伞状支撑骨移植术治疗股骨头坏死的生物力学研究

目的 观察伞状支撑骨移植术治疗股骨头坏死的生物力学变化.方法 应用伞状支撑骨移植术(A组)治疗山羊股骨头坏死模型,并通过生物力学检测与单纯股方肌骨柱移植术组(B组)、骨髓间充质干细胞和松质骨移植术组(C组)进行对照研究(每组均14只).结果 术后3个月A组手术侧股骨头软骨下骨、松质骨的最大压强和弹性模量为:(77.43±2.65)、(120.60±4.18)MPa;(46.63±1.32)、(81.74±3.96)MPa.高于B组、C组(P＜0.05),与正常侧比较差异无统计学意义(P＞0.05).结论 伞状支撑骨移植术能有效恢复股骨头的生物力学强度,防止塌陷.     

Effects of rapid distraction rate on new bone formation during mandibular distraction osteogenesis in goats

Objective

Distraction osteogenesis typically requires a long treatment period, which can lead to bone and soft-tissue infection and considerable patient discomfort. Use of a rapid distraction rate in craniofacial distraction osteogenesis to shorten the distraction period is possible owing to the unique characteristics of craniofacial bones, including an abundant blood supply and rapid bone healing compared with long bones. The effects of using a rapid distraction rate in the treatment of craniofacial deformities are currently unclear, however. The objective of this study was to investigate the effects of a rapid distraction rate on new bone formation during mandibular distraction osteogenesis in goats.

Methods

Sixteen goats were randomly divided into four groups consisting of four goats each. In Groups A, B, and C, the right mandible of each goat was distracted at a rate of 0.8 mm/d, 1.6 mm/d, and 2.0 mm/d, respectively; Group D was the control group and did not undergo distraction. Six weeks after the conclusion of distraction, bone densitometry and three-point bending testing were performed in all groups.

Results

The mean bone density value of goats in Group A was significantly higher than those of all the other groups (p < 0.05), and the mean bone density value of goats in Group C was significantly lower than those of all the other groups (p < 0.05). The mean curve slope, peak stress, bending modulus, and energy to failure values of Groups A, B, and C were all significantly lower than those of the control group (p < 0.05). As the distraction rate increased, the curve slope and peak stress values gradually declined (p < 0.05).

Conclusions

Use of a rapid distraction rate in mandibular distraction osteogenesis may have detrimental effects on the quality of new bone, despite the abundant blood supply of craniofacial bones.     

Therapeutic effect of osteogenically induced adipose derived stem cells on vascular deprivation-induced osteonecrosis of the femoral head in rabbits

Objective: To explore the therapeutic effect of osteogenically induced adipose-derived stem cells (ADSCs) on vascular deprivation-induced osteonecrosis of the femoral head (ONFH) in rabbit model. Methods: Vascular deprivation-induced ONFH was established by intramuscular injection of methylprednisolone, and vascular occlusion of the capital femoral epiphysis by electrocoagulation in adult New Zealand white rabbits. Eight weeks after the establishment of vascular deprivation-induced ONFH, animals were randomly divided into three equal groups. In Group A (control), no therapy was given. In Group B, core decompression was performed by drilling a hole (1.2 mm in diameter) from the outer cortex 2.5 cm distal to the proximal end of the greater trochanter. In Group C, 1 ×107 osteogenically induced ADSCs were resuspended in 0.5 ml PBS, and then injected directly into the femoral head. Femoral head specimens were obtained at postoperative 8 weeks. The bone formation and three-dimensional microstructure of the femoral head was evaluated by micro-computed tomography scans (μ-CT). Immunohistochemical analysis was performed to detect the expression of osteocalcin. Angiogenesis and repair of the femoral head were observed histologically. Results: In trabecular bone at the proximal femur region, the trabecular volume was higher in Group C (130.70 mm3± 4.33 mm3) than that in Groups A (101.07 mm3±7.76 mm3) and B (107.89 mm3±8.68 mm3, P＜0.01). Bone volume was significantly increased in Group C (40.09 mm3±6.35 mm3) than in Groups A (29.65 mm3±4.61 mm3) and B (31.80 mm3± 4.01 mm3, P＜0.01). The trabecular number was higher in Groups C (1.58±0.25) than other two groups (1.15±0.18, 1.16± 0.21, P＜0.01). Bone mineral density showed statistically significant difference between Groups C and A or B (375.38± 23.06) mg HA/ccm, vs (313.73 ±19.30) mg HA/ccm and (316.09± 16.45) mg HA/ccm, P<0.01). Histological examination indicated that there was more new bone formation in Group C than in other groups. Conclusion: Treatment with autologous osteogenically induced ADSCs transplantation results in an enhanced osteogenesis and microstructure of the vascular deprivation-induced osteonecrosis in rabbits.     

自体脂肪干细胞复合珊瑚修复犬颅骨标准缺损的初步研究

目的 应用自体脂肪干细胞(adipose-derived stem cells,ADSCs)复合珊瑚构建组织工程化骨,修复犬颅骨标准缺损.方法 体外扩增培养、成骨诱导Beagle犬ADSCs,将第2代细胞接种在珊瑚支架上共同培养.制造实验犬双侧颅骨全层标准缺损(20 mm×20 mm),一侧以细胞材料复合物修复作为实验组(n=7),另一侧以单纯珊瑚材料修复作为对照组(n=7).术后24周分别通过影像学、大体形态观察、生物力学检测、组织学方法检测颅骨缺损的修复效果.结果 成骨诱导的犬ADSCs体外呈现成骨特性,在珊瑚支架上生长良好.3D-CT重建显示术后12周实验组有新生骨痂形成,对照组材料大部分降解;24周时实验组为骨性愈合,对照组为骨不连.24周时实验组缺损修复百分比为(84.19±6.45)%,显著高于对照组的(25.04 ±18.82)%(P<0.01).大体观察见实验组由新生骨痂修复缺损,对照组缺损边缘可见少量骨痂形成,主要为软组织充填;24周生物力学检测修复组织能耐受的最大压力载荷,实验组为(73.45±17.26)N,为犬顶骨最大压力负荷(104.27±22.71)N的70%,两者比较差异有统计学意义(P<0.01),对照组为软组织无法完成上述检测.HE染色见实验组有较多成熟骨呈骨性愈合,对照组为纤维性愈合.结论 自体成骨诱导的ADSCs复合珊瑚形成的组织工程化骨可修复犬颅骨标准缺损.     

Influence of the ratio of particulate autogenous bone graft/platelet‐rich plasma on bone healing in critical‐size defects: A histologic and histometric study in rat calvaria

The purpose of this study was to analyze histomorphometrically the influence of the ratio of particulate autogenous bone (AB) graft/platelet‐rich plasma (PRP) on bone healing in surgically created critical‐size defects (CSD) in rat calvaria. Fifty rats were divided into five groups: Group C (control), Group AB, Group AB/PRP‐50, Group AB/PRP‐100, and Group AB/PRP‐150. A 5‐mm diameter critical‐size defect was created in the calvarium of each animal. In Group C, the defect was filled by blood clot only. In Group AB, the defect was filled with 0.01 mL of AB graft. In Groups AB/PRP‐50, AB/PRP‐100, and AB/PRP‐150, the defects were filled with 0.01 mL of AB graft combined with 50, 100, and 150 µL of PRP, respectively. All animals were euthanized at 30 days postoperative. Histomorphometry, using image analysis software, and histology analyses were performed. New Bone Area (NBA) and the remaining bone graft particles area (RPA) were calculated as a percentage of the total area of the original defect. Percentage data were transformed into arccosine for analysis. No defect completely regenerated with bone. Group AB/PRP‐50 (41.78 ± 13.48%) had a significantly greater NBA than Groups C (19.29 ± 5.11%), AB (27.43 ± 10.90%) or AB/PRP‐150 (19.17 ± 8.45%) (p < 0.05). No significant differences were observed between groups AB/PRP‐50 and AB/PRP‐100 or among groups AB, AB/PRP‐100, and AB/PRP‐150 with regard to NBA (p > 0.05). Group AB/PRP‐150 (31.59 ± 3.22%) had a significantly greater RPA than Groups AB (19.09 ± 5.21%), AB/PRP‐50 (17.33 ± 4.43%), and AB/PRP‐100 (19.72 ± 3.62%) (p < 0.001). No significant differences were observed among groups AB, AB/PRP‐50, and AB/PRP‐100 with regard to RPA (p > 0.05). The ratio AB graft/PRP influences bone healing in surgically created CSD in rat calvaria. © 2009 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 28:468–473, 2010     

异体皮质骨板不同固定方式的生物力学比较

目的探讨异体皮质骨板采用不同固定方式的强度差异及机制。方法由南华大学解剖室提供的14具(男8具,女6具)尸体上取下股骨27根,X线排除骨病后,用游标卡尺测量,取各骨最细部分的直径,制作27个不稳定骨折模型,随机分成A、B、C组,每组9个,分别采用3种方式固定:A组:用2块大小为110mm×10mm×3mm异体皮质骨板嵌合固定;B组:用2块110mm×10mm×3mm异体皮质骨板和5枚骨螺钉固定;C组:用1块110mm×10mm×3mm骨板和5枚骨螺钉固定。分别进行生物力学实验,测试其压缩、弯曲及扭转刚度和极限载荷。结果不同固定方式显示不同的力学特征。A组的轴向刚度与B组相似,且高于C组,但抗弯和扭转刚度显著高于B、C两组,差异有统计学意义(P<0.05)。A组的压缩、弯曲、扭转极限载荷分别为1.65±0.34kN,554.33±49.34N,7.78±0.82Nm;B组分别为1.12±0.37kN,428.00±37.40N,3.39±0.22Nm,两组比较有统计学意义(P<0.05),而C组分别为0.71±0.46kN,218.67±36.53N,1.74±0.12Nm,与A组比较差异有统计学意义(P<0.01)。结论异体皮质骨板固定的强度与固定方式有关。双板嵌合固定比骨板骨螺钉固定具有更大的强度和刚度,可满足临床需要。     

人工骨联合自体骨髓移植技术的骨缺损修复研究与应用

目的分析人工骨联合自体骨髓移植技术治疗骨缺损的临床疗效。方法选取2011年4月至2013年9月,来本院诊治的四肢粉碎性骨折术后骨缺损患者40例,随机分为两组（A、B组）,分别行自体髂骨植骨和人工骨联合自体骨髓移植治疗四肢粉碎性骨折所致骨缺损。术后观察两组骨折愈合时间,骨折愈合率,并发症的发生及骨缺损的修复和功能重建优良率。结果两组均行6～12个月随访,平均（9.14±1.36）月,所有患者植骨术后均无切口感染、发热等并发症。A组15例骨缺损区愈合良好,住院时间平均（19.36±2.54）天,骨折愈合时间平均（5.67±1.52）个月,骨缺损的修复和功能重建评价标准,优12例,良3例,可3例,差2例,优良率75%;B组18例骨缺损区愈合良好,住院时间平均（12.19±1.52）天,骨折愈合时间平均（3.61±1.13）个月,骨缺损的修复和功能重建评价标准,优16例,良2例,可2例,差0例,优良率90%。B组骨缺损治疗效果显著优于A组。结论人工骨联合自体骨髓移植较单纯自体髂骨移植治疗骨缺损更能促进骨痂生长,加速骨折后骨缺损愈合,更加有效地减少住院时间及骨折愈合时间,骨折愈合率更高,骨缺损修复和功能重建效果更加显著。     

帽式颈椎椎间融合器的活体实验研究

目的 本研究在活体山羊颈椎上从椎间支撑能力、二期生物力学稳定性及椎间融合组织学方面比较三面皮质骨、Harms椎间融合器（cage）、Carboncage及自行所研制的帽式颈椎椎间融合器（hat　type　cervical　intervertebral　fusion　cage,HCIFC）的术后效果。方法　取32头山羊随机平均分为4组：第1组自体三面皮质髂骨;第2组Harmscage;第3组Carboncage;第4组HCIFC。分别行C3,4椎间盘切除术并分别植入以上内植物。术后共观察12周并测量平均椎间高度（DSH）、椎间角（IVA）及前凸角（LA）,处死后进行影像学、生物力学及组织学评估。结果 术后1周方盒形HCIFC、Carboncage组的平均DSH、IVA及LA要显著大于垂直圆柱体Harmscage和三面皮质骨组（P〈0．05）;术后12周时3个cage组的平均DSH、IVA及LA显著高于三面皮质骨组（P〈0．05）。垂直圆柱体Harmscage轴向旋转和侧屈时平均刚度显著大于其他组（P〈0．001）,轴向旋转时的最大活动度要显著低于其他组（P〈0．05）。与三面皮质骨组相比,3个cage组的椎间融合效果略好。结论HCIFC的椎间支撑能力、生物力学性能及椎间融合效果均适合于临床使用。     

壳聚糖复合骨髓间充质干细胞修复兔骨缺损的研究

目的 观察壳聚糖复合骨髓间充质干细胞(MSCs)修复兔骨缺损的作用.方法 将45只骨缺损模型兔随机分为3组.A组:骨缺损不填充任何材料;B组:骨缺损填充单纯壳聚糖微球;C组:骨缺损填充壳聚糖微球复合MSCs.分别在治疗后第4、8和12周对3组动物模型的骨缺损部位行影像学和组织学观察,并检测骨形成蛋白-2 (BMP-2)的表达.结果 影像学和组织学显示,C组复合材料有良好的诱导成骨能力,治疗第4周即有明显的成骨反应和新骨形成,治疗第12周基本修复骨缺损;B组修复能力较C组差,但B组和C组均优于A组;C组毛细血管数、管径及骨陷窝空缺百分比依次为(7.8±1.4)、(9.0±1.7) μm和(24.8±5.6)%,与A、B两组比较差异均有统计学意义(P<0.05);各时期C组BMP-2的表达水平依次为(9.8±1.5)%、(11.2±2.0)%和(16.7±2.5)%,与A、B两组同时期比较均明显升高(P<0.05).B组和C组对壳聚糖无明显异物反应.结论 壳聚糖是修复兔骨缺损的良好移植材料,复合MSCs后能促进骨缺损的修复.

Abstract：

Objective To investigate the effects of chitosan combined with bone marrow mesenchymal stem cells (MSCs) on the repair of rabbit with bone defect. Methods 45 rabbits with bone defect were randomly divided into 3 groups.Group A: defect was not filled with any implants;Group B: defect was filled with chitosan; Group C: defect was filled with chitosan combined with bone MSCs.The expression of bone morphogenetic protein-2 (BMP-2) in the 3 groups were observed by imaging and histology in the 4, 8 and 12 week after treatment. Results Group C had a better osteogenesis ability than group A and B. Group B had a better osteogenesis ability than group A.New bones and osteogenesis were obviously observed in group C in the 4 week, and the defect areas in group C were almost repaired 12 weeks after operation;The number and diameter of capillaries,percentage of vacant lacunae in group C were (7.8±1.4), (9.0±1.7) μm and (24.8±5.6)%, compared with the group A and B, it improved significantly (P<0.05);The expression of BMP-2 in group C every time were (9.8±1.5)%, (11.2±2.0)% and (16.7±2.5)%, compared with the group A and B,it improved significantly (P<0.05) during all periods.There was no significant foreign body reaction to chitosan in group B and C. Conclusion Chitosan is a superior material for repairing bone defect, and chitosan combined with MSCs have potential applications in treating bone defect.     

抗滑动钢板治疗Letenneur Ⅰ型Hoffa骨折的生物力学研究

目的 通过对Letenneur Ⅰ型Hoffa骨折使用抗滑动钢板(使用锁定螺钉和松质骨螺钉两组)与松质骨螺钉(由前向后和由后向前固定两组)四种固定方式固定Letenneur Ⅰ型Hoffa骨折的力学进行比较,探讨抗滑动钢板在Hoffa骨折中的应用.方法 20个模型股骨造成相同的Letenneur Ⅰ型Hoffa骨折,随机分为四组,每组5个.A组使用由前向后两枚松质骨螺钉固定,B组使用由后向前两枚松质骨螺钉固定,C组使用抗滑动钢板加锁定螺钉固定,D组使用抗滑动钢板加松质骨螺钉固定.所有标本通过循环负荷试验和最大失效负荷试验,对最大位移平均值和最大失效负荷平均值进行比较.结果 在循环负荷试验中,第10、100、1000、10 000周期下,四组骨折块最大位移平均值间差异均无统计学意义(P>0.05).而在最大失效负荷试验中,A组[(1224±72)N]和C[(2183±227)N]、D组[(2124±235)N]差异有统计学意义(P<0.05),B组[(1405±235)N]和C、D组差异有统计学意义(P<0.05),A组和B组、c组和D组差异均无统计学意义(P>0.05). 结论对于简单的Hoffa骨折,固定后初期给予适当保护条件,四种固定方式都能取得满意的力学稳定性和强度.但对于预计骨折愈合时间长、体质量指数大、患者依从性差的患者,建议使用抗滑动钢板.     

rhBMP-6 stimulated osteoprogenitor cells enhance posterolateral spinal fusion in the New Zealand white rabbit.

BACKGROUND CONTEXT: The nonunion rate after posterolateral spinal fusion can be as high as 35%. This has stimulated interest in the development of techniques for enhancing new bone formation, including the addition of bioactive peptides or the use of cell-based therapies, including genetically modified cells. In previous studies we have demonstrated that exposing autologous, marrow-derived osteoprogenitor cells to a recombinant human bone morphogenetic protein-6 (rhBMP-6) containing extracellular matrix induces osteoblastic differentiation, and that these cells are capable of increasing new bone formation. Growth of autologous cells on a synthetic rhBMP-6 containing matrix yields a population of stimulated osteoprogenitor cells, without the expense of adding large amounts of rhBMP-6 directly, or the risks inherent in the use of genetically altered cells. PURPOSE: This study was performed to evaluate the potential of rhBMP-6 stimulated osteoprogenitor cells (stOPC) to enhance the rate and strength of posterolateral spinal fusion. STUDY DESIGN: Prospective in vivo animal study OUTCOME MEASURES: Radiographic evidence of spinal fusion, biomechanical testing of explanted spines, histological analysis of new bone formation METHODS: Single-level posterolateral spinal arthrodeses were performed in 69 New Zealand white rabbits. Autologous marrow stem cells were concentrated and then plated on an rhBMP-6-rich extracellular matrix synthesized by genetically engineered mouse C3H10T1/2 cells. Animals in Groups I (n=18) and II (n=18) received autografts of 30M and 60M rhBMP-6 stOPCs in guanidine extracted demineralized bone matrix (gDBM), respectively, whereas those in Group III (n=13) received iliac crest bone graft (ICBG). Those in Group IV (n=10) received gDBM, and those in Group V (n=10) underwent decortication only. Assessment of fusion was made with serial radiographs, manual palpation of the explanted spines, and biomechanical testing. The fusion masses from two animals each in Groups I, II, and IV were evaluated histologically. RESULTS: Fifty-three animals were available for analysis at the conclusion of the study. In these animals, the arthrodesis rate was significantly higher after treatment with rhBMP-6 stOPCs (77% for both Groups I and II by palpation) than ICBG, gDBM, or decortication alone (Group III=55%, IV=20% and V=0%, respectively). Similarly, the peak loads to failure of the fusion masses in Groups I and II (212.5+/-37.8 N and 234.6+/-45.7 N) were significantly greater than the corresponding values in the other groups (Group III=155.9+/-36.4N, Group IV=132.7+/-59.9N, and Group V=92.8+/-18.4N), though when only the fused specimens in Groups I, II, and III were compared, only Group II was significantly different than Group III (234.6+/-45.7N and 155.9+/-36.4N, respectively). The fusion masses in the rhBMP-6 stOPC-treated animals were typified by a thin, fusiform cortical shell, newly formed trabecular bone emanating from the decorticated transverse processes, and residual unremodeled gDBM carrier particles. The fusion masses in the gDBM treated bones were morphologically similar, though they contained less newly formed bone. CONCLUSIONS: The use of rhBMP-6 stOPCs in a carrier of gDBM significantly enhanced the rate and strength of single-level posterolateral spinal arthrodeses in the New Zealand white rabbit, compared with ICBG, gDBM, and decortication alone. Our results confirm that the stimulation of marrow-derived osteoprogenitor cells by growing them on a rhBMP-6 containing extracellular matrix is feasible. Further investigation is warranted to determine the relative contribution of rhBMP-6 stimulation and the number of cells implanted, as well as strategies for optimizing the technique for clinical application.     

退变性腰椎滑脱三种后路融合方法的远期疗效比较

目的比较退变性腰椎滑脱(degenerative lumbar spondylolisthesis,DLS)3种后路融合方法的远期疗效。方法回顾性分析62例DLS患者的资料,按融合方法分为3组:A组后外侧融合,B组椎间自体髂骨融合,C组椎间Cage置入融合,进行5～9年的随访。对术前、术后及随访时影像学资料和临床评价指标进行比较。结果 3组间日本骨科学会(Japanese Orthopaedic Association,JOA)评分改善率、优良率和融合率等差异无统计学意义(P>0.05)。随访时3组滑脱复位率分别丢失(1.61±1.09)%、(0.88±1.45)%和(0.06±0.12)%,椎间高度分别丢失(2.00±0.77)mm、(0.39±0.35)mm和(0.03±0.18)mm,椎间盘角分别丢失2.78°±1.26°、1.39°±0.76°和0.75°±0.61°,差异均有统计学意义(P<0.05),C组丢失最少。结论 3种融合方法均能获得良好的远期临床疗效,椎间Cage置入融合有更好的影像学表现。     

颈椎自张式记忆合金椎间融合器山羊动物模型实验研究

目的建立颈椎自张式记忆合金椎间融合器山羊动物模型,比较其与三面皮质髂骨、钛网的融合效果及并发症。方法18只成年公山羊随机分为自体三面皮质髂骨（A组）、钛网（B组）、记忆合金椎间融合器（C组）3组,均行C4椎体次全切除植骨术,附加颈前路钢板内固定。术后即刻及12周摄颈椎X线片,术后12周取标本行组织学检查。结果A组出现1例髂骨血肿,B组出现1例不全瘫及1例钛网下沉,B组、C组出现1例切口感染。术后12周各组山羊颈椎获得放射学及组织学融合。C组山羊颈椎获得牢固的椎体间融合。结论颈椎自张式记忆合金椎间融合器可获得满意的融合效果,手术并发症较少。     

带血供脂肪筋膜瓣对骺板缺损骨桥形成的预防作用

目的 制作未成年兔的股骨远端中心型骺板缺损模型,观察带血供脂肪筋膜瓣充填骺板缺损后对骨桥形成的预防作用.方法 用3.5mm克氏针造成兔一侧股骨远端中心型骺板缺损,另一侧作正常参照.实验动物分为3组,A组用带血供脂肪筋膜瓣填塞骺板缺损;B组用游离脂肪筋膜瓣填塞;C组不做任何填塞,为单纯缺损组.20周后,取3组手术侧股骨长度、膝关节外翻角与健侧的差值进行比较,评价股骨的畸形.并通过组织学的方法观察骨桥形成及骺板自身修复情况.结果 3组的手术侧股骨长度较对侧正常股骨短,A、B、C组短缩的程度分别为(1.73±1.37)、(3.89±1.49)、(6.52±1.62) mm,3组之间差异有统计学意义(P＜0.05);3组手术侧股骨与健侧对比均有不同程度的外翻畸形,外翻角的差异分别为A组(3.73±3.41)°,B组(6.34±6.07)°,C组( 18.38±10.65)°,C组外翻畸形明显,而A、B两组之间无统计学意义(P＞0.05).组织学观察,A组脂肪筋膜瓣未被吸收,并有较规则的骺板再生;B组脂肪筋膜瓣大部分吸收,与骺板之间有骨桥形成,骺板再生不规则;C组有明显骨桥形成.结论 带血供脂肪筋膜瓣对中心型骺板缺损后的骨桥形成有明显的预防作用,且能减小骺板缺损后股骨的畸形程度.     

Study of gelatinized marrow stroma osteoblasts and true bone ceramic active bone

Trueboneceramic(TBC)isacomparativelygoodframematerialinbonetissueengineeringbecauseofitsadvantagesofnaturalbonetrabeculestructure, easydegradation, nonimmunogenicity, easymanufacture, abundantresources, andlowcost, etc1.Owingtoitsfragileness, nonductility, andasmoothsurfaceunfitforseedcelladhesion, itisstilldifficultforwidespreadclinicaluse. Bytakingadvantageofthepeculiaritiesofsodiumalginatethatwilltransformfromliquidstateintogelatinationstateandproducelateralconjunctionwhencombiningwithbiva…     

Functionally improved bone in calbindin-D28k knockout mice

In vitro studies indicate that Calbindin-D28k, a calcium binding protein, is important in regulating the life span of osteoblasts as well as the mineralization of bone extracellular matrix. The recent creation of a Calbindin-D28k knockout mouse has provided the opportunity to study the physiological effects of the Calbindin-D28k protein on bone remodeling in vivo. In this experiment, histomorphometry, microCT, and bend testing were used to characterize bones in Calbindin-D28k KO (knockout) mice. The femora of Calbindin-D28k KO mice had significantly increased cortical bone volume (60.4% +/- 3.1) compared to wild-type (WT) mice (45.4% +/- 4.6). The increased bone volume was due to a decrease in marrow cavity area, and significantly decreased endosteal perimeters (3.397 mm +/- 0.278 in Calbindin-D28k KO mice, and 4.046 mm +/- 0.450 in WT mice). Similar changes were noted in the analysis of the tibias in both mice. The bone formation rates were similar in the femoral and tibial cortical bones of both mice. microCT analysis of the trabecular bone in the tibial plateau indicated that Calbindin-D28k KO mice had an increased bone volume (35.2% +/- 3.1) compared to WT mice (24.7% +/- 4.9) which was primarily due to increased trabecular number (8.99 mm(-1) +/- 0.94 in Calbindin-D28k KO mice compared to 6.75 mm(-1) +/- 0.85 in WT mice). Bone mineral content analysis of the tibias indicated that there is no difference in the calcium or phosphorus content between the Calbindin-D28k KO and WT mice. Cantilever bend testing of the femora demonstrated significantly lower strains in the bones of Calbindin-D28k KO mice (4135 micro strain/kg +/- 1266) compared to WT mice (6973 micro strain/kg +/- 998) indicating that the KO mice had stiffer bones. Three-point bending demonstrated increased failure loads in bones of Calbindin-D28k KO mice (31.6 N +/- 2.1) compared to WT mice (15.0 N +/- 1.7). In conclusion, Calbindin-D28k KO mice had increased bone volume and stiffness indicating that Calbindin-D28k plays an important role in bone remodeling.     

新型扩张器辅助伤椎内植骨结合椎弓根内固定治疗胸腰段爆裂性骨折

目的 探讨采用新型椎体扩张器经椎弓根椎体内自体骨植骨结合椎弓根内固定治疗胸腰段爆裂性骨折的近期疗效.方法 2007年8月至2008年3月共收治胸腰段爆裂性骨折16例,根据AO分型:A2型10例.A3型6例.按ASIA脊髓神经功能障碍分级标准:A级2例,B级2例,C级2例,D级3例,E级7例.采用自行设计的新型椎体扩张器经伤椎椎弓根椎体内自体骨植骨,椎管减压(或不减压),相邻节段椎弓根内固定. 结果 伤椎椎体前缘高度由术前(18.3±2.5)mm恢复到术后(25.1±2.8)mm,Cobb角由术前36.33°±2.14°恢复到术后2.77°±0.41°(术后1周),差异均有统计学意义(P<0.01).伤椎经扩张器扩张后平均椎体内植骨量(10.53±3.62)cm3 椎体扩张器下伤椎椎体内植骨未引起神经、血管损伤等术中和术后并发症,术后随访6个月,椎体内植骨融合良好,伤椎前缘高度丢失和Cobb角与术后1周相比无明显变化,不完全性神经损伤术后脊髓神经功能有1～2级的恢复. 结论 采用新型椎体扩张器经伤椎椎弓根椎体内自体骨植骨治疗胸腰段爆裂性骨折可有效恢复伤椎椎体高度,重建前中柱的稳定性,防止术后由于椎体高度丢失所导致的并发症;椎体扩张器具有良好的临床运用价值.     

一期后路病灶清除植骨融合内固定治疗胸腰椎结核

目的:探讨一期后路病灶清除植骨融合内固定治疗胸腰椎结核的可行性及疗效,并与前后路联合手术相比较.方法:同顾分析2006年1月至2008年10月收治的67例胸腰椎结核患者,其中后路手术组(A组)38例.行一期后路病灶清除、植骨融合、内固定术;前后路联合手术组(B组)29例,行一期前路病灶清除、植骨融合、后路内固定术.评价两组患者的手术时间、术中出血量、住院天数及手术前后的ASIA分级、Cobb角、血沉变化情况,并进行比较分析.结果:A组手术时间平均为160.4±20.5min,术中出血平均为760.7±146.2ml,住院天数平均为13.6±3.2d;B组分别为231.4±27.3min、1023.8±197.9ml和18.7±3.6d,两组间比较有显著性差异(PO.05).结论:一期后路病灶清除、植骨融合、内固定术治疗胸腰椎结核与前后路联合术式均可获得较好的治疗效果,但后路术式手术时间短、出血少、住院时间短.     

组织工程骨联合外固定修复大鼠股骨节段性骨缺损

目的 观察以外固定器固定,骨髓间充质干细胞 (BMSCs) 联合双相磷酸钙(BCP)修复大鼠股骨节段性骨缺损的效果.方法 A组:BMSCs与BCP复合植入缺损区;B组:BCP植入缺损区;C组:空白组.定期摄X线片,术后12周取材.结果 A组随时间延长X线评分递增,12周时平均为4.17分,B组为1.18分,C组为1.08分,差异有统计学意义(P<0.05).组织学检查见A组缺损区有大量的新生骨生成,而B、C组无新生骨生成.A组的抗压刚度和扭转刚度分别为(8.09±2.42)N/mm、(1.89±0.72)Nmm/deg;B组为(1.75±0.90)N/mm、(0.40±0.21)Nmm/deg,差异有统计学意义(P<0.05).结论 组织工程骨联合外固定可以修复节段性骨缺损.

Abstract：

Objective To evaluate the efficacy of bone mesenchymal stem cells (BMSCs) combined with biphasic calcium phosphate (BCP) repair of segmental bone defect, which was stabilized with an adaptable external fixation system.Methods In group A, the femoral defect was filled with BCP combined with BMSCs; In group B, the femoral defect was filled with BCP, and in group C, defects were left empty. Animals were sacrificed 12 weeks post-operation.Results In group A, radiographic scores were average 4.17, significantly (P<0.05) greater than in group B (1.18) and group C (1.08). Histological evaluations displayed the bridging of the defect in group A, with remarkable new bone formation. In contrast, group B and group C showed no formation of new bone. The mechanical testing revealed that axial stiffness was (8.09±2.42) N/mm and torsional stiffness was (1.89±0.72) Nmm/deg in group A, and those in group B were (1.75±0.90) N/mm and (0.40±0.21) Nmm/deg respectively. There was significant difference in biomechanical tests between group A and group B (P<0.05).Conclusion External fixator combined with tissue engineered bone can repair segmental bone defect.