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.

Split-Block Graft Versus Cortico-cancellous Block Graft for Horizontal Ridge Augmentation: Cone Beam Computed Tomography and Histomorphometric Study / Enxerto de bloco dividido versus enxerto de bloco córtico-esponjoso para aumento horizontal do rebordo: imagens de tomografia computadorizada de feixe cônico e estudo histomorfométrico

Objective: The aim of this study was to compare the horizontal dimensional changes of split-bone block and cortico-cancellous block graft in horizontal ridge augmentation using Cone Beam Computed Tomography (CBCT). The quality of the regenerated bone in both groups was compared histologically and histomorphometrically. Material and methods: Twenty patients were randomly divided in two equal groups (n= 10): Split-bone block group which was harvested from the external oblique ridge or cortico-cancellous block graft group which was harvested from the mandibular symphysis. Pre-augmentation crestal ridge width was measured using bone caliper. CBCT scans were taken on the 2nd week and 4th month post-operatively to measure crestal and total horizontal ridge dimensions. A biopsy was collected from the regenerated ridge immediately before implant insertion on the 4thmonth post-operatively. Results: Pre-augmentation crestal bone widths of both groups were comparable (P= 0.870). On the 2nd week and 4th month post-operatively, split-bone block showed a significantly wider crestal (P= 0.028 and P= 0.001 respectively) and total horizontal ridge dimension (P= 0.025 and P= 0.002 respectively), and on the 4th month post-operatively, it showed significantly lesser resorption at crest (P= 0.040) and in total horizontal ridge dimension (P= 0.017) than cortico-cancellous block. Histologically, the regenerated bone quality was similar in both groups. Histomorphometric analysis showed a non-significant difference in percentage of mature (P= 0.365) and immature collagen (P= 0.531) between both groups. Conclusion: Split-bone block maintained a significantly wider ridge and experienced less resorption after 4 months than the cortico-cancellous block graft, with no difference in regenerated bone quality between both groups. (AU)

Objetivo: O objetivo deste estudo foi comparar as mudanças dimensionais horizontais do enxerto de bloco ósseo dividido e do enxerto de bloco córtico-esponjoso no aumento de rebordo horizontal por meio da Tomografia computadorizada de feixe cônico (TCFC). A qualidade do osso regenerado em ambos os grupos foi comparada histológica e histomorfometricamente. Material e Métodos:Vinte pacientes foram divididos aleatoriamente em dois grupos iguais (n=10): Grupo de blocos de osso dividido retirado da crista oblíqua externa ou Grupo de enxerto em bloco córtico-esponjoso retirado da sínfise mandibular. A largura da crista pré-aumentada foi medida usando calibrador ósseo. Os exames de TCFC foram realizados na segunda semana e quarto mês de pós operatório para medir as dimensões da crista e dimensões horizontais totais do rebordo. Uma biopsia foi coletada da crista regenerada imediatamente antes da inserção do implante no quarto mês pós-operatório. Resultados: As larguras do osso crestal pré-aumentado de ambos os grupos eram compatíveis (p = 0,870). Na segunda semana e quarto mês pós-operatórios, o bloco ósseo dividido mostrou uma crista significativamente mais larga (p = 0,28 e p = 0,001 respectivamente) e a dimensão da crista horizontal total (p = 0,025 e p = 0,002 respectivamente), e no quarto mês pós-operatório, apresentou reabsorção significativamente menor na crista (p = 0,040) e na dimensão da crista horizontal total (p = 0,017) em comparação ao bloco córtico-esponjoso. Histologicamente, a qualidade do osso regenerado foi semelhante em ambos os grupos. A análise histomorfométrica mostrou uma diferença não significativa na porcentagem de colágeno maduro (p = 0.365) e colágeno imaturo (p = 0,531) entre ambos os grupos. Conclusão: O bloco ósseo dividido manteve uma crista significativamente mais larga e apresentou menos reabsorção após 4 meses, em comparação ao enxerto em bloco córtico-esponjoso, sem diferença na qualidade do osso regenerado entre ambos os grupos. (AU)

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.

Comparison outcome in management of femoral neck fracture using multiple cancellous screws with and without fibular graft

Multiple cancellous cannulated screw is preferred method in fresh cases of fracture neck of femur in young patients. Fibular strut graft is sometimes used along with multiple cancellous cannulated screws to enhance union and early restoration of function. We conducted a retrospective study to patients aged between 20-50 years old with femoral neck fracture treated with multiple cancellous screws either with or without fibular graft between the period of January 2016 to January 2018. We obtained total of six patients (five males and one female) with femoral neck fracture treated with multiple cancellous screws either with or without fibular graft. All fractures were garden type II-IV fresh femoral neck fractures. The functional outcome based on Harris hip score was excellent for all patients. The mean time of full weight bearing was 16±8 weeks in both multiple cancellous screws without fibular group and multiple cancellous screws with fibular group. The mean time of union was also 16±8 weeks in both groups. There is no complication such as non-union, avascular necrosis of femoral head and/or broken fibular graft in both the groups occurrences. Fixation with cancellous screws and fibular strut grafts for femoral neck fractures is cost effective and technically less demanding and associated with good outcomes. There is no added advantage of non-vascularized fibular grafting with multiple hip screw fixation in fresh femoral neck fractures in young adults over multiple hip screw fixation alone.

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.

Hoffa Fracture of Medial Femoral Condyle in a 9-Year-Old Child: A Case Report

Hoffa fractures are intra-articular fractures of the distal femoral condyles in coronal plane. These fractures may be of either condylebut lateral condyle is most commonly affected and medial condyle is extremely rare. Non-operative treatment of unicondylarfemur fractures, including Hoffa fractures, yields poor result. We present a case of 9-year-old child with Hoffa fracture of medialfemoral condyle with understanding of the mechanism of injury and its further management. He had history of fall from height ofabout 5 feet on his right knee which was in flexed position at around 90°. X-ray of knee showed fracture of medial femoral condylein coronal plane. Three-dimensional (3D) reconstruction of computed tomography (CT) scan confirmed the coronal fracture ofmedial femoral condyle and was classified as Type 33 B3 according to orthopedic trauma association classification and Type 1as per Letenneur classification. Open reduction and internal fixation were performed with partially threaded cancellous screws.The fixation of coronal fracture of medial femoral condyle done through cancellous screws in anterior to posterior direction wasadequate in giving stable fixation and aided in union without disturbing the physis of the child. At 1 year, the child could do fullextension and 130° flexion. There was no posterior or varus, valgus instability of the knee. We believe that a medial condyleHoffa fracture is extremely rare in children, and the diagnosis can be missed. ORIF using partially threaded cancellous screwsin the epiphysis provides stable fixation and can lead to a good functional outcome in the long term. The mechanism of injuryin this fracture pattern was found to be direct impact on the knee in flexed position of 90°.

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.

Surgical Treatment of Calcaneal Fractures of Sanders Type II and III by A Minimally Invasive Technique with 6.5 mm Cancellous Screw / 대한족부족관절학회지

PURPOSE: This study evaluated the clinical and radiological results of 6.5 mm full threaded cancellous bone screw fixation of calcaneal fractures. MATERIALS AND METHODS: Thirty seven patients diagnosed with Sanders type II or III calcaneal fractures, who underwent open reduction and internal fixation with a 6.5 mm full threaded cancellous bone screw between August 2014 and August 2017, were analyzed. Both the preoperative and postoperative Böhler angle and Gissane angle were measured radiographically. American Orthopaedic Foot and Ankle Society (AOFAS) ankle-hindfoot scale on the final follow-up were also assessed. RESULTS: The mean age of the patients was 52.7 years and the mean follow-up period was 29.5 months. In the Sanders classification, type II and III were 16 and 24 cases, respectively. The Böhler and Gissane angles improved from 21.2° and 122.6° preoperatively to 21.6° and 120.3°, respectively, in the postoperative radiographs. All cases achieved bony union, and the AOFAS ankle-hindfoot scale was 90.7 and 91.3 in Sanders type II and III, respectively, at the final follow-up. CONCLUSION: The treatment of calcaneal fractures using a 6.5 mm full threaded cancellous bone screw can reduce the complications with minimally invasive surgery and achieve firm fixation.

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.

ESTABLISHING FREEZE DRYING PROCESS FOR CORTICAL AND CANCELLOUS BONE ALLOGRAFT CUBES

@#Freeze drying is a dehydration method to dry bone under freezing environment, enabling removal of water with no or minimial effects on bone strength and durability. Larger size bones obviously require longer freeze drying time to reduce water content to the required level for long term storage at room temperature. For small size bone cubes or chips, it is a normal practice to pool cortical and cancellous bones for freeze drying. The study was aimed at determining if different type of bones of the same size influence the drying time. Human bone cubes of 10 mm x 10 mm x 10 mm were prepared from cortical bone of tibiae and cancellous bone from femoral heads. The bone cubes were freeze dried to reduce water content to less than 6%. Moisture content was monitored using gravimetric method.Weight and density of cortical bone were significantly higher than cancellous bone despite of having similar small size (p<0.05). Cortical bones (density 2.05 ± 0.35 g/cm3) with initial water content of 10.93% required 5 hours to freeze dry, while cancellous bone cubes (density 0.72 ± 0.44 g/cm3) with initial water content of 78.95% required only 1.87 hours. This study confirmed that the structure hence density of human bone cubes determine the freeze drying time. Therefore in the standard operating procedure for freeze drying of bone allograft cubes, high density cortical bone cubes and low density cancellous bone cubes must be freeze dried separately despite being of similar small size

Implicit Dynamic Analysis on Tightening Procedure of Cancellous Lag Screw Placement / 医用生物力学

Objective To simulate the tightening procedure of a cancellous lag screw by using the implicit dynamic analysis method, and to evaluate the stress distributions on the screw-bone interface. Methods Finite element models of a lag screw with the surrounding bone were developed, and the implicit solver was set up for implicit dynamic analysis on the tightening procedure of the lag screw. The mechanical properties of the screw-bone interface were also analyzed according to strain and stress distributions on the screw and the surrounding bone. Results The stress of the lag screw was mainly distributed in the proximal portion of the screw thread rod. The high-stress region of the bone around the screw was located outside the outer edge of the screw, and it was approximately equal to the depth of the thread. The area of high-stress distributions on the bone was the main region that resisted screw stripping. Conclusions The method of implicit dynamic analysis can accurately simulate the mechanical properties of the screw-bone interface during screw tightening. The discovery of high-stress distributions on the surrounding bone can help researchers to further understand and improve the stability of screw insertion.

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.

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>

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)

Functional Outcome of Isolated Hoffa Fractures Treated with Cannulated Cancellous Screw

Introduction: Isolated Hoffa fracture is an infrequent injury and little research has been done on this subject. The purpose of this study was to evaluate the functional outcome and complications of surgically managed Hoffa fractures with cannulated cancellous screw. Materials and Methods: Between 2011 and 2014, eight isolated Hoffa fractures in seven adult patients with mean age 39.8±11.9 years (range 25-60 years) were managed with cannulated cancellous screw of 6.5mm diameter applied in anterior to posterior direction using swashbuckler and medial parapatellar approach for lateral and medial Hoffa fractures respectively. All patients were evaluated using knee evaluation score after two years or longer. Mean follow up was 28±3.8 months (range 24-36 months). Results: All fractures in the eight patients healed clinicoradiologically by the 16th week with excellent result in 87.5% cases and good in 12.5% cases. By the end of union, the range of motion (ROM) of the knee was 0° to 110° except in two patients. One patient had ROM 10°-100° and other had 15°-90°. Mean knee evaluation score was 87.5±10.4. There was no incidence of non-union, infection or avascular changes in the patients or loss of reduction till final follow up. Conclusion: Open reduction and fixation with two 6.5 mm cannulated cancellous screws with early mobilization yielded good functional outcome in isolated Hoffa fractures.

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.