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71.
An advanced analysis of the mechanical properties of bone should include information about the microarchitecture of cancellous bone in addition to its density. It has recently been shown that high-resolution quantitative computed tomography and magnetic resonance imaging have the potential to assess such information in a noninvasive way in patients. Both techniques, however, lack sufficient spatial resolution to image the individual trabeculae with true precision. In this work, a new parameter, Ridge number density (RND), is introduced. RND is a measure for the trabecular number, which can be extracted directly from high-resolution three-dimensional (3D) images of patients. We applied the RND technique to a test group of nine healthy, postmenopausal women measured repetitively with a high-resolution 3D peripheral quantitative computed tomography (3D-pQCT) system with 165 × 165 × 165 μm3 voxel size. Simultaneously with the RND determination, the trabecular bone density (TBD) was also assessed in the same volume of interest. The examination site was the distal radius. The intersubject variability of the measured test group was 10.5% for RND and 26.3% for TBD. The root mean square error between first and second examinations (midterm reproducibility) was 1.6% and 1.1%, respectively. RND is determined independently from TBD and pertains to the structure of the cancellous bone. As such, it might add crucial information in cases where bone mass or bone density measurements alone give ambigous results. 相似文献
72.
近3年来,用制备的胎骨充填良性骨肿瘤及病样病变术后骨缺损,经观察10例效果良好。胎骨因其自身组织学和生理学特点,具有抗原性小、诱导成骨活性高,利于“爬行各代”等优点。而且来源丰富、采制简单、储存容易、费用低度,是一种良好的植骨材料,特别适于儿童及年老体弱患者自身取骨困难的骨缺损植骨需要。但其为异体骨,有一定免疫原性,抗支撑强度略差,应注意严格无菌操作、消除免疫原性、配合使用内、外固定等措施。 相似文献
73.
18例慢性肾衰继发性甲旁亢病人发现有锁骨骨吸收。发病部位包括锁骨内端、外端、外1/3下缘及内段下缘4个部位。其中锁骨内、外端骨吸收属软骨下骨吸收,内、外段下缘骨吸收属韧带下骨吸收。作者对锁骨骨吸收的X线表现及发病机制作了讨论。认为锁骨骨吸收是继发性甲旁亢的重要X线征象,对诊断肾性骨病具有重要的意义。 相似文献
74.
Alpha2-HS glycoprotein phenotypes and quantitative hormone and bone measures in postmenopausal women
June E. Eichner Christopher A. Friedrich Jane A. Cauley Mohammad I. Kamboh James P. Gutai Lewis H. Kuller Robert E. Ferrell 《Calcified tissue international》1990,47(6):345-349
Summary It has been suggested that inherited traits play a role in the development of osteoporosis by providing a background for the
modulation of gene expression. In this study, we examine the influence of the different alleles of alpha2-HS glycoprotein (AHSG), a protein of the bone matrix, on quantitative estrogens, estrone and estradiol, and bone measures,
bone area and density. Estrogens provide a protective effect against fractures in older women and were thus included in the
analyses. Isoelectric focusing of AHSG from sera followed by immunoblotting was used to type 163 white post-menopausal women
participating in a clinical trial of the effects of walking on bone loss. Plasma hormones were measured by a combination of
extraction, column chromatography, and radioimmunoassay; bone measures on the dominant radius were determined with computerized
tomography. Analysis of variance was done on estrogen and bone measures after controlling for the effects of age and body
mass index. The two major alleles of AHSG result in three phenotypes, designated AHSG 1-1, AHSG 2-1, and AHSG 2-2. The AHSG
1-1 homozygote showed a decreased concentration of estradiol, the AHSG 2-2 homozygote showed an increased concentration, and
the AHSG 2-1 heterozygote was intermediate (P=0.001). Estrone demonstrated a similar pattern in residual analysis although it did not reach statistical significance. 相似文献
75.
Masatoshi Chiba Takashi Shigihara Seishi Echigo Teiichi Teshima 《Journal of bone and mineral metabolism》1990,8(3):24-29
Summary In this study, we examined histologically the effect of a bone morphogenetic protein (BMP) derived from bovine tooth on the
periosteum. Supraperiosteal injection of crude BMP into femurs of Wistar rats (28 day old) resulted in periosteal cell proliferation
with subsequent bone and cartilage formation. Moreover, proliferating periosteal cells migrated into injected BMP, and formed
both cartilage and bone. These observations show that exogenous BMP stimulates mesenchymal cells of the periosteum to proliferate
and differentiate into osteoblasts, and therefore BMP may be one of factors which are involved in differentiation of osteoblasts
in the periosteum. 相似文献
76.
Summary A study of the association between the rate of proliferation of marrow fibroblast-like stromal cells (in vitro) and the rate of endosteal bone mineralization (EsMR) (in vivo) was undertaken in an osteopenic rat model. We report than 200 g male rats treated with cortisone acetate (5 mg/day for 7
days) exhibit decreases in marrow fibroblast colony-forming units (FCFU) and tetracycline-based measurements of EsMR at the
level of the femoral midshaft. In cortisone-treated rats recovering for 1–3 weeks, the FCFU census and EsMR normalized during
the first posttreatment week, remained at control levels after 2–3 weeks, and exhibited a relapse in the third week which
signified only partial recovery. These changes were unrelated to patterns of body weight gain. The data indicate that the
FCFU census can serve to index endosteal osteoblast vigor. 相似文献
77.
Summary It is generally accepted that osteoclasts are responsible for the breakdown and removal of bone matrix constituents. However,
very little is known about the fate of osteocytes during bone resorption. In the present study we have examined sites of bone
destruction in calvaria of young rats aged 4–9 days in the hope of obtaining information on the fate of osteocytes. Decalcified
glutaraldehyde-formaldehyde-fixed specimens were prepared for ultrathin section electron microscopy. When sequentially arranged,
the images obtained suggest that osteoclasts engulf and destroy osteocytes during bone degradation. We propose that the following
sequence of events takes place when a lacuna is opened up by an osteoclast: (1) When the osteoclast comes in contact with
an osteocyte, the villi of the ruffled border become flat and broad. (2) Long osteoclastic extensions surround the osteocyte.
(3) The osteocyte is subsequently internalized with apparent degradation. 相似文献
78.
E. I. Barengolts M. Berman S. C. Kukreja T. Kouznetsova C. Lin E. V. Chomka 《Calcified tissue international》1998,62(3):209-213
Estrogen deficiency is a risk factor for osteoporosis and coronary artery disease. Osteoporosis can be evaluated by measuring
bone mineral density (BMD). Coronary atherosclerotic burden can be evaluated by measuring coronary calcium using electron
beam computed tomography (EBT) of the heart. We compared coronary calcium scores in 45 asymptomatic postmenopausal women with
normal and low BMD. BMD of the lumbar spine and proximal femur was measured by dual X-ray absorptiometry (DXA), and coronary
calcium was measured quantitatively by EBT. Women were divided into control, osteopenia, and osteoporosis groups based on
the T score of the lumbar spine. Women were similar in age, years since menopause, height, weight, and body mass index (BMI).
BMD ± SD (g/cm2) of L1–L4 was 0.96 ± 0.11, 0.83 ± 0.03, and 0.73 ± 0.05, in control, osteopenia, and osteoporosis group, respectively. The
total coronary calcium score ± SD (relative units) was 41.9 ± 83.1, 115.1 ± 181.9, and 221.7 ± 355.4 for control, osteopenia,
and osteoporosis group, respectively; the score was significantly higher in the osteoporosis than in the control group. This
study provides initial data suggesting that women with osteoporosis may have a higher risk of developing coronary atherosclerosis. 相似文献
79.
小儿先天性髋关节脱位近年来应用术式的演变及其评估 总被引:5,自引:2,他引:3
本文介绍本院近4年来小儿先天性髋脱位治疗应用术式的演变。由20多年来一直喜欢用骨盆截骨术演变为近1年来用得最多的是造盖术。近4年共手术463例,565髋。实践证明:比起骨盆截骨术,造盖术显得更简便,侵袭小,不需二次手术拔除内固定针。因在我国大龄髋脱位偏多,造盖术更适合我国国情。经过一些改进,可以克服造盖折断和吸收问题。 相似文献
80.
P. Rokkanen O. Böstman E. Hirvensalo E. A. Mäkelä E. Partio H. Pätiälä S. Vainionpää K. Vihtonen P. Törmälä 《European journal of orthopaedic surgery & traumatology : orthopedie traumatologie》1992,2(2):107-110
Résumé L'utilisation de matériaux d'ostéosynthèse biodégradables a l'avantage d'éviter la réintervention pour extraire le matériel. Les biomatériaux de polymères polyglycolides ont été expérimentés sur plus de 3 600 animaux de laboratoire avant leur introduction en pratique clinique. Depuis 1984 nous les avons utilisés comme matériau d'ostéosynthèse dans près de 1 700 cas parmi lesquels 880 cas de fracture malléolaire, 226 cas d'ostéotomie en chevron pour hallux valgus, 65 cas de fracture de la tête radiale et 54 cas de fracture de l'olécrane. Parmi les 800 premiers cas traités par broches biodégradables nous avons obtenu des résultats favorables et sans incidents dans 91 pour cent des cas. Il y eut 7 cas de fixation défaillante nécessitant une réintervention. Il y a eu 7 cas d'infection superficielle et 3 cas d'infection profonde. Nous avons observé la formation d'une collection séreuse sous-cutanée sans influence sur le résultat radiologique ou clinique dans 52 cas (6,5 %). Au vue de ces résultats et compte tenu des avantages économiques et psychologiques des matériaux biodégradables (pas de réintervention), on peut penser que l'usage de biomatériaux rivalise favorablement avec l'usage de matériaux conventionnels dans certains types d'ostéosynthèse.
Utilization of biodegradable implants in the surgical treatment of fractures and osteotomies
Summary The utilization of biodegradable implants instead of metals in orthopaedic surgery abolishes the need to remove the fixation material. For this study biodegradable rods and screws of self-reinforced polyglycolide, polylactide and lactide-glycolide copolymer were developed and manufactured. The clinical introduction of these implants was preceded by thorough experimental studies with 3 600 animals. From November 1984 the developed biodegradable method of osteofixation was used in 1 700 operations. These included 880 displaced malleolar fractures, 226 chevron-osteotomy for hallux valgus, 65 displaced fracture of the radial head, 54 displaced frature of the olecranon and other fresh fractures or orthopaedic operations. In the first 800 cases operated on using self-reinforced polyglycolide rods the postoperative course was uneventful (91%). Because of failure in the fixation reoperation was needed in 7 cases. A superficial wound infection was observed in 7 cases, deep infection in 3 and transient fluid accumulation in 52 cases (6,5%). Fluid accumulation did not influence the radiological or clinical end-result. The advantages of biodegradable fixation are many-sided. There is a costbenefit and clinical capacity is free for other use, and psychological advantages must be emphasised because removal of implants is not needed. The over all results of this study were considered favourable.相似文献