early growth in rats

The increase of total collagen and its destruction were compared for whole calvaria and long bones from young growing rats prelabeledin utero with³H-L-proline. Rats were compared from birth to 16 weeks of age. Long bones and calvaria were isolated as intact anatomical units for autoradiography or separated by collagenase into calcified and uncalcified collagens. Autoradiography using¹⁴C-L-proline demonstrated eccentric remodeling of bone collagen. With growth the mass of calcified collagen (bone) increased rapidly in calvaria and long bones. A similar increase in the mass of uncalcified collagen (mainly cartilage) occurred in the long bones; a very small increase occurred in the fibrous tissue of calvaria. Total and specific radioactivities of collagens at each age were compared to that present at birth. With growth remodeling an almost complete loss of pre-existing radioactive collagen occurred from uncalcified fibrous tissue of calvaria as compared to a smaller but substantial loss from the uncalcified cartilage of long bones. A marked loss of calcified collagen occurred in long bones as compared to a smaller loss from calvarial bones. The isotopic data indicate a large turnover of fibrous tissue (type I collagen) with growth remodeling as compared to a smaller turnover of bone (calcified, type I collagen) and cartilage (type II collagen). The turnover rate of skeletal collagens depends upon whether the collagen is calcified or not, and not upon the type of collagen.     

自体与同种异体骨移植修复四肢长骨骨缺损的对比研究

目的比较自体与同种异体骨移植修复四肢长骨骨缺损的临床效果。方法回顾性分析132例异体骨和97例自体骨修复重建四肢长骨骨缺损患者的临床治疗资料,比较两种方法愈合时间、骨性愈合评分（按Jorgenson标准）、并发症发生率及植骨失败率。结果异体骨重建组132例,4例因感染致植骨失败需行病灶清除灌洗加自体骨移植,10例发生局部排斥反应,其余118例患者术后骨缺损获得良好修复,愈合时间（17．6±1．9）周。骨性愈合评分2．7±0．5。自体骨重建组97例,9例出现供区疼痛、切口感染及局部皮肤麻木等供区并发症,骨缺损均获得良好修复,愈合时间（17．4±23）周,骨性愈合评分2．84±0.3。两组之间在愈合时间、并发症发生率以及愈合评分方面的差异无统计学意义（P〉0．05）;在植骨失败率方面的差异有统计学意义（P〈0．05）。结论运用同种异体骨和自体骨移植重建四肢长骨骨缺损,均能获得满意结果且疗效相似。异体骨移植术后感染致植骨失败以及排斥反应发生率较高,而自体骨移植则多表现为供区的并发症。     

Comparison of whole calvarial bones and long bones during early growth in rats. Histology and collagen composition

The distribution of ossified collagen (bone) and uncalcified collagen (fibrous tissue and cartilage) was compared histologically for rat and dog calvaria at birth. The relative amount of bone and uncalcified collagen was quantitated morphologically for rat calvaria during the first four weeks of rapid growth. Whereas dog calvaria are essentially ossified at birth, rat calvaria at birth consist mostly of fibrous tissue but rapidly become ossified with growth. Bacterial collagenase was used to separate uncalcified collagen from calcified collagen of whole membranous bones (frontal and parietal) and long bones (femur and humerus) at birth from man, monkey, dog, guinea pig, rabbit and rat. By this means quantitative changes in the relative fractions of the two forms of collagen were determined during the first eight weeks of postnatal growth for each type of rat bone. Quantitative biochemical data on whole rat bones (calvarium, femur, humerus) confirmed measurements based on histology which showed that at birth rat calvaria are mostly uncalcified as compared to other species whose bones are mostly ossified at birth. With growth rat membranous bones ossify more rapidly than long bones.