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  本文關(guān)鍵詞：兔骨質(zhì)疏松模型的快速建立和硫酸鈣復(fù)合bBMP在椎體強化中的實驗研究　出處：《第四軍醫(yī)大學(xué)》2009年博士論文　論文類型：學(xué)位論文

  更多相關(guān)文章： 骨質(zhì)疏松癥 骨形態(tài)發(fā)生蛋白 硫酸鈣 PMMA 椎體 骨密度 顯微CT 生物力學(xué) 兔

【摘要】： 一、研究背景 骨質(zhì)疏松癥最常見的并發(fā)癥是椎體壓縮骨折,手術(shù)治療包括脊柱內(nèi)固定和椎體成形術(shù)或球囊擴(kuò)張椎體成形術(shù)。椎體成形術(shù)是近年來發(fā)展起來一種新的脊柱微創(chuàng)手術(shù),該技術(shù)已廣泛應(yīng)用于治療椎體的多種良惡性病變及骨質(zhì)疏松性骨折,取得了很好的臨床療效,可以快速緩解疼痛,糾正脊柱畸形,由于椎體成形術(shù)創(chuàng)傷小、效果好且療效快,已成為脊柱微創(chuàng)介入治療的又一重要方法。臨床上現(xiàn)在最常用的椎體成形術(shù)的材料為聚甲基丙烯酸甲酯(PMMA)。但PMMA充填材料具有許多缺點:病變椎體術(shù)后與相鄰椎體的力學(xué)強度不同,因應(yīng)力集中易導(dǎo)致相鄰椎體的骨折;組織相容性差,無成骨作用,無生物降解性,最終不被自體骨取代;單體有細(xì)胞毒性,放熱反應(yīng),其體外聚合溫度達(dá)40～122℃,術(shù)中可能會引起鄰近組織和神經(jīng)元的熱損傷。而且臨床越來越要求成形材料能夠攜帶有特殊治療作用的藥物,而PMMA并不能滿足這些臨床治療的需要。如何探索一種具有良好生物相容性的成形材料,其在作為固定材料的同時又能成為攜帶具有特殊治療作用的藥物的載體,是本研究的目的。 二、研究目的 1.探索采用去勢法+甲強龍誘導(dǎo)法快速建立兔子骨質(zhì)疏松模型的方法;評估去勢+甲強龍誘導(dǎo)后松質(zhì)骨及皮質(zhì)骨的微觀結(jié)構(gòu)和宏觀力學(xué)性能的改變;從而建立一種適用于骨科領(lǐng)域研究的兔骨質(zhì)疏松模型的快速建模方法。 2.在已經(jīng)建立的骨質(zhì)疏松模型體內(nèi),采用“二維組織形態(tài)—三維空間結(jié)構(gòu)—生物力學(xué)特性”的綜合手段,評估硫酸鈣以及硫酸鈣復(fù)合bBMP對提高骨質(zhì)疏松椎體骨密度、骨小梁微觀結(jié)構(gòu)及力學(xué)強度的作用。 三研究內(nèi)容和方法 第一部分建立并分析評價兔骨質(zhì)疏松動物模型 采用隨機(jī)對照研究方案,將20只新西蘭大白兔隨機(jī)分為去勢(OVX)A組(n=4)、B組(n=8)和假手術(shù)組(Sham,n=8)。A組為單純OVX組,B組為OVX+甲強龍肌注(4周)組。所有動物術(shù)前和術(shù)后2月均采用雙能X線吸收骨密度儀測定腰椎骨密度。于術(shù)后2個月:①采用組織病理學(xué)切片方法對骨小梁結(jié)構(gòu)進(jìn)行組織病理學(xué)觀察;②采用DEXA測定所有動物股骨髁部及皮質(zhì)骨的骨密度;③采用顯微CT分析松質(zhì)骨骨小梁三維結(jié)構(gòu)改變;④采用生物力學(xué)實驗,比較實驗組和對照組的松質(zhì)骨和皮質(zhì)骨的力學(xué)強度。 第二部分硫酸鈣(calcium sulfate CSC)復(fù)合bBMP材料在椎體強化中的實驗研究 采用隨機(jī)對照研究方案,將60只新西蘭大白兔隨機(jī)分為C1組、C2組、C3組、C4組(n=12)和假手術(shù)組(Sham,n=12)。C組按照實驗一方法建立骨質(zhì)疏松模型,實驗分為假手術(shù)對照組(Sham),骨質(zhì)疏松對照組(C1),注射PMMA組(C2),注射CSC組(C3),注射CSC/bBMP組(C4),通過模擬椎體成形術(shù),分別在每只兔子L2、L4、L6椎體注射材料,每組均于術(shù)后24小時,6周、12周處死4只。①采用組織病理學(xué)對骨小梁結(jié)構(gòu)進(jìn)行組織病理學(xué)觀察;②采用MicroCT對骨小梁微觀三維結(jié)構(gòu)進(jìn)行分析;③采用生物力學(xué)實驗評估椎體骨質(zhì)的結(jié)構(gòu)力學(xué)強度。通過“微觀結(jié)構(gòu)-宏觀密度-功能強度”的方法,全面衡量硫酸鈣和硫酸鈣復(fù)合bBMP材料對脊柱骨質(zhì)疏松的治療作用。 四研究結(jié)果 第一部分:手術(shù)前,Sham組、OVX-A組和OVX-B組的腰椎BMD分別為(266.7±38.58)mg/cm2、(270.1±25.38)mg/cm2和(272.8±27.08)mg/cm2手術(shù)2個月后,Sham組、OVX-A組和OVX-B組的BMD分別為(281.8±39.22)mg/cm2、(248.9±26.14)mg/cm2和(199.9±30.76)mg/cm2。OVX-B組的BMD較術(shù)前平均下降為26.72%。組織學(xué)切片觀察發(fā)現(xiàn),去勢2個月后,OVX-B組椎體及股骨松質(zhì)骨骨小梁明顯稀疏、變細(xì),局部存在骨小梁骨折及骨缺損;而對Sham和OVX-A照組骨小梁結(jié)構(gòu)完整,呈圓形或橢圓形拱形結(jié)構(gòu)。MicroCT分析表明,OVX-B組的骨小梁三維構(gòu)筑較Sham組及OVX-A組均有顯著改變(骨小梁明顯變細(xì)、連接率明顯下降),而OVX-A組骨小梁結(jié)構(gòu)與Sham組無顯著性差別。生物力學(xué)研究顯示,OVX-B組椎體抗壓縮強度(6.8±2.02MPa)較Sham組(14.5±3.74MPa)和OVX-A組(12.8±3.12MPa)均有顯著性降低,而OVX-A組與Sham組無顯著性差異。 第二部分:組織形態(tài)學(xué)觀察發(fā)現(xiàn),CSC組和CSC/bBMP組骨小梁連接性在術(shù)后6周和12周明顯優(yōu)于C1對照組,形態(tài)較為規(guī)則,小梁間連接程度優(yōu)于對照組。骨小梁變粗,骨折、微骨缺損處出現(xiàn)連接和修復(fù);12周時骨小梁結(jié)構(gòu)已經(jīng)接近Sham對照組。MicroCT三維重建顯示,6周時, CSC組和CSC/bBMP組骨小梁組的骨小梁三維結(jié)構(gòu)參數(shù)明顯優(yōu)于C1對照組(P0.05),骨密度值也明顯優(yōu)于C1對照組(P0.05);12周時,已與Sham對照組無顯著性差別。生物力學(xué)實驗結(jié)果表明,在6周時,CSC組椎體的最大抗壓縮強度有增加,但與C1對照組相比無顯著性差異,而CSC/bBMP組椎體抗壓縮強度在6周時顯著高于C1對照組;在12周時,CSC組和CSC/bBMP組椎體最大抗壓縮強度均較C1對照組有顯著性差異(P0.05),與Sham組及PMMA組相比,未見顯著性差異(P0.05)。 五結(jié)論 1.通過去勢+甲強龍肌注的方法,可以在2個月內(nèi)快速建立兔的骨質(zhì)疏松模型。 2.兔骨質(zhì)疏松模型建成后,二維及三維圖像顯示椎體松質(zhì)骨內(nèi)骨小梁稀疏、變細(xì)、斷裂,微觀三維構(gòu)筑受到破壞,并且局部形成骨小梁微骨折及微骨缺損,最終導(dǎo)致其力學(xué)性能下降。是一種理想可用的骨質(zhì)疏松動物模型。 3.CSC以及CSC為載體復(fù)合bBMP的注射型成骨材料具有強大的骨誘導(dǎo)能力,可以迅速有效地改善骨質(zhì)疏松椎體骨小梁的三維構(gòu)筑,提高其椎體力學(xué)強度,是具有良好應(yīng)用前景的椎體充填材料。
[Abstract]:First, research background
The most common complication of osteoporosis is vertebral compression fractures, surgical treatment including spinal fixation and vertebroplasty or kyphoplasty, vertebroplasty is developed in recent years a new minimally invasive spine surgery, the technology has been widely used in the treatment of benign and malignant vertebral lesions and osteoporotic fractures. We have got good curative effect, can quickly relieve pain, correct spinal deformity, because vertebroplasty has small trauma, good effect and quick effect, has become an important method of minimally invasive interventional therapy in clinic. Now the most commonly used materials for vertebroplasty polymethyl methacrylate (PMMA). But the PMMA filling material has many disadvantages: the mechanical strength of vertebral lesions and postoperative adjacent vertebral body is different, due to the stress concentration easily lead to adjacent vertebral fractures; bad histocompatibility, no osteogenesis, no biological Degradation, eventually not be replaced with autogenous bone; single cell toxicity, exothermic reaction, the in vitro polymerization temperature reaches 40 to 122 DEG C, may cause thermal damage to adjacent tissues and neurons in operation. The clinical and more and more requirements of forming materials can carry drugs special treatment function, but PMMA does not meet the the need of clinical treatment. To explore a biological forming material, it becomes the carrier of carrying drugs with special therapeutic effect in materials at the same time as fixed, is the purpose of this study.
Two, the purpose of the study
1. the ovariectomy + method of methylprednisolone induced by the rapid establishment of rabbit model of osteoporosis; microstructure and mechanical properties evaluation of OVX + methylprednisolone induced cancellous and cortical bone after the change; rapid modeling method to establish a suitable field of Department of orthopedics rabbit model of osteoporosis.
2. in vivo model of osteoporosis has been established, the organizational form of two-dimensional three-dimensional space structure and biomechanical properties of the comprehensive evaluation method, calcium sulfate and calcium sulfate combined with bBMP to improve the osteoporosis vertebral bone mineral density, trabecular bone microstructure and mechanical strength.
Three research content and method
The first part is to establish and analyze the animal model of rabbit osteoporosis
A randomized study, 20 New Zealand white rabbits were randomly divided into ovariectomized (OVX) group A (n=4), B group (n=8) and sham operation group (Sham, n=8).A group, pure OVX group, B group for OVX+ intramuscular injection of methylprednisolone (4 weeks) group. All the animal before operation and after February were measured by dual energy X-ray absorptiometry bone mineral density of lumbar spine bone density instrument. In 2 months after operation: using histopathological methods for histopathological observation of bone trabecular structure; bone density of femoral condyle were measured in all animal and cortical bone by DEXA; the changes of bone little Liang Sanwei bone structure loose by micro CT; the biomechanical experiment, comparing the experimental group and control group of cancellous bone and cortical bone strength.
Experimental study of second parts of calcium sulfate (calcium sulfate CSC) composite bBMP in vertebral enhancement
A randomized controlled study, 60 New Zealand white rabbits were randomly divided into C1 group, C2 group, C3 group, C4 group (n=12) and sham operation group (Sham, n=12).C group to establish the model of osteoporosis according to a method of experiment, the experiment was divided into sham operation group (Sham), according to osteoporosis group (C1), PMMA (C2) injection group, CSC injection group (C3), CSC/bBMP injection group (C4), through the simulation of vertebroplasty, respectively in each rabbit L2, L4, L6 body injection materials, each group in 24 hours after surgery, 6 weeks, 12 weeks and 4 Dead only. The trabecular structure for histopathological observation using histopathology; using MicroCT to analyze trabecular micro 3D structure; evaluation of structural mechanics of the vertebral bone strength by biomechanical experiment. Through the method of "micro - macro - structure density functional strength", a comprehensive measure of calcium sulfate and calcium sulfate composite material bBMP of spinal osteoporosis Therapeutic effect.
Four research results
The first part: before the operation, Sham group, OVX-A group and OVX-B group respectively for lumbar BMD (266.7 + 38.58) mg/cm2, (270.1 + 25.38) mg/cm2 and (272.8 + 27.08) mg/cm2 2 months after surgery, Sham group, OVX-A group and OVX-B group BMD respectively (281.8 + 39.22) mg/cm2. (248.9 + 26.14) mg/cm2 and (199.9 + 30.76) mg/cm2.OVX-B group BMD compared with the preoperative average decline of 26.72%. histological observation found that 2 months after ovariectomy group OVX-B vertebral and femoral cancellous bone Liang Mingxian sparse, thin, the local existence of trabecular bone fracture and bone defects of Sham; OVX-A and control group trabecular bone structure, a round or oval arch structure.MicroCT analysis showed that OVX-B group of trabecular structures compared with Sham group and OVX-A group were significantly changed (trabecular bone was significantly thinner, the connection rate decreased significantly, while OVX-A group) of trabecular bone structure and Sham was not significant difference. Biomechanical study showed that OV The compressive strength of vertebral body in group X-B (6.8 + 2.02MPa) was significantly lower than that in group Sham (14.5 + 3.74MPa) and OVX-A group (12.8 + 3.12MPa), but there was no significant difference between OVX-A group and Sham group.
The second part: the morphological observation, CSC group and CSC/bBMP group trabecular connectivity after 6 weeks and 12 weeks were significantly better than the control group C1, form a more rules, small beam connection degree than the control group. Bone fracture, micro Liang Biancu, bone defects and repair connection; at 12 weeks, bone the beam structure is close to the Sham control group.MicroCT three-dimensional reconstruction showed that at 6 weeks, CSC group and CSC/bBMP group of trabecular bone group trabecular structure parameters was significantly better than the control group (C1 P0.05), the bone density was significantly better than the control group (C1 P0.05); at 12 weeks, and control group without Sham significant differences in biomechanical. Experimental results show that, at 6 weeks, the maximum compressive strength of CSC vertebral body increased, but with the C1 control group had no significant difference compared with CSC/bBMP group, vertebral compressive strength at 6 weeks was significantly higher than that of C1 control group; after 12 weeks, CSC group and CSC/bBMP group of vertebral body The maximum compressive strength was significantly different from that of the C1 control group (P0.05), and there was no significant difference compared with that of the Sham group and the PMMA group (P0.05).
Five conclusion
1. the osteoporotic model of rabbit can be quickly established within 2 months by the method of castration + methylprednisolone intramuscular injection.
Built in 2. rabbit osteoporosis model, 2D and 3D images show vertebral cancellous bone trabecular sparse, thin, micro fracture, three-dimensional damage and local formation of trabecular bone micro fractures and micro bone defect, result in the decrease of mechanical properties. It is an ideal animal model of osteoporosis can be used.
3.CSC and CSC as carrier compound bBMP have strong osteoinductive ability, which can rapidly and effectively improve the three-dimensional structure of vertebral trabecular bone and improve their vertebral mechanical strength. It is a promising filling material for vertebral body.

【學(xué)位授予單位】：第四軍醫(yī)大學(xué)
【學(xué)位級別】：博士
【學(xué)位授予年份】：2009
【分類號】：R580;R-332;R687

【引證文獻(xiàn)】

相關(guān)期刊論文 前1條

1 李素萍;;骨質(zhì)疏松動物模型的研究現(xiàn)狀[J];中國組織工程研究與臨床康復(fù);2011年20期

相關(guān)博士學(xué)位論文 前1條

1 石磊;骨質(zhì)疏松條件下椎弓根螺釘?shù)母男匝芯縖D];第四軍醫(yī)大學(xué);2011年

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本文編號：1376675