前臂骨折愈合过程中骨痂骨密度的变化

目的：应用双有Ｘ线骨密度测定仪（ＤＥＸＡ）观察前臂骨折愈合过程中骨痂的骨密度变化,为临床提供一种测定骨折愈人事程度的方法。方法：对１７１例前臂骨折在正常愈合过程中骨折端区及其相邻两侧非骨折区骨矿物密度（ＢＭＤ）变化,将结果进行自身对照研究。结果：在观察期内,骨折区ＢＭＤ值呈显著上升趋势。非骨折区的ＢＭＤ则明显降低。结论：ＢＥＸＡ对骨折谪蝗ＢＭＤ跟踪测定可客观准确地反映骨折端骨痂生长状况,从而使骨折     

矩形髓内钉对实验性骨折愈合过程中骨痂含量的影响

目的：探讨矩形髓内钉（Rectangle -shaped Intramedullary,Nail,简称RIN）对骨折愈合过程中骨痂含量的影响。方法：用兔胫骨骨折内固定模型将RIN和传统的Ender's钉（Ender's Nalis，简称END）、四孔接骨板（Stainless Steel Plates，简称SPL）进行对比研究，通过阅片及计算机图像分析系统对不同内固定后不同时期的骨痂X线片进行分析。结果：骨痂直径测量显示：同组相比，8周时骨痂直径最大；同期比较，RIN组骨痂直径最大，END组次之，SPL组最少。RIN、END组和SPL组组间均有显著差异，RIN和END组相比则无显著差异；骨痂灰度密度分析显示：同组的骨痂灰度密度值随术后时间的增加而增大；同期比较，8周组的骨痂灰度密度值最高，END组次之，SPL组最少。RIN、END组和SPL组组间均有显著差异，RIN和END组相比，RIN组8周后组间差异显著。结论：RIN组和END组在骨折的不同时期的骨痂量较SPL组多，而且骨痂的钙化也较早，促进了骨折愈合。     

骨折愈合过程中骨痂骨密度的定量分析

目的：应用双能X线骨密度测定仪（DEXA）观察骨折愈合过程中骨痂听骨密度变化，说明临床测定骨折愈合程度的方法。方法：对171例前臂骨折在正常愈合过程中骨折端区有其相邻两侧非骨折区骨矿物密度（BMD）变化，将结果进行自身对照研究。结果：在整个观察期内，骨折区BMD值呈显著上升趋势（P＜0．01）。结论：DEXA对骨折端听BMD跟踪可测定可客观准确地反映骨折端骨痂生长状况，从而使骨折愈合检测数量化。     

卵巢切除对SD大鼠骨折骨痂形态的影响

目的研究卵巢切除对SD大鼠骨折骨痂形态的影响。方法雌性SD大鼠56只,随机分为两组,每组28只。实验组大鼠3月龄时切除双侧卵巢建立绝经后骨质疏松症模型,另一组行假手术对照。4周后建立双侧股骨骨折模型。分别在骨折前、骨折后6周、16周采用QCT及自动图像分析仪检测两组大鼠骨折区域骨痂情况,指标包括骨痂面积、骨痂组成成分、骨含量、骨密度、骨矿化面积、骨矿化率及骨生成率等。结果卵巢切除导致在不同时期大鼠股骨骨密度均降低,与对照组比较差异有统计学意义(P<0.05)。骨折后6周实验组骨生成率、骨痂面积较对照组大,而骨矿化面积、骨矿化率与对照组无显著差异。实验组骨痂成分以编织骨为主,与对照组相比差异有统计学意义(P<0.05)。骨折后16周实验组骨痂面积及骨痂成分与对照组相比,差异无统计学意义(P>0.05);而破骨细胞表面及数量较对照组增加,差异有统计学意义(P<0.05)。与对照组相比,实验组股骨髓腔面积增大,骨皮质面积减少,差异均有统计学意义(P<0.05)。结论卵巢切除导致的高骨转换可能会加快骨痂改建速度,从而促进骨折愈合。     

骨折周围骨痂移植治疗骨不愈合

目的观察用骨痂移植对骨折不愈合作用的临床疗效。方法1995年1月～2003年12月共收治增生型骨折不愈合19例,采用骨痂移植加内固定或外固定治疗。其中男16例,女3例;年龄19～57岁。骨折部位：肱骨4例,尺桡骨2例,股骨8例,胫骨5例。均为增生型骨折端有大量骨痂形成,其中普通钢板固定松动变形10例,加压钢板松动2例,梅花针固定变形3例,带锁髓内钉断裂2例,普通钢板断裂2例。骨折不愈合时间8～24个月。结果19例均获6～18个月随访,平均15.6个月。骨折愈合时间为6～8个月,其中1例术后7个月外伤后再骨折,钢板弯曲,经手术及骨痂骨植骨后7个月愈合。钢板内固定及交锁髓内钉治疗者无伤口感染;外固定架固定者1例针道感染,经消炎、换药痊愈。上肢骨折6例功能恢复良好;下肢骨折13例除上述1例再骨折功能恢复稍差外,其余功能恢复良好。结论采用骨痂移植简便易行,骨折愈合率高,可作为一种治疗骨不愈合的骨移植材料。     

骨折愈合中的软骨骨痂──形态学演变及超微结构观察

通过光镜下不脱钙骨组织学、组织化学和透射电镜对雄性兔桡骨标准缺损骨折模型愈合中软骨骨痂的形成、演变及超微结构进行了观察，结果显示：软骨骨痂由骨折后进入断端间的肉芽组织分化而成，其形成和改建并不完全相同于骺板软骨内化骨。电镜下，骨痂内软骨细胞可分为５个发育阶段：成软骨细胞、软骨细胞、肥大软骨细胞、变性软骨细胞和残存软骨细胞。我们认为１）软骨骨痂由断端周围组织内的间充质细胞分化而成；２）在改建过程中，软骨骨痂能直接形成骨小梁，我们支持肥大软骨细胞能转化为骨细胞的假说；３）软骨骨痂对骨折愈合有重要的作用，能早期填充骨缺损，联接断端，是骨折在重力负载下完成愈合的基础组织之一。     

椎体压缩性骨折愈合过程中骨痂骨密度变化及其临床意义

目的观察椎体压缩性骨折骨痂骨密度变化与病程长度的关系,探讨双能X线骨密度仪术前定位陈旧性椎体骨折不愈合的可行性。方法本院2013年1月至2016年1月采用椎体后凸成形术(percutaneous kyphoplasty,PKP)治疗腰1椎体压缩性骨折(均经磁共振成像或SPECT-CT明确诊断)患者66例,年龄60~80岁,均为绝经后女性。按病程长度分为A组(对照组)、B组(新鲜骨折组)、C组(亚急性期骨折组)、D组(陈旧性骨折不愈合组)。运用方差分析观察骨密度比率(腰1椎体骨密度/腰2椎体骨密度×100%)与病程长度的关系。结果各组间年龄、身高、体重差异无统计学意义(P0.05),各组间骨密度比率差异有统计学意义(F=34.839,P0.05),在各组多重比较中,A组与B组间差异无统计学意义(P0.05),其余两组间差异有统计学意义(P0.05)。结论椎体压缩性骨折骨痂骨密度随病程延长而增加,陈旧性骨折不愈合期骨痂骨密度较邻近椎体明显增高,在条件有限的情况下,双能X线骨密度仪不失为术前定位"责任椎"的一种好方法。     

高能震波对骨痂中骨形成蛋白表达的影响

目的 观察高能震波（ＨＥＳＷ）对骨痂中骨形成蛋白（ＢＭＰ）表达的影响，探讨其促进骨折愈合的机理。方法 手术造成家兔双侧胫骨中段标准骨折模型，对一侧胫骨骨折部施以ＨＥＳＷ，另一侧为对照组，术后每周进行Ｘ线及组织学检查，并取骨痂组织切片用ＢＭＰ抗体进行免疫组化染色（ＳＡＢＣ法（）。结果 实验组骨痂中ＢＭＰ表达强度在第２－４周时明在于对照组（Ｐ〈０．０１），且Ｘ线摄片及组织学观察均显示实验组骨折愈合时间     

骨折周围骨痂移植治疗骨不愈合的形态学观察

目的　观察骨不愈合采用骨折断端周围自体骨痂移植治疗的效果。方法　新西兰兔 42只 ,双侧桡骨中段模拟骨折 ,观察至明显骨痂生长随机分配实验Ⅰ组 36只 ,实验Ⅱ组 6只 ,随机选择一侧髂骨切取部分全层骨和双侧骨折处周围骨痂备用 ,并建立 1 0cm骨缺损的标准不愈合模型。实验Ⅰ组 ,左桡骨移植骨痂为A组 ,右桡骨移植髂骨为B组 ,术后分别于 2、 4、 6、9、 12、 15周各处死 6只兔并取标本作X线摄片和图像分析、标本大体观察 ,组织切片检查。实验Ⅱ组 ,左桡骨移植髂骨为C组 ,右桡骨空白对照为D组 ,术后定期X线摄片检查。结果　①术后 15周 ,A、B、C组全部完成骨不愈合的修复 ;②D组无一例骨不愈合完整修复 ;③A、B组修复骨不愈合的病理过程相仿 ,首先是桥梁骨痂和连接骨痂形成 ,而后是成熟骨板期 ,最后是塑形期 ,但修复进程在实验 9周存在明显差异 (P <0 0 5 ) ,A组优于B组。结论　骨折周围骨痂和髂骨都是较为理想的骨移植材料 ,在治疗骨不愈合过程中 ,骨痂移植在早期有加速骨缺损修复的趋势。     

Calcitonin and fracture healing. An experimental study on rats

The effects of systemically administered calcitonin (CT) on fracture healing were analyzed in an experimental study on rats. The healing of a fracture was followed from 3 days up to 9 weeks postoperatively. Half of the rats in each age group were given daily CT 10 MRC-U/kg body wt s.c. Mechanical properties of the healing tibial fractures (tension strength) as well as various connective tissue components of the callus tissue were analyzed. No difference in the radiological or microscopical appearance of the fractures was detectable between the animals receiving CT and the controls. In the biochemical analysis matrix production as assessed from the concentrations of nitrogen, hexosamines, and hydroxyproline within the callus followed the usual lines of undistributed fracture union without any difference between the groups with and without CT. No differences could be detected in the mineralization of the callus between the specimens from animals receiving CT and those without. The tensile strength values of the fractures increased almost linearly up to 9 weeks. At 1 week the tensile strength values for fractures union in the animals without CT were approximately 50% higher, but later on no differences could be detected between the groups. These results indicate that although in the early phases of long-term CT therapy collagen synthesis may be impaired, there will be no effect on the net content of collagen or calcifying tissue in the callus or on the mechanical strength of healing fractures.     

Systemic leptin administration alters callus VEGF levels and enhances bone fracture healing in wildtype and ob/ob mice

IntroductionLeptinʼs role in bone formation has been reported, however, its mechanism of affecting bone metabolism is remaining unclear. In this study, we aimed to test whether leptin has a positive effect on fracture healing through the possible mechanism of increasing vascular endothelial growth factor (VEGF) expression in callus tissue.MethodsStandardized femur fractures were created in leptin-deficient ob/ob and wildtype C57BL/6J mice, and recombinant mouse leptin or its vehicle (physiological saline) was administered intraperitoneally during the study. Body weight, radiological, histologic and immunoblotting analyses were performed at different stages of fracture healing.Key findingsThe results showed that leptin treatment led to lower rate of body weight change in both mice genotypes. Radiological and histological analyses showed that the experimental groups had better fracture healing at 14, 21 and 28 days compared to the control groups. Leptin-treated groups had significantly higher VEGF expression in callus compared with the control groups at 2 and 3 weeks post-fracture except normal mice at 2 weeks, and leptin-deficient mice had higher VEGF levels in calluses than normal mice at the same timepoint.ConclusionLow-dose systemically-administered leptin has a positive effect on promoting fracture healing during the latter stages in a clinically-relevant mouse bone fracture model, and increase callus VEGF levels.     

饲料中不同水平的铜对大鼠骨折愈合的影响

目的 探讨饲料中添加铜的化合物对大鼠骨折愈合的影响。方法 120只SD大鼠,手术造成右胫骨的部分缺损后,分为4组,每组30只,分别饲喂每公斤饲料含铜1.3,5.0,21.0和82.8mg的人工半合成饲料。手术后第14,21和28天时,每组分别断头处死10只大鼠。取胫骨,并于骨痂段行计算机断层扫描(CT),定量测定胫骨骨痂处骨灰度值;三点弯曲力学实验测定胫骨的生物力学参数:最后,测定其中钙、磷、镁、铜、锌和铁的含量。结果 随着饲料中铜水平的增加,骨痂灰度值增加,饲料含铜最高的第4组大鼠骨痂灰度值(652±131)HU显著高于其他3组[(490±80.0),(468±98.9)和(508±86.6)HU];从反映骨质内在硬度的弹性模量的测定结果可以看到,饲料含铜较高的3个实验组大鼠均高于第1组,其中第3组(1809±321)N/mm2显著高于第1组(1305±666)N/mm2(P<0.05);对胫骨中矿物质元素的测定表明,术后28 d,第3,4组骨中钙、镁、磷的含量均高于第1,2组。结论 饲料中适量补铜,对骨折的愈合有较好的效果。     

A study of fracture callus material properties: relationship to the torsional strength of bone

This study was designed to quantitate the local material properties of fracture callus during gap healing and to relate these local properties to the torsional strength of bone in a canine model under external fixation. Bilateral tibial transverse osteotomies were performed in 32 dogs and stabilized using unilateral external skeletal fixators with a 2-mm gap. Dogs were divided into four equal groups and euthanized at either 2, 4, 8, or 12 weeks. The torsional properties of one bone of each pair were determined. In both bones of each pair, the indentation stiffness, calcium content, and histomorphometric properties of six sites of periosteal callus, six sites of endosteal callus, four sites of cortical bone, and two sites of gap tissue were determined. Each of the four types of tissue had a specific structural or material property change during the study period. The indentation stiffness of periosteal callus increased up to 8 weeks and then plateaued. Endosteal callus stiffness peaked at 8 weeks and then decreased by 12 weeks. Gap tissue stiffness increased linearly over time. Cortical bone stiffness decreased over time. Indentation stiffness was significantly associated with the calcium content of periosteal callus (R2 = 0.50, p less than 0.0001) and gap tissue (R2 = 0.66, p less than 0.0001). The local stiffnesses of gap tissue and periosteal callus were significantly associated with the maximum torque (gap, R2 = 0.50, p less than 0.0001; periosteal, R2 = 0.34, p less than 0.05) and the torsional stiffness (gap, R2 = 0.44, p less than 0.0001; periosteal, R2 = 0.65, p less than 0.0001) of the bone.(ABSTRACT TRUNCATED AT 250 WORDS)     

运用高频率低能量振动促进骨折愈合的实验研究

目的 本研究旨在探讨全身性的高频率低能量振动对骨折愈合的作用.方法 建立大鼠闭合性股骨骨折髓内固定模型(n=55),并随机分为治疗组(n=28)和对照组(n=27).骨折后第5天开始对治疗组使用高频率低能量振动平台(35 Hz,峰振幅0.3 g)治疗,对照组则行假治疗.采用二维(X线)及三维(显微计算机断层扫描)的影像学方法和生物力学测试对骨折愈合的情况进行评估,并行统计学比较分析.结果 治疗后2周治疗组新生的矿化骨痂在上维及三维定量分析中均明显多于对照组,差异有统计学意义(P<0.001和P=0.014).治疗后4周治疗组的骨折愈合率(85.7%)高于对照组(57.1%),骨折愈合的生物力学属性也优于埘照组,差异有统计学意义(P=0.023).结论 高频率低能量振动可刺激骨折部位骨痂的生成及矿化,从而促进骨折愈合.     

Low-dose X-irradiation promotes mineralization of fracture callus in a rat model

Objectives  This study investigated the hypothesized beneficial effect of low-dose irradiation (LDI) on fracture callus mineralization in a rat model. Methods  Seventy-two male Sprague–Dawley rats were averagely randomized into LDI group (rats treated with LDI) and SHAM group (rats treated with sham irradiation). Right after either LDI or sham irradiation, a standardized closed fracture on the right femur was established. At 2, 3 and 4 weeks postfracture, 12 rats in each group were euthanized. Fracture callus was assessed by using radiography and MicroCT for callus bridging, peripheral quantitative computed tomography (pQCT) for quantifying bone mineral content (BMC) and cross sectional area (CSA), confocal laser scanning microscopy for measuring area fraction of fluorescence labeling (AFFL) and four-point bending test for examining mechanical properties. Results  The CSA and AFFL were found to be 22 and 33% smaller in the LDI group compared to the SHAM group at 2 weeks (P < 0.05 for both), whereas the BMC and AFFL were 15 and 34% higher in the LDI group at 3 weeks (P < 0.05 for both). The changing patterns were consistent with the findings in 3-D MicroCT reconstructions. The mechanical parameters (Max-Load, Stiffness and Energy) were also 18, 30 and 24% higher in the LDI group than in the SHAM group at 3 weeks (P < 0.05 for all). At 4 weeks, there was no difference found for all assessments between the two groups. Conclusion  The results indicated LDI promoted mineralization at the stage of hard callus formation in a rat fracture model.     

The fracture gap size influences the local vascularization and tissue differentiation in callus healing

Background Revascularization of a fracture depends on fracture stability and fracture gap conditions. The aim of the study was to determine quantitatively the revascularization and tissue differentiation in an animal model with different fracture gaps and controlled biomechanical conditions.Materials and method The study was performed on ten sheep with an osteotomy on the right metatarsal. The fracture was stabilized by an external fixator that allowed adjustable axial interfragmentary movement. Two groups of five sheep each were adjusted to a medium sized gap (M, 2.1 mm) and a large gap (L, 5.7 mm) under comparable interfragmentary strain (30–32%). The animals were killed after 9 weeks, and the metatarsals were prepared for undecalcified histology and analysis of tissue differentiation and vessel distribution.Results Group M showed significantly more revascularization (M=1.62, L=0.85 vessels/mm²), more bone formation (M=37.2%, L=13.9%) and less fibrocartilage tissue (M=18.1%, L=39.1%) than group L. Larger vessels (>40 m) were found mainly in the medullary channel, and smaller vessels (<20 m) mainly in the peripheral callus. Histologically, group M showed partial bony bridging of the osteotomy gap, and the group L had delayed healing.Conclusion A good reduction of a fracture with small interfragmentary gaps is important for its revascularization and healing.     

天鹅型形状记忆接骨器对骨折愈合时应力遮挡率及骨痂成熟过程的影响

目的：探讨天鹅型形状记忆接骨器固定下骨折愈合时应力遮挡率随时间的变化以及骨折处超微结构和力学性能的特点。方法：新西兰兔行单侧肱骨干横断截骨,实验组以天鹅记忆接骨器内固定,对照组以加压钢板固定。分别于术后第2、4、8、12、16周时取材,测定应力遮挡率和愈合骨的生物力学性能,并观察骨折端的超微结构变化。结果：愈合过程的前12周内实验组的应力遮挡率明显较低而力学性能则高于对照组,电镜观察则显示实验组矿物质沉积领先于对照纽且胶原纤维排列整齐。结论：天鹅记忆接骨器应力遮挡效应较小,加快了成骨细胞的分化成熟,促进了骨痂细胞外基质的生成和钙化,从而提高了愈合骨的力学性能。     

Effect of EHDP on fracture healing in dogs

Ethane-1-hydroxy-1,1-diphosphonate (EHDP) was administered subcutaneously to mature beagle dogs at dose levels of 0.1, 0.5, and 5.0 mg/kg/day for a 20 week period to determine the drug's effects on fracture healing. Uniform, transverse fractures of the midshaft radius were created in one limb and treated by external splintage. Drug-induced effects on fracture healing were monitored radiographically, histologically, and histomorphometrically; mechanical properties of the healing bones were determined in 4-point bending tests. At a dose of 0.1 mg/kg/day, ultimate load at failure and flexural rigidity of the fractured limbs equaled or exceeded that of saline control animals, and radiographic healing was normal. At a dose of 0.5 mg/kg/day ultimate load at failure and flexural rigidity of the fractured limbs proved inferior to saline control values, and radiographic healing appeared delayed. At a dosage of 5.0 mg/kg/day, there was obvious radiographic nonunion, and the callus of fractured radii had little inherent flexural rigidity or strength. Histomorphometrically, no differences were noted between control animals and the 0.1 or 0.5 mg/kg/day groups; however, mineralization activity appeared totally disrupted at the higher dosage level (5.0 mg/kg/day). In the 5.0 mg/kg/day group, EHDP-induced effects proved reversible with mineralization evident as early as 3 weeks following drug withdrawal. In mature beagle dogs EHDP proved to have dose-dependent and reversible inhibitory effects on secondary fracture healing.     

Human parathyroid hormone (1-34) accelerates natural fracture healing process in the femoral osteotomy model of cynomolgus monkeys

Several studies in rats have demonstrated that parathyroid hormone accelerates fracture healing by increasing callus formation or stimulating callus remodeling. However the effect of PTH on fracture healing has not been tested using large animals with Haversian remodeling system. Using cynomolgus monkey that has intracortical remodeling similar to humans, we examined whether intermittent treatment with human parathyroid hormone [hPTH(1–34)] accelerates the fracture healing process, especially callus remodeling, and restores geometrical shapes and mechanical properties of osteotomized bone.

Seventeen female cynomolgus monkeys aged 18–19 years were allocated into three groups: control (CNT, n = 6), low-dose PTH (0.75 μg/kg; PTH-L, n = 6), and high-dose PTH (7.5 μg/kg; PTH-H, n = 5) groups. In all animals, twice a week subcutaneous injection was given for 3 weeks. Then fracture was produced surgically by transversely cutting the midshaft of the right femur and fixing with stainless plate. After fracture, intermittent PTH treatment was continued until sacrifice at 26 weeks after surgery. The femora were assessed by soft X-ray, three-point bending mechanical test, histomorphometry, and degree of mineralization in bone (DMB) measurement. Soft X-ray showed that complete bone union occurred in all groups, regardless of treatment. Ultimate stress and elastic modulus in fractured femur were significantly higher in PTH-H than in CNT. Total area and percent bone area of the femur were significantly lower in both PTH-L and PTH-H than in CNT. Callus porosity decreased dose-dependently following PTH treatment. Mean DMB of callus was significantly higher in PTH-H than in CNT or PTH-L. These results suggested that PTH decreased callus size and accelerated callus maturation in the fractured femora.

PTH accelerates the natural fracture healing process by shrinking callus size and increasing degree of mineralization of the fracture callus, thereby restoring intrinsic material properties of osteotomized femur shaft in cynomolgus monkeys although there were no significant differences among the groups for structural parameters.