by Chong Wai Sing, Wilson. / Thesis submitted in: August 2002. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2003. / Includes bibliographical references (leaves 116-126). / Abstracts in English and Chinese. / ACKNOWLEDGEMENT --- p.i / ABBREVIATION --- p.ii / ABSTRACT (Chinese & English) --- p.iii / TABLE OF CONTENT --- p.vii / INDEX FOR FIGURES --- p.x / INDEX FOR TABLES --- p.xiii / Chapter 1. --- Introduction --- p.1 / Chapter 1.1 --- "Bone-tendon junction - types, structures and functions" --- p.2 / Chapter 1.1.1 --- Indirect insertion --- p.3 / Chapter 1.1.2 --- Direct insertion --- p.3 / Chapter 1.1.3 --- Functional adaptations of insertions --- p.4 / Chapter 1.2 --- Incidence and type of injuries near insertion site --- p.5 / Chapter 1.3 --- Treatment protocol for injuries near insertion site --- p.5 / Chapter 1.3.1 --- Non-operative versus operative approach --- p.5 / Chapter 1.3.2 --- Previous studies on validations of outcomes of difference repair methods --- p.6 / Chapter 1.4 --- Modes of healing underlying different repair approach --- p.7 / Chapter 1.4.1 --- Fracture healing --- p.7 / Chapter 1.4.2 --- Tendon healing --- p.8 / Chapter 1.4.3 --- Bone-tendon healing --- p.9 / Chapter 1.5 --- Objectives --- p.9 / Chapter 2. --- Materials and Methods --- p.12 / Chapter 2.1 --- Animal model --- p.13 / Chapter 2.2 --- Experimental design --- p.13 / Chapter 2.3 --- Surgery --- p.13 / Chapter 2.3.1 --- Bone-to-bone repair --- p.14 / Chapter 2.3.2 --- Bone-to-tendon repair --- p.14 / Chapter 2.3.3 --- Tendon-to-tendon repair --- p.15 / Chapter 2.4 --- Post-operative follow-up --- p.15 / Chapter 2.4.1 --- Radiographic examination --- p.15 / Chapter 2.4.2 --- Polychrome sequential labeling --- p.16 / Chapter 2.4.2.1 --- Reagents --- p.16 / Chapter 2.4.2.2 --- Route of administration --- p.16 / Chapter 2.5 --- Sampling --- p.17 / Chapter 2.6 --- Histology --- p.17 / Chapter 2.6.1 --- Decalcification --- p.17 / Chapter 2.6.1.1 --- Tissue decalcification --- p.17 / Chapter 2.6.1.2 --- Tissue processing --- p.17 / Chapter 2.6.1.3 --- Immunohistochemistry of collagen type II and III --- p.18 / Chapter 2.6.1.3.1 --- Reagents and solution preparation --- p.18 / Chapter 2.6.1.3.2 --- Experimental procedures --- p.20 / Chapter 2.6.2 --- Undecalcification --- p.22 / Chapter 2.6.2.1 --- Specimen preparations --- p.22 / Chapter 2.6.2.2 --- Toluidine blue staining --- p.22 / Chapter 2.7 --- Mechanical test --- p.23 / Chapter 2.7.1 --- Sample preparation --- p.23 / Chapter 2.7.2 --- Embedding procedures --- p.23 / Chapter 2.7.3 --- Measurement of cross-sectional area of healing interface --- p.23 / Chapter 2.7.3.1 --- CSA for BB --- p.23 / Chapter 2.7.3.2 --- CSA for BT and TT --- p.24 / Chapter 2.7.4 --- Tensile test --- p.24 / Chapter 2.7.4.1 --- Testing procedures --- p.24 / Chapter 2.7.4.2 --- Interpretation of testing results --- p.25 / Chapter 2.7.5 --- Statistical analysis --- p.26 / Chapter 3. --- Results --- p.42 / Chapter 3.1 --- Surgical outcome --- p.43 / Chapter 3.1.1 --- Radiographic examination --- p.43 / Chapter 3.1.1.1 --- Bone-to-bone healing --- p.43 / Chapter 3.1.1.2 --- Bone-to-tendon healing --- p.44 / Chapter 3.1.2 --- Fluorochrome injection --- p.44 / Chapter 3.2 --- Histology --- p.45 / Chapter 3.2.1 --- Bone-to-bone healing --- p.45 / Chapter 3.2.1.1 --- Gross anatomy --- p.45 / Chapter 3.2.1.2 --- Microscopic examination --- p.45 / Chapter 3.2.1.3 --- Polarised light microscopy --- p.46 / Chapter 3.2.1.4 --- Fluorochrome microscopy --- p.46 / Chapter 3.2.2 --- Bone-to-tendon healing --- p.47 / Chapter 3.2.2.1 --- Gross anatomy --- p.47 / Chapter 3.2.2.2 --- Microscopic examination --- p.47 / Chapter 3.2.2.3 --- Polarised light microscopy --- p.48 / Chapter 3.2.2.4 --- Fluorochrome microscopy --- p.49 / Chapter 3.2.3 --- Tendon-to-tendon healing --- p.49 / Chapter 3.2.3.1 --- Gross anatomy --- p.49 / Chapter 3.2.3.2 --- Microscopic examination --- p.49 / Chapter 3.2.3.3 --- Polarised light microscopy --- p.50 / Chapter 3.3 --- Mechanical testing --- p.50 / Chapter 3.3.1 --- Bone-to-bone healing --- p.50 / Chapter 3.3.1.1 --- Change of cross sectional area --- p.50 / Chapter 3.3.1.2 --- Load at failure --- p.50 / Chapter 3.3.1.3 --- Strength --- p.51 / Chapter 3.3.1.4 --- Energy --- p.51 / Chapter 3.3.2 --- Bone-to-tendon healing --- p.51 / Chapter 3.3.2.1 --- Change of cross sectional area --- p.51 / Chapter 3.3.2.2 --- Load at failure --- p.52 / Chapter 3.3.2.3 --- Strength --- p.52 / Chapter 3.3.2.4 --- Energy --- p.52 / Chapter 3.3.3 --- Tendon-to-tendon healing --- p.52 / Chapter 3.3.3.1 --- Change of cross sectional area --- p.53 / Chapter 3.3.3.2 --- Load at failure --- p.53 / Chapter 3.3.3.3 --- Strength --- p.53 / Chapter 3.3.3.4 --- Energy --- p.53 / Chapter 3.3.4 --- "Comparison of healing quality among BB, BT, and TT repair" --- p.54 / Chapter 3.3.4.1 --- Change of cross sectional area --- p.54 / Chapter 3.3.4.2 --- Load at failure --- p.54 / Chapter 3.3.4.3 --- Strength --- p.54 / Chapter 3.3.4.4 --- Failure mode --- p.55 / Chapter 4. --- Discussion --- p.102 / Chapter 4.1 --- Use of goat calcaneus-Achilles junction as a bone-tendon reseach model --- p.103 / Chapter 4.2 --- "Bone-to-bone, bone-to-tendon, and tendon-to-tendon fixation" --- p.104 / Chapter 4.3 --- Histological characterization of different healing tissues --- p.105 / Chapter 4.3.1 --- Bone-to-bone healing (Fracture healing) --- p.105 / Chapter 4.3.2 --- Bone-to-tendon healing --- p.106 / Chapter 4.3.3 --- Tendon-to-tendon healing --- p.106 / Chapter 4.3.4 --- Regeneration versus repair --- p.107 / Chapter 4.4 --- Spatial and temporal expression of different type of collagen in different form of healing --- p.108 / Chapter 4.5 --- Mechanical properties of healing interface under different form of fixation --- p.108 / Chapter 4.5.1 --- Failure mode --- p.110 / Chapter 4.6 --- Limitations --- p.111 / Chapter 4.6.1 --- Goat animal model --- p.111 / Chapter 4.6.2 --- Immunohistochemistry --- p.111 / Chapter 4.7 --- Future study --- p.112 / Chapter 5. --- Conclusion --- p.113 / Chapter 6. --- References --- p.116

骨科醫生面臨著老年婦女的骨修復受損或者癒合延遲的挑戰，這使得康復過程變長，甚至引發高死亡率。至今為止，臨床上仍然沒有促進老年骨癒合的滿意治療方法，因此亟需其他治療策略。骨癒合重現了胚胎後的骨骼發育過程。直接由骨外膜成骨（膜內骨化）以及通過軟骨介質成骨（軟骨內骨化）是骨癒合中的兩個重要過程。 雌激素受體β（ERβ基因敲除雌性小鼠的研究表明ERβ信號通路在骨骼發育過程中同時參與了抑制膜內骨化和軟骨內骨化這兩個過程。臨床活檢的資料顯示，在絶經後婦女的骨痂中，ERβ陽性的增生軟骨細胞數量增加。然而，ERβ在正常和老年骨癒合的作用還沒有研究。 / 本研究通過下述部分檢查了ERβ在正常和老年骨癒合的作用，以及其將來的藥物應用：1) 建立一個以膜內骨化為主的骨癒合模型。2) 通過連個骨癒合模型，檢查ERβ在正常骨癒合中的作用。3) 檢查ERβ在老年骨癒合中的作用並檢查ERβ拮抗劑PHTPP 對老年骨癒合的潛在藥物療效。 / 實驗1是建立一個以膜內骨化為主的骨癒合模型。以前建立的小鼠股骨中段骨折模型是軟骨內骨化為主的骨癒合模型。由於技術難度，該模型可重複性不高，而且其金屬內固定器會造成金屬偽影，進而不能應用高解析度微焦點CT跟蹤觀察的技術。為了檢查ERβ在膜內骨化中的作用，並且應用微焦點CT跟蹤觀察技術，我們首先建立了一個小鼠鑽孔缺損模型。該實驗同時也確認了去勢誘導的骨質疏鬆小鼠相比正常小鼠，在鑽孔缺損模型中骨癒合受阻。 / 實驗2檢驗了阻斷ERβ能促進正常骨癒合的假設。本實驗應用ERβ基因敲除小鼠，在兩個模型中檢驗了實驗假設。第一個是傳統的小鼠股骨中段骨折模型，第二個是由實驗1建立的鑽孔缺損模型。兩個模型都證實ERβ基因敲除小鼠骨癒合和野生型小鼠相比，早期的血管新生和中期的礦化有所增強，末期的骨癒合沒有明顯差異。 / 實驗3 進一步研究ERβ在老年骨癒合中的作用。實驗應用老年小鼠股骨中段骨折模型，比較ERβ基因敲除小鼠和野生型小鼠之間的癒合過程。結果顯示ERβ基因敲除小鼠骨癒合和野生型小鼠相比，早期的血管新生，中期的礦化以及末期的力學性能都有所增強。該結果預示阻斷ERβ能作為另一種治療老年骨折癒合的治療策略。同時，我們也檢測了ERβ的拮抗劑PHTPP（4 - [2 - 苯基- 5,7 -二（三氟甲基）吡唑並[1,5 - A]嘧啶3 - 基]苯酚, 在老年骨癒合中的治療效果。 通過比較用藥組小鼠與安慰劑組小鼠的骨癒合品質，顯示PHTPP治療小鼠血管新生，骨痂礦化和最終的力學性質均優於對照安慰劑組小鼠。 / 綜上所述，本研究描述了ERβ在正常和老年骨癒合中的作用。骨癒合的關鍵過程包括血管新生，膜內骨化以及軟骨內骨化在阻斷ERβ後都得到增強，從而加快正常骨和老年骨的骨痂形成，礦化並增強力學性質。ERβ的拮抗劑PHTPP在老年小鼠骨折模型中能促進骨癒合。本研究提出了一個新的骨癒合治療策略，並為將來的臨床實驗提供了堅實的基礎。 / Orthopaedic surgeons are challenged by impaired or delayed bone healing in elderly women, which requires prolongation of rehabilitation process or even induces high mortality. Up to date, there are no satisfactory therapeutic modalities for promoting aged bone healing clinically, and alternative therapeutic stratagem is therefore desirable. Bone healing recapitulates postnatal bone development. Direct periosteam-dependent bone formation (intramembranous ossification) and the formation of bone through a cartilage intermediate (endochondral ossification) are the two important processes during bone healing. Evidences from Estrogen Receptor β (ERβ), gene knockout female mouse studies have demonstrated that ERβ signaling participates in inhibiting both intramembranous and endochondral ossification during bone development. Clinical biopsy data demonstrated that the number of ERβ positive proliferative chondrocytes within fracture callus was increased in postmenopausal women. However, the role of ERβ in normal and aged bone healing is not examined yet. / This study examined role of ERβ in normal and aged bone healing and the future pharmaceutical application though the following part: 1) Establish an intramembranous ossification-dominant bone healing model. 2) Examine the role of ERβ in normal bone healing though two models. 3) Examine the role of ERβ in aged bone healing and investigate the potential therapeutical efficacy of an ERβ antagonist PHTPP in aged bone healing. / Study I was to establish an intramembranous ossification dominant bone healing mouse model. Previous available mouse femoral shaft fracture model was a endochondral ossification dominant bone healing model. This model was technically difficult to generate high reproducibility and the inside metal stabilization devices prevented the application of high-resolution in vivo micro-CT monitoring due to the metal artifact. In order to examine the role of ERβ in intramembranous ossification and apply the micro-CT monitoring technique, a drill-hole defect mouse model was developed. The study also confirmed bone healing was impaired in mice with ovariectomy -induced osteoporosis in drill-hole defect model. / Study II was to test the hypothesis that blockade of ERβ could promote normal bone healing. ERβ knockout mice were employed in this study and the hypothesis was examined in two models, the first is the traditional mouse femoral shaft fracture model, and the second is the drill-hole defect model that was developed in study I. Both models demonstrated that the bone healing in ERβ knockout mice was enhanced in the early stage of neovascularization and the middle stage of ossification but not by the end of healing compare to the wild type mice. / Study III was designed to further investigate the role of ERβ in aged bone healing. Femoral shaft fracture model was created in aged mice. The healing process was compared between the ERβ knockout mice and wild type mice. The results demonstrated that ERβ knockout mice was enhanced in the early stage of neovascularization, the middle stage of ossification and end stage of mechanical strength. The findings implied blockade of ERβ can be considered as another therapeutic strategy for aged fracture healing. PHTPP (4-[2-Phenyl-5,7-bis(trifluoromethyl)pyrazolo[1,5-a]pyrimidin-3-yl] phenol), an ERβ antagonist, was employed in aged mice femoral shaft fracture model. The bone healing quality of treated mice was compared with that of the vehicle control mice. It showed PHTPP treated mice had enhanced neovascularization, callus ossification and finally better mechanical properties than vehicle mice. / The present study depicted the role of ERβ in normal and aged bone healing. Key processes including neovascularization, intramembranous and endochondral ossification were all enhanced by blockade of ERβ, which led to fast callus formation, mineralization in normal bone and better mechanical properties in aged bone. ERβ antagonist PHTPP could promote aged bone healing in mouse osteotomy model. This study raised an alternative therapeutic stratagem for bone healing and provided solid basis for future clinical trials. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / He, Yixin. / Thesis (Ph.D.)--Chinese University of Hong Kong, 2012. / Includes bibliographical references (leaves 147-167). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstract also in Chinese. / ABSTRACT --- p.i / 中文摘要 --- p.iv / PUBLICATIONS AND AWARDS --- p.vi / ACKNOWLEDGEMENTS --- p.xi / TABLE OF CONTENTS --- p.xii / LIST OF ABBREVIATIONS --- p.xvi / LIST OF FIGURES --- p.xviii / LIST OF TABLES --- p.xx / Chapter CHAPTER 1 --- INTRODUCTION AND LITERATURE REVIEW --- p.1 / Chapter 1.1 --- Fracture and Bone Healing --- p.2 / Chapter 1.1.1 --- Epidemiology and Impacts of Fractures --- p.2 / Chapter 1.1.2 --- Current Management and Limitations --- p.3 / Chapter 1.1.3 --- Bone Structures --- p.5 / Chapter 1.1.4 --- Bone Healing --- p.7 / Chapter 1.1.5 --- Aged Bone Healing --- p.12 / Chapter 1.1.6 --- Enhancements of Bone Healing --- p.17 / Chapter 1.2 --- Estrogen and Estrogen Receptors --- p.19 / Chapter 1.2.1 --- Estrogen Receptors α and β --- p.19 / Chapter 1.2.2 --- Molecular Actions of Estrogens --- p.20 / Chapter 1.2.3 --- Estrogen receptors in bone homeostasis --- p.24 / Chapter 1.3 --- Hypothesis --- p.28 / Chapter 1.4 --- Study Plan and Objectives --- p.32 / Chapter 1.4.1 --- Bone Healing Models --- p.32 / Chapter 1.4.2 --- Study Outline --- p.32 / Chapter 1.5 --- Figures and Tables --- p.34 / Chapter CHAPTER 2 --- ESTABLISHMENT OF DRILL-HOLE DEFECT HEALING MODEL IN MICE --- p.39 / Chapter 2.1 --- Introduction --- p.40 / Chapter 2.1.1 --- Limitations in currently available mouse models of osteoporotic bone healing --- p.40 / Chapter 2.1.2 --- Creation of a drill-hole defect at the mid-diaphysis of the femur for in vivo monitoring of bone healing in mice --- p.40 / Chapter 2.2 --- Materials and Methods --- p.43 / Chapter 2.2.1 --- Experimental animals --- p.43 / Chapter 2.2.2 --- Surgical protocol and experimental design --- p.43 / Chapter 2.2.3 --- Micro-CT analysis of intact femur --- p.44 / Chapter 2.2.4 --- In vivo micro-CT analysis of new bone formation in the drill-hole site --- p.45 / Chapter 2.2.5 --- Micro-CT-based angiography --- p.45 / Chapter 2.2.6 --- Histological examination --- p.46 / Chapter 2.2.7 --- Immunohistochemistry --- p.46 / Chapter 2.2.8 --- Quantitative real-time PCR --- p.47 / Chapter 2.2.9 --- Analysis of bone formation and resorption markers --- p.47 / Chapter 2.2.10 --- Mechanical testing --- p.48 / Chapter 2.2.11 --- Statistical analysis --- p.48 / Chapter 2.3 --- Results --- p.51 / Chapter 2.3.1 --- Confirmation of osteoporotic bone prior to generation of a drill-hole defect --- p.51 / Chapter 2.3.2 --- General observation of mice following drill-hole surgery --- p.51 / Chapter 2.3.3 --- In vivo micro-CT analysis of new bone in the drill-hole site of mouse femurs --- p.51 / Chapter 2.3.4 --- In vivo micro-CT analysis of new bone in drill-hole sites is highly reproducible --- p.52 / Chapter 2.3.5 --- Micro-CT angiography --- p.52 / Chapter 2.3.6 --- Histological observation of bone healing --- p.53 / Chapter 2.3.7 --- Immunohistochemical analysis of ER expressions during bone healing --- p.54 / Chapter 2.3.8 --- Quantitative real-time PCR analysis of gene expression during bone healing --- p.54 / Chapter 2.3.9 --- Analysis of bone formation and resorption markers during bone healing --- p.54 / Chapter 2.3.10 --- Mechanical testing of femurs from Sham and OVX mice --- p.55 / Chapter 2.4 --- Discussion --- p.56 / Chapter 2.4.1 --- Bone healing with dominant intramembranous ossification --- p.56 / Chapter 2.4.2 --- Impaired osteoporotic bone healing --- p.57 / Chapter 2.4.3 --- Reproducibility of the in vivo micro-CT method for analysis of bone healing --- p.58 / Chapter 2.4.4 --- Dysregulated expression of estrogen receptors and bone healing in OVX mice --- p.59 / Chapter 2.4.5 --- Study limitations --- p.60 / Chapter 2.4.6 --- Conclusions --- p.60 / Chapter 2.5 --- Figures and Tables --- p.61 / Chapter CHAPTER 3 --- ROLE OF ERβ IN NORMAL BONE HEALING --- p.72 / Chapter 3.1 --- Introduction --- p.73 / Chapter 3.2 --- Materials and Methods --- p.75 / Chapter 3.2.1 --- Part I Study --- p.75 / Chapter 3.2.1.1 --- Experimental animals --- p.75 / Chapter 3.2.1.2 --- Fracture model and experimental design --- p.75 / Chapter 3.2.1.3 --- Radiographic Analysis --- p.76 / Chapter 3.2.1.4 --- Micro-CT-based angiography --- p.76 / Chapter 3.2.1.5 --- Micro-CT analysis of callus --- p.77 / Chapter 3.2.1.6 --- Histological examination --- p.78 / Chapter 3.2.1.7 --- Dynamic Bone histomorphometric analysis --- p.78 / Chapter 3.2.1.8 --- Mechanical testing --- p.79 / Chapter 3.2.1.9 --- Quantitative real-time PCR --- p.80 / Chapter 3.2.1.10 --- Analysis of bone formation and resorption markers --- p.80 / Chapter 3.2.1.11 --- Statistical analysis --- p.81 / Chapter 3.2.2 --- Part II Study --- p.81 / Chapter 3.2.2.1 --- Experimental animals and design --- p.81 / Chapter 3.2.2.2 --- Evaluation protocols --- p.82 / Chapter 3.2.2.3 --- Statistical analysis --- p.82 / Chapter 3.3 --- Results --- p.83 / Chapter 3.3.1 --- Part I Study --- p.83 / Chapter 3.3.1.1 --- Radiographic Analysis --- p.83 / Chapter 3.3.1.2 --- Micro-CT angiography --- p.83 / Chapter 3.3.1.3 --- Micro-CT analysis of callus --- p.83 / Chapter 3.3.1.4 --- Histological and dynamic histomorphometric analysis --- p.84 / Chapter 3.3.1.5 --- Mechanical testing of the callus --- p.85 / Chapter 3.3.1.6 --- Quantitative real-time PCR analysis of gene expression --- p.85 / Chapter 3.3.1.7 --- Analysis of bone formation and resorption markers during bone healing --- p.85 / Chapter 3.3.2 --- Part II Study --- p.86 / Chapter 3.3.2.1 --- In vivo micro-CT analysis of new bone in the drill-hole site of mouse femurs --- p.86 / Chapter 3.3.2.2 --- Micro-CT angiography --- p.87 / Chapter 3.3.2.3 --- Histological observation of bone healing --- p.87 / Chapter 3.3.2.4 --- Quantitative real-time PCR analysis of gene expression --- p.88 / Chapter 3.3.2.5 --- Analysis of bone formation and resorption markers during bone healing --- p.88 / Chapter 3.3.2.6 --- Mechanical testing of femurs from WT and KO mice --- p.88 / Chapter 3.4 --- Discussion --- p.90 / Chapter 3.4.1 --- Angiogenesis --- p.90 / Chapter 3.4.2 --- Fracture Healing --- p.91 / Chapter 3.4.3 --- Estrogen receptor β and endochondral and intramembranous ossification --- p.93 / Chapter 3.4.4 --- Estrogen receptor β in aged bone --- p.94 / Chapter 3.4.5 --- Conclusions --- p.94 / Chapter 3.5 --- Figures and Tables --- p.95 / Chapter CHAPTER 4 --- ROLE OF ERβ AND ITS ANTAGONIST PHTPP IN AGED BONE HEALING --- p.113 / Chapter 4.1 --- Introduction --- p.114 / Chapter 4.2 --- Materials and Methods --- p.116 / Chapter 4.2.1 --- Experimental animals --- p.116 / Chapter 4.2.2 --- Fracture model and experimental design --- p.116 / Chapter 4.2.3 --- Radiographic Analysis --- p.117 / Chapter 4.2.4 --- Micro-CT-based angiography --- p.118 / Chapter 4.2.5 --- Micro-CT analysis of callus --- p.118 / Chapter 4.2.6 --- Histological examination --- p.119 / Chapter 4.2.7 --- Dynamic Bone histomorphometric analysis --- p.120 / Chapter 4.2.8 --- Mechanical testing --- p.120 / Chapter 4.2.9 --- Quantitative real-time PCR --- p.121 / Chapter 4.2.10 --- Analysis of bone formation and resorption markers --- p.122 / Chapter 4.2.11 --- Statistical analysis --- p.122 / Chapter 4.3 --- Results --- p.123 / Chapter 4.3.1 --- Radiographic Analysis --- p.123 / Chapter 4.3.2 --- Micro-CT angiography --- p.123 / Chapter 4.3.3 --- Micro-CT analysis of callus --- p.123 / Chapter 4.3.4 --- Histological and dynamic histomorphometric analysis --- p.124 / Chapter 4.3.5 --- Mechanical testing of the callus --- p.125 / Chapter 4.3.6 --- Quantitative real-time PCR analysis of gene expression during fracture healing --- p.125 / Chapter 4.3.7 --- Analysis of bone formation and resorption markers during bone healing --- p.126 / Chapter 4.4 --- Discussion --- p.127 / Chapter 4.4.1 --- Angiogenesis --- p.127 / Chapter 4.4.2 --- Fracture Healing --- p.128 / Chapter 4.4.3 --- Estrogen receptor β and endochondral ossification --- p.129 / Chapter 4.4.4 --- ERβ antagonist PHTPP --- p.130 / Chapter 4.4.5 --- Conclusions --- p.130 / Chapter 4.5 --- Figures and Tables --- p.131 / Chapter CHAPTER 5 --- STUDY LINITATIONS, FURTHER RESEARCH AND CONCLUDSIONS --- p.142 / Chapter 5.1 --- Limitations --- p.143 / Chapter 5.1.1 --- Bone healing model --- p.143 / Chapter 5.1.2 --- Estrogen receptors and transgenic mouse --- p.143 / Chapter 5.1.3 --- ERβ antagonist PHTPP --- p.144 / Chapter 5.2 --- Further Research --- p.144 / Chapter 5.2.1 --- ERβ signaling --- p.144 / Chapter 5.2.2 --- Preclinical Trial --- p.145 / Chapter 5.3 --- Conclusions --- p.146 / BIBLIOGRAPHY --- p.147

No description available.

In summary, the biomechanical stimulations can augment osteotendinous healing processes by facilitating better fibrocartilagious transitional zone regeneration as well as the restoration of proprioceptions, and the early application showed the more beneficial effects. However, further experimental and clinical studies are still needed to explore the optimal timing, intensity, frequency, and duration of the proposed postoperative biomechanical stimulation protocols. / LIPUS is a "non-contact" biomechanical stimulation, which can provide a direct mechanical stimulation through cavitation and acoustic microstreaming effects to improve tissue healing in a less-than-rigid biomechanical environment. So the mechanical stimulation induced from LIPUS could be applied immediately after surgery without worrying about the mechanical strain exceed the structural property at the osteotendinous healing interface in the early phase of repair. In this part of study, we also examined the effects of the regime of biomechanical stimulations applying immediately after repair on the osteotendinous healing interface. By using the same healing junction model, forty-two female New Zealand white rabbits were randomly divided into two groups; daily mechanical stimulation was applied immediately after surgery lasting up to post-operative 12 weeks on the healing interface in the treatment group. The regime of mechanical stimulations included by LIPUS was 20 minutes, 5 days per week for 4 weeks, followed by cyclic mechanical stimulation generated from quadriceps muscles induced by FES for 8 weeks. Results showed that early application of biomechanical stimulations on the osteotendinous healing interface were significantly better radiologically, histologically and biomechanically than that of not any or later application of the biomechanical stimulations during the osteotendinous healing processes when assessing at the same healing time point. In addition, the early application of biomechanical stimulations showed the better functional recovery in terms of the restoration of the proprioceptions, which an increased numbers of sensory nerve endings labeled by calcitonin gene-relate peptide (CGRP) was detected in the whole osteotendinous healing complex. / Sports or trauma injuries around osteotendinous junctions are common; treatments usually require surgical reattachment of the involved tendon to bone. Restoration of osteotendinous junction after repair is slow and difficult due to regenerating the intermitted fibrocartilage zone to connect two different characteristic tissues, tendon to bone. Although the factors influencing fibrocartilage zone regeneration and remodeling during osteotendinous repair are poorly understood, however, is believed that the mechanical environment plays an important role in such healing process. In present study, the effects of mechanical stimulation on osteotendinous healing process were examined, in the way of mechanical stimulations induced by biophysical stimulations, surface functional electric stimulation (FES) and low intensity pulsed ultrasound (LIPUS), applying on the patellar tendon to patellar bone healing interface in an established partial patellectomy model in rabbits. / The mechanotransductive stimulation linked to the transmission of forces across osteotendinous junction can be generated from its muscle contraction induced by FES. In the partial patellectomy model, thirty-five female New Zealand white rabbits were randomly divided into two groups with initial immobilization for 6 weeks, daily FES was applied to quadriceps muscles for 30 minutes, 5 days per week for 6 weeks in treatment group and compared with non-treatment control group at postoperative week 6, 12 and 18, radiologically, histologically and biomechanically. Results showed that FES-induced cyclic mechanical stimulation significantly increased new bone formation and its bone mineral density. An elevated expression of tenascin C and TGFbeta1; an increased proteoglycant stainability; mature fibrocartilage zone formation with better resumptions of biomechanical properties also observed on the osteotendinous healing interface, indicating that the post-operative programmed cyclic mechanical stimulation generated from its muscle contraction has beneficial effects on osteotendinous healing processes by facilitating the fibrocartilagious transitional zone regeneration. / by Wang Wen. / Advisers: Kai Ming Chan; Ling Qin. / Source: Dissertation Abstracts International, Volume: 68-03, Section: B, page: 1550. / Thesis (Ph.D.)--Chinese University of Hong Kong, 2006. / Includes bibliographical references (p. 159-175). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Electronic reproduction. [Ann Arbor, MI] : ProQuest Information and Learning, [200-] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstracts in English and Chinese. / School code: 1307.

Establishment of animal model for studying treatment efficacy of low-intensity pulsed ultrasound stimulations for accelerating bone-tendon repair. Standard partial patellectomy was conducted in the 18-week old rabbits that were then divided into the LIPUS treatment and control groups. The animals were followed for 2, 4, 8, and 16 weeks for various tissue analyses. LIPUS was applied to the experimental animals from postoperative day 3 to 16 weeks. We demonstrated that the healing process of PPT junction was initiated through endochondral ossification. The results showed that the size and length of newly formed bone, and its bone mineral content (BMC), but not its bone mineral density (BMD) were correlated with the failure load, ultimate strength and energy at failure. Using radiographic, biomechanical, histomorphologic and biomechanical methods, it was found that LIPUS had significant accelerating effect on PPT junction repair. We validated our study hypothesis in that LIPUS enhances bone-tendon junction healing by stimulating angiogenesis, chondrogenesis and osteogenesis. / Establishment of in vitro model for mechanism study on effects of low-intensity pulsed ultrasound stimulations. An in vitro model of osteoblast-like cell line (SaOS-2 cells) was studied using cDNA microarray to explore the molecular mechanism mediated by LIPUS. This microarray analysis revealed a total of 165 genes that were regulated at 4 and 24 hours by LIPUS treatment in osteoblastic-like cells. These genes belonged to more than ten protein families based on their function and were involved in some signal transduction pathways. This study has validated the hypothesis that LIPUS can regulate a number of critical genes transient expressions in osteoblast cell line Saos-2. / Keywords. partial patellectomy model; bone-tendon junction repair; low intensity pulsed ultrasound stimulations (LIPUS); gene expression; complementary DNA microarray; rabbit. / This study explored the intact morphology, regular healing and the augmented healing under the effects of low intensity pulsed ultrasound stimulations (LIPUS) on the patella-patella tendon (PPT) junction in a rabbit partial patellectomy model. To probe its possible mechanism, the key genes involved in regulating osteogenesis mediated by LIPUS were identified using the state-of-the-art methods---complementary DNA microarray. / Lu Hongbin. / "June 2006." / Advisers: Ling Qin; Kwok Sui Leung. / Source: Dissertation Abstracts International, Volume: 68-03, Section: B, page: 1548. / Thesis (Ph.D.)--Chinese University of Hong Kong, 2006. / Includes bibliographical references (p. 259-288). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Electronic reproduction. [Ann Arbor, MI] : ProQuest Information and Learning, [200-] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstracts in English and Chinese. / School code: 1307.

A direct bone tendon junction consists of four zones: tendon, uncalcified fibrocartilage, calcified fibrocartilage, and bone. The uncalcified and calcified fibrocartilage together forms the transition zone. This organization ensures a gradual transition in stiffness and material properties, and protects the junction from failure. Transition zone regeneration during bone tendon junction healing is important to restore this unique protective mechanism. / Bone tendon junction repair is involved in many orthopaedic reconstructive procedures. Healing is observed to be slow. The junction often heals by fibrous tissue formation. Previous attempts to enhance bone tendon junction healing have resulted in increased bone formation. However, fibrocartilage transition zone is not restored. / This thesis describes a series of studies on transition zone regeneration in bone tendon junction healing using two partial patellectomy animal models. The healing process inside a bone trough was first studied and characterized. Little transition zone regeneration was observed except near the articular cartilage cut surface. The possibility of using articular cartilage to stimulate transition zone regeneration was explored. Both articular cartilage autograft and allogeneic cultured chondrocyte pellet implantations resulted in significantly increased fibrocartilage transition zone regeneration. Cell tracking indicated that the regenerated tissue likely originated from host cells. To elucidate the mechanism of stimulation by allogeneic cultured chondrocyte pellet, the role of cellular and matrix component needed to be differentiated. Freezing and rapid freeze thaw cycles permanently devitalized the allogeneic cultured chondrocyte pellet, but retained its structural integrity and matrix contents. Preliminary results indicated that implantation of the devitalized allogeneic cultured chondrocyte pellet could still increase fibrocartilage transition zone regeneration. Cellular activity seemed not to be essential for the stimulatory effect. / With further research and development, it is envisioned that a cartilage-based stimulation method for fibrocartilage transition zone regeneration in bone tendon junction healing will be developed for clinical application. / Wong Wan Nar, Margaret. / Source: Dissertation Abstracts International, Volume: 70-06, Section: B, page: 3423. / Thesis (M.D.)--Chinese University of Hong Kong, 2008. / Includes bibliographical references (leaves 216-231). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Electronic reproduction. [Ann Arbor, MI] : ProQuest Information and Learning, [200-] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstracts in English and Chinese. / School code: 1307.

Khoo, Chyi Chyi. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2010. / Includes bibliographical references (leaves 177-204). / Abstracts in English and Chinese; appendix in Chinese. / Abstract(English version) --- p.i / Abstract(Chinese version) --- p.iii / Acknowledgements --- p.iv / List of Tables --- p.vii / List of Figures --- p.ix / List of Abbreviations --- p.x / Publications from this Thesis --- p.xi / Chapter Chapter 1 --- Introduction and Objectives / Chapter 1.1 --- Introduction --- p.1 / Chapter 1.2 --- Objectives --- p.3 / Chapter Chapter 2 --- Literature Review / Chapter 2.1 --- Definitions --- p.4 / Chapter 2.2 --- Epidemiology of Osteoporosis and Fracture --- p.5 / Chapter 2.3 --- Burden --- p.7 / Chapter 2.4 --- Osteoporosis in Men --- p.9 / Chapter 2.5 --- Risk factor of Osteoporosis --- p.11 / Chapter 2.6 --- Prediction of Osteoporosis --- p.13 / Chapter 2.7 --- Risk Factors of Osteoporotic Fracture --- p.15 / Chapter 2.8 --- Prediction of Fracture --- p.28 / Chapter 2.9 --- Difference between men and women --- p.29 / Chapter 2.10 --- DXA and Fracture --- p.31 / Chapter 2.11 --- QUS and Fracture --- p.32 / Chapter 2.12 --- pQCT and Fracture --- p.35 / Chapter 2.13 --- Self-report of Fracture --- p.37 / Chapter Chapter 3 --- Research Outline / Chapter 3.1 --- Non-spine fracture of older men --- p.39 / Chapter 3.2 --- Subjects --- p.40 / Chapter 3.3 --- Measurements of study --- p.41 / Chapter 3.4 --- Record of Fracture --- p.50 / Chapter 3.5 --- Statistical Methods --- p.51 / Chapter Chapter 4 --- Predictors of Non-spine Fracture of Hong Kong Elderly Chinese Men / Chapter 4.1 --- Introduction --- p.52 / Chapter 4.2 --- Subjects and Methods --- p.54 / Chapter 4.3 --- Results --- p.61 / Chapter 4.4 --- Discussions --- p.74 / Chapter 4.5 --- Conclusions --- p.80 / Chapter 4.6 --- Key Points --- p.81 / Chapter Chapter 5 --- Predictive values of QUS for non-spine fracture / Chapter 5.1 --- Introduction --- p.82 / Chapter 5.2 --- Subjects and Methods --- p.84 / Chapter 5.3 --- Results --- p.87 / Chapter 5.4 --- Discussions --- p.92 / Chapter 5.5 --- Conclusions --- p.97 / Chapter 5.6 --- Key Points --- p.98 / Chapter Chapter 6 --- Predictive values of pQCT for non-spine fracture / Chapter 6.1 --- Introduction --- p.99 / Chapter 6.2 --- Subjects and Methods --- p.101 / Chapter 6.3 --- Results --- p.103 / Chapter 6.4 --- Discussions --- p.109 / Chapter 6.5 --- Conclusions --- p.112 / Chapter 6.6 --- Key Points --- p.113 / Chapter Chapter 7 --- Accuracy of self-report of fracture in Asian elderly men / Chapter 7.1 --- Introduction --- p.114 / Chapter 7.2 --- Subjects and Methods --- p.115 / Chapter 7.3 --- Results --- p.116 / Chapter 7.4 --- Discussions --- p.118 / Chapter 7.5 --- Conclusions --- p.121 / Chapter 7.6 --- Key Points --- p.122 / Chapter Chapter 8 --- Conclusions / Chapter 8.1 --- Predictors of Non-spine Fracture of Hong Kong Elderly Chinese Men --- p.123 / Chapter 8.2 --- Predictive values of QUS for non-spine fracture --- p.124 / Chapter 8.3 --- Predictive values of pQCT for non-spine fracture --- p.125 / Chapter 8.4 --- Accuracy of self-report of fracture in Asian elderly men --- p.126 / Chapter 8.5 --- Strength and limitations --- p.127 / Chapter 8.6 --- Implications of the results --- p.129 / Chapter 8.7 --- Future research --- p.130 / Appendix A --- p.131 / Bibliography --- p.178