Effect of micro-CT acquisition parameters and individual analysis on the assessment of bone repair

Abstract This study aimed to investigate whether two acquisition parameters, voxel size and filter thickness, used in a micro-computed tomography (micro-CT) scan, together with the examiner's experience, influence the outcome of bone repair analysis in an experimental model. Bone defects were created in rat tibiae and scanned using two voxel sizes of 6- or 12-µm and two aluminum filter thickness of 0.5- or 1-mm. Then, bone volume fraction (BV/TV) and trabecular thickness (Tb.Th) were analyzed twice by two groups of operators: experienced and inexperienced examiners. For BV/TV, no significant differences were found between scanning voxel sizes of 6 and 12 µm for the experienced examiners; however, for the inexperienced examiners, the analysis performed using a 12-µm voxel size resulted in higher BV/TV values (32.4 and 32.9) than those acquired using a 6-µm voxel size (25.4 and 24.8) (p < 0.05). For Tb.Th, no significant differences between the analyses performed by experienced and inexperienced groups were observed when using the 6-µm voxel size. However, inexperienced examiners' analysis revealed higher Tb.Th values when using the 12-µm voxel size compared with 6 µm (0.05 vs. 0.03, p < 0.05). Filter thickness had no influence on the results of any group. In conclusion, voxel size and operator experience affected the measured Tb.Th and BV/TV of a region with new bone formation. Operator experience in micro-CT analysis is more critical for BV/TV than for Tb.Th, whereas voxel size significantly affects Tb.Th evaluation. Operators in the initial phases of research training should be calibrated for bone assessments.

Multiscale Analysis on Changes in Bone Microstructure of Osteoporotic Rats / 医用生物力学

Objective To study changes in bone microstructure of osteoporotic rats by multiscale analysis. Methods A total of 20 5-month-old female SD rats were randomly divided into two groups, i.e., ovariectomy (OVX) group (n=12) and the SHAM group (n=8), respectively. The rats in OVX group were subjected to bilateral ovariectomy and became osteoporosis models after 8 weeks, while sham operation was performed for the SHAM group. Changes in microstructure of cortical bone and cancellous bone at tissue scale, and osteocyte lacunar-canalicular network (LCN) and extracellular matrix (ECM) at cell scale were quantitatively analyzed using Micro-CT and SR-Nano-CT. Results At tissue scale, the cross-sectional area of cortical bone in OVX group was significantly higher than that in SHAM group (P<0.05), and the bone mineral density (BMD) and thickness of cortical bone were not significantly different from those in SHAM group. The trabecular BMD, bone volume fraction, trabecular thickness and trabecular number in OVX group were significantly decreased in comparison with SHAM group (P<0.01), while the trabecular separation was significantly increased (P<0.01). At cell scale, there was no significant difference in the semiaxes of lacunae between OVX group and SHAM group, but the thickness of lacunae and the diameter of canaliculi in OVX group were significantly increased in comparison with SHAM group (P<0.05). At the same time, the porosity of cortical bone in OVX group was significantly higher than that in SHAM group at cell scale (P<0.05). Conclusions The bone microstructure in OVX group varied to different extents at tissue and cell scales. At tissue scale, the cancellous bone loss was severe, while the cortical bone had fewer changes. At cell scale, porosity of the lacunar-canalicular network significantly increased, which directly affected the BMD and strength of cortical bone. Multiscale analysis on changes in bone microstructure of OP rats has potential application value for clinical diagnosis and pathological analysis of osteoporosis.

Effectiveness of iliac cancellous bone grafting in alveolar cleft repair and analysis of factors affecting it / 华西口腔医学杂志

OBJECTIVES@#To review the effectiveness of secondary alveolar bone grafting using iliac cancellous bone in patients with unilateral complete alveolar cleft and to investigate the factors influencing it.@*METHODS@#A retrospective study of 160 patients with unilateral complete alveolar clefts who underwent iliac cancellous bone graft repair at the Department of Cleft Lip and Palate Surgery, West China Hospital of Stomatology, Sichuan University, was conducted. Eighty patients in the young age group (6-12 years) and 80 in the old age group (≥13 years) were included. Bone bridge formation was determined using Mimics software, and the volume was measured to calculate the iliac implantation rate, residual bone filling rate, and resorption rate. The factors that affected bone grafting in both subgroups were investigated.@*RESULTS@#Using bone bridge formation as the clinical success criterion, the success rate for the entire population was 71.25%, with a significant difference of 78.75% and 63.75% for the young and old age groups, respectively (P=0.036). The gap volume in the latter was significantly larger than that in the former (P<0.001). The factors that influenced bone grafting in the young group were the palatal bone wall (P=0.006) and history of cleft palate surgery (P=0.012), but only the palatal bone wall affected the outcome in the old age group (P=0.036).@*CONCLUSIONS@#The results of alveolar bone grafting for the old age group were worse than those for the young age group. The palatal bone wall was an important factor that affected alveolar bone grafting, and alveolar bone grafting in the young patients was influenced by the history of cleft palate surgery.

The effects of casein kinase 2 interacting protein-1 on the growth and development of craniomaxillofacial soft and hard tissues in mice / 口腔疾病防治

Objective@# To investigate the effect of casein kinase 2 interacting protein-1 (CKIP-1) on craniofacial soft tissues and hard tissues, to provide the basis for the study and treatment of craniomaxillofacial related diseases.@*Methods@#6-month- old male CKIP-1 knockout (KO) mice were selected as the experimental group, and wild-type (WT) mice were selected as the control group. The craniomaxillofacial hard tissues (parietal bone, nasal bone, incisors and molars) were analyzed through micro- CT, and the morphological changes of maxillofacial soft tissues (nasal cartilage, lip mucosa and tongue) were analyzed through HE staining and toluidine blue staining.@* Results@#CKIP-1 negatively regulated bone mass of cancellous bone of cranial and maxillofacial bones and dentin mineralization. Compared with the WT mice, the thickness of the parietal baffle layer increased by 93% in KO mice, while cortical bone showed no significant difference between the two groups. The nasal cancellous bone thickness increased by 160% in KO-mice, while cortical bone showed no significant difference between the two groups; the enamel thickness was normal, but the pulp cavity became smaller and the dentin thickness increased by 48%. Compared with the WT mice, the HE staining and toluidine blue staining analyses of the soft tissues revealed that the thickness of the alar cartilage plate of KO mice increased by 57%, and local ossification was found within the cartilage plate. The thickness of the keratinized layer of the labial mucosa increased by 170% in KO mice and the muscle fiber diameter of the lingual muscle increased by 45%. @*Conclusion@#CKIP-1 genes have different effects on the growth and development of various soft and hard tissues in the maxillofacial region of mice.

Quantum of cortico-cancellous bone safe for harvest from anterior iliac wing of pediatric patients: a finite element analysis with clinical correlation

Background: Objective was to assess the maximum quantum of cortico- cancellous bone that can be harvested from the Anterior Iliac Wing (AIW) of paediatric population.Methods: All patients reporting to the unit for the correction of bilateral cleft alveolus were included. A Computed Tomogram (CT) of the hip was recorded and the volume of cancellous bone available for harvest was assessed. Finite element model of the hip was generated using D2P and Geomagic Free form software and the impact of bone harvest on stress distribution along the anterior iliac wing was assessed by substituting the muscle forces (hip abductors and sartorius group) and was clinically correlated to volume harvested and donor site morbidities.Results: 10 patients were enrolled, 5 patients were excluded. CT volumetric evaluation revealed an average 0.5 cc to 4.7 ccof cancellous bone and 6.7 cc to 11 cc of cortical bone was available for harvest. Harvest of 50% of available graft volume was safe with minimal stress distributed along the line joining the tuberosity to the area between Antero Superior and Inferior spines (4.2 MPa at rest and 18.5 MPa at stance). The stress levels increased with increase in volume of bone harvested. Intra operatively 1.9 cc to 6.2 cc of cortico cancellous graft was harvested, which was equivalent to 60% of the graft available with no long-term morbidities.Conclusions: The volume of bone graft harvest should be restricted (up to 6 cc) to avoid long term morbidities.

Addition Of Adipose Derived Stem Cell To Beta Tricalcium Phosphate and Human Cancellous Bone for Craniofacial Bone Tissue Engineering: An In Vitro Study

@#Introduction: Autologous bone graft remains the method of choice for correction of osseous defects despite its shortcomings related to its limited availability, donor side effects and post-surgical potential complications of the recipient. It is imperative to develop more innovative substitute that offers little to no adverse effects. We aimed to assess the impact of addition human adiposed derived stem cell to Beta tricalcium phosphate (βTCP) and human cancellous bone in vitro. Methods: Experimental study was carried out in vitro, where βTCP and human cancellous freeze-dried bone graft were seeded onto a 24-well microplate (each well containing 2x106 hADSCs). A colorimetric assay (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide/MTT) was carried out for three days using the second passage of hADSCs to calculate the cell viability using ELISA reader at optical density (OD) 590nm. Results: MTT Assay showed that the percentage of viable cells in both groups were more than 70%, of which the βTCP showed significantly higher percentage than cancellous bone groups. Conclusion: This study proved that the addition of human adipose derived stem cell to βTCP and human cancellous bone in vitro is harmless and significantly improve cell viability in vitro.

Extraction of porcine cancellous bone by supercritical carbon dioxide / 中国组织工程研究

BACKGROUND: In recent years, there have been many studies on the use of supercritical fluids for biological material treatment in countries outside China. However, little is reported on application of supercritical fluids to bone tissue extraction, in particular in China. OBJECTIVE: To evaluate the effectiveness of supercritical carbon dioxide extraction technology in the treatment of porcine femur cancellous bone and its effect on bone biological properties. METHODS: Porcine femoral bone blocks that were subjected to supercritical carbon dioxide extraction (study group) or not (control group) were prepared to determine bone mineral density, microstructure, maximum compressive strength, elastic modulus, bone tissue composition, collagen content and perform histological analysis. Bone marrow mesenchymal stem cells (BMSCs) were inoculated into two groups of bone blocks, and cultured for 1 day. The microporous structure of trabecular bone and cell adhesion and growth in bone material-cell composite were observed by scanning electron microscopy. The two groups of bone blocks were implanted subcutaneously in SD rats. The inflammatory reaction of subcutaneous tissue was observed histologically at 1, 2 and 4 weeks after surgery. The experimental protocol had been approved by the Animal Ethics Committee of Chinese PLA General Hospital, China. RESULTS AND CONCLUSION: There were no significant differences in pore size, bone mineral density, maximum compressive strength, elastic modulus and collagen content between the study and control groups (P>0.05). Scanning electron microscopy showed that in the control group, the material pores had poor connectivity and there was soft tissue residue; in the study group, material pores were connected to each other and the structure was intact. Fourier transform infrared spectroscopy and X-ray diffraction analysis showed that the two groups of bone tissue materials had similar absorption and diffraction peaks. Thermogravimetric analysis showed that supercritical carbon dioxide extraction could reduce water content in bone tissue. Hematoxylin-eosin staining showed that there were no soft tissue residues in the bone, and the cell residues in the bone pit were significantly reduced in the study group, while soft tissue and cell residues were observed in the control group. Sirius red staining and modified Masson staining showed that the structure of bone collagen in the study group was intact, the cytoplasmic components reduced, and the cytoplasmic components in the control group remained significantly. Scanning electron microscopy showed that there was no obvious cell adhesion in the control group, but cell adhesion growth was obvious in the study group. Perivascular inflammatory response in the bone tissue implantation region was obviously weaker in the study group than in the study group. These results suggest that supercritical carbon dioxide extraction technology is an effective and environment-friendly bone tissue processing technology. It can effectively remove porcine cancellous bone cells and soft tissue without affecting its collagen structure and content and mechanical properties, retaining intact bone pore structure, increasing cell adhesion and growth, and effectively reducing inflammatory rejection.

Undernutrition impairs the quality of growth plate and trabecular and cortical bones in growing rats

Abstract Purpose: To investigate the effects of dietary restriction on the growth plate and long bone tissue in growing rats. Methods: Sixty male Wistar rats were randomly assigned to two groups: Control (Con) and Diet-restricted (Res). After weaning, the Res rats were offered 50% of the chow ingested by the control (ad libitum food intake). The animals were subdivided into two subgroups with follow-ups up to 56 or 70 days. After euthanasia, the growth plate of tibias was analyzed by histomorphometry, micro-computed tomography, and mechanical test. The trabecular and compact bones were evaluated by histomorphometry, dual-energy X-ray absorptiometry, and micro-computed tomography (μCT). Real-time PCR was used to analyze gene expression. Results: Although dietary restriction did not alter gene expression, several phenotypic changes were seen in the growth plate; i.e., decrease in volume, reduction in total area and height, decrease in the area ossified zones, mechanical weakening, reduction in mass of trabecular and cortical bone, lower bone density, deterioration of the trabecular and cortical microarchitecture, and trabeculae with lower collagen deposition. Conclusion: Dietary restriction had severe detrimental effects on the growth plate and trabecular and cortical bone.

Method for Automated Selection of the Trabecular Area in Digital Periapical Radiographic Images Using Morphological Operations / 대한의료정보학회지

OBJECTIVES: The aim of this study is to propose a method that automatically select the trabecular bone area in digital periapical radiographic images using a sequence of morphological operations. METHODS: The study involved 50 digital periapical radiographic images of women aged from 36 to 58 years old. The proposed method consists of three stages: teeth detection, trabecular identification, and validation. A series of morphological operations-top-hat and bottom-hat filtering, automatic thresholding, closing, labeling, global thresholding, and image subtraction-are performed to automatically obtain the trabecular bone area in images. For validation, the results of the proposed method were compared with those of two dentists pixel by pixel. Three parameters were used in the validation: trabecular area, percentage of agreed area, and percentage of disagreed area. RESULTS: The proposed method obtains the trabecular bone area in a polygon. The obtained trabecular bone area is usually larger than that of previous studies, but is usually smaller than the dentists'. On average over all images, the trabecular area produced by the proposed method is 5.83% smaller than that identified by dentists. Furthermore, the average percentage of agreed area and the average percentage of disagreed area of the proposed method against the dentists' results were 75.22% and 8.75%, respectively. CONCLUSIONS: The shape of the trabecular bone area produced by the proposed method is similar and closer to that identified by dentists. The method, which consists of only simple morphological operations on digital periapical radiographic images, can be considered for selecting the trabecular bone area automatically.

Demineralized cancellous bone seeded with allogeneic chondrocytes for repairing articular osteochondral defects in rabbits / 南方医科大学学报

<p><b>OBJECTIVE</b>To evaluate the effect of demineralized cancellous bone (DCB) seeded with allogeneic chondrocytes for repairing articular osteochondral defects in rabbits.</p><p><b>METHODS</b>Articular chondrocytes were isolated from a 1-month-old male New Zealand rabbit for primary culture. The passage 1 chondrocytes were seeded onto prepared rabbit DCB scaffold to construct tissue-engineered cartilage and cultured for 2 weeks. Full-thickness articular osteochondral defects (3 mm both in diameter and depth) were created on both sides of the femoral medial condyles in 30 New Zealand white rabbits (age 4- 5 months). In 20 of the rabbits, the defects were filled with the tissue-engineered cartilage on the right side (group A) and with DCB only on the left side (group B); the remaining 10 rabbits did not receive any implantation in the defects to serve as the control (group C). At 1, 3, and 6 months after the implantation, tissue samples were collected from the defects for macroscopic observation and histological examination with Toluidine blue (TB) and collagen type Ⅱ staining. The effect of defect repair using the tissue-engineered cartilage was assessed at 6 months based on the histological scores.</p><p><b>RESULTS</b>The prepared DCB had a spongy 3D structure with open and interconnected micropores of various sizes and showed good plasticity and mechanical strength. DCB began to degrade within 1 month after implantation and was totally absorbed at 3 months. At 6 months after implantation, the defects filled with the chondrocyte-seeded DCB were repaired mainly by hyaline-like cartilage tissues, which were well integrated to the adjacent cartilage without clear boundaries and difficult to recognize. The chondrocytes were located in the lacunate and arranged in vertical columns in the deep repaired tissue, where matrix proteoglycans and collagen type Ⅱ were distributed homogeneously close to the normal cartilage. The subchondral bone plate was reconstructed completely. The defects implanted with DCB only were filled with fibrocartilage tissue, as compared with fibrous tissue in the control defects. The histological scores in group A were significantly superior to those in group B and C ( < 0.05), but the scores for subchondral bone plate reconstruction were comparable between groups A and B at 6 months.</p><p><b>CONCLUSIONS</b>DCB is a good scaffold material for preparing tissue-engineered cartilage, and chondrocyte- seeded DCB can repair articular osteochondral defects by inducing the generation of hayline-like cartilage.</p>

Autogenous distal tibial cancellous bone graft with periosteum for the treatment of cartilage injury of talus with Hepple III-IV type / 中国骨伤

OBJECTIVE@#To analyze the operative methods and clinical effects of autologous distal tibial cancellous bone graft with periosteum in treating cartilage injury of talus with Hepple III-IV type.@*METHODS@#From June 2014 to August 2017, 25 patients (25 feet) with Hepple III to IV cartilage injury of talus were treated with autogenous ipsilateral distal tibial cancellous bone graft. Including 14 males and 11 females, aged from 18 to 52 years with an average of (38.4±3.1) years; left foot was in 8 cases and right foot was in 17 cases. According to Hepple classification, type III of 9 cases, type IV of 16 cases. The curative effect was assessed by Amercian orthopedic foot and ankle society (AOFAS) and visual analogue scale (VAS) before operation and 12 months after operation.@*RESULTS@#All 25 patients were followed up for 12 to 28 months with an average of (14.2±2.5) months. AOFAS and VAS scores were improved from preoperative 53.02±10.06, 8.02±1.14 to 88.04±7.45, 1.26±1.74 at 12 months after operation (<0.05). According to AOFAS standard, 16 cases got excellent results, 6 good, 3 poor.@*CONCLUSIONS@#Autologous distal tibial cancellous bone graft with periosteum is an effective method for Hepple III-IV cartilage injury of talus. It can effectively relieve ankle pain and improve ankle joint function.

Efeito da terapia de longa duração com ácido zoledrônico no osso esponjoso da mandíbula e fêmur de ratos Wistar / Effect of long-term zoledronic acid treatment on cancellous bone in the mandible and femur of Wistar rats

Os bisfosfonatos (BF) são amplamente utilizados no tratamento de doenças osteolíticas como metástases ósseas e osteoporose. A osteonecrose dos maxilares associada ao uso de BF (OMAB) é caracterizada pela presença de osso exposto ou que pode ser sondado através de uma fístula que persiste por mais de oito semanas em pacientes com história de terapia de BF e sem história de radioterapia na região de cabeça e pescoço e/ou sem doença metastática nos maxilares. A incidência de OMAB aumenta com a potência, duração do tratamento e dose de BF recebida. Até o presente momento, a fisiopatologia da OMAB não está clara, dificultando a prevenção e o tratamento. O objetivo deste estudo foi avaliar o efeito da administração de altas doses Ácido Zoledrônico (AZ) por período prolongado no osso esponjoso da mandíbula e da metáfise proximal do fêmur de ratos Wistar. Para relacionar as descobertas à fisiopatologia da OMAB, o regime de administração de BF de um modelo animal relevante desta lesão foi reproduzido. Seis animais receberam AZ (0,6 mg / kg) e seis receberam solução salina no mesmo volume (Controles). Os compostos foram administrados por via intraperitoneal em cinco doses a cada 28 dias. A eutanásia dos animais ocorreu após 150 dias de início da terapia. As hemimandíbulas e fêmures direitos foram escaneados usando Micro-tomografia computadorizada (Micro-CT) de alta resolução (14 m). Para a primeira análise realizada neste estudo, os dados morfométricos do osso esponjoso foram calculados na região do segundo e primeiro molar na mandíbula e na metáfise do fêmur usando CTAnalyzer (Bruker, Bélgica). Para a segunda análise, cinco amostras de hemimandíbulas de cada grupo foram cortadas em lâminas histológicas (5 m) e coradas com Hematoxilina e Eosina. Para comparar os parâmetros morfométricos na Micro-CT e histologia, as imagens de Micro-CT foram espacialmente alinhadas à histologia. Os dados morfométricos do osso alveolar foram calculados usando o software CTAnalyzer (Bruker, Bélgica) na região entre as raízes mesial e distal do primeiro molar. A densidade da área vascular (área vascular/área total; VA/TA) e os dados histomorfométricos ósseos foram estimados usando Axiovision na mesma região (entre as raízes mesial e distal do primeiro molar). Foi adotada significância estatística de 5% ( = 0,05). Os animais tratados com AZ apresentaram aumento significativo na porcentagem de volume ósseo (p <0,05) com trabéculas mais espessas, osso mais compacto com menor separação trabecular na mandíbula e no fêmur. Na mandíbula, o aumento da densidade óssea e diminuição da separação trabecular foram fortemente correlacionados com a diminuição da área vascular observada no grupo AZ (p <0,05). Em conclusão, o tratamento de longa duração com altas doses de AZ foi significativamente associado ao aumento na densidade óssea e à diminuição dos espaços medulares, canais nutritivos e vasculatura do osso alveolar. A análise com Micro-CT revelou alterações semelhantes na estrutura óssea tanto na mandíbula quanto no fêmur do grupo AZ.(AU)

Bisphosphonates (BFs) are widely used in the treatment of osteolytic diseases such as bone metastases and osteoporosis. The osteonecrosis of the jaws related to BF (ONB) is characterized by the presence of exposed bone or bone that can be probed through a fistula that persists for more than eight weeks in patients with a history of BF therapy and without history of head and neck radiotherapy and / or without metastatic disease in the jaws. The incidence of ONB increases with potency, duration of treatment and dose of BF received. Thus far, the pathophysiology of ONB is unclear, hampering prevention and treatment. The aim of this study was to objectively assess the effect of long-term high-dose Zoledronic Acid (ZA) on cancellous bone in the jaw and femur of Wistar rats. In order to link our findings to the physiopathology of ONB, the therapeutic regiment of a relevant ONB animal model was reproduced. Twelve Wistar rats were randomly divided in two groups: six received Zoledronic acid (ZA; 0.6 mg / kg) and six (Controls) received saline solution in the same volume. The compounds were administrated intraperitoneally in five doses each 28 days. The rats were killed after 150 days of the therapy onset. Mandibles and femurs were scanned using a high-resolution (14m) micro-computerized tomography (Micro-CT). For the first analysis carried in this study, cancellous bone morphometric data were calculates in the region of the second and first molar in the mandible and in the proximal femur using CTAnalyzer (Bruker, Belgium). For the second analysis five samples were cut into histological slices (5m) and stained with Hematoxylin and Eosin. In order to compare the same morphological structures in Micro-CT and histology, the Micro-CT images were aligned to histology. Alveolar bone morphometric data (Micro-CT) was calculated using CTAnalyzer (Bruker, Belgium) in the region between the mesial and distal roots of the first molar. Blood vessels density and bone histomorphometric data were calculated using Axiovision (Carl Zeiss, Germany) in the same region used for Micro-CT evaluation. Statistical significance of 5% (=0.05) was adopted. ZA treated rats presented significant increase in the percentage of bone volume (p<0.05) with thicker trabeculae and more compact bone with smaller marrow spaces in the mandible and femur. In the mandible, the increase in bone density and decrease of marrow spaces size was strongly correlated with the decrease in the vascular area noticed in the ZA group (p<0.05). In conclusion, long-term high-dose ZA treatment was significant associated with the increase of bone density and the diminution of medullary spaces and nutritive canals size as well as decrease in vascularity of the alveolar bone. Micro-CT investigation showed similar changes in bone structure in the mandible and femur in the ZA group.(AU)

Allogeneic demineralized cancellous bone for cartilage tissue engineering / 西安交通大学学报(医学版)

Objective Chondrocytes were seeded on allogeneic demineralized cancellous bone (DCB ) constructing tissue-engineered cartilage to evaluate the feasibility of DCB as scaffolds for tissue engineering cartilage.Methods Allogeneic DCB was prepared by successive defatting and decalcification and then observed under scanning electronic microscope.One-month old rabbit articular chondrocytes were isolated and proliferated by monolayer culture.Passage 1 chondrocytes were seeded on DCB to construct tissue-engineered cartilage in vitro for 6 weeks.Specimens were taken after 7,14,21,28,35 and 42 days'culture and evaluated by hematoxylin and eosin (HE),toluidine blue (TB),and immunohistochemistry for collagen type Ⅰ and Ⅱ.Results Prepared DCB showed three-dimensional porous structure of 100 - 500 μm with good plasticity and certain mechanical strength. Chondrocytes grew well on and inside the DCB,and were located in lacunae and expressed matrix proteoglycan and type collagen Ⅱ,which formed cartiageous tissues on DCB up to 42 days'culture.Conclusion DCB combined with allogeneic chondrocytes successfully constructed tissue-engineered cartilage in vitro ,which is an ideal scaffold for tissue engineering cartilage.

Allogeneic demineralized cancellous bone for cartilage tissue engineering / 西安交通大学学报(医学版)

Objective Chondrocytes were seeded on allogeneic demineralized cancellous bone (DCB ) constructing tissue-engineered cartilage to evaluate the feasibility of DCB as scaffolds for tissue engineering cartilage.Methods Allogeneic DCB was prepared by successive defatting and decalcification and then observed under scanning electronic microscope.One-month old rabbit articular chondrocytes were isolated and proliferated by monolayer culture.Passage 1 chondrocytes were seeded on DCB to construct tissue-engineered cartilage in vitro for 6 weeks.Specimens were taken after 7,14,21,28,35 and 42 days'culture and evaluated by hematoxylin and eosin (HE),toluidine blue (TB),and immunohistochemistry for collagen type Ⅰ and Ⅱ.Results Prepared DCB showed three-dimensional porous structure of 100 - 500 μm with good plasticity and certain mechanical strength. Chondrocytes grew well on and inside the DCB,and were located in lacunae and expressed matrix proteoglycan and type collagen Ⅱ,which formed cartiageous tissues on DCB up to 42 days'culture.Conclusion DCB combined with allogeneic chondrocytes successfully constructed tissue-engineered cartilage in vitro ,which is an ideal scaffold for tissue engineering cartilage.

Effect of Sodium ferulate on glucocorticoid-induced osteoporosis / 中国药理学通报

Aim To study the influence of Sodium fer-ulate ( SF) on bone metabolism in glucocorticoid–in-duced osteoporosis rats. Methods Thirty cases of fe-male Wistar Rats(3-month-old) were divided into con-trol group, model group and SF group ( low-dose group, middle-dose group, high-dose group ) by ran-domized block design. Double fluorochrome labeling with calcein was performed before necropsy. The left tibia was taken for bone histomorphometry. Results In static parameters, the proximal tibia cancellous bone trabecular thickness, trabecular quantity and area ratio were significantly reduced in model group compared with control group;while compared with model group, those were increased in middle and high-dose SF group. Trabecular separation degree was increased in model group compared with control group, while it was decreased in middle and high-dose SF group compared with model group. In dynamic parameters, the calcula-tion parameters of cancellous bone mark perimeter rate and the bone formation rate were increased in model group compared with control group, in middle and high-dose SF group the bone formation rate was in-creased compared with model group. In bone cells, os-teoclast number per mm, osteoblast number per mm, percent osteoblast surface perimeter and percent osteo-clast surface perimeter were increased in model group compared with control group. In growth-plate, the thickness of growth-plate was increased in model group compared with control group. In bone cells and growth-plate there was no statistical significance between treat-ment group and model group. Conclusion This study demonstrates that SF can increase bone mass and im-prove bone structure,which may be related to the im-provement of bone formation. SF is effective for GIOP in rats.

Influence of thickness of cancellous bone and cortical bone in stress distribution in vicinity of an implant / 吉林大学学报(医学版)

Objective:To investigate the stress distribution surrounding an implant under different thickness of cancellous bone and cortical bone,and to analyze the influence of thickness ratio and total thickness of bone tissues on the reliability of an implant.Methods:By using the commercial finite element method software Abaqus, a simplified three-dimensional model of a jawbone consisting of a cancellous bone,a cortical bone,an implant,and a ceramic crown was constructed,and then the computation was performed.Under the condition that the system was loaded by lateral and normal stresses, the influence of thickness ratio and total thickness of cancellous bone and cortical bone in the stress distribution surrounding the implant was studied,where the thickness ratios were 3∶1, 2∶1, 1∶1, 1∶2, and 1∶3;the total thickness were 0.5, 1.0, 2.0, 3.0 and 4.0 mm, respectively. Results:The maximum stresses on the cortical bone,the cancellous bone as well as the implant were all found to decrease with the increasing of the total thickness of cortical and cancellous bones,with a higher decreasing rate in the range between 0.5-2.0 mm and a lower decreasing rate between 2.0-4.0 mm. More importantly, the maximum value of stress in the cortical bone within the neck region of the implant was observed to increase dramatically via reducing the total thickness below 2 mm, while it was increased insignificantly when the total thickness was above 2.0 mm. Conclusion:The thickness ratio and the total thickness of cancellous bone and cortical bone have strong influence in the stress distribution surrounding the implant.In dental implantation surgery, the total thickness of cancellous bone and cortical bone should be at least 2 mm, and therefore 2 mm is an optimal value.

Effects of ClC-3 gene overexpression on bone mass and structure in mice / 中国病理生理杂志

[ ABSTRACT] AIM:To investigate the effect of the overexpression of voltage-gated chloride channel family protein 3 ( ClC-3) gene on bones of mice .METHODS: The tail gene detection assay was used to confirm the overexpression of ClC-3.The male FVB mice of three months old were divided into two groups , the wild type ( WT) group and the ClC-3 overexpressed (ClC-3 transgene) group.The body weight, length and weight of the right tibias were measured .The upper and middle parts of the tibias were dissected , decalcified, paraffin-imbed, sectioned and stained with HE staining .The bone morphology metrology was used to analyze the changes of bone structures .The percent trabecular area (%Tb.Ar), trabecular number ( Tb.N) , trabecular width ( Tb.Wi) and trabecular separation ( Tb.Sp) of cancellous bone in the upper part of the tibia were measured.The total tissue area (T.Ar), cortical area (Ct.Ar), percent cortical area (%Ct.Ar), marrow area ( Ma.Ar) and percent marrow area (%Ma.Ar) of the cortical bone in the middle part of the tibia were detec-ted .RESULTS:The wild type mice and the ClC-3-overexpressed mice were verified by the tail gene detection assay . Compared with WT group , the body weight and the length and weight of the tibia were decreased in ClC -3 transgene mice (P<0.05).In the cancellous bones of ClC-3 transgene mice, the%Tb.Ar and Tb.Wi were decreased (P<0.05), the Tb.Sp was increased (P<0.05) and the Tb.N was not significantly changed .In the cortical bones of ClC-3 transgene mice, the T.Ar, Ct.Ar and%Ct.Ar were decreased (P<0.05), the%Ma.Ar was increased (P<0.05), and the Ma. Ar was not significantly changed .CONCLUSION:ClC-3 overexpression may lead to the reduction of the bone mass and the destructure of the cancellous and cortical bones .The results suggest that ClC-3 may be involved in the regulation of bone resorption and/or formation.

Effects of saxagliptin and exenatide on humerus cancellous bone of diabetes-induced osteopenia rats / 中国药学杂志

OBJECTIVE: To determine the effects of saxagliptin and exenatide on humerus cancellous bone of diabetes-induced osteopenia rats by histomorphometry. METHODS: Thirty-five Cases of female SD rats were randomly divided into normal group (N group, n=7), control group (C group, n=7), and the remaining rats were used to establish the type 2 diabetic model by combination of high-fat&sugar-diet feeding for 4 weeks and then low-dose streptozotocin injection(STZ, 30 mg·kg-1). After 10 d, the oral glucose tolerance test and the fasting blood glucose were measured, rats with high OGTT(2 h) above 11.1 mmol·L-1 and high FBG above 16.7 mmol·L-1 were divided into model group (M group, n=5), saxagliptin group (G group, n=5) and exenatide group (D group,n=6), and continuously treated for 30 d. The left humerus (proximal humeru metaphometry, PHM) were fixed with 4% paraformaldehyde for 48 h, uncalcified embedded in methyl methacrylate after dehydrated and cleared, and sections were taken for bone histomorphometry after Masson-Goldner Trichrome stained. RESULTS: In PHM, there was no statistical significance between N and C group, the trabecular bone area ratio(BV/TV) and trabecular quantity were significantly decreased (P<0.01) in M group, while the trabecular separation degree was increased, comparing with those in C group (P<0.01), and the trabecular bone area ratio(BV/TV) and trabecular quantity in G and D group were higher (P<0.01) than those of model rats, while the trabecular separation degree was decreased, comparing with those in M group (P<0.01). Cell parameters showed no statistical significance between N and C group, the osteocllast number and percentage of osteocllast surface perimeter were significantly reduced(P<0.05, P<0.01) in M group, while the osteoclast number and percent osteocllast surface perimeter were significantly increased (P<0.01) as compared with those in C group, saxagliptin and exenatide were found to significantly induce osteocllast number (P<0.01) and percentage of osteoblast surface perimeter (G group P<0.05, D group P<0.01), while reduce osteoclast number (P<0.01) and percent osteoblast surface perimeter (P<0.05) compared with M group. In growth-plate, there was no statistical significance between N and C group, the thickness of growth-plate and the diameter of the mast cells were reduced in M groups (P<0.01), while the thickness of growth-plate (P<0.01) and the diameter of the mast cells (P<0.05) were increased in G and D group,compared with M group. CONCLUSION: Therapeutic effects of saxagliptin and exenatide on diabetes-induced osteopenia rats was showed, and the mechanism may be related to the improved growth rate of growth-plate and the changed bone turnover status.

Non-Structural Cancellous Bone Graft and Headless Compression Screw Fixation for Treatment of Scaphoid Waist Nonunion

PURPOSE: The authors performed an autologous cancellous bone graft from the iliac crest and headless compression screw fixation for the treatment of Mack-Lichtman type II scaphoid waist nonunion. The purpose of this study was to determine whether this procedure was effective in achieving bony union and restoration of alignment. METHODS: We retrospectively reviewed medical records and radiographs of 30 patients who underwent a cancellous bone graft and headless compression screw fixation for scaphoid waist nonunion. There 28 men and 2 women with a mean age of 32.8 year-old (range, 21–63 year-old). The mean time to surgery from initial injury was 10 months (range, 3–25 months) and the average follow-up duration was 37.5 months (range, 15–52 months). The authors analyzed bony union, lateral intrascaphoid angle (LISA), scapholunate angle (SLA), radiolunate angle (RLA), and scaphoid length in radiographs and evaluated the modified Mayo wrist score (MMWS) as a functional outcome. RESULTS: Bony union was achieved in all cases. In lateral plain X-ray, preoperative anatomic alignment including LISA, SLA, RLA, and scaphoid length was recovered at immediate postoperative measurement. Those alignment restoration was likely to maintain in final follow-up in despite of statistical difference. The wrist motion and the MMWS improved significantly at the last follow-up. CONCLUSION: A non-structural autologous cancellous bone graft from the iliac crest and headless screw fixation provided reliable results and can be one of the effective treatment options for patients with symptomatic Mack-Lichtman type II nonunion in the middle one-third of the scaphoid.

Autogeneic cancellous bone transplantation for non-traumatic and posteromedial subchondral osteonecrosis of trochlea tali / 医学研究生学报

Objective Non-traumatic and posteromedial subchondral osteonecrosis of trochlea tali (NTPSOTT) is a special type of necrosis of the talus , for which early diagnosis and treatment are particularly important .This study investigated the clinical ef-fectiveness of autogeneic cancellous bone transplantation in the treatment of NTPSOTT . Methods We retrospectively analyzed 21 cases of NTPSOTT treated by autogeneic cancellous bone transplantation and evaluated using the Clinical Rating System of the American Orthopedic Foot and Ankle Society ( AOFAS) , Visual Analogue Scale ( VAS) , and X-ray and CT examinations . Results The pa-tients were followed up for 12-26 months and all healed desirably , with the graft well integrated into the surrounding tissue , but no as-similation, collapse of the articular surface , or narrowing of the joint space .The last follow-up visit revealed significantly improved AOFAS score (90.55 ±6.73 vs 50.87 ±11.42, P=0.009) and VAS score (1.32 ±0.81 vs 6.43 ±1.66, P=0.027) as compared with the baseline . Conclusion Autogeneic cancellous bone transplantation is preferable for the treatment of NTPSOTT , which can effectively reduce the pain in the ankle , maintain the joint space , and protect the function of the ankle .