干细胞动员对骨创伤大鼠免疫功能的保护作用

目的：观察自体干细胞动员对骨创伤大鼠的免疫功能的保护作用，为战创伤后的免疫抑制及继发性感染、系统性炎症反应等治疗提供依据。方法：挤压折断法复制大鼠双后肢股骨骨折模型，于致伤后0、24、48h连续给模型动物肌肉注射GM—CSF20μg／kg，致伤后72h细胞增殖法检测T、B淋巴细胞活性，ELISA法检测血清IL-1、IL-2、IFN-7、TNF—α浓度，自动系列化分析法检测C3、CA、IgM、IgG浓度，称重法观察脾重与体重的比例变化。结果：股骨骨折模型大鼠致伤后72h，GM—CSF动员骨髓干细胞组大鼠的T、B淋巴细胞活性和血清IFN-γ、IL-2浓度高于对照组（P〈0．01），IL-1、TNF—α浓度低于对照组（P〈0．01），血清C3、CA、IgM、IgG浓度及脾／体重比值高于对照组（P〈0．01）。结论：GM—CSF动员自体干细胞动员对大鼠骨创伤诱导的免疫功能抑制具有保护作用。     

Smoking delays chondrogenesis in a mouse model of closed tibial fracture healing.

Smoking delays the healing process and increases morbidity associated with many common musculoskeletal disorders, including long bone fracture. In the current study, a murine model of tibial fracture healing was used to test the hypothesis that smoking delays chondrogenesis after fracture. Mice were divided into two groups, a nonsmoking control group and a group exposed to cigarette smoke for 1 month prior to surgical tibial fracture. Mice were euthanized at 7, 14, and 28 days after surgery. The outcomes measured were immunohistochemical staining for type II collagen protein expression as a marker of cartilage matrix and proliferating cell nuclear antigen (PCNA) staining to measure proliferation at the site of injury. Toluidine blue staining and histomorphometry were used to quantify areas of cartilaginous and noncartilaginous fracture callus. Radiographs were analyzed for evidence of remodeling after injury. At day 7 after injury, mice exposed to cigarette smoke had a smaller fracture callus with less cartilage matrix compared to controls. Proliferation was present at high levels in both groups at this time point, but proliferating cells had a more immature morphology in the smoking group. At day 14, chondrogenesis was more active in smokers compared to controls, while a higher percentage of bone was present in the control animals. At day 28, X-ray analysis revealed a larger fracture callus remaining in the smoking animals. Together, these findings show that the chondrogenic phase of tibial fracture healing is delayed by smoking. This study represents, to our knowledge, the first analysis of molecular and cellular mechanisms of healing in a smoking mouse fracture model.     

Global gene profiling reveals a downregulation of BMP gene expression in experimental atrophic nonunions compared to standard healing fractures.

Nonunion is a challenging problem that may occur following certain bone fractures. However, there has been little investigation of the molecular basis of nonunions. Bone morphogenetic proteins (BMPs) play a significant role in osteogenesis. However, little is known about the expression patterns of BMPs in abnormal bone healing that results in nonunion formation. These facts prompted us to investigate and compare the gene expression patterns of BMPs and their antagonists in standard healing fractures and nonunions using rat experimental models. Standard closed healing fractures and experimental atrophic nonunions produced by periosteal cauterization at the fracture site were created in rat femurs. At postfracture days 3, 7, 10, 14, 21, and 28, total RNA was extracted from the callus of standard healing fracture and fibrous tissue of nonunion (n=4 per each time point and each group). Gene expression of BMPs, BMP antagonists, and other regulatory molecules were studied by methods including Genechip microarray and real-time quantitative RT-PCR. Gene expression of BMP-2, 3, 3B, 4, 6, 7, GDF-5, 7, and BMP antagonists noggin, drm, screlostin, and BAMBI were significantly lower in nonunions compared to standard healing fractures at several time points. Downregulation in expression of osteogenic BMPs may account for the nonunions of fracture. The balance between BMPs and their endogenous antagonists is critical for optimal fracture healing.     

不同钉位布局影响股骨颈骨折内固定效应的生物力学研究

目的:观察应用多枚钉内固定治疗股骨颈骨折时采取不同钉位布局对骨折断端固定效应的影响,为临床操作中寻求最佳钉位布局奠定基础。方法:通过特制壮年人体尸骨股骨颈骨折模型,进行直视下解剖复位后,分别应用3钉倒三角形、3钉正三角形和双钉平行3种不同钉位布局内固定方法完成内固定。在生物力学万能试验机上进行轴向压缩和扭转实验,观察不同生物应力下断端相对的位移距离、轴向刚度、水平剪切刚度和扭转强度等项目,取得试验数据后经统计学处理,进行组间对比,观察其差异的显著性。结果:在3种钉位布局的内固定方法之中,以股骨矩核心下2～3mm处进钉位为下位顶点的倒三角形钉位布局能获得最坚强的固定效应,相同应力下其位移距离最小而各项刚度最大;而股骨矩核心上位和中下位双钉固定法固定效应最差,表现为相同应力下位移距离最大和各项刚度最小。结论:尽可能选择以股骨矩核心下2～3mm处进钉位为下位顶点的倒三角钉位布局法,尽可能减少应用双钉位布局法。     

可吸收球囊椎体成形术治疗胸腰椎爆裂骨折的实验研究

[目的]探讨结合短节段椎弓根螺钉系统撑开复位内固定的可吸收球囊椎体成形术治疗胸腰椎爆裂骨折的生物力学性能变化。[方法]采集6具新鲜固定湿润成人尸体胸腰椎标本，制成T11-L1，L2～4、L1～3节段标本10个，用自由落体撞击试验造成中间椎体爆裂型骨折，行APF椎弓根螺钉撑开复位，经椎弓根于伤椎椎体内置入可吸收高分子材料-DL-乳酸与ε-己内酯（70：30）的共聚物（PDLLA-CL）制作的可吸收球囊，注入自固化磷酸钙骨水泥行可吸收球囊椎体成形术。分别于骨折前、骨折撑开复位椎体成形术后，用万能材料试验机测定中间椎体在前屈、后伸、侧屈状态下应力-应变、轴向刚度变化及扭转应力下刚度的变化。[结果]伤椎经可吸收球囊椎体成形术治疗后，抗压强度均有所增加，前屈为8％，后伸15％，侧屈9．8％，其中以后伸时增加显著（P〈0．05）。治疗后的轴向刚度普遍得到提高，与骨折前相比，前屈增加11％，后伸增加8％，侧屈增加3％。治疗后椎体在扭转应力下刚度小于骨折前，但两者差异不明显（P〉0．05）。[结论]（1）结合短节段椎弓根螺钉系统撑开复位内固定的可吸收球囊椎体成形术，有助于伤椎的重建，术后脊柱的生物力学特性接近骨折前水平；（2）可吸收球囊椎体成形术治疗胸腰椎爆裂骨折，在避免骨水泥渗漏可能导致的潜在危险之前提下，从本质上恢复胸腰椎爆裂型骨折伤椎椎体结构的完整性，恢复其高度，从而恢复和维持脊柱的生理弧度，防止继发性脊柱后凸畸形变引起的迟发性腰背痛及脊髓、神经损伤，以从根本上解决单纯用经椎弓根内固定器治疗胸腰椎爆裂型骨折遗留的并发症，为临床治疗胸腰椎爆裂骨折提供了一个新的方法。     

Catastrophic failure of modular Zirconia—Ceramic femoral head components after total hip arthroplasty

Catastrophic failure of two zirconia—ceramic modular femoral heads occurred, despite the theoretical improved toughness of zirconia—ceramic relative to alumina—ceramic. This experience led the authors to return to cobalt—chromium as the metal of choice for articulation against polyethylene in total hip arthroplasty.     

胸腰椎爆裂骨折椎管内骨片侵入倾向与对策

根据98例中获得随访的39例的X线、CT和MRI(24例)影像学资料,分析胸腰椎爆裂骨折椎管内骨片侵入倾向及对策。将爆裂骨折侵入椎管分为四类八型,宜采用Harrington器械钢丝或椎弓根螺钉钢板轴向撑开系统,使骨折复位,椎管容积恢复,毋需行后路椎管减压。本组取得良好效果。仅对骨片游离型需要切开椎管直接摘除骨片。     

加压滑动鹅头钉治疗股骨转子间骨折的临床与实验研究

探讨加压滑动鹅头钉在治疗股骨转子间骨折中的作用。临床应用４５例。男３４例，女１１例。平均年龄６１岁。稳定型１３例，不稳定型３２例。经临床应用和生物力学实验测定，结果表明：（１）对不稳定型转子间骨折，恢复小转子区内后侧皮质骨的连续性在骨折的稳定中具有重要作用。（２）内后侧骨折块解剖复位，加压螺丝钉固定或大转子骨折端加压螺丝钉固定能显著增强加压滑动鹅头钉的固定作用，明显提高不稳定型转子间骨折的术后稳定性。（３）该装置设计合理，性能坚固，对转子间骨折具有很强的固定作用，能有效地达到早期下床和避免长期卧床的目的，是目前临床最理想的内固定装置。     

Polylactic acid (PLA) root replica in ridge maintenance after loss of a vertically fractured incisor

Abstract A periodontally affected tooth was prepared for a special treatment: Calcium hydroxide was introduced into the apical half of the root canal whereas its cervical part was filled with glass ionomer cement. The tooth was shortened subgingivally. After 6 weeks of epithelization over the residual root a palatal full-thickness flap was mobilized. The root was carefully extracted and chairside copy-milled from the biodegradable polylactic acid (PLA) material. The PLA-replica was implanted immediately into the socket and the flap was sutured. Aim of the treatment was to prevent the ridge collapse of the extraction area. Ridge height could be preserved during the 21 months of observation. With time the radiographic density of the cancellous bone increased in the implanted area, indicating that a PLA-replica is replaced by host's bone tissue.     

Hip fracture incidence in the canton of Vaud,Switzerland, 1986–1991

The objective of this study was to estimate the incidence of hip fracture in the canton of Vaud, Switzerland (total population 584 000), for the period 1986–1991 using routine hospital discharge data collected by the Cantonal Service of Statistical Research and Information (SCRIS). For the survey period, the estimated average annual crude incidence rate of hip fractures was 167 per 100 000 persons aged 20 or older (241 for women and 84 for men). For the population aged 50 years or older, the crude incidence rate was 388 per 100 000 persons (546 for women and 185 for men). The average annual age-specific rates rose exponentially by successive 5-year age groups. The median age of patients at the time of the fracture was 82 years in women and 74 years in men. There was no significant difference between the total number of cervical and trochanteric fractures. Between the ages of 20 and 84 years, the cumulative risk for a woman to be admitted to hospital with a hip fracture was twice that of a man (15.8% vs 7.8%). From 1986 to 1991, the age- and sex-adjusted incidence, like the ratio of cervical to trochanteric fractures, did not show any significant trend, although it was consistent with an increase in men (p=0.09). However, the annual number of fractures rose from 644 to 776, particularly among very aged men. The mean length of stay in the acute care hospital fell from 38 days in 1986 to 25 days in 1991. Finally, the comparison of these results with those obtained in 1986 for the same population from more exhaustive sources has confirmed the provision of a consistent, although overestimated, assessment of hip fracture incidence by means of these routine hospital statistics in the canton of Vaud, Switzerland.