曲古抑菌素A促进去卵巢大鼠钛植入物骨整合

目的 探讨TSA对去卵巢大鼠TI骨整合的影响。方法 将30只健康3月龄雌性SD大鼠随机分为Sham组（n=5）和OVX组（n=25）。正常饲养3个月后,两组各选取5只大鼠处死,取股骨远端样本行Micro-CT和HE染色以鉴定是否成功建立骨质疏松模型。随后在OVX组剩余大鼠双侧股骨干骺端植入直径1.5 mm TI,并将其分为2组：Control组（n=10）和TSA组（n=10）。连续给药4周。给药结束后处死全部大鼠并取股骨样本行Micro-CT扫描、HE染色以及Masson染色,ELISA法检测,拔钉实验。结果 与Sham组对比,Micro-CT显示OVX组BMD、BV/TV、Tb.Th、Tb.N降低（P<0.05）,而Tb.Sp、SMI升高（P<0.05）,HE染色显示OVX组骨小梁数量明显降低。与Control组对比,Micro-CT显示TSA组BMD、BV/TV、Tb.Th、Tb.N 、Conn.D均升高（P<0.05）,而Tb.Sp、SMI降低（P<0.05）,HE染色、Masson染色显示TSA组骨小梁数量、新生骨数量均升高,ELISA法检测结果显示TSA组OCN、BMP2均升高,拔钉实验显示TSA组TI轴向拔出力增大。结论 TSA通过上调OCN、BMP2等成骨相关蛋白,促进骨小梁形成和新骨形成,进而改善去卵巢大鼠TI骨整合。     

甲状旁腺素（1-34)对去卵巢大鼠掺锶羟基磷灰石涂层植体骨整合的影响

目的 探索甲状旁腺素（1 -34)对去卵巢大鼠掺锶羟基磷灰石涂层种植体骨整合的影响。方法行双侧卵巢摘除术后12 w,大鼠随机分为Control组、PTH组、Sr组及PTH + Sr组,之后分别在双侧股骨植人羟基磷灰石或掺锶羟基磷灰石涂层的钛钉,PTH组及PTH + Sr组术后给予PTH治疗。12 w后处死大鼠取双侧行Micro-CT、组织学及生物力学检测。结果 Micro-CT三维重建显示,PTH + Sr组钛棒周围有最多的骨组织形成,微观参数定量结果表明与Control组相比,PTH +Sr组骨体积分数BV/TV增加了 2. 45倍,骨小梁数量（Tb.N)增加了2. 94倍,骨小梁连接密度（Conn. D)增加了 2.31倍,骨小梁厚度 (Tb.Th)增加了1.56倍,而骨小梁分离度（Tb.Sp)降低了 1.65倍（P<0.05)。骨生物力学结果表明,相对Control组而言,Sr 组,PTH组及PTH+Sr组的最大推力分别增加了 1.27倍、1.36倍及1.61倍（P<0.05)。组织学结果显示12w时,Sr组,PTH 组及PTH + Sr组的骨面积比率（BAR)相较于Control组分别提高了 1. 52倍、1. 73倍及2. 30倍（P < 0. 05),其骨-种植体接触率 (BIC)分别提高了 1.35倍、1.56倍及2. 21倍（P<0.05)。结论 掺锶羟基磷灰石涂层结合PTH (1-34)可以加强植人体在骨质疏松骨中的骨整合。     

Resveratrol treatment promotes titanium implant osseointegration in diabetes mellitus rats

Type II diabetes mellitus (T2DM) is the most common metabolic disorder; it is characterized by hyperglycemia and causes implant failure by influencing implant osseointegration. Resveratrol promotes bone formation, but it is unclear if resveratrol improves implant osseointegration. Thirty 12-week-old Sprague-Dawley rats were divided into control (CTL), diabetes mellitus (DM), and resveratrol treatment (DM + Res) groups. In the DM and DM + Res groups (n = 10 each), T2DM was induced via streptozotocin injections; the remaining 10 rats were considered the CTL group. Eight weeks after the insertion of a rod-like Ti implant with a 12-mm length and 1-mm diameter in the left leg, the rats were euthanized. We analyzed implant osseointegration using microcomputed tomography (micro-CT), histological analyses, and biomechanical tests. The parameters showed that T2DM negatively influenced implant osseointegration in the tibia. Compared to that in the DM group, the bone loss of peri-implant bone mass in the DM + Res group was decreased significantly. However, resveratrol still did not induce the same level of implant osseointegration as that observed in the CTL group according to the histological and micro-CT analyses. These results indicated that resveratrol reduced the influence of DM in implant osseointegration, resulting in increased peri-implant bone density, improved trabecular architecture, and enhanced biomechanical fixation.     

糖尿病对钛合金假体骨整合影响的实验研究

[目的]了解骨-假体整合生物力学强度与血糖改变的相互关系以及血糖改变对假体周围骨代谢的影响,明确胰岛素治疗对于提高假体与骨整合的作用.[方法]将90只2个月龄、体重220～250 g的健康雄性SD大鼠随机分为两组,其中45只大鼠先在双侧胫骨近端干骺端置入假体,假体置入后8周随机分成正常对照组(C1组)、DM组(D1组)和胰岛素治疗组(I1组)各15只,DM组和胰岛素治疗组30只腹腔注射1％链脲佐菌素(STZ)液(65mg/kg)诱导建立DM模型.另外45只大鼠随机分成正常对照组(C2组)、DM组(D2组)和胰岛素治疗组(I2组)各15只,DM组和胰岛素治疗组30只腹腔注射1％STZ液(65mg/kg)诱导建立DM模型,造模4周后给大鼠双侧胫骨近端干骺端置入假体.胰岛素治疗组接受胰岛素治疗,8周后将各组大鼠处死,取双侧胫骨分别行骨生物力学和硬组织切片检测.[结果]糖尿病组较胰岛素治疗组和正常对照组假体实验最大载荷以及假体-骨整合面积的比率明显降低,差异有统计学意义(P＜0.01).[结论]糖尿病是导致糖尿病模型大鼠骨质量下降、人工置人假体骨整合减少的原因之一.胰岛素的使用可改善大鼠的骨质量,增加骨-假体结合力.     

A single dose of zoledronic acid reverses the deleterious effects of glucocorticoids on titanium implant osseointegration

Summary  

This study evaluates the effect of zoledronic acid (ZOL) on the osseointegration of titanium implants in rabbits with glucocorticoid (GC)-induced bone loss, and our findings demonstrated that a single dose of ZOL is able to reverse the detrimental effects of GCs on the osseointegration of titanium implants.     

Vitamin D3 and insulin combined treatment promotes titanium implant osseointegration in diabetes mellitus rats

This study investigated the effect of insulin and vitamin D₃ (VD₃) treatment on implant osseointegration in diabetic mellitus (DM) rats. DM was induced by administration of streptozotocin in rats, which received implants insertion in the femur. Then animals were subjected to different treatment and divided to the following group: control, diabetic, insulin-treated diabetic, VD₃-treated diabetic, insulin and VD₃ combination-treated diabetic rats. The glucose levels and weight of rats were periodically evaluated, and serum 25(OH)D₃ levels in rats were measured at the end of the experiment. Animals were sacrificed at 12 weeks after surgery, the peri-implant trabecular microstructure, implant fixation and implant osseointegration were measured by microscopic computerized tomography (micro-CT) evaluation, push-out test and histomorphometric analysis. Diabetic rats displayed significantly higher blood glucose level, lower body weight, lower serum 25(OH)D₃ levels, and less implant osseointegration than controls. Insulin treatment showed restorative effect on body weight and serum 25(OH)D₃ levels of diabetic rats, but the blood glucose level in diabetic rats were still substantially higher compared to controls after 14 days therapy of insulin. Combined treatment restored hyperglycemia in diabetic rats to be normal, and reversed the impaired osseointegration capacity of implants, with the bone volume ratio and percent osseointegration increased by 1.37-fold and 1.6-fold in micro-CT evaluation, the maximal push-out force and ultimate shear strength by 1.3-fold and 2.1-fold in push-out test, and the bone-to-implant contact and bone area ratio increased by 2.57-fold and 1.44-fold in histomorphometric analysis. Monotreatment also enhanced implant fixation, but less. These results indicated that insulin and VD₃ combined treatment may be an effective approach to enhance implant fixation in diabetic rats, but whether the results could be extrapolated to human needs further study.     

Effect of locally administered zoledronic acid on injury-induced intramembranous bone regeneration and osseointegration of a titanium implant in rats

Background  Intramedullary implantation causes injury-induced stimulation of intramembranous bone regeneration. Intramedullary bone injury along with stress shielding may induce periimplant bone loss and cause early aseptic loosening of an implant. The aim of this study was to determine the effect of locally administered zoledronic acid on periimplant bone and injury-induced stimulation of intramembranous bone regeneration in a rat model. Methods  A total of 28 male rats had a titanium implant inserted into their right femur. During the operation, the medullary canal was lavaged using 20 μM zoledronic acid (Zometa 4 mg/5 ml) or sodium chloride. Follow-up times were 4 and 12 weeks, with each follow-up group consisting of seven rats. The femurs with the titanium implants in situ were harvested, and three microscope sections were cut from each femur. The sections were photographed and analyzed with the Analysis computer program. Results  Between 4 and 12 weeks, the length of fluorescence bone contact increased significantly in both groups (control 15.7% SD and zoledronic acid 18.8% SD), although the difference between the groups was not significant. Periimplant bone volume (thickness) was increased in the 4-week zoledronic acid group compared to the controls (±13.4%, P = 0.002) but at 12 weeks the groups no longer differed from each other. Conclusions  Our results suggest that zoledronic acid may prevent injury-induced bone loss near an intramedullary implant by inhibiting bone resorption shortly after implantation. This may provide better periimplant bone stock during the early postoperative period.     

Additive manufacturing of porous titanium metaphyseal components: Early osseointegration and implant stability in revision knee arthroplasty

AimsMetaphyseal cones and sleeves are components used in revision knee arthroplasty to ensure load transfer, encourage bone on-growth and prevent stress shielding. Additive manufacturing of titanium alloy implants is a novel technique with limited clinical outcome reports in the literature. The aim of this study was to determine radiographic evidence of osseointegration and early results of a single manufacturer porous titanium metaphyseal components in the proximal tibia.MethodsWe retrospectively reviewed the prospectively collected database of two institutions. Patients who underwent revision knee arthroplasty using porous titanium components by a single manufacturer were identified. Immediate post-operative and latest follow-up radiographs were independently analysed by 2 reviewers to determine metaphyseal bone contact and level of osseointegration in relevant Knee Society Radiographic Evaluation and Scoring System zones.Results22 patients (15 males; 7 females) with a mean age of 71 (49–92) years were included. The mean follow-up period was 14 months (2–44 months). Cones were used in 16 patients and sleeves in 6. Interobserver reliability assessment showed substantial agreement (weighted Kappa 0.71, (95% CI: 0.60, 0.81). There was significant correlation between the bone contact in the immediate postop radiograph and osseointegration at final follow-up (kendall’s tau-b: 0.698, p < 0.001). Infection free prosthetic joint survival was 20/22 at final follow-up.ConclusionPorous titanium metaphyseal components produced with additive manufacturing provided excellent osseointegration and no early clinical failures. Partial or complete contact of the cone with native bone in the immediate postoperative radiograph resulted in osseointegration in all cases.     

The bisphosphonate ibandronate improves implant integration in osteopenic ovariectomized rats

Osteoporosis is known to impair the process of implant osseointegration. Bisphosphonates are drugs that inhibit osteoclast-mediated bone resorption and normalize the high rate of bone turnover that characterizes this disease. Consequently, there is a rationale for using bisphosphonates to enhance the early stabilization of implants in subjects with low bone mass. In this study, 84 rats received titanium-only or hydroxyapatite (HA)-coated titanium femoral implants, 3 months after being ovariectomized (OVX) or sham operated. They were then treated for 4 weeks. The OVX rats were randomly assigned to daily subcutaneous injections of either saline or the bisphosphonate ibandronate (at a dose of 1 microg/kg or 25 microg/kg), while the sham-operated animals received saline throughout. The 1 microg/kg or 25 microg/kg ibandronate doses are considered translatable to doses used to treat osteoporosis and metastatic bone disease (MBD), respectively, in rats, and roughly reflect those used in humans. At the end of the treatment period, bone mineral density (BMD) at the lumbar spine increased in both of the ibandronate-treated groups when compared with the OVX control animals and to a level similar to that of the sham-operated control group. Osseointegration, determined by histomorphometric analysis and expressed as percentage of osseointegration implant surface (OIS), did not differ between groups for the titanium-only implants. For the HA-coated implants, however, OIS was 113.5% and 185% higher in the groups receiving 1 microg/kg or 25 microg/kg ibandronate, respectively, relative to the OVX controls. In turn, the OIS of the HA-coated implants was 56.5% lower in the OVX control group than in the sham control group. These findings clearly demonstrate that OVX-induced osteopenia impairs the osseointegration of HA-coated titanium implants and that ibandronate, administered at doses analogous to those used to clinically treat osteoporosis and MBD, counters this harmful effect. Ibandronate may, therefore, have a role in improving the osseointegration of implants in patients with osteoporosis and MBD.     

The effect of ipriflavone on osteopenia in ovariectomized women

This study evaluated the preventative effect of ipriflavone on osteopenia in 21 female patients who had either reached natural menopause or had been bilaterally ovariectomized at least 3 years before the beginning of the study. Out of the 21 patients, 18 had been ovariectomized, 11 of whom were monitored continuously for more than 48 weeks. These 11 patients were divided into groups A and B. The remaining three patients who reached natural menopause were administered the drug for less than 48 weeks, and were excluded from the study. Ipriflavone 600 mg/day was administered to group A (n=4), and ipriflavone 600 mg plus ‘Premarin’ 0.625 mg/day to group B (n=7), each day for 48 weeks. The bone mineral density (BMD) of L2–L4 of the subjects who were monitored continuously for 48 weeks was measured using dual-energy x-ray absorptiometry (DXA) (Norland XR-26). The BMD of those subjects who received ipriflavone alone decreased only slightly for the first 36 weeks, a smaller decrease than those who did not, and at 48 weeks a slight improvement appeared. Those subjects receiving ipriflavone plus ‘Premarin’ showed an increase in BMD at 24 weeks but at 48 weeks the BMD had returned to the pretreatment level. Next we divided groups A and B into 2 sub-groups (A₁, A₂; B₁, B₂) according to their BMD levels following the 48-week treatment. In all groups, there was a tendency for serum osteocalcin, urinary hydroxyproline/creatinine ratio, and urinary calcium/creatinine ratio to decrease; the decrease in the hydroxyproline/creatinine ratio was especially evident in groups A₁ and B₁. Thus, our study suggested ipriflavone, administered alone, had a potentially preventative effect on rapid bone loss in females who had recently been ovariectomized.     

齿科种植体钛的耐磨损性质探讨

目的：探讨齿科种植体材料钛的耐磨损性及其对种植体牙周维护的远期影响。方法：应用Martens划痕实验与超声洁牙机磨损实验对钛板进行耐磨损性检测。结果：Martens划痕实验与超声洁牙机磨损实验结果显示其在不同的荷重下均会对钛板造成不同程度的划痕及磨损。讨论：采用常规牙周维护方法可能会对钛种植体造成磨损,可能加重种植体表面上牙石及菌斑的沉积与结合,对钛种植体的远期预后产生不良影响。     

应用microCT技术对中药干预去卵巢小鼠骨组织微结构的分析

目的应用micro CT技术观察健骨颗粒对C57小鼠去卵巢骨质疏松模型骨组织骨量、骨微结构及生物力学的影响。方法将4周龄清洁级C57小鼠30只随机分为三组(假手术组10只、卵巢切除小鼠两组各10只),两组卵巢切除小鼠术后1周开始,分别用健骨颗粒和生理盐水进行灌胃,假手术组用生理盐水灌胃。2个月后,小鼠左胫骨行micro CT检测及图像分析、右胫骨行生物力学三点抗压最大载荷检测。结果与假手术组比较,去卵巢组BMC、BMD、Mean、BV、BS显著下降(P0.01),TMC下降(0.01P0.05);与去卵巢组比较,去卵巢中药组BMC、BMD、Mean指标显著提高(P0.01);图像分析结果显示去卵巢组较假手术组骨皮质薄,骨小梁数量少,形态细小、不连续呈扭曲或断裂状等明显骨质疏松病理特征,去卵巢中药组介于两者之间。生物力学结果显示三组胫骨三点抗压最大载荷均具有明显差异(P0.01)。结论去卵巢2月成功建立小鼠绝经后骨质疏松症模型;健骨颗粒抗骨质疏松作用明显,主要通过增加骨量和改善骨小梁微结构来最终提高骨强度;micro CT对骨质疏松参数分析简洁、高效,图像多维、全面,与传统的检测方法相比,具有一定的优势。     

Biomechanical effect of one session of low-level laser on the bone–titanium implant interface

Low-level laser (LLL) has been used on peri-implant tissues for accelerating bone formation. However, the effect of one session of LLL in the strength of bone–implant interface during early healing process remains unclear. The present study aims to evaluate the removal torque of titanium implants irradiated with LLL during surgical preparation of implant bed, in comparison to non-irradiation. Sixty-four Wistar rats were used. Half of the animals were included in LLL group, while the other half remained as control. All animals had the tibia prepared with a 2 mm drill, and a titanium implant (2.2?×?4 mm) was inserted. Animals from LLL group were irradiated with laser (gallium aluminum arsenide), with a wavelength of 808 nm, a measured power output of 50 mW, to emit radiation in collimated beams (0.4 cm²), for 1 min and 23 s, and an energy density of 11 J/cm². Two applications (22 J/cm²) were performed immediately after bed preparation for implant installation. Flaps were sutured, and animals from both groups were sacrificed 7, 15, 30, and 45 days after implant installation, when load necessary for removing implant from bone was evaluated by using a torquimeter. In both groups, torque values tended to increase overtime; and at 30 and 45 days periods, values were statistically higher for LLL group in comparison to control (ANOVA test, p?<?0.0001). Thus, it could be suggested that a single session of irradiation with LLL was beneficial to improve bone–implant interface strength, contributing to the osseointegration process.     

大豆苷原防治去卵巢大鼠骨质疏松症的量效作用

目的 观察不同剂量大豆苷原对去卵巢大鼠血清骨代谢生化指标、骨密度、骨生物力学和骨形态学的影响.方法 选用4月龄Sprague-Dawley 雌性大鼠60只,随机分6组:假手术组(Sham)、去势组(OVX)、戊酸雌二醇手术组(E2)、高剂量大豆苷原手术组(H-Dai)、中剂量大豆苷原手术组(M-Dai)和低剂量大豆苷原手术组(L-Dai).于术后4周开始分别给予相应的药物灌胃,治疗3个月后处死大鼠,进行相关的检测.结果 去卵巢大鼠的雌二醇水平显著低于其余各组,而碱性磷酸酶和骨钙素活性明显高于其余各组(P<0.05、P<0.01).去卵巢后大鼠腰椎的骨密度、最大压缩载荷、骨小梁与椎体总面积比值以及股骨骨密度和最大三点弯曲载荷均比Sham组降低,经过大豆苷原治疗后各项指标有不同程度的提高,但是50和200/(kg·d)的大豆苷原组不及10/(kg·d)大豆苷原组效果显著(P<0.05、P<0.01).结论 大豆苷原对去卵巢大鼠骨质疏松有防治作用,呈现剂量依赖性方式,低剂量时作用更为显著.     

仿生电活性涂层钛植入材料促进骨结合的实验研究

目的评价仿生电活性钛酸钡(BaTiO3,BTO)/聚偏氟乙烯-三氟乙烯P(VDF-TrFE)涂层钛植入材料促进骨结合性能的效果。方法首先将直径为2 mm、长度为5 mm的医用纯钛圆柱进行表面喷砂-酸蚀处理,然后将BaTiO3/P(VDF-TrFE)溶液均匀涂覆在钛柱表面。待烘干后对涂层表面进行电晕极化处理。采用扫描电镜、能谱分析、原子力显微镜、水接触角测量仪分别对材料表面形貌、元素组成、表面粗糙度和亲疏水性进行表征检测,PLLA涂层钛柱作为对照材料。选取实验兔4只,在双侧胫骨位置各制备3个间隔为1 cm的圆形缺损,在左侧胫骨植入PLLA涂层钛柱,右侧胫骨植入仿生电活性涂层钛柱,术后4周和12周分别取材进行硬组织的骨形态检测分析。采用SPSS15.0软件对数据进行统计分析。结果理化性能表征检测显示,BaTiO3/P(VDF-TrFE)涂层和PLLA涂层均匀附着在钛柱表面,涂层厚度约50μm,且表面结构致密。电活性涂层可见钛酸钡纳米颗粒均匀分布在P(VDF-TrFE)基体内。两种涂层表面的粗糙度和水接触角无明显差异。电活性涂层具有稳定的压电性能,且压电常数接近生理量级。动物实验显示,术后4周,仿生电活性涂层材料表面和新骨结合紧密,涂层材料稳定无降解;而PLLA涂层材料表面由于材料有部分降解导致新骨结合较差,电活性涂层的骨结合率明显高于PLLA涂层。术后12周,两组的新骨成熟程度均增加,骨陷窝明显,仿生电活性涂层仍然保持稳定状态;而PLLA涂层进一步发生降解,和新骨结合程度弱于电活性涂层组。结论仿生电活性BaTiO3/P(VDF-TrFE)涂层钛可能作为一种具有促进骨整合功能的种植体涂层材料。     

Effect of zoledronate acid treatment on osseointegration and fixation of implants in autologous iliac bone grafts in ovariectomized rabbits

One main problem associated with alveolar bone augmentation in implant dentistry is resorption of grafted bone, which may be further compromised by systemic skeletal disorders such as osteoporosis. Zoledronate acid (ZOL) is the most potent bisphosphonate to treat osteoporosis and therefore it is hypothesized to be able to invert the negative effect of osteoporosis on osseointegration and fixation of dental implants in autologous bone grafts. In this study, 56 rabbits received bilateral ovariectomy (OVX) (40 rabbits) or sham operation (16 rabbits). Three months later, 8 animals from each group were sacrificed for bone mineral density (BMD) examination. Then the remaining animals underwent bilateral autologous iliac bone grafting with simultaneous implantation of titanium implants in tibiae and were divided into 5 groups (n = 8): Sham, OVX, Loc-ZOL (local treatment), Sys-ZOL (systemic treatment) and Loc + Sys-ZOL (local plus systemic) group. At 3 months after implantation, all animals were sacrificed and specimens were harvested for examinations. Both BMD and histological examinations of femurs showed osteoporotic changes after ovariectomy, while systemic treatment with ZOL restored mineralized bone. Micro-CT examination demonstrated that OVX group showed significant decrease of mineralized bone and implant-bone contact when compared with sham control, whereas both systemic and local treatments of ZOL significantly increased mineralized bone and implant-bone contact in ovariectomized animals. However, the best effects were observed in Loc + Sys-ZOL group (combined use of ZOL) and most of bone indices were similar to (IBCR, p > 0.05) or higher than (BV/TV, Conn.D and Tb.N) (p < 0.01) those of the sham group, except Tb.Th, which was still significantly lower (p < 0.01), and Tb.Sp, which was further decreased (p < 0.01). The aforementioned effects were also confirmed by histomorphometric analysis of bone indices on implant-bone contact and mineralized bone. In addition, biomechanical testing further supported the beneficial effect of ZOL treatment and maximal removal torque of titanium implants was observed in Loc + Sys-ZOL group. In conclusion, our study suggests that both systemic and local treatments with ZOL can invert negative effect of osteoporosis and promote osseointegration and fixation of dental implants in autologous bone grafts under osteoporotic condition. Combined systemic and local use of ZOL exerts best effects when compared to their single use.     

Effect of alendronate and intermittent parathyroid hormone on implant fixation in ovariectomized rats

Background  Intermittent administration of parathyroid hormone (PTH) leads to bone formation by increasing osteoblast numbers and activity levels. Animal studies have shown that intermittent PTH administration increases implant fixation in normal rats. The purpose of this study was to analyze the osseous incorporation of an implant in osteoporotic rats while treating them with intermittent PTH (1–34) or alendronate. Methods  A total of 36 ovariectomized (OVX) Wistar rats were randomized into three groups. Polymethylmethacrylate cement rods were implanted in one tibia in each rat. The three groups received daily PTH (60 μg/kg body weight [BW]), alendronate (200 μg/kg BW), or saline (0.5 ml/kg BW). A sham-ovariectomized group (n = 12) was treated with saline. After 2 weeks, the area around the implants was analyzed by histomorphometry for bone volume density (BVD) and implant bone contact. Bone mineral density (BMD) was evaluated by dual-energy X-ray absorptiometry. Results  The BVD was higher in the specimens treated with PTH than in the other groups. PTH improved the BVD, BMD, and implant bone contact. Alendronate doubled the implant bone contact compared to the OVX and sham groups but did not improve BVD or BMD. Conclusions  These findings confirm that intermittent PTH enhances implant fixation in osteoporotic bone. The clinical significance of these findings is that application of intermittent PTH may be beneficial for early implant fixation in fractures, nonunions, and prosthetic replacements when bone density is decreased.     

利用计算机辅助设计／计算机辅助制造技术制造的钛合金补片修复颅骨大面积缺损

目的探索应用计算机辅助设计／计算机辅助制造（CAD／CAM）技术制造的钛合金补片修复大面积颅骨缺损的方法。方法2006年4月至、2008年6月期间,收治因肿瘤和外伤所致颅骨大面积缺损患者7例,采集电子计算机断层扫描（CT）数字化图像数据,利用快速成型技术制作患者的颅骨树脂模型,应用铸造技术制备修复颅骨缺损的钛合金。结果制造出个性化的颅骨树脂模型和精密的钛合金补片,置入体内,紧密覆盖颅骨缺损区。术后7例患者伤口均I期愈合,随访6个月至1年,缺损区颅骨外形恢复满意。结论利用CAD／CAM技术加工出的钛合金补片可以修复颅骨的大面积缺损,获得理想的修复效果。该方法操作简单,修复精确,很高的临床应用价值。     

特立帕肽对去势大鼠骨缺损修复影响的实验研究

目的 探索特立帕肽（PTH）对去势大鼠骨缺损修复的影响。方法 选取SPF级3月龄雌性SD大鼠20只,行双侧卵巢切除术,饲养3月后骨质疏松动物模型成功建立,然后于大鼠两侧股骨髁上行直径3mm贯通性骨缺损手术,术后随机分为对照组和PTH治疗组,PTH治疗组于缺损手术1w后,每周给予背部皮下注射特立帕肽5次（30μg/kg）,空白对照组注射等量的生理盐水。术后4,8w进行组织病理学观察,Micro-CT分析检测。结果 术后4、8w,PTH治疗组和对照组对比发现：PTH治疗组股骨骨密度均高于同时间段的对照组,缺损区Micro-CT扫描显示PTH治疗组较对照组有更为明显的新生骨组织形成,骨缺损术后4、8w时,两组大鼠股骨干骺端骨缺损区域骨小梁体积分数（BV/TV）、骨小梁厚度(Tb.Th)、骨小梁数量(Tb.N)均逐渐增加,骨小梁分离度(Tb.Sp)降低, PTH治疗组BV/TV、Tb.Th及Tb.N均较同时期的空白对照组增高,骨小梁分离度(Tb.Sp)则低于空白对照组,差异有统计学意义(P<0.05)。缺损术后8w时PTH治疗组骨缺损区域可见大量排列致密且形态粗大的骨小梁,骨缺损区域基本愈合,而对照组缺损区域愈合欠佳。结论 PTH可较好地促进骨质疏松性大鼠股骨干骺端骨缺损的修复。