An Ice Block: A Novel Technique of Successful Prevention of Cement Leakage Using an Ice Ball

DOE Office of Scientific and Technical Information (OSTI.GOV)

Uri, Ishaq Fahmi, E-mail: uri.isaac@gmail.com; Garnon, Julien, E-mail: juliengarnon@gmail.com; Tsoumakidou, Georgia, E-mail: georgia.tsoumakidou@chru-strasbourg.fr

2015-04-15

We report three cases of painful bone metastases with extraosseous invasion treated with cementoplasty and cryoablation. Due to significant cortical loss in all cases, the ice ball was used simultaneously during cementoplasty to deter potential cement leakage. This was achieved by direct application of the ice ball against the cortical surface, resulting in adequate consolidation and successful containment of the cement within the treated bones. To the authors’ knowledge, this is the first report to describe such a combined technique.

Automatic graph-cut based segmentation of bones from knee magnetic resonance images for osteoarthritis research.

PubMed

Ababneh, Sufyan Y; Prescott, Jeff W; Gurcan, Metin N

2011-08-01

In this paper, a new, fully automated, content-based system is proposed for knee bone segmentation from magnetic resonance images (MRI). The purpose of the bone segmentation is to support the discovery and characterization of imaging biomarkers for the incidence and progression of osteoarthritis, a debilitating joint disease, which affects a large portion of the aging population. The segmentation algorithm includes a novel content-based, two-pass disjoint block discovery mechanism, which is designed to support automation, segmentation initialization, and post-processing. The block discovery is achieved by classifying the image content to bone and background blocks according to their similarity to the categories in the training data collected from typical bone structures. The classified blocks are then used to design an efficient graph-cut based segmentation algorithm. This algorithm requires constructing a graph using image pixel data followed by applying a maximum-flow algorithm which generates a minimum graph-cut that corresponds to an initial image segmentation. Content-based refinements and morphological operations are then applied to obtain the final segmentation. The proposed segmentation technique does not require any user interaction and can distinguish between bone and highly similar adjacent structures, such as fat tissues with high accuracy. The performance of the proposed system is evaluated by testing it on 376 MR images from the Osteoarthritis Initiative (OAI) database. This database included a selection of single images containing the femur and tibia from 200 subjects with varying levels of osteoarthritis severity. Additionally, a full three-dimensional segmentation of the bones from ten subjects with 14 slices each, and synthetic images with background having intensity and spatial characteristics similar to those of bone are used to assess the robustness and consistency of the developed algorithm. The results show an automatic bone detection rate of 0.99 and an average segmentation accuracy of 0.95 using the Dice similarity index. Copyright © 2011 Elsevier B.V. All rights reserved.

Comparative Efficacies of Collagen-Based 3D Printed PCL/PLGA/β-TCP Composite Block Bone Grafts and Biphasic Calcium Phosphate Bone Substitute for Bone Regeneration.

PubMed

Hwang, Kyoung-Sub; Choi, Jae-Won; Kim, Jae-Hun; Chung, Ho Yun; Jin, Songwan; Shim, Jin-Hyung; Yun, Won-Soo; Jeong, Chang-Mo; Huh, Jung-Bo

2017-04-17

The purpose of this study was to compare bone regeneration and space maintaining ability of three-dimensional (3D) printed bone grafts with conventional biphasic calcium phosphate (BCP). After mixing polycaprolactone (PCL), poly (lactic-co-glycolic acid) (PLGA), and β-tricalcium phosphate (β-TCP) in a 4:4:2 ratio, PCL/PLGA/β-TCP particulate bone grafts were fabricated using 3D printing technology. Fabricated particulate bone grafts were mixed with atelocollagen to produce collagen-based PCL/PLGA/β-TCP composite block bone grafts. After formation of calvarial defects 8 mm in diameter, PCL/PLGA/β-TCP composite block bone grafts and BCP were implanted into bone defects of 32 rats. Although PCL/PLGA/β-TCP composite block bone grafts were not superior in bone regeneration ability compared to BCP, the results showed relatively similar performance. Furthermore, PCL/PLGA/β-TCP composite block bone grafts showed better ability to maintain bone defects and to support barrier membranes than BCP. Therefore, within the limitations of this study, PCL/PLGA/β-TCP composite block bone grafts could be considered as an alternative to synthetic bone grafts available for clinical use.

Fracture Gap Reduction With Variable-Pitch Headless Screws.

PubMed

Roebke, Austin J; Roebke, Logan J; Goyal, Kanu S

2018-04-01

Fully threaded, variable-pitch, headless screws are used in many settings in surgery and have been extensively studied in this context, especially in regard to scaphoid fractures. However, it is not well understood how screw parameters such as diameter, length, and pitch variation, as well as technique parameters such as depth of drilling, affect gap closure. Acutrak 2 fully threaded variable-pitch headless screws of various diameters (Standard, Mini, and Micro) and lengths (16-28 mm) were inserted into polyurethane blocks of "normal" and "osteoporotic" bone model densities using a custom jig. Three drilling techniques (drill only through first block, 4 mm into second block, or completely through both blocks) were used. During screw insertion, fluoroscopic images were taken and later analyzed to measure gap reduction. The effect of backing the screw out after compression was evaluated. Drilling at least 4 mm past the fracture site reduces distal fragment push-off compared with drilling only through the proximal fragment. There were no significant differences in gap closure in the normal versus the osteoporotic model. The Micro screw had a smaller gap closure than both the Standard and the Mini screws. After block contact and compression with 2 subsequent full forward turns, backing the screw out by only 1 full turn resulted in gapping between the blocks. Intuitively, fully threaded headless variable-pitch screws can obtain compression between bone fragments only if the initial gap is less than the gap closed. Gap closure may be affected by drilling technique, screw size, and screw length. Fragment compression may be immediately lost if the screw is reversed. We describe characteristics of variable-pitch headless screws that may assist the surgeon in screw choice and method of use. Copyright © 2018 American Society for Surgery of the Hand. Published by Elsevier Inc. All rights reserved.

Basic investigation of dual-energy x-ray absorptiometry for bone densitometry using computed radiography

NASA Astrophysics Data System (ADS)

Shimura, Kazuo; Nakajima, Nobuyoshi; Tanaka, Hiroshi; Ishida, Masamitsu; Kato, Hisatoyo

1993-09-01

Dual-energy X-ray absorptiometry (DXA) is one of the bone densitometry techniques to diagnose osteoporosis, and has been gradually getting popular due to its high degree of precision. However, DXA involves a time-consuming examination because of its pencil-beam scan, and the equipment is expensive. In this study, we examined a new bone densitometry technique (CR-DXA) utilizing an X-ray imaging system and Computed Radiography (CR) used for medical X-ray image diagnosis. High level of measurement precision and accuracy could be achieved by X-ray rube voltage/filter optimization and various nonuniformity corrections based on simulation and experiment. The phantom study using a bone mineral block showed precision of 0.83% c.v. (coefficient of variation), and accuracy of 0.01 g/cm2, suggesting that a practically equivalent degree of measurement precision and accuracy to that of the DXA approach is achieved. CR-DXA is considered to provide bone mineral densitometry to facilitate simple, quick and precise bone mineral density measurement.

Bone remodeling in onlay beta-tricalcium phosphate and coral grafts to rat calvaria: microcomputerized tomography analysis.

PubMed

Anavi, Yakir; Avishai, Gal; Calderon, Shlomo; Allon, Dror M

2011-08-01

This study was conducted to establish the efficiency of microcomputerized tomography (micro-CT) in detection of trabecular bone remodeling of onlay grafts in a rodent calvaria model, and to compare bone remodeling after onlay grafts with beta-tricalcium phosphate (TCP) or coral calcium carbonate. Ten rats received calvarial onlay blocks-5 with TCP and 5 with coral calcium carbonate. The grafts were fixed with a titanium miniplate screw and were covered with a collagen resorbable membrane. Three months after surgery, the calvaria were segmented, and a serial 3-dimensional micro-CT scan of the calvarium and grafted bone block at 16-micrometer resolution was performed. Image analysis software was used to calculate the percentage of newly formed bone from the total block size. Newly formed bone was present adjacent to the calvarium and screw in all specimens. The mean area of newly formed bone of the total block size ranged from 34.67%-38.34% in the TCP blocks, and from 32.41%-34.72% in the coral blocks. In the TCP blocks, bone remodeling was found to be slightly higher than in the coral blocks. Micro-CT appears to be a precise, reproducible, specimen-nondestructive method of analysis of bone formation in onlay block grafts to rat calvaria.

Application of interconnected porous hydroxyapatite ceramic block for onlay block bone grafting in implant treatment: A case report.

PubMed

Ohta, Kouji; Tada, Misato; Ninomiya, Yoshiaki; Kato, Hiroki; Ishida, Fumi; Abekura, Hitoshi; Tsuga, Kazuhiro; Takechi, Masaaki

2017-12-01

Autogenous block bone grafting as treatment for alveolar ridge atrophy has various disadvantages, including a limited availability of sufficiently sized and shaped grafts, donor site morbidity and resorption of the grafted bone. As a result, interconnected porous hydroxyapatite ceramic (IP-CHA) materials with high porosity have been developed and used successfully in orthopedic cases. To the best of the author's knowledge, this is the first report of clinical application of an IP-CHA block for onlay grafting for implant treatment in a patient with horizontal alveolar atrophy. The present study performed onlay block grafting using an IP-CHA block to restore bone volume for implant placement in the alveolar ridge area without collecting autogenous bone. Dental X-ray findings revealed that the border of the IP-CHA block became increasingly vague over the 3-year period, whereas CT scanning revealed that the gap between the block and bone had a smooth transition, indicating that IP-CHA improved the process of integration with host bone. In follow-up examinations over a period of 5 years, the implants and superstructures had no problems. An IP-CHA block may be useful as a substitute for onlay block bone grafting in implant treatment.

Comparison of the Pullout Strength of Different Pedicle Screw Designs and Augmentation Techniques in an Osteoporotic Bone Model.

PubMed

Kiyak, Gorkem; Balikci, Tevfik; Heydar, Ahmed Majid; Bezer, Murat

2018-02-01

Mechanical study. To compare the pullout strength of different screw designs and augmentation techniques in an osteoporotic bone model. Adequate bone screw pullout strength is a common problem among osteoporotic patients. Various screw designs and augmentation techniques have been developed to improve the biomechanical characteristics of the bone-screw interface. Polyurethane blocks were used to mimic human osteoporotic cancellous bone, and six different screw designs were tested. Five standard and expandable screws without augmentation, eight expandable screws with polymethylmethacrylate (PMMA) or calcium phosphate augmentation, and distal cannulated screws with PMMA and calcium phosphate augmentation were tested. Mechanical tests were performed on 10 unused new screws of each group. Screws with or without augmentation were inserted in a block that was held in a fixture frame, and a longitudinal extraction force was applied to the screw head at a loading rate of 5 mm/min. Maximum load was recorded in a load displacement curve. The peak pullout force of all tested screws with or without augmentation was significantly greater than that of the standard pedicle screw. The greatest pullout force was observed with 40-mm expandable pedicle screws with four fins and PMMA augmentation. Augmented distal cannulated screws did not have a greater peak pullout force than nonaugmented expandable screws. PMMA augmentation provided a greater peak pullout force than calcium phosphate augmentation. Expandable pedicle screws had greater peak pullout forces than standard pedicle screws and had the advantage of augmentation with either PMMA or calcium phosphate cement. Although calcium phosphate cement is biodegradable, osteoconductive, and nonexothermic, PMMA provided a significantly greater peak pullout force. PMMA-augmented expandable 40-mm four-fin pedicle screws had the greatest peak pullout force.

Prototyped grafting plate for reconstruction of mandibular defects.

PubMed

Zhou, Libin; Wang, Peilin; Han, Haolun; Li, Baowei; Wang, Hongnan; Wang, Gang; Zhao, Jinlong; Liu, Yanpu; Wu, Wei

2014-12-01

To esthetically and functionally restore a 40-mm canine mandibular discontinuity defect using a custom-made titanium bone-grafting plate in combination with autologous iliac bone grafts. Individualized titanium bone-grafting plates were manufactured using a series of techniques, including reverse engineering, computer aided design, rapid prototyping and titanium casting. A 40-mm discontinuous defect in the right mandibular body was created in 9 hybrid dogs. The defect was restored immediately using the customized plate in combination with autologous cancellous iliac blocks. Sequential radionuclide bone imaging was performed to evaluate the bone metabolism and reconstitution of the grafts. The specimens were evaluated by biomechanical testing, 3-dimensional microcomputed tomographic scanning, and histological examination. The results revealed that the symmetry of the mandibles was reconstructed using the customized grafting plate, and the bony continuity of the mandibles was restored. By 12 weeks after the operation, the cancellous iliac grafts became a hard bone block, which was of comparable strength to native mandibles. A fibrous tissue intermediate was found between the remodelled bone graft and the titanium plate. The results indicate that the prototyped grafting plate can be used to restore mandibular discontinuous defects, and satisfactory aesthetical and functional reconstruction can be achieved. Copyright © 2014 European Association for Cranio-Maxillo-Facial Surgery. Published by Elsevier Ltd. All rights reserved.

Piezosurgery applied to implant dentistry: clinical and biological aspects.

PubMed

Pereira, Cassiano Costa Silva; Gealh, Walter Cristiano; Meorin-Nogueira, Lamis; Garcia-Júnior, Idelmo Rangel; Okamoto, Roberta

2014-07-01

Piezosurgery is a new and modern technique of bone surgery in implantology. Selective cutting is possible for different ultrasonic frequencies acting only in hard tissues (mineralized), saving vital anatomical structures. With the piezoelectric osteotomy technique, receptor site preparation for implants, autogenous bone graft acquistition (particles and blocks), osteotomy for alveolar bone crest expansion, maxillary sinus lifting, and dental implant removal can be performed accurately and safely, providing excellent clinical and biological results, especially for osteocyte viability. The aim of this review was, through literature review, to present clinical applications of piezosurgery in implant dentistry and outline their advantages and disadvantages over conventional surgical systems. Moreover, this study addressed the biological aspects related to piezosurgery that differentiate it from those of bone tissue approaches. Overall, piezosurgery enables critical operations in simple and fully executable procedures; and effectively, areas that are difficult to access have less risk of soft tissue and neurovascular tissue damage via piezosurgery.

Histomorphometric analysis following augmentation of the anterior atrophic maxilla with cancellous bone block allograft.

PubMed

Nissan, Joseph; Marilena, Vered; Gross, Ora; Mardinger, Ofer; Chaushu, Gavriel

2012-01-01

Grafting with bone blocks may be required to restore the alveolar process in extremely atrophic maxillae prior to implant placement to ensure both function and esthetics. The present study was conducted to histologically and histomorphometrically evaluate the application of allograft cancellous bone blocks for the augmentation of the anterior atrophic maxilla. Consecutive patients with severe atrophy in the anterior maxilla underwent augmentation with cancellous bone block allografts. Bony deficiencies of at least 3 mm horizontally and up to 3 mm vertically according to computed tomographic para-axial reconstructions served as inclusion criteria. After 6 months, implants were placed and a cylindric sample core from the graft area was collected. All specimens were prepared for histologic and histomorphometric examination. Forty patients were included in the study. Eighty-three implants were placed in bone that was augmented with 60 cancellous freeze-dried bone block allografts. The implant survival rate was 98.8%. Mean follow-up was 48 ± 22 months (range, 14 to 82 months). The mean percentage of newly formed bone was 33% ± 18%, that of the residual cancellous block allograft was 26% ± 17%, and marrow and connective tissue comprised 41% ± 2%. Statistically significant histomorphometric differences regarding newly formed bone and residual cancellous block allograft were found between younger (< 40 years) and older (≥ 40 years) patients, respectively. Age did not appear to influence the percentage of marrow and connective tissue. Cancellous bone block allograft is biocompatible and osteoconductive, permitting new bone formation following augmentation of extremely atrophic anterior maxillae in a two-stage implant placement procedure. New bone formation was age-dependent.

Influence of bicortical techniques in internal connection placed in premaxillary area by 3D finite element analysis.

PubMed

Verri, Fellippo Ramos; Cruz, Ronaldo Silva; Lemos, Cleidiel Aparecido Araújo; de Souza Batista, Victor Eduardo; Almeida, Daniel Augusto Faria; Verri, Ana Caroline Gonçales; Pellizzer, Eduardo Piza

2017-02-01

The aim of study was to evaluate the stress distribution in implant-supported prostheses and peri-implant bone using internal hexagon (IH) implants in the premaxillary area, varying surgical techniques (conventional, bicortical and bicortical in association with nasal floor elevation), and loading directions (0°, 30° and 60°) by three-dimensional (3D) finite element analysis. Three models were designed with Invesalius, Rhinoceros 3D and Solidworks software. Each model contained a bone block of the premaxillary area including an implant (IH, Ø4 × 10 mm) supporting a metal-ceramic crown. 178 N was applied in different inclinations (0°, 30°, 60°). The results were analyzed by von Mises, maximum principal stress, microstrain and displacement maps including ANOVA statistical test for some situations. Von Mises maps of implant, screws and abutment showed increase of stress concentration as increased loading inclination. Bicortical techniques showed reduction in implant apical area and in the head of fixation screws. Bicortical techniques showed slight increase stress in cortical bone in the maximum principal stress and microstrain maps under 60° loading. No differences in bone tissue regarding surgical techniques were observed. As conclusion, non-axial loads increased stress concentration in all maps. Bicortical techniques showed lower stress for implant and screw; however, there was slightly higher stress on cortical bone only under loads of higher inclinations (60°).

Histometric analyses of cancellous and cortical interface in autogenous bone grafting

PubMed Central

Netto, Henrique Duque; Olate, Sergio; Klüppel, Leandro; do Carmo, Antonio Marcio Resende; Vásquez, Bélgica; Albergaria-Barbosa, Jose

2013-01-01

Surgical procedures involving the rehabilitation of the maxillofacial region frequently require bone grafts; the aim of this research was to evaluate the interface between recipient and graft with cortical or cancellous contact. 6 adult beagle dogs with 15 kg weight were included in the study. Under general anesthesia, an 8 mm diameter block was obtained from parietal bone of each animal and was put on the frontal bone with a 12 mm 1.5 screws. Was used the lag screw technique from better contact between the recipient and graft. 3-week and 6-week euthanized period were chosen for histometric evaluation. Hematoxylin-eosin was used in a histologic routine technique and histomorphometry was realized with IMAGEJ software. T test was used for data analyses with p<0.05 for statistical significance. The result show some differences in descriptive histology but non statistical differences in the interface between cortical or cancellous bone at 3 or 6 week; as natural, after 6 week of surgery, bone integration was better and statistically superior to 3-week analyses. We conclude that integration of cortical or cancellous bone can be usefully without differences. PMID:23923071

Finding the right fit: studying the biomechanics of under-tapping with varying thread depths and pitches.

PubMed

Jazini, Ehsan; Petraglia, Carmen; Moldavsky, Mark; Tannous, Oliver; Weir, Tristan; Saifi, Comron; Elkassabany, Omar; Cai, Yiwei; Bucklen, Brandon; O'Brien, Joseph; Ludwig, Steven C

2017-04-01

Compromise of pedicle screw purchase is a concern in maintaining rigid spinal fixation, especially with osteoporosis. Little consistency exists among various tapping techniques. Pedicle screws are often prepared with taps of a smaller diameter, which can further exacerbate inconsistency. The objective of this study was to determine whether a mismatch between tap thread depth (D) and thread pitch (P) and screw D and P affects fixation when under-tapping in osteoporotic bone. This study is a polyurethane foam block biomechanical analysis. A foam block osteoporotic bone model was used to compare pullout strength of pedicle screws with a 5.3 nominal diameter tap of varying D's and P's. Blocks were sorted into seven groups: (1) probe only; (2) 0.5-mm D, 1.5-mm P tap; (3) 0.5-mm D, 2.0-mm P tap; (4) 0.75-mm D, 2.0-mm P tap; (5) 0.75-mm D, 2.5-mm P tap; (6) 0.75-mm D, 3.0-mm P tap; and (7) 1.0-mm D, 2.5-mm P tap. A pedicle screw, 6.5 mm in diameter and 40 mm in length, was inserted to a depth of 40 mm. Axial pullout testing was performed at a rate of 5 mm/min on 10 blocks from each group. No significant difference was noted between groups under axial pullout testing. The mode of failure in the probe-only group was block fracture, occurring in 50% of cases. Among the other six groups, only one screw failed because of block fracture. The other 59 failed because of screw pullout. In an osteoporotic bone model, changing the D or P of the tap has no statistically significant effect on axial pullout. Osteoporotic bone might render tap features marginal. Our findings indicate that changing the characteristics of the tap D and P does not help with pullout strength in an osteoporotic model. The high rate of fracture in the probe-only group might imply the potential benefit of tapping to prevent catastrophic failure of bone. Copyright © 2016 Elsevier Inc. All rights reserved.

Esthetic considerations for the treatment of the edentulous maxilla based on current informatic alternatives: a case report.

PubMed

Rodríguez-Tizcareño, Mario H; Barajas, Lizbeth; Pérez-Gásque, Marisol; Gómez, Salvador

2012-06-01

This report presents a protocol used to transfer the virtual treatment plan data to the surgical and prosthetic reality and its clinical application, bone site augmentation with computer-custom milled bovine bone graft blocks to their ideal architecture form, implant insertion based on image-guided stent fabrication, and the restorative manufacturing process through computed tomography-based software programs and navigation systems and the computer-aided design and manufacturing techniques for the treatment of the edentulous maxilla.

Does Combined Spinal Epidural Anesthesia Decrease the Morbidity of Iliac Block Bone Grafting for Deficient Alveolar Ridges Compared With General Anesthesia?

PubMed

Cansiz, Erol; Gultekin, B Alper; Sitilci, Tolga; Isler, S Cemil

2016-12-01

To evaluate the morbidity of iliac block bone grafting performed under general anesthesia (GA) or combined spinal epidural anesthesia (CSEA). We implemented a retrospective study including patients who underwent anterior iliac block bone grafting for deficient maxillary alveolar ridges. The anesthetic technique (GA or CSEA) was the primary predictor variable. The outcome variables were pain, gait disturbance, neurosensory disturbance (0 to 5 weeks), vomiting tendency (0 to 7 days), and postoperative hospitalization period (0 to 2 days). The sample comprised 22 patients, with 10 in the GA group and 12 in the CSEA group. No surgical complications except sensory disturbance in 2 patients were observed during the study period. Pain during initial healing (P < .001), the gait disturbance rate at 3 weeks after surgery (P = .003), and the vomiting tendency on the day of surgery (P < .001) were significantly higher in the GA group than in the CSEA group; all variables showed significant improvement with time in both groups. The postoperative hospitalization period was also significantly longer for the GA group than for the CSEA group (P < .001). No significant difference was observed between groups with regard to neurosensory disturbance. Iliac block bone grafting for deficient maxillary ridges can be successful under both GA and CSEA, although CSEA results in less pain and vomiting and early recovery, thus increasing patient comfort. Copyright © 2016 American Association of Oral and Maxillofacial Surgeons. Published by Elsevier Inc. All rights reserved.

Histomorphometric analysis following augmentation of the posterior mandible using cancellous bone-block allograft.

PubMed

Nissan, Joseph; Marilena, Vered; Gross, Ora; Mardinger, Ofer; Chaushu, Gavriel

2011-06-15

The present study was conducted to histologically and histomorphometrically evaluate the application of cancellous bone-block allografts for the augmentation of the posterior atrophic mandible. Twenty-four consecutive patients underwent augmentation with cancellous bone-block allografts in the posterior mandible. A bony deficiency of at least 3 mm horizontally and/or vertically according to CT para-axial reconstruction served as inclusion criteria. Following 6 months, 85 implants were placed and a cylindrical sample core was collected. All specimens were prepared for histological and histomorphometrical examination. Implant survival rate was 95.3%. Follow-up ranged 12-66 months (mean 43 ± 19 months). The mean newly formed bone was 44 ± 28%, that of the residual cancellous bone-block allograft 29 ± 24%, and of the marrow and connective tissue 27 ± 21%. Statistically significant histomorphometric differences regarding newly formed bone (69% vs. 31%, p = 0.05) were found between younger (< 45 years) and older (> 45 years) patients, respectively. Histomorphometric differences regarding residual cancellous bone-block allograft (17% vs. 35%) and of the marrow and connective tissue (14% vs. 34%) were not statistically significant. Cancellous bone-block allograft is biocompatible and osteoconductive, permitting new bone formation following augmentation of extremely atrophic posterior mandible with a two-stage implant placement procedure. New bone formation was age-dependent. Copyright © 2011 Wiley Periodicals, Inc.

Evaluation of Vertical Bone Regeneration Using Block and Particulate Forms of Bio-Oss Bone Graft: A Histologic Study in the Rabbit Mandible.

PubMed

Veis, Alexander; Dabarakis, Nikolaos; Koutrogiannis, Christos; Barlas, Irodis; Petsa, Elina; Romanos, Georgios

2015-06-01

The aim of the present study was to evaluate histologically vertical bone regeneration outcomes after using bovine bone graft material in block and granular forms. The buccal bony plates of the outer mandibles of 10 New Zealand rabbits received Bio-Oss blocks that were immobilized using orthopedic mini-plates, and another 10 received granular forms that were gently packed and stabilized into the custom-made perforated metallic cubes. The mean graft area (GA), new bone area (NBA), bone-to-graft contact (BGC), and maximum vertical height reached by the new bone development (MVH) were histometrically evaluated and showed no significant differences between 2 graft types. The new bone was observed mostly close to the basal bone and developed penetrating the trabecular scaffold in the form of seams that covered the intralumen surfaces of the block type graft, while in the granular graft type the new bone was observed to grow between the graft particles usually interconnecting them. Either form of Bio-Oss was capable of providing considerable vertical bone augmentation.

Measurement of bone mineral density in the tunnel regions for anterior cruciate ligament reconstruction by dual-energy X-ray absorptiometry, computed tomography scan, and the immersion technique based on Archimedes' principle.

PubMed

Tie, Kai; Wang, Hua; Wang, Xin; Chen, Liaobin

2012-10-01

To determine, for anterior cruciate ligament (ACL) reconstruction, whether the bone mineral density (BMD) of the femoral tunnel was higher than that of the tibial tunnel, to provide objective evidence for choosing the appropriate diameter of interference screws. Two groups were enrolled. One group comprised 30 normal volunteers, and the other comprised 9 patients with ACL rupture. Dual-energy X-ray absorptiometry was used to measure the BMD of the femoral and tibial tunnel regions of the volunteers' right knees by choosing a circular area covering the screw fixation region. The knees were also scanned by spiral computed tomography (CT), and the 3-dimensional reconstruction technique was used to determine the circular sections passing through the longitudinal axis of the femoral and tibial tunnels. Grayscale CT values of the cross-sectional area were measured. Cylindrical cancellous bone blocks were removed from the femoral and tibial tunnels during the ACL reconstruction for the patients. The volumetric BMD of the bone blocks was measured using a standardized immersion technique according to Archimedes' principle. As measured by dual-energy X-ray absorptiometry, the BMD of the femoral and tibial tunnel regions was 1.162 ± 0.034 g/cm(2) and 0.814 ± 0.038 g/cm(2), respectively (P < .01). The CT value of the femoral tunnel region was 211.7 ± 11.5 Hounsfield units, and the value of the tibial tunnel region was 104.9 ± 7.4 Hounsfield units (P < .01). The volumetric BMD of the bone block from the femoral tunnel (2.80 ± 0.88 g/cm(3)) was higher than the value from the tibial tunnel (1.88 ± 0.59 g/cm(3)) (P < .01). Comparing the data between male and female patients, we found no significant difference in both femoral and tibial tunnel regions. For ACL reconstruction, the BMD of the femoral tunnel is higher than that of the tibial tunnel. This implies that a proportionally larger-diameter interference screw should be used for fixation in the proximal tibia than that used for fixation in the distal femur. Level IV, therapeutic case series. Copyright © 2012 Arthroscopy Association of North America. Published by Elsevier Inc. All rights reserved.

Bone marrow induced osteogenesis in hydroxyapatite and calcium carbonate implants.

PubMed

Vuola, J; Göransson, H; Böhling, T; Asko-Seljavaara, S

1996-09-01

In this experimental study, blocks of natural coral (calcium carbonate) and its structurally similar derivate in the form of hydroxyapatite (calcium phosphate) were implanted in rat latissimus dorsi muscle with autogenous bone marrow to compare their bone-forming capability. A block without marrow placed in the opposite latissimus muscle served as a control. The animals were killed at 3, 6 and 12 weeks and, in the hydroxyapatite group, also at 24 weeks. The sections were analysed histologically and histomorphometrically. Bone was found only in implants containing bone marrow. Bone formation was significantly (p < 0.05) higher in coral than in hydroxyapatite implants at 3 weeks (10.8% versus 4.8%) and at 12 weeks (13.7% versus 6.3%, bone/total original block area). At 12 weeks all the coral implants had lost their original structure, and the cross-sectional area of the block had diminished to 40% of the original area.

Histomorphometric analysis after maxillary sinus floor augmentation using cancellous bone-block allograft.

PubMed

Chaushu, Gavriel; Vered, Marilena; Mardinger, Ofer; Nissan, Joseph

2010-08-01

Cancellous bone-block allografts may contribute to improved initial implant stability during sinus augmentation in cases with posterior atrophic maxillary ridge height < or =4 mm. The present study histologically and histomorphometrically evaluates the application of cancellous bone-block allografts for maxillary sinus-floor augmentation. Thirty-one consecutive patients, 16 females and 15 males (age range, 25 to 65 years; mean age: 54 +/- 9 years) underwent sinus augmentation with simultaneous implant placement with cancellous bone-block allografts. After 9 months, a second-stage surgery was performed. The previous window location was determined. A cylindrical sample core was collected. All specimens were prepared for histologic and histomorphometric examinations. Seventy-two of 76 implants were clinically osseointegrated (94.7%). All patients received a fixed implant-supported prosthesis. The mean t values of newly formed bone, residual cancellous bone-block allograft, marrow and connective tissue were 26.1% +/- 15% (range: 10% to 58%); 24.7% +/- 19.4% (range: 0.6% to 71%), and 49.2% +/- 20.4% (range: 14.9% to 78.9%), respectively. No statistically significant histomorphometric differences regarding newly formed bone were found between genders (27.02% in males versus 25.68% in females; P = 0.446), ages (29.82% in subjects < or =40 years old versus 24.43% in subjects >40 years old; P = 0.293), presence of membrane perforations (25.5% in non-perforated sinuses versus 27.3% in perforated sinuses; P = 0.427), and residual alveolar bone height (25.85% for residual alveolar bone height <2 mm versus 26.48% for residual alveolar bone height of 2 to 4 mm; P = 0.473). The cancellous bone-block allograft is biocompatible and osteoconductive and permits new bone formation in sinus augmentations with simultaneous implant-placement procedures in extremely atrophic posterior maxillae.

[Recent advances in treatment of aseptic femoral shaft nonunion].

PubMed

Zhang, Wei; Chen, Hua; Tang, Peifu

2018-05-01

To review the recent advances in treatment of aseptic femoral shaft nonunion. The clinical studies about the treatments of aseptic femoral shaft nonunion in recent years were widely reviewed and analyzed. There are several surgical methods for aseptic femoral shaft nonunion. Due to uncertain clinical outcome, dynamization of nail should be carefully selected. The exchange nailing is suitable for the hypertrophic nonunion of the isthmal femoral shaft fracture. The exchange lateral plating is suitable for nonunion with obvious malformation. However, wave plate or dual plate should be chosen when the bone nonuinon is combined with the medial defect. The augmentation plating improves the success rate of nailing for femoral shaft nonunion, but it should be carefully selected for patients with obvious deformity or bone defect. Ilizarov technique is suitable for various bone nonunion, especially with complicated or large segmental bone defects. Induced membrane technique is also an important method for the treatment of bone nonunion with large bone defects. The clinical efficacy of the blocking screw remains to be supported by further evidence. Biological stimulants are mainly used for atrophic nonunion, and the clinical efficacy of them alone are still controversial. Due to lack of comparative studies between different surgical methods, the orthopedist should choose the appropriate treatment according to the individual situations of the patient and the types of bone nonunion.

Evaluation of carbonate apatite blocks fabricated from dicalcium phosphate dihydrate blocks for reconstruction of rabbit femoral and tibial defects.

PubMed

Kanazawa, Masayuki; Tsuru, Kanji; Fukuda, Naoyuki; Sakemi, Yuta; Nakashima, Yasuharu; Ishikawa, Kunio

2017-06-01

This study aimed to evaluate in vivo behavior of a carbonate apatite (CO 3 Ap) block fabricated by compositional transformation via a dissolution-precipitation reaction using a calcium hydrogen phosphate dihydrate [DCPD: CaHPO 4 ·2H 2 O] block as a precursor. These blocks were used to reconstruct defects in the femur and tibia of rabbits, using sintered dense hydroxyapatite (HAp) blocks as the control. Both the CO 3 Ap and HAp blocks showed excellent tissue response and good osteoconductivity. HAp block maintained its structure even after 24 weeks of implantation, so no bone replacement of the implant was observed throughout the post-implantation period in either femoral or tibial bone defects. In contrast, CO 3 Ap was resorbed with increasing time after implantation and replaced with new bone. The CO 3 Ap block was resorbed approximately twice as fast at the metaphysis of the proximal tibia than at the epiphysis of the distal femur. The CO 3 Ap block was resorbed at an approximately linear change over time, with complete resorption was estimated by extrapolation of data at approximately 1-1.5 years. Hence, the CO 3 Ap block fabricated in this study has potential value as an ideal artificial bone substitute because of its resorption and subsequent replacement by bone.

The biomechanical strength of a hardware-free femoral press-fit method for ACL bone-tendon-bone graft fixation.

PubMed

Arnold, M P; Burger, L D; Wirz, D; Goepfert, B; Hirschmann, M T

2017-04-01

The purpose was to investigate graft slippage and ultimate load to failure of a femoral press-fit fixation technique for anterior cruciate ligament (ACL) reconstruction. Nine fresh-frozen knees were used. Standardized harvesting of the B-PT-B graft was performed. The femora were cemented into steel rods, and a tunnel was drilled outside-in into the native ACL footprint and expanded using a manual mill bit. The femoral bone block was fixed press-fit. To pull the free end of the graft, it was fixed to a mechanical testing machine using a deep-freezing technique. A motion capture system was used to assess three-dimensional micro-motion. After preconditioning of the graft, 1000 cycles of tensile loading were applied. Finally, an ultimate load to failure test was performed. Graft slippage in mm ultimate load to failure as well as type of failure was noted. In six of the nine measured specimens, a typical pattern of graft slippage was observed during cyclic loading. For technical reasons, the results of three knees had to be discarded. 78.6 % of total graft slippage occurred in the first 100 cycles. Once the block had settled, graft slippage converged to zero, highlighting the importance of initial preconditioning of the graft in the clinical setting. Graft slippage after 1000 cycles varied around 3.4 ± 3.2 mm (R = 1.3-9.8 mm) between the specimens. Ultimate loading (n = 9) revealed two characteristic patterns of failure. In four knees, the tendon ruptured, while in five knees the bone block was pulled out of the femoral tunnel. The median ultimate load to failure was 852 N (R = 448-1349 N). The implant-free femoral press-fit fixation provided adequate primary stability with ultimate load to failure pull forces at least equal to published results for interference screws; hence, its clinical application is shown to be safe.

Vertical ridge augmentation using xenogenous bone blocks: a comparison between the flap and tunneling procedures.

PubMed

Xuan, Feng; Lee, Chun-Ui; Son, Jeong-Seog; Fang, Yiqin; Jeong, Seung-Mi; Choi, Byung-Ho

2014-09-01

Previous studies have shown that the subperiosteal tunneling procedure in vertical ridge augmentation accelerates healing after grafting and prevents graft exposure, with minor postoperative complications. It is conceivable that new bone formation would be greater with the tunneling procedure than with the flap procedure, because the former is minimally invasive. This hypothesis was tested in this study by comparing new bone formation between the flap and tunneling procedures after vertical ridge augmentation using xenogenous bone blocks in a canine mandible model. Two Bio-Oss blocks were placed on the edentulous ridge in each side of the mandibles of 6 mongrel dogs. The blocks in each side were randomly assigned to grafting with a flap procedure (flap group) or grafting with a tunneling procedure (tunneling group). The mean percentage of newly formed bone within the block was 15.3 ± 6.6% in the flap group and 46.6 ± 23.4% in the tunneling group. Based on data presented in this study, when a tunneling procedure is used to place xenogenous bone blocks for vertical ridge augmentation, bone formation in the graft sites is significantly greater than when a flap procedure is used. Copyright © 2014 American Association of Oral and Maxillofacial Surgeons. Published by Elsevier Inc. All rights reserved.

New technique targeting the C5 nerve root proximal to the traditional interscalene sonoanatomical approach is analgesic for outpatient arthroscopic shoulder surgery.

PubMed

Dobie, Katherine H; Shi, Yaping; Shotwell, Matthew S; Sandberg, Warren S

2016-11-01

Regional anesthesia and analgesia for shoulder surgery is most commonly performed via interscalene nerve block. We developed an ultrasound-guided technique that specifically targets the C5 nerve root proximal to the traditional interscalene block and assessed its efficacy for shoulder analgesia. Prospective case series. Vanderbilt Bone and Joint Surgery Center. Patients undergoing shoulder arthroscopy at an ambulatory surgery center. Thirty-five outpatient shoulder arthroscopy patients underwent an analgesic nerve block using a new technique where ultrasound visualization of the C5 nerve root served as the primary target at a level proximal to the traditional interscalene approach. The block was performed with 15mL of 0.5% plain ropivicaine. Post anesthesia care unit pain scores, opioid consumption, hand strength, and duration of block were recorded. Cadaver dissection after injection with methylene blue confirmed that the primary target under ultrasound visualization was the C5 nerve root. Pain scores revealed 97% patients had 0/10 pain at arrival to PACU, with 91% having a pain score of 3/10 or less at discharge from PACU. Medical Research Council (MRC) hand strength mean (SD) score was 4.17 (0.92) on a scale of 1-5. The mean (SD) duration of the block was 13.9 (3.5) hours. A new technique for ultrasound-guided blockade at the level of the C5 nerve root proximal to the level of the traditional interscalene block is efficacious for shoulder post-operative pain control. Copyright © 2016 Elsevier Inc. All rights reserved.

[Construction of porous hydroxyapatite (HA) block loaded with cultured chondrocytes].

PubMed

Yan, M; Dang, G

1999-07-01

To construct a kind of bone healing enhancing implant with cultured chondrocytes bound to hydroxyapatite (HA). Chondrocytes were obtained from the costicartilage of rat and were cultured on the porous HA blocks, 3 mm x 3 mm x 4 mm size, for three and seven days. Scanning electron micrograph was taken to show whether the cells grew outside and inside the pore of HA block. The cells cultured on tiny glass sheet for 2 days were used to prove where the cells come from by in situ hybridization technique with alpha1 (II) cDNA probe. Scanning electron micrographs showed that the pores of the HA surface and inside of the blocks are filled with cultured cells, especially the longer cultured block. The cells were chondrocytes confirmed by in situ hybridization. The porous HA can be used as cell cultured substrate and chondrocyte can adhere and proliferate inside the porous HA block.

Piezosurgery in Bone Augmentation Procedures Previous to Dental Implant Surgery: A Review of the Literature

PubMed Central

Magrin, Gabriel Leonardo; Sigua-Rodriguez, Eder Alberto; Goulart, Douglas Rangel; Asprino, Luciana

2015-01-01

The piezosurgery has been used with increasing frequency and applicability by health professionals, especially those who deal with dental implants. The concept of piezoelectricity has emerged in the nineteenth century, but it was applied in oral surgery from 1988 by Tomaso Vercellotti. It consists of an ultrasonic device able to cut mineralized bone tissue, without injuring the adjacent soft tissue. It also has several advantages when compared to conventional techniques with drills and saws, such as the production of a precise, clean and low bleed bone cut that shows positive biological results. In dental implants surgery, it has been used for maxillary sinus lifting, removal of bone blocks, distraction osteogenesis, lateralization of the inferior alveolar nerve, split crest of alveolar ridge and even for dental implants placement. The purpose of this paper is to discuss the use of piezosurgery in bone augmentation procedures used previously to dental implants placement. PMID:26966469

Efficacy of cancellous block allograft augmentation prior to implant placement in the posterior atrophic mandible.

PubMed

Nissan, Joseph; Ghelfan, Oded; Mardinger, Ofer; Calderon, Shlomo; Chaushu, Gavriel

2011-12-01

The present study evaluated the outcome of ridge augmentation with cancellous freeze-dried block bone allografts in the posterior atrophic mandible followed by placement of dental implants. A bony deficiency of at least 3 mm, horizontally, vertically, or both, according to computerized tomography (CT) para-axial reconstruction served as inclusion criteria. Implants were inserted after a healing period of 6 months. Bone measurements were taken prior to bone augmentation, during implant placement, and at second-stage surgery. Marginal bone loss and crown-to-implant ratio were also measured. Twenty-nine cancellous allogeneic bone blocks were placed in 21 patients. The mean follow-up was 37 months. Bone block survival rate was 79.3%. Mean horizontal and vertical bone gains were 5.6 and 4.3 mm, respectively. Mean buccal bone resorption was 0.5 mm at implant placement and 0.2 mm at second-stage surgery. A total of 85 implants were placed. Mean bone thickness buccal to the implant neck was 2.5 mm at implant placement and 2.3 mm at second-stage surgery. There was no evidence of vertical bone loss between implant placement and second-stage surgery. Implant survival rate was 95.3%. All patients received a fixed implant-supported prosthesis. At the last follow-up, the mean marginal bone loss was 0.5 mm. The mean crown-to-implant ratio was 0.96. Implant placement in the posterior atrophic mandible following augmentation with cancellous freeze-dried bone block allografts may be regarded as a viable treatment alternative. © 2009 Wiley Periodicals, Inc.

Treatment of Spinal Tuberculosis by Debridement, Interbody Fusion and Internal Fixation via Posterior Approach Only.

PubMed

Tang, Ming-xing; Zhang, Hong-qi; Wang, Yu-xiang; Guo, Chao-feng; Liu, Jin-yang

2016-02-01

Surgical treatment for spinal tuberculosis includes focal tuberculosis debridement, segmental stability reconstruction, neural decompression and kyphotic deformity correction. For the lesions mainly involved anterior and middle column of the spine, anterior operation of debridement and fusion with internal fixation has been becoming the most frequently used surgical technique for the spinal tuberculosis. However, high risk of structural damage might relate with anterior surgery, such as damage in lungs, heart, kidney, ureter and bowel, and the deformity correction is also limited. Due to the organs are in the front of spine, there are less complications in posterior approach. Spinal pedicle screw passes through the spinal three-column structure, which provides more powerful orthopedic forces compared with the vertebral body screw, and the kyphotic deformity correction effect is better in posterior approach. In this paper, we report a 68-year-old male patient with thoracic tuberculosis who underwent surgical treatment by debridement, interbody fusion and internal fixation via posterior approach only. The patient was placed in prone position under general anesthesia. Posterior midline incision was performed, and the posterior spinal construction was exposed. Then place pedicle screw, and fix one side rod temporarily. Make the side of more bone destruction and larger abscess as lesion debridement side. Resect the unilateral facet joint, and retain contralateral structure integrity. Protect the spinal cord, nerve root. Clear sequestrum, necrotic tissue, abscess of paravertebral and intervertebral space. Specially designed titanium mesh cages or bone blocks were implanted into interbody. Fix both side rods and compress both sides to make the mesh cages and bone blocks tight. Reconstruct posterior column structure with allogeneic bone and autologous bone. Using this technique, the procedures of debridement, spinal cord decompression, deformity correction, bone grafting, and internal fixation can be completed with only one incision and surgical position, and the deformity correction efficiency is higher than anterior surgery. © 2016 Chinese Orthopaedic Association and John Wiley & Sons Australia, Ltd.

Large Bone Vertical Augmentation Using a Three-Dimensional Printed TCP/HA Bone Graft: A Pilot Study in Dog Mandible.

PubMed

Carrel, Jean-Pierre; Wiskott, Anselm; Scherrer, Susanne; Durual, Stéphane

2016-12-01

Osteoflux is a three-dimensional printed calcium phosphate porous structure for oral bone augmentation. It is a mechanically stable scaffold with a well-defined interconnectivity and can be readily shaped to conform to the bone bed's morphology. An animal experiment is reported whose aim was to assess the performance and safety of the scaffold in promoting vertical growth of cortical bone in the mandible. Four three-dimensional blocks (10 mm length, 5 mm width, 5 mm height) were affixed to edentulous segments of the dog's mandible and covered by a collagen membrane. During bone bed preparation, particular attention was paid not to create defects 0.5 mm or more so that the real potential of the three-dimensional block in driving vertical bone growth can be assessed. Histomorphometric analyses were performed after 8 weeks. At 8 weeks, the three-dimensional blocks led to substantial vertical bone growth up to 4.5 mm from the bone bed. Between 0 and 1 mm in height, 44% of the surface was filled with new bone, at 1 to 3 mm it was 20% to 35%, 18% at 3 to 4, and ca. 6% beyond 4 mm. New bone was evenly distributed along in mesio-distal direction and formed a new crest contour in harmony with the natural mandibular shape. After two months of healing, the three-dimensional printed blocks conducted new bone growth above its natural bed, up to 4.5 mm in a canine mandibular model. Furthermore, the new bone was evenly distributed in height and density along the block. These results are very promising and need to be further evaluated by a complete powerful study using the same model. © 2016 Wiley Periodicals, Inc.

Two dimensional alveolar ridge augmentation using particulate hydroxyapatite and collagen membrane: A case report

PubMed Central

Singh, Aparna; Daing, Anika; Anand, Vishal; Dixit, Jaya

2014-01-01

Background Ridge augmentation procedures require bone regeneration outside of the existing bony walls or housing and are therefore often considered to be the most challenging surgical procedures. The bony deficiencies can be managed with GBR techniques involving bone grafting material and membrane while vertical augmentation may require the use of space-creating support mechanisms. Non-degradable membranes have been used for ridge augmentation with encouraging results however; requirement of second surgery for its removal and associated infection on exposure may compromise the desired results. These problems can be overcome by employing resorbable collagen membranes. Different bone graft materials are also used in combination with resorbable membranes, for prevention of membrane collapse and maintenance of space, as they lack sufficient rigidity. Particulate hydroxyapatite bone graft may be better alternative, because it treats the underlying bone defect to restore the natural support of the tissue architecture. Moreover, its use avoids potential donor site complications associated with autogenous block grafts. Method Patient described in this report presented with missing right maxillary incisor with ridge deficiency. A treatment approach involving localised ridge augmentation with particulate hydroxyapatite and collagen membrane was used. Result Six month post-operative periapical radiograph demonstrated a significant vertical bone fill. Conclusion The clinical and radiographic findings of the present case suggests that HA in conjunction with a resorbable collagen membrane may be an acceptable alternative to the autogenous block graft and non-resorbable membrane in the treatment of compromised alveolar ridge deficiencies. PMID:25737935

Evaluation of novel resorbable membranes for bone augmentation in a rat model.

PubMed

Zeng, Ni; van Leeuwen, Anne; Yuan, Huipin; Bos, Ruud R M; Grijpma, Dirk W; Kuijer, Roel

2016-02-01

Our study compared two novel, biodegradable poly(trimethylene carbonate) (PTMC) barrier membranes to clinically applied barrier membranes in maintaining volume of block autologous bone grafts in a rat mandible model. Two hundred and forty rats were included in this study. Block autologous bone grafts of 5 mm in diameter were harvested from the mandibular angles and transplanted onto the contralateral side. The bone grafts were either covered with a membrane or left uncovered. The applied membranes included pure PTMC membranes, biphasic calcium phosphate (BCP) incorporated PTMC composite membranes, expanded poly(tetrafluoroethylene) (e-PTFE) membranes (Tex) and collagen membranes (Geistlich Bio-Gide). After 2, 4 and 12 weeks, the rat mandibles were retrieved and analysed by histological evaluation and μCT quantification. The histological evaluation revealed that in time the block autologous bone graft was well integrated to the recipient bone via gradually maturing newly formed bone and did not show signs of resorption, independent of membrane coverage or types of membrane. μCT quantification showed the volume of the bone graft and recipient bone together was maintained by new bone formation and recipient bone resorption. Our study showed that the use of PTMC membranes and PTMC-BCP composite membranes resulted in similar bone remodelling to the collagen membranes and e-PTFE membranes and that the use of barrier membranes did not interfere with bone remodelling of the bone grafts and recipient bones. However, the used barrier membranes seemed not to contribute in maintaining the volume of block autologous bone grafts. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Volume changes of autogenous bone after sinus lifting and grafting procedures: a 6-year computerized tomographic follow-up.

PubMed

Sbordone, Carolina; Toti, Paolo; Guidetti, Franco; Califano, Luigi; Bufo, Pantaleo; Sbordone, Ludovico

2013-04-01

To evaluate long-term bone remodelling of autografts over time (annually, for 6 years), comparing the block and particulate bone procedures for sinus floor elevation, as well as to evaluate the survival of positioned dental implants. Twenty-three sinus lift procedures with autogenous bone were performed: seven sinus lift procedures using particulate graft and 10 with block autogenous bone were performed in 17 patients. Employing a software program, pre- and post-surgical computerized tomography (CT) scans were used to compare the volume (V) and density (D) of inlay grafts over time (up to 6 years), and to determine the percentage of remaining bone (%R). All variable (V, D and %R) measurements were then compared statistically. At the 6-year survey for block form, a resorption of 21.5% was seen, whereas for particulate grafts there was a resorption of 39.2%. Both groups exhibited bone remodelling between the first and second follow-up which was significant regarding volume for the block form and regarding density for the particulate group. During the initial period of healing, the cortico-cancellous block bone grafted into the maxillary sinus underwent a negative remodelling of the volume, which is most probably due to graft cortex resorption, coupled with, primarily, an increase in density in the spongious area; for the particulate grafts, significant augmentations in density were obtained. The lack of significant differences among volumes was due to the wide degree of dispersion of the data. The rough data presented in this paper seem to support the use of a bone-block grafting procedure in maxillary sinus augmentation. Copyright © 2012 European Association for Cranio-Maxillo-Facial Surgery. Published by Elsevier Ltd. All rights reserved.

Pullout strength of bone-patellar tendon-bone allograft bone plugs: a comparison of cadaver tibia and rigid polyurethane foam.

PubMed

Barber, F Alan

2013-09-01

To compare the load-to-failure pullout strength of bone-patellar tendon-bone (BPTB) allografts in human cadaver tibias and rigid polyurethane foam blocks. Twenty BPTB allografts were trimmed creating 25 mm × 10 mm × 10 mm tibial plugs. Ten-millimeter tunnels were drilled in 10 human cadaver tibias and 10 rigid polyurethane foam blocks. The BPTB anterior cruciate ligament allografts were inserted into these tunnels and secured with metal interference screws, with placement of 10 of each type in each material. After preloading (10 N), cyclic loading (500 cycles, 10 to 150 N at 200 mm/min) and load-to-failure testing (200 mm/min) were performed. The endpoints were ultimate failure load, cyclic loading elongation, and failure mode. No difference in ultimate failure load existed between grafts inserted into rigid polyurethane foam blocks (705 N) and those in cadaver tibias (669 N) (P = .69). The mean rigid polyurethane foam block elongation (0.211 mm) was less than that in tibial bone (0.470 mm) (P = .038), with a smaller standard deviation (0.07 mm for foam) than tibial bone (0.34 mm). All BPTB grafts successfully completed 500 cycles. The rigid polyurethane foam block showed less variation in test results than human cadaver tibias. Rigid polyurethane foam blocks provide an acceptable substitute for human cadaver bone tibia for biomechanical testing of BPTB allografts and offer near-equivalent results. Copyright © 2013 Arthroscopy Association of North America. Published by Elsevier Inc. All rights reserved.

Implant-supported restoration of congenitally missing teeth using cancellous bone block-allografts.

PubMed

Nissan, Joseph; Mardinger, Ofer; Strauss, Morris; Peleg, Michael; Sacco, Roberto; Chaushu, Gavriel

2011-03-01

Patients with congenitally missing teeth may present with undeveloped alveolar bone morphology, making implant reconstruction a challenge. The aim of the present study was to evaluate the outcome of dental implants after ridge augmentation with cancellous freeze-dried block bone allografts in patients with congenitally missing teeth. Twelve patients with a mean age of 21 ± 4 years, were included. Congenitally missing teeth included maxillary lateral incisors, a maxillary canine, and mandibular central and lateral incisors. A bony deficiency of ≥3 mm horizontally and ≤3 mm vertically according to computerized tomography served as inclusion criteria. Twenty-one implants were inserted after a healing period of 6 months. Five out of 21 implants were immediately restored. Bone measurements were taken before bone augmentation, during implant placement, and at second-stage surgery. Nineteen cancellous allogeneic bone-blocks were used. The mean follow-up time was 30 ± 16 months. Bone block and implant survival rates were 100% and 95.2%, respectively. Mean bone gain was statistically significant (P < .001): 5 ± 0.5 mm horizontally and 2 ± 0.5 mm vertically. All of the patients received a fixed implant-supported prosthesis. Soft tissue complications occurred in 4 patients (30%). Complications after cementation of the crowns were seen in 1 implant (4.8%). All implants remained clinically osseointegrated at the end of the follow-up examination. There was no crestal bone loss around the implants beyond the first implant thread. Cancellous bone block-allografts can be used successfully for implant-supported restorations in patients with congenitally missing teeth. Copyright © 2011 Mosby, Inc. All rights reserved.

Analysis of complications following augmentation with cancellous block allografts.

PubMed

Chaushu, Gavriel; Mardinger, Ofer; Peleg, Michael; Ghelfan, Oded; Nissan, Joseph

2010-12-01

Bone grafting may be associated with soft and hard tissue complications. Recipient site complications encountered using cancellous block allografts for ridge augmentation are analyzed. A total of 101 consecutive patients (62 females and 39 males; mean age 44 ± 17 years) were treated with implant-supported restoration of 137 severe atrophic alveolar ridges augmented with cancellous bone-block allografts. Alveolar ridge deficiency locations were classified as anterior maxilla (n = 58); posterior maxilla (n = 32 sinuses); posterior mandible (n = 32); and anterior mandible (n = 15). A total of 271 rough-surface implants were placed. Recipient site complications associated with block grafting (infection, membrane exposure, incision line opening, perforation of mucosa over the grafted bone, partial graft failure, total graft failure, and implant failure) were recorded. Partial and total bone-block graft failure occurred in 10 (7%) and 11 (8%) of 137 augmented sites, respectively. Implant failure rate was 12 (4.4%) of 271. Soft tissue complications included membrane exposure (42 [30.7%] of 137); incision line opening (41 [30%] of 137); and perforation of the mucosa over the grafted bone (19 [14%] of 137). Infection of the grafted site occurred in 18 (13%) of 137 bone blocks. Alveolar ridge deficiency location had a statistically significant effect on the outcome of recipient site complications. More complications were noted in the mandible compared to the maxilla. Age and gender had no statistically significant effect. Failures caused by complications were rarely noted in association with cancellous block grafting. The incidence of complications in the mandible was significantly higher. Soft tissue complications do not necessarily result in total loss of cancellous block allograft.

The Presence of Thyroid-Stimulation Blocking Antibody Prevents High Bone Turnover in Untreated Premenopausal Patients with Graves' Disease.

PubMed

Cho, Sun Wook; Bae, Jae Hyun; Noh, Gyeong Woon; Kim, Ye An; Moon, Min Kyong; Park, Kyoung Un; Song, Junghan; Yi, Ka Hee; Park, Do Joon; Chung, June-Key; Cho, Bo Youn; Park, Young Joo

2015-01-01

Osteoporosis-related fractures are one of the complications of Graves' disease. This study hypothesized that the different actions of thyroid-stimulating hormone receptor (TSHR) antibodies, both stimulating and blocking activities in Graves' disease patients might oppositely impact bone turnover. Newly diagnosed premenopausal Graves' disease patients were enrolled (n = 93) and divided into two groups: patients with TSHR antibodies with thyroid-stimulating activity (stimulating activity group, n = 83) and patients with TSHR antibodies with thyroid-stimulating activity combined with blocking activity (blocking activity group, n = 10). From the stimulating activity group, patients who had matched values for free T4 and TSH binding inhibitor immunoglobulin (TBII) to the blocking activity group were further classified as stimulating activity-matched control (n = 11). Bone turnover markers BS-ALP, Osteocalcin, and C-telopeptide were significantly lower in the blocking activity group than in the stimulating activity or stimulating activity-matched control groups. The TBII level showed positive correlations with BS-ALP and osteocalcin levels in the stimulating activity group, while it had a negative correlation with the osteocalcin level in the blocking activity group. In conclusion, the activation of TSHR antibody-activated TSH signaling contributes to high bone turnover, independent of the actions of thyroid hormone, and thyroid-stimulation blocking antibody has protective effects against bone metabolism in Graves' disease.

Anaesthetic management for awake craniotomy in brain glioma resection: initial experience in Military Hospital Mohamed V of Rabat.

PubMed

Meziane, Mohammed; Elkoundi, Abdelghafour; Ahtil, Redouane; Guazaz, Miloudi; Mustapha, Bensghir; Haimeur, Charki

2017-01-01

The awake brain surgery is an innovative approach in the treatment of tumors in the functional areas of the brain. There are various anesthetic techniques for awake craniotomy (AC), including asleep-awake-asleep technique, monitored anesthesia care, and the recent introduced awake-awake-awake method. We describe our first experience with anesthetic management for awake craniotomy, which was a combination of these techniques with scalp nerve block, and propofol/rémifentanil target controlled infusion. A 28-year-oldmale underwent an awake craniotomy for brain glioma resection. The scalp nerve block was performed and a low sedative state was maintained until removal of bone flap. During brain glioma resection, the patient awake state was maintained without any complications. Once, the tumorectomy was completed, the level of anesthesia was deepened and a laryngeal mask airway was inserted. A well psychological preparation, a reasonable choice of anesthetic techniques and agents, and continuous team communication were some of the key challenges for successful outcome in our patient.

Periodontal tissue reaction to customized nano-hydroxyapatite block scaffold in one-wall intrabony defect: a histologic study in dogs

PubMed Central

Lee, Jung-Seok; Park, Weon-Yeong; Cha, Jae-Kook; Jung, Ui-Won; Kim, Chang-Sung; Lee, Yong-Keun

2012-01-01

Purpose This study evaluated histologically the tissue responses to and the effects of a customized nano-hydroxyapatite (n-HA) block bone graft on periodontal regeneration in a one-wall periodontal-defect model. Methods A customized block bone for filling in the standardized periodontal defect was fabricated from prefabricated n-HA powders and a polymeric sponge. Bilateral 4×4×5 mm (buccolingual width×mesiodistal width×depth), one-wall, critical-size intrabony periodontal defects were surgically created at the mandibular second and fourth premolars of five Beagle dogs. In each dog, one defect was filled with block-type HA and the other served as a sham-surgery control. The animals were sacrificed following an 8-week healing interval for clinical and histological evaluations. Results Although the sites that received an n-HA block showed minimal bone formation, the n-HA block was maintained within the defect with its original hexahedral shape. In addition, only a limited inflammatory reaction was observed at sites that received an n-HA block, which might have been due to the high stability of the customized block bone. Conclusions In the limitation of this study, customized n-HA block could provide a space for periodontal tissue engineering, with minimal inflammation. PMID:22586523

Periodontal tissue reaction to customized nano-hydroxyapatite block scaffold in one-wall intrabony defect: a histologic study in dogs.

PubMed

Lee, Jung-Seok; Park, Weon-Yeong; Cha, Jae-Kook; Jung, Ui-Won; Kim, Chang-Sung; Lee, Yong-Keun; Choi, Seong-Ho

2012-04-01

This study evaluated histologically the tissue responses to and the effects of a customized nano-hydroxyapatite (n-HA) block bone graft on periodontal regeneration in a one-wall periodontal-defect model. A customized block bone for filling in the standardized periodontal defect was fabricated from prefabricated n-HA powders and a polymeric sponge. Bilateral 4×4×5 mm (buccolingual width×mesiodistal width×depth), one-wall, critical-size intrabony periodontal defects were surgically created at the mandibular second and fourth premolars of five Beagle dogs. In each dog, one defect was filled with block-type HA and the other served as a sham-surgery control. The animals were sacrificed following an 8-week healing interval for clinical and histological evaluations. Although the sites that received an n-HA block showed minimal bone formation, the n-HA block was maintained within the defect with its original hexahedral shape. In addition, only a limited inflammatory reaction was observed at sites that received an n-HA block, which might have been due to the high stability of the customized block bone. In the limitation of this study, customized n-HA block could provide a space for periodontal tissue engineering, with minimal inflammation.

Cancellous bone block allografts for the augmentation of the anterior atrophic maxilla.

PubMed

Nissan, Joseph; Mardinger, Ofer; Calderon, Shlomo; Romanos, George E; Chaushu, Gavriel

2011-06-01

Pre-implant augmentative surgery is a prerequisite in many cases in the anterior maxilla to achieve a stable, long-term esthetic final result. The aim of the present study was to evaluate the outcome of ridge augmentation with cancellous freeze-dried block bone allografts in the anterior atrophic maxilla followed by placement of dental implants. Thirty-one consecutive patients were included in the study. A bony deficiency of at least 3 mm horizontally and up to 3 mm vertically according to computerized tomography (CT) served as inclusion criteria. Sixty-three implants were inserted after a healing period of 6 months. Nineteen of sixty-three implants were immediately restored. Bone measurements were taken prior to bone augmentation, during implant placement, and at second-stage surgery. Forty-six cancellous allogeneic bone blocks were used. The mean follow-up was 34 ± 16 months. Mean bone gain was 5 ± 0.5 mm horizontally, and 2 ± 0.5 mm vertically. Mean buccal bone resorption was 0.5 ± 0.5 mm at implant placement, and 0.2 ± 0.2 mm at second-stage surgery. Mean bone thickness buccal to the implant neck was 2.5 ± 0.5 mm at implant placement, and 2.3 ± 0.2 mm at second-stage surgery. There was no evidence of vertical bone loss between implant placement and second-stage surgery. Block and implant survival rates were 95.6 and 98%, respectively. All patients received a fixed implant-supported prosthesis. Cancellous block allografts appear to hold promise for grafting the anterior atrophic maxilla. © 2009 Wiley Periodicals, Inc.

Scaffolds for Bone Tissue Engineering: State of the art and new perspectives.

PubMed

Roseti, Livia; Parisi, Valentina; Petretta, Mauro; Cavallo, Carola; Desando, Giovanna; Bartolotti, Isabella; Grigolo, Brunella

2017-09-01

This review is intended to give a state of the art description of scaffold-based strategies utilized in Bone Tissue Engineering. Numerous scaffolds have been tested in the orthopedic field with the aim of improving cell viability, attachment, proliferation and homing, osteogenic differentiation, vascularization, host integration and load bearing. The main traits that characterize a scaffold suitable for bone regeneration concerning its biological requirements, structural features, composition, and types of fabrication are described in detail. Attention is then focused on conventional and Rapid Prototyping scaffold manufacturing techniques. Conventional manufacturing approaches are subtractive methods where parts of the material are removed from an initial block to achieve the desired shape. Rapid Prototyping techniques, introduced to overcome standard techniques limitations, are additive fabrication processes that manufacture the final three-dimensional object via deposition of overlying layers. An important improvement is the possibility to create custom-made products by means of computer assisted technologies, starting from patient's medical images. As a conclusion, it is highlighted that, despite its encouraging results, the clinical approach of Bone Tissue Engineering has not taken place on a large scale yet, due to the need of more in depth studies, its high manufacturing costs and the difficulty to obtain regulatory approval. PUBMED search terms utilized to write this review were: "Bone Tissue Engineering", "regenerative medicine", "bioactive scaffolds", "biomimetic scaffolds", "3D printing", "3D bioprinting", "vascularization" and "dentistry". Copyright © 2017 Elsevier B.V. All rights reserved.

Piezoelectric osteotomy for intraoral harvesting of bone blocks.

PubMed

Sohn, Dong-Seok; Ahn, Mi-Ra; Lee, Won-Hyuk; Yeo, Duk-Sung; Lim, So-Young

2007-04-01

Grafting with intraoral bone blocks is a good way to reconstruct severe horizontal and vertical bone resorption in future implant sites. The Piezosurgery System (Mectron) creates an effective osteotomy with minimal or no trauma to soft tissue, in contrast to conventional surgical burs or saws. In addition, piezoelectric surgery produces less vibration and noise because it uses microvibration, in contrast to the macrovibration and extreme noise that occur with a surgical saw or bur. Microvibration and reduced noise minimize a patient's psychologic stress and fear during osteotomy under local anesthesia. The purpose of this article is to describe the harvesting of intraoral bone blocks using the piezoelectric surgery device.

In Vivo Evaluation of 3D-Printed Polycaprolactone Scaffold Implantation Combined with β-TCP Powder for Alveolar Bone Augmentation in a Beagle Defect Model

PubMed Central

Park, Su A.; Lee, Hyo-Jung; Kim, Keun-Suh; Lee, Jung-Tae; Kim, Sung-Yeol; Chang, Na-Hee

2018-01-01

Insufficient bone volume is one of the major challenges encountered by dentists after dental implant placement. This study aimed to evaluate the efficacy of a customized three-dimensional polycaprolactone (3D PCL) scaffold implant fabricated with a 3D bio-printing system to facilitate rapid alveolar bone regeneration. Saddle-type bone defects were surgically created on the healed site after extracting premolars from the mandibles of four beagle dogs. The defects were radiologically examined using computed tomography for designing a customized 3D PCL scaffold block to fit the defect site. After fabricating 3D PCL scaffolds using rapid prototyping, the scaffolds were implanted into the alveolar bone defects along with β-tricalcium phosphate powder. In vivo analysis showed that the PCL blocks maintained the physical space and bone conductivity around the defects. In addition, no inflammatory infiltrates were observed around the scaffolds. However, new bone formation occurred adjacent to the scaffolds, rather than directly in contact with them. More new bone was observed around PCL blocks with 400/1200 lattices than around blocks with 400/400 lattices, but the difference was not significant. These results indicated the potential of 3D-printed porous PCL scaffolds to promote alveolar bone regeneration for defect healing in dentistry. PMID:29401707

The effect of implant design and bone quality on insertion torque, resonance frequency analysis, and insertion energy during implant placement in low or low- to medium-density bone.

PubMed

Wang, Tong-Mei; Lee, Ming-Shu; Wang, Juo-Song; Lin, Li-Deh

2015-01-01

This study investigated the effect of implant design and bone quality on insertion torque (IT), implant stability quotient (ISQ), and insertion energy (IE) by monitoring the continuous change in IT and ISQ while implants were inserted in artificial bone blocks that simulate bone of poor or poor-to-medium quality. Polyurethane foam blocks (Sawbones) of 0.16 g/cm³ and 0.32 g/cm³ were respectively used to simulate low density and low- to medium-density cancellous bone. In addition, some test blocks were laminated with a 1-mm 0.80 g/cm³ polyurethane layer to simulate cancellous bone with a thin cortical layer. Four different implants (Nobel Biocare Mk III-3.75, Mk III-4.0, Mk IV-4.0, and NobelActive-4.3) were placed into the different test blocks in accordance with the manufacturer's instructions. The IT and ISQ were recorded at every 0.5-mm of inserted length during implant insertion, and IE was calculated from the torque curve. The peak IT (PIT), final IT (FIT), IE, and final ISQ values were statistically analyzed. All implants showed increasing ISQ values when the implant was inserted more deeply. In contrast to the ISQ, implants with different designs showed dissimilar IT curve patterns during the insertion. All implants showed a significant increase in the PIT, FIT, IE, and ISQ when the test-block density increased or when the 1-mm laminated layer was present. Tapered implants showed FIT or PIT values of more than 40 Ncm for all of the laminated test blocks and for the nonlaminated test blocks of low to medium density. Parallel-wall implants did not exhibit PIT or FIT values of more than 40 Ncm for all of the test blocks. NobelActive-4.3 showed a significantly higher FIT, but a significantly lower IE, than Mk IV-4.0. While the existence of cortical bone or implant designs significantly affects the dynamic IT profiles during implant insertion, it does not affect the ISQ to a similar extent. Certain implant designs are more suitable than others if high IT is required in bone of poor quality. The manner in which IT, IE, and ISQ represent the implant primary stability requires further study.

Ridge Preservation After Tooth Extraction With Buccal Bone Plate Deficiency Using Tunnel Structured β-Tricalcium Phosphate Blocks: A 2-Month Histologic Pilot Study in Beagle Dogs.

PubMed

Ikawa, Takahiro; Akizuki, Tatsuya; Matsuura, Takanori; Hoshi, Shu; Ammar, Shujaa Addin; Kinoshita, Atsuhiro; Oda, Shigeru; Izumi, Yuichi

2016-02-01

Reduction in alveolar ridge volume is a direct consequence of tooth extraction. Tunnel β-tricalcium phosphate (β-TCP) blocks were manufactured from randomly organized tunnel-shaped β-TCP ceramic. Efficacy of these blocks compared to extraction alone for alveolar ridge preservation after tooth extraction with buccal bone deficiency was evaluated. Maxillary first premolars of six beagle dogs were extracted after removing the buccal bone, and bone defects of 4 × 4 × 5 mm (mesio-distal width × bucco-palatal width × depth) were created. Fresh extraction sockets with buccal bone defects were filled with tunnel β-TCP blocks at test sites. Two months after the operation, histologic and histometric evaluations were performed. Regarding histologic sections, coronal and middle horizontal widths of the alveolar ridge were significantly greater at test sites (3.2 ± 0.5 and 3.6 ± 0.4 mm, respectively) than at control sites (1.2 ± 0.3 and 2.0 ± 0.6 mm, respectively). The amount of woven bone was significantly greater at test sites (62.4% ± 7.9%) than at control sites (26.8% ± 5.3%), although that of connective tissue and bone marrow was significantly greater at control sites (38.1% ± 6.2% and 16.0% ± 6.9%, respectively) than at test sites (10.7% ± 5.7% and 4.1% ± 2.2%, respectively). Regarding basic multicellular units, no statistically significant difference was found between the test and control sites (0.5% ± 0.1% and 0.6% ± 0.1%, respectively). Tunnel β-TCP blocks represent an effective bone-graft material for alveolar ridge preservation in fresh extraction sockets with buccal bone defects.

Surgical strategies to improve fixation in the osteoporotic spine: the effects of tapping, cement augmentation, and screw trajectory.

PubMed

Kuhns, Craig A; Reiter, Michael; Pfeiffer, Ferris; Choma, Theodore J

2014-02-01

Study Design Biomechanical study of pedicle screw fixation in osteoporotic bone. Objective To investigate whether it is better to tap or not tap osteoporotic bone prior to placing a cement-augmented pedicle screw. Methods Initially, we evaluated load to failure of screws placed in cancellous bone blocks with or without prior tapping as well as after varying the depths of tapping prior to screw insertion. Then we evaluated load to failure of screws placed in bone block models with a straight-ahead screw trajectory as well as with screws having a 23-degree cephalad trajectory (toward the end plate). These techniques were tested with nonaugmented (NA) screws as well as with bioactive cement (BioC) augmentation prior to screw insertion. Results In the NA group, pretapping decreased fixation strength in a dose-dependent fashion. In the BioC group, the tapped screws had significantly greater loads to failure (p < 0.01). Comparing only the screw orientation, the screws oriented at 23 degrees cephalad had a significantly higher failure force than their respective counterparts at 0 degrees (p < 0.01). Conclusions Standard pedicle screw fixation is often inadequate in the osteoporotic spine, but this study suggests tapping prior to cement augmentation will substantially improve fixation when compared with not tapping. Angulating screws more cephalad also seems to enhance aging spine fixation.

Randomized, controlled clinical two-centre study using xenogeneic block grafts loaded with recombinant human bone morphogenetic protein-2 or autogenous bone blocks for lateral ridge augmentation.

PubMed

Thoma, Daniel S; Payer, Michael; Jakse, Norbert; Bienz, Stefan P; Hüsler, Jürg; Schmidlin, Patrick R; Jung, Ui-Won; Hämmerle, Christoph H F; Jung, Ronald E

2018-02-01

To test whether or not the use of a xenogeneic block loaded with recombinant human bone morphogenetic protein-2 (rhBMP-2) results in different bone quantity and quality compared to an autogenous bone block. Twenty-four patients with insufficient bone volume for implant placement were randomly assigned to two treatment modalities: a xenogeneic bone block loaded with rhBMP-2 (test) and an autogenous bone block (control). The horizontal ridge width was evaluated prior to augmentation, after augmentation and at 4 months. Patient-reported outcome measures (PROMs) were assessed at suture removal and at 4 months. Biopsies were obtained at 4 months and histologically evaluated. Intergroup comparisons were tested by a two-sided Wilcoxon-Mann-Whitney test, intra-group comparisons were performed with Wilcoxon-signed rank test, and all categorical variables were tested with Chi-squared tests. One autogenous bone block failed. This patient was replaced, and in all subsequently treated 24 patients, implant placement was possible 4 months later. The median ridge width increased from 4.0 mm (Q1 = 2.0; Q3 = 4.0) (test) and 2.0 mm (Q1 = 2.0; Q3 = 3.0) (control) to 7.0 mm (Q1 = 6.0; Q3 = 8.0) (test) and 7.0 mm (Q1 = 6.0; Q3 = 8.0) (control) at 4 months (intergroup p > .05). A higher morbidity was reported at the augmented site in the control group during surgery. Sensitivity was more favourable in the test than that in the control group at 4 months. The biopsies revealed more mineralized tissue in the control group (p < .0043). Both treatment modalities were successful in regenerating bone to place dental implants. PROMs did not reveal any significant differences between the groups except for pain during surgery at the recipient site (in favour of the test group). Histologically, a higher amount of mineralized tissue was observed for the control group at 4 months. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Quantitative Kinetics Evaluation of Blocks Versus Granules of Biphasic Calcium Phosphate Scaffolds (HA/β-TCP 30/70) by Synchrotron Radiation X-ray Microtomography: A Human Study.

PubMed

Giuliani, Alessandra; Manescu, Adrian; Mohammadi, Sara; Mazzoni, Serena; Piattelli, Adriano; Mangano, Francesco; Iezzi, Giovanna; Mangano, Carlo

2016-02-01

Successful bone regeneration using both granules and blocks of biphasic calcium phosphate materials has been reported in the recent literature, in some clinical applications for maxillary sinus elevation, but the long-term kinetics of bone regeneration has still not been fully investigated. Twenty-four bilateral sinus augmentation procedures were performed and grafted with hydroxyapatite/β-tricalcium phosphate 30/70, 12 with granules and 12 with blocks. The samples were retrieved at different time points and were evaluated for bone regeneration, graft resorption, neovascularization, and morphometric parameters by computed microtomography and histology. A large amount of newly formed bone was detected in the retrieved specimens, together with a good rate of biomaterial resorption and the formation of a homogeneous and rich net of new vessels. The morphometric values were comparable at 5/6 months from grafting but, 9 months after grafting, revealed that the block-based specimens mimicked slightly better than granule-based samples the healthy native bone of the maxillary site. The scaffold morphology was confirmed to influence the long-term kinetics of bone regeneration.

MicroSaw and Piezosurgery in Harvesting Mandibular Bone Blocks from the Retromolar Region: A Randomized Split-Mouth Prospective Clinical Trial.

PubMed

Hanser, Thomas; Doliveux, Romain

The aim of this randomized prospective split-mouth clinical trial was to evaluate the outcome of bone block harvesting from the retromolar region using the MicroSaw and Piezosurgery. Fifty-three patients for extensive bilateral bone grafting procedures with or without concomitant implant placement in the maxilla and/or mandible were scheduled. In each patient, bone blocks were harvested in the retromolar area within the external oblique ridge of the mandible. Using a randomized protocol, bone blocks were harvested with the MicroSaw and Piezosurgery either from the right or the left side. Clinical outcome parameters were the comparison of osteotomy time; volume of block graft; and clinical determination of intraoperative complications such as hemorrhage, nerve injury, pain, swelling, and healing of the donor site. The mean osteotomy time for harvesting including luxating a bone block was 5.63 (± 1.37) minutes using the MicroSaw and 16.47 (± 2.74) minutes using Piezosurgery (P < .05). A mean graft volume of 1.62 (± 0.27) cm 3 was measured with the MicroSaw and 1.26 (± 0.27) cm 3 with the piezoelectric surgical device (P < .05). No heavy bleeding at the donor site occurred in any of the cases. Complications due to injury of adjacent teeth or nerve lesion of the mandibular nerve were not observed in any cases. According to a scale, there was little postoperative pain with both instruments, and it decreased within 14 days postoperatively (P > .05). Swelling did not appear significantly different either (P > .05), and none of the donor sites showed primary healing complications. The data described in this randomized prospective split-mouth clinical trial indicate that the MicroSaw and Piezosurgery allowed efficient and safe bone block harvesting from the external oblique ridge. Clinically, concerning harvesting time and volume of the grafts, the MicroSaw performed significantly better, whereas pain, swelling, and healing did not appear to be considerably different. Given the improved visibility, precise cut geometries, and the margin of safety afforded by the MicroSaw and Piezosurgery, they are both instruments of choice when harvesting bone from the retromolar area.

Comparison of Er:YAG laser and surgical drill for osteotomy in oral surgery: an experimental study.

PubMed

Gabrić Pandurić, Dragana; Bago, Ivona; Katanec, Davor; Zabkar, Janez; Miletić, Ivana; Anić, Ivica

2012-11-01

High-energy lasers have been proposed as an alternative to the conventional surgical drill in oral and maxillofacial surgery. The aims of this study were to compare thermal changes of the bone surface, procedure time, and volume of the removed bone after drilling with an erbium (Er):yttrium-aluminum-garnet (YAG) laser versus a low-speed surgical drill. The bone sections were observed under light microscopy and examined histologically. Thirty bone blocks were prepared from porcine ribs. On each block 2 holes (tunnel preparations) were performed using a low-speed, 1.0-mm-wide, surgical pilot drill and an Er:YAG laser (pulse energy, 1,000 mJ; pulse duration, 300 μs; frequency, 20 Hz). The temperature induced by the preparation techniques was measured using an infrared camera. The removed bone volume was calculated by a modified mathematical algorithm. The time required for the preparation was measured with a digital stopwatch and a time-measurement instrument integrated within the computer program. The cortical and spongiose surfaces of the specimens were examined microscopically and histologically under a light microscope with a high-resolution camera. The Er:YAG laser removed significantly more bone tissue than the drill (P < .01) in a significantly shorter time (P < .01). The temperature was statistically lower during the laser preparation (P < .01). Cavities prepared with the laser were regular with clear sharp edges and knifelike cuts. In the drill group, the preparations exhibited irregular edges full of bone fragments and fiberlike debris. Histologic examination of the laser sides showed a 30-μm-thick altered sublayer. The tissue in the drill group was covered with a smear layer without any alterations. The Er:YAG laser produced preparations with regular and sharp edges, without bone fragments and debris, in a shorter time, and with less generated heat. Thermal alterations in the treated surface were minimal. Copyright © 2012 American Association of Oral and Maxillofacial Surgeons. Published by Elsevier Inc. All rights reserved.

Anthropometric and Radiologic Measurements of Coracoid Dimensions and Clinical Implications in an Indian Population.

PubMed

Joshi, Deepak; Gupta, Lalit Mohan; Tanwar, Milind; Lal, Ajay; Chaudhary, Deepak

2018-03-01

Recurrent shoulder dislocation and anterior instability are most commonly attributed to pathology of the capsulolabral complex with the presence of bony loss at the humeral and glenoid surfaces. Unassessed bone loss has been a cause of failure of primary soft tissue procedures or recurrence of symptoms, despite adequate address of soft tissue pathology. To study the anthropometric and radiologic dimensions of the coracoid in relation to glenoid bone loss, its adequacy in filling glenoid defects in an Indian population, and whether the choice of surgical technique (congruent arc vs classical) and graft positioning alters the surgical results. This study also intended to establish whether computed tomography measurements correlate with actual anthropometric measurements. Cross-sectional study; Level of evidence, 3. A total of 64 participants with 108 healthy shoulders were included in this study. Additionally, 100 skeletally mature bone specimens of the scapula were measured to assess glenoid diameter as well as coracoid width and length in 2 perpendicular planes with a humeral subtraction 3-dimensional en face glenoid view. Specimen and participant measurements proved that the congruent arc technique was able to fill up to 50% more glenoid bone loss than the classical technique in an Indian population (mean ± SD, 13.45 ± 6.97 vs 7.96 ± 4.89 mm, respectively), with computed tomography being the best and most accurate modality to study it. The mean difference in the bone block length restoration of the glenoid bony arc was 5.41 ± 2.08 mm. Radii of curvature were congruent in populations of the Indian subcontinent. The congruent arc technique can be performed in an Indian population but with caution and careful presurgical assessment of bone loss. However, adequate coracoid dimension to accommodate the implant for fixation without failure must be ensured, as anthropometry suggests the existence of a subset of the population in whom the graft may have compromised width for accommodating standard implants for fixation.

Crestal Sinus Augmentation in the Presence of Severe Sinus Mucosal Thickening: A Report of 3 Cases.

PubMed

Fang, Yiqin; An, Xueyin; Jeong, Seung-Mi; Choi, Byung-Ho

2018-06-01

In the presence of severe sinus mucosal thickening, the ostium can be blocked when the sinus membrane is lifted, causing drainage disturbances and sinusitis. Here, we present 3 cases in which maxillary sinus floor elevation was performed using a crestal approach in the presence of severe sinus mucosal thickening (>10 mm). The effects of maxillary sinus floor elevation using the crestal approach technique on sinus mucosal thickening and bone formation in the sinus were evaluated using cone beam computed tomography. None of the patients exhibited an increase in sinus membrane thickness. No complications were encountered during the follow-up periods, and bone formation was observed around the implants at the sinus floor. All implants were functioning successfully. Maxillary sinus floor elevation using the crestal approach technique in the presence of severe sinus mucosal thickening allows for minimally invasive sinus grafting and simultaneous implant placement and does not increase sinus membrane thickness.

Press-fit fixation using autologous bone in the tibial canal causes less enlargement of bone tunnel diameter in ACL reconstruction--a CT scan analysis three months postoperatively.

PubMed

Akoto, Ralph; Müller-Hübenthal, Jonas; Balke, Maurice; Albers, Malte; Bouillon, Bertil; Helm, Philip; Banerjee, Marc; Höher, Jürgen

2015-08-19

Bone tunnel enlargement is a phenomenon present in all anterior cruciate ligament (ACL)- reconstruction techniques. It was hypothesized that press-fit fixation using a free autograft bone plug reduces the overall tunnel size in the tibial tunnel. In a prospective cohort study twelve patients who underwent primary ACL reconstruction using an autologous quadriceps tendon graft and adding a free bone block for press-fit fixation (PF) in the tibial tunnel were matched to twelve patients who underwent ACL reconstruction with a hamstring graft and interference screw fixation (IF). The diameters of the bone tunnels were analysed by a multiplanar reconstruction technique (MPR) in a CT scan three months postoperatively. Manual and instrumental laxity (Lachman test, Pivot-shift test, Rolimeter) and functional outcome scores (International Knee Documentation Committee sore, Tegner activity level) were measured after one year follow up. In the PF group the mean bone tunnel diameter at the level of the joint entrance was not significantly enlarged. One and two centimeter distal to the bone tunnel diameter was reduced by 15% (p = .001). In the IF group the bone tunnel at the level of the joint entrance was enlarged by 14% (p = .001). One and two centimeter distal to the joint line the IF group showed a widening of the bone tunnel by 21% (p < .001) One and two centimeter below the joint line the bone tunnel was smaller in the PF group when compared to the IF group (p < .001). No significant difference for laxity test and functional outcome scores could be shown. This study demonstrates that press-fit fixation with free autologous bone plugs in the tibial tunnel results in significantly smaller diameter of the tibial tunnel compared to interference screw fixation.

Anaesthetic management for awake craniotomy in brain glioma resection: initial experience in Military Hospital Mohamed V of Rabat

PubMed Central

Meziane, Mohammed; Elkoundi, Abdelghafour; Ahtil, Redouane; Guazaz, Miloudi; Mustapha, Bensghir; Haimeur, Charki

2017-01-01

The awake brain surgery is an innovative approach in the treatment of tumors in the functional areas of the brain. There are various anesthetic techniques for awake craniotomy (AC), including asleep-awake-asleep technique, monitored anesthesia care, and the recent introduced awake-awake-awake method. We describe our first experience with anesthetic management for awake craniotomy, which was a combination of these techniques with scalp nerve block, and propofol/rémifentanil target controlled infusion. A 28-year-oldmale underwent an awake craniotomy for brain glioma resection. The scalp nerve block was performed and a low sedative state was maintained until removal of bone flap. During brain glioma resection, the patient awake state was maintained without any complications. Once, the tumorectomy was completed, the level of anesthesia was deepened and a laryngeal mask airway was inserted. A well psychological preparation, a reasonable choice of anesthetic techniques and agents, and continuous team communication were some of the key challenges for successful outcome in our patient. PMID:28904684

Painful lumbosacral melorheostosis treated by fusion.

PubMed

Robertson, Peter A; Don, Angus S; Miller, Mary V

2003-06-15

A case report of low back pain associated with a diagnosis of melorheostosis of the lumbosacral spine. To describe a rare presentation of melorheostosis and subsequent successful surgical treatment. Melorheostosis is a rare condition and spinal pain has not been described in association with the condition. A patient with disabling low back pain and suspected melorheostosis of the lumbosacral spine responded favorably to diagnostic facet joint blocks. Treatment was lumbosacral fusion and biopsy of the abnormal bone. The densely sclerotic bone presented technical difficulties requiring modification of surgical technique. Dramatic pain and disability reduction occurred following lumbosacral fusion. Histologic examination was consistent with melorheostosis. Melorheostosis rarely causes severe low back pain that can respond favorably to fusion surgery.

Autogenous bone grafts in the esthetic zone: optimizing the procedure using piezosurgery.

PubMed

Majewski, Piotr

2012-12-01

Soft and hard tissue defects pose a therapeutic challenge in modern implant dentistry. There are a multitude of surgical techniques available, and it is necessary to match the problem with the solution. This report describes the reconstruction of the alveolar ridge in the esthetic zone with the help of autogenous bone blocks harvested from the chin that were shaped to fit and stabilized at the recipient site. The procedures were performed using Piezosurgery, which made it possible to introduce surgical modifications and had a significant impact on the accuracy of the procedure. An observation period of 2 to 7 years showed positive stable results for treatment in terms of function and esthetics.

Single-trabecula building block for large-scale finite element models of cancellous bone.

PubMed

Dagan, D; Be'ery, M; Gefen, A

2004-07-01

Recent development of high-resolution imaging of cancellous bone allows finite element (FE) analysis of bone tissue stresses and strains in individual trabeculae. However, specimen-specific stress/strain analyses can include effects of anatomical variations and local damage that can bias the interpretation of the results from individual specimens with respect to large populations. This study developed a standard (generic) 'building-block' of a trabecula for large-scale FE models. Being parametric and based on statistics of dimensions of ovine trabeculae, this building block can be scaled for trabecular thickness and length and be used in commercial or custom-made FE codes to construct generic, large-scale FE models of bone, using less computer power than that currently required to reproduce the accurate micro-architecture of trabecular bone. Orthogonal lattices constructed with this building block, after it was scaled to trabeculae of the human proximal femur, provided apparent elastic moduli of approximately 150 MPa, in good agreement with experimental data for the stiffness of cancellous bone from this site. Likewise, lattices with thinner, osteoporotic-like trabeculae could predict a reduction of approximately 30% in the apparent elastic modulus, as reported in experimental studies of osteoporotic femora. Based on these comparisons, it is concluded that the single-trabecula element developed in the present study is well-suited for representing cancellous bone in large-scale generic FE simulations.

Biomechanical Three-Dimensional Finite Element Analysis of Single Implant-Supported Prostheses in the Anterior Maxilla, with Different Surgical Techniques and Implant Types.

PubMed

Verri, Fellippo Ramos; Santiago, Joel Ferreira; Almeida, Daniel Augusto; de Souza Batista, Victor Eduardo; Araujo Lemos, Cleidiel Aparecido; Mello, Caroline Cantieri; Pellizzer, Eduardo Piza

The aim of this study was to use three-dimensional finite element analysis to analyze the stress distribution transferred by single implant-supported prostheses placed in the anterior maxilla using different connections (external hexagon, internal hexagon, or Morse taper), inclinations of the load (0, 30, or 60 degrees), and surgical techniques for placement (monocortical/conventional, bicortical, or bicortical with nasal floor elevation). Nine models representing a bone block of this region were simulated by computer-aided design software (InVesalius, Rhinoceros, SolidWorks). Each model received one implant, which supported a cemented metalloceramic crown. Using FEMAP software, finite elements were discretized while simulating a 178-N load at 0, 30, and 60 degrees relative to the long axis of the implant. The problem was solved in NEi Nastran software, and postprocessing was performed in FEMAP. Von Mises stress and maximum principal stress maps were made. The von Mises stress analysis revealed that stress increased with increasing inclination of the load, from 0 to 30 to 60 degrees. Morse taper implants showed less stress concentration around the cervical and apical areas of the implant. The bicortical technique, associated or not with nasal floor elevation, contributed to decreasing the stress concentration in the apical area of the implant. Maximum principal stress analysis showed that the increase in inclination was proportional to the increase in stress on the bone tissue in the cervical area. Lower stress concentrations in the cortical bone were obtained with Morse taper implants and the bicortical technique compared with other connections and surgical techniques, respectively. Increasing the inclination of the applied force relative to the long axis of the implant tended to overload the peri-implant bone tissue and the internal structure of the implants. The Morse taper connection and bicortical techniques seemed to be more favorable than other connections or techniques, respectively, for restoring the anterior maxilla.

Enhanced bone screw fixation with biodegradable bone cement in osteoporotic bone model.

PubMed

Juvonen, Tiina; Koistinen, Arto; Kröger, Heikki; Lappalainen, Reijo

2012-09-27

The purpose of this study was to study the potential of novel biodegradable PCL bone cement to improve bone screw fixation strength in osteoporotic bone. The biomechanical properties of bone cement (ε-polycaprolactone, PCL) and fixation strength were studied using biomechanical tests and bone screws fixed in an osteoporotic bone model. Removal torques and pullout strengths were assessed for cortical, self-tapping, and cancellous screws inserted in the osteoporotic bone model (polyurethane foam blocks with polycarbonate plate) with and without PCL bone cement. Open cell and cellular rigid foam blocks with a density of 0.12 g/cm3 were used in this model. Removal torques were significantly (more than six-fold) improved with bone cement for cancellous screws. Furthermore, the bone cement improved pullout strengths three to 12 times over depending on the screw and model material. Biodegradable bone cement turned out to be a very potential material to stabilize screw fixation in osteoporotic bone. The results warrant further research before safe clinical use, especially to clarify clinically relevant factors using real osteoporotic bone under human body conditions and dynamic fatigue testing for long-term performance.

Post-traumatic implant-supported restoration of the anterior maxillary teeth using cancellous bone block allografts.

PubMed

Nissan, Joseph; Gross, Ora; Mardinger, Ofer; Ghelfan, Oded; Sacco, Roberto; Chaushu, Gavriel

2011-12-01

To prospectively evaluate the outcome of dental implants placed in the post-traumatic anterior maxilla after ridge augmentation with cancellous freeze-dried block bone allografts. Patients presenting with a history of anterior dentoalveolar trauma with bony deficiencies in the sagittal (≥3 mm) and vertical (<3 mm) planes according to computed tomography were included. The recipient sites were reconstructed with cancellous bone block allografts. After 6 months of healing, implants were placed. The primary outcomes of interest were 1) bone measurements taken before grafting, at the time of implant placement, and at stage 2 operations; 2) implant survival; and 3) complications. The sample was composed of 20 consecutive patients with a mean age of 25 ± 7 years. We used 28 cancellous allogeneic bone blocks, and 31 implants were inserted. Of the 31 implants, 12 were immediately restored. The mean follow-up was 42 ± 15 months. Graft and implant survival rates were 92.8% and 96.8%, respectively. Mean bone gain in the sagittal and vertical planes was 5 ± 0.5 mm horizontally and 2 ± 0.5 mm (P < .001). Successful restoration was achieved in all patients with fixed implant-supported prostheses. Soft tissue complications occurred in 7 patients (35%). Complications after cementation of the crowns were seen in 3 implants (9.6%). All implants remained clinically osseointegrated at the end of the follow-up examination. There was no crestal bone loss around the implants beyond the first implant thread. Cancellous block allograft can be used successfully for post-traumatic implant-supported restoration in the anterior maxilla. Copyright © 2011 American Association of Oral and Maxillofacial Surgeons. Published by Elsevier Inc. All rights reserved.

Quantitative analysis of the patella following the harvest of a quadriceps tendon autograft with a bone block.

PubMed

Ferrer, Gerald A; Miller, R Matthew; Murawski, Christopher D; Tashman, Scott; Irrgang, James J; Musahl, Volker; Fu, Freddie H; Debski, Richard E

2016-09-01

The objective of this study was to determine parameters associated with patellar fracture after quadriceps tendon autograft harvest. Thirteen non-fractured and five fractured patella surface models were created based on patient data obtained from a prospective randomized clinical trial in order to assess geometric parameters and bending stress. Measurements that describe the bone block harvest site geometry were used to calculate three normalized parameters. The relative depth parameter describes the thickness of the bone block harvest site with respect to the thickness of the patella at the harvest site. The asymmetry parameter defines the medial-lateral location of the bone bock harvest site. The normalized bending stress parameter assesses the bending stress experienced by the remaining bone beneath the bone block harvest site. The relative depth of the bone block harvest site in the non-fractured patellae was 27 ± 12 % and for the fractured patellae was 42 ± 14 % (p < 0.05). With a value <1 indicating a more lateral location of the harvest site, asymmetry for the non-fractured group was 1.0 ± 0.5 and 0.7 ± 0.4 for the fractured group (n.s.). The maximum bending stress experienced by the non-fractured patellae was (1.8 × 10(-3) ± 1.3 × 10(-3)) mm(-3) × M and for the fractured patellae was over three times greater (6.3 × 10(-3) ± 3.7 × 10(-3)) mm(-3) × M (p < 0.05). Based on the non-uniform geometry of the patella, an emphasis should be made on harvesting a standard percentage of patella thickness rather than a fixed depth. In order to minimize the incidence of a patellar fracture, bone blocks should not be taken laterally and should not exceed 30 % of the total patella thickness at the harvest site.

Bone tissue reactions to biomimetic ion-substituted apatite surfaces on titanium implants.

PubMed

Ballo, Ahmed M; Xia, Wei; Palmquist, Anders; Lindahl, Carl; Emanuelsson, Lena; Lausmaa, Jukka; Engqvist, Håkan; Thomsen, Peter

2012-07-07

The aim of this study was to evaluate the bone tissue response to strontium- and silicon-substituted apatite (Sr-HA and Si-HA) modified titanium (Ti) implants. Sr-HA, Si-HA and HA were grown on thermally oxidized Ti implants by a biomimetic process. Oxidized implants were used as controls. Surface properties, i.e. chemical composition, surface thickness, morphology/pore characteristics, crystal structure and roughness, were characterized with various analytical techniques. The implants were inserted in rat tibiae and block biopsies were prepared for histology, histomorphometry and scanning electron microscopy analysis. Histologically, new bone formed on all implant surfaces. The bone was deposited directly onto the Sr-HA and Si-HA implants without any intervening soft tissue. The statistical analysis showed significant higher amount of bone-implant contact (BIC) for the Si-doped HA modification (P = 0.030), whereas significant higher bone area (BA) for the Sr-doped HA modification (P = 0.034), when compared with the non-doped HA modification. The differences were most pronounced at the early time point. The healing time had a significant impact for both BA and BIC (P < 0.001). The present results show that biomimetically prepared Si-HA and Sr-HA on Ti implants provided bioactivity and promoted early bone formation.

Age-related new bone formation following the use of cancellous bone-block allografts for reconstruction of atrophic alveolar ridges.

PubMed

Nissan, Joseph; Kolerman, Roni; Chaushu, Liat; Vered, Marilena; Naishlos, Sarit; Chaushu, Gavriel

2018-02-01

An age-related decrease in the number of osteogenic progenitor cells may compromise bone augmentation. Histomorphometrical assessment of age-related new bone formation, following atrophic alveolar ridge reconstruction, using cancellous bone-block allografts. Ninety-three consecutive patients (58 females and 35 males) were referred for implant-supported restoration of 122 severe atrophic alveolar ridges. Alveolar ridge deficiency locations were classified as anterior maxilla (n = 58), posterior maxilla (n= 32), and posterior mandible (n = 32). A bony deficiency of at least 3 mm horizontally and up to 3 mm vertically according to computerized tomography (CT) in the posterior mandible and anterior maxilla, served as inclusion criteria. In the posterior maxilla, a residual alveolar ridge up to 4 mm vertically according to CT served as inclusion criteria. Augmentation was performed by the use of cancellous bone-block allografts. Bone biopsies (9-month posterior maxilla, 4 months anterior maxilla and posterior mandible) of young (≤40 years) versus older (>40 years) patients were histomorphometrically evaluated. In the posterior maxilla, no statistically significant histomorphometric differences were noted. While at the anterior maxilla and posterior mandible, statistically significant more newly formed bone was found in young versus older individuals, respectively (38.6% vs 19.8%, P = 0.04 and 69% vs 31%, P = .05). New bone formation following residual alveolar ridge bone grafting is age-related. Longer bone consolidation and healing time may be recommended for older individuals. © 2017 Wiley Periodicals, Inc.

Custom-Made Synthetic Scaffolds for Bone Reconstruction: A Retrospective, Multicenter Clinical Study on 15 Patients

PubMed Central

Macchi, Aldo; Luongo, Giuseppe

2016-01-01

Purpose. To present a computer-assisted-design/computer-assisted-manufacturing (CAD/CAM) technique for the design, fabrication, and clinical application of custom-made synthetic scaffolds, for alveolar ridge augmentation. Methods. The CAD/CAM procedure consisted of (1) virtual planning/design of the custom-made scaffold; (2) milling of the scaffold into the exact size/shape from a preformed synthetic bone block; (3) reconstructive surgery. The main clinical/radiographic outcomes were vertical/horizontal bone gain, any biological complication, and implant survival. Results. Fifteen patients were selected who had been treated with a custom-made synthetic scaffold for ridge augmentation. The scaffolds closely matched the shape of the defects: this reduced the operation time and contributed to good healing. A few patients experienced biological complications, such as pain/swelling (2/15: 13.3%) and exposure of the scaffold (3/15: 20.0%); one of these had infection and complete graft loss. In all other patients, 8 months after reconstruction, a well-integrated newly formed bone was clinically available, and the radiographic evaluation revealed a mean vertical and horizontal bone gain of 2.1 ± 0.9 mm and 3.0 ± 1.0 mm, respectively. Fourteen implants were placed and restored with single crowns. The implant survival rate was 100%. Conclusions. Although positive outcomes have been found with custom-made synthetic scaffolds in alveolar ridge augmentation, further studies are needed to validate this technique. PMID:28070512

Evaluation of implant osseointegration with different regeneration techniques in the treatment of bone defects around implants: an experimental study in a rabbit model.

PubMed

Guerra, Isabel; Morais Branco, Fernando; Vasconcelos, Mário; Afonso, Américo; Figueiral, Helena; Zita, Raquel

2011-03-01

The aim of this study was to evaluate the osseointegration of implants placed in areas with artificially created bone defects, using three bone regeneration techniques. The experimental model was the rabbit femur (16), where bone defects were created and implants were placed. The peri-implant bone defects were filled with a deproteinized bovine bone mineral, NuOss™ (N), NuOss™ combined with plasma rich in growth factors (PRGF) (N+PRGF), NuOss™ covered by an RCM(6) membrane (N+M), or remained unfilled (control group [C]). After 4 and 8 weeks, the animals were euthanized and bone tissue blocks with the implants and the surrounding bone tissue were removed and processed according to a histological protocol for hard tissues on non-decalcified ground sections. The samples were studied by light and electron scanning microscopy, histometric analysis was performed to assess the percentage of bone in direct contact with the implant surface and a statistical analysis of the results was performed. In the samples analyzed 4 weeks after implantation, the percentage of bone tissue in direct contact with the implant surface for the four groups were 57.66±24.39% (N), 58.62±20.37% (N+PRGF), 70.82±20.34 % (N+M) and 33.07±5.49% (C). In the samples with 8 weeks of implantation time, the percentage of bone in direct contact was 63.35±27.69% (N), 58.42±24.77% (N+PRGF), 78.02±15.13% (N+M) and 40.28±27.32% (C). In terms of the percentage of bone contact, groups N and N+M presented statistically significant differences from group C in the 4-week trial test (P<0.05; ANOVA). For the 8-week results, only group N+M showed statistically significant differences when compared with group C (P<0.05; ANOVA). In conclusion, the NuOss™ granules/RCM(6) membrane combination presented a percentage of bone contact with the implant surface statistically greater than in the other groups. © 2010 John Wiley & Sons A/S.

Comparison of conventional twist drill protocol and piezosurgery for implant insertion: an ex vivo study on different bone types.

PubMed

Sagheb, Keyvan; Kumar, Vinay V; Azaripour, Adriano; Walter, Christian; Al-Nawas, Bilal; Kämmerer, Peer W

2017-02-01

The aim of this ex vivo study was to compare implant insertion procedures using piezosurgery and conventional drilling in different qualities of bone. Implant bed preparation time, generated heat, and primary implant stability were analyzed. Fresh ex vivo porcine bone block samples (cancellous, mixed, and cortical bone) were obtained. The bone quality was quantified by ultrasound transmission velocity (UTV). Each bone sample received three implants of the same diameter using each of the techniques of piezosurgery and conventional twist drills. Time for preparation was taken and the temperature while performing the osteotomy was measured using infrared spectroscopy. The primary implant stability after osteotomy was measured using resonance frequency analysis (RFA) and extrusion torque (ET). ANOVA with post hoc Tukey test was carried out to compare the values for the three different groups. The UTV values strongly correlated with the density of the bone samples. There was a significant increase in time (threefold, P < 0.05 [302 s vs. 122 s in cortical bone]) but no difference in the temperature for the piezo group (~37°C in cortical bone). Regardless of the osteotomy technique, there was a statistically significant increase in RFA and ET values in implants inserted in cancellous bone (RFA: piezo 77, drill 76; ET: piezo 22, drill 21), mixed bone (RFA: piezo 85, drill 86; ET: piezo 105, drill 61), and cortical bone (RFA: piezo 90, drill 87; ET piezo 184, drill 79) samples, respectively (P < 0.05). In between the different osteotomy groups, there was no difference in the RFA values but significant higher ET values in mixed/cortical bone samples in favor for the piezosurgery group. Piezosurgery and conventional implant bed drilling procedure do have similar mechanical outcomes regarding primary stability with high RFA values, but the preparation does need more time for piezosurgery group, so that piezosurgery might be a valuable tool in only very specific cases for implant bed preparation. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

μCT-based, in vivo dynamic bone histomorphometry allows 3D evaluation of the early responses of bone resorption and formation to PTH and alendronate combination therapy.

PubMed

de Bakker, Chantal M J; Altman, Allison R; Tseng, Wei-Ju; Tribble, Mary Beth; Li, Connie; Chandra, Abhishek; Qin, Ling; Liu, X Sherry

2015-04-01

Current osteoporosis treatments improve bone mass by increasing net bone formation: anti-resorptive drugs such as bisphosphonates block osteoclast activity, while anabolic agents such as parathyroid hormone (PTH) increase bone remodeling, with a greater effect on formation. Although these drugs are widely used, their role in modulating formation and resorption is not fully understood, due in part to technical limitations in the ability to longitudinally assess bone remodeling. Importantly, it is not known whether or not PTH-induced bone formation is independent of resorption, resulting in controversy over the effectiveness of combination therapies that use both PTH and an anti-resorptive. In this study, we developed a μCT-based, in vivo dynamic bone histomorphometry technique for rat tibiae, and applied this method to longitudinally track changes in bone resorption and formation as a result of treatment with alendronate (ALN), PTH, or combination therapy of both PTH and ALN (PTH+ALN). Correlations between our μCT-based measures of bone formation and measures of bone formation based on calcein-labeled histology (r=0.72-0.83) confirm the accuracy of this method. Bone remodeling parameters measured through μCT-based in vivo dynamic bone histomorphometry indicate an increased rate of bone formation in rats treated with PTH and PTH+ALN, together with a decrease in bone resorption measures in rats treated with ALN and PTH+ALN. These results were further supported by traditional histology-based measurements, suggesting that PTH was able to induce bone formation while bone resorption was suppressed. Copyright © 2014 Elsevier Inc. All rights reserved.

Clinical and Radiological Regeneration of Large and Deep Osteochondral Defects of the Knee by Bone Augmentation Combined With Matrix-Guided Autologous Chondrocyte Transplantation.

PubMed

Zellner, Johannes; Grechenig, Stephan; Pfeifer, Christian G; Krutsch, Werner; Koch, Matthias; Welsch, Goetz; Scherl, Madeleine; Seitz, Johannes; Zeman, Florian; Nerlich, Michael; Angele, Peter

2017-11-01

Large osteochondral defects of the knee are a challenge for regenerative treatment. While matrix-guided autologous chondrocyte transplantation (MACT) represents a successful treatment for chondral defects, the treatment potential in combination with bone grafting by cancellous bone or bone block augmentation for large and deep osteochondral defects has not been evaluated. To evaluate 1- to 3-year clinical outcomes and radiological results on magnetic resonance imaging (MRI) after the treatment of large osteochondral defects of the knee with bone augmentation and MACT. Special emphasis is placed on different methods of bone grafting (cancellous bone grafting or bone block augmentation). Case series; Level of evidence, 4. Fifty-one patients were included. Five patients were lost to follow-up. This left 46 patients (mean age, 28.2 years) with a median follow-up time of 2 years. The 46 patients had 47 deep, large osteochondral defects of the knee joint (1 patient with bilateral defects; mean defect size, 6.7 cm 2 ). The origin of the osteochondral defects was osteochondritis dissecans (n = 34), osteonecrosis (n = 8), or subchondral cysts (n = 5). Depending on the depth, all defects were treated by cancellous bone grafting (defect depth ≤10 mm; n = 16) or bone block augmentation (defect depth >10 mm; n = 31) combined with MACT. Clinical outcomes were followed at 3 months, 6 months, 1 year, 2 years, and 3 years and evaluated using the International Knee Documentation Committee (IKDC) score and Cincinnati score. A magnetic resonance imaging (MRI) evaluation was performed at 1 and 2 years, and the magnetic resonance observation of cartilage repair tissue (MOCART) score with additional specific subchondral bone parameters (bone regeneration, bone signal quality, osteophytes, sclerotic areas, and edema) was analyzed. The clinical outcome scores revealed a significant increase at follow-up (6 months to 3 years) compared with the preclinical results. The median IKDC score increased from 42.6 preoperatively to 75.3 at 1 year, 79.7 at 2 years, and 84.3 at 3 years. The median Cincinnati score significantly increased from 39.8 preoperatively to 72.0 at 1 year, 78.0 at 2 years, and 80.3 at 3 years. The MRI evaluation revealed a MOCART score of 82.6 at 1 year without a deterioration at the later follow-up time point. Especially, the subchondral bone analysis showed successful regeneration. All bone blocks and cancellous bone grafts were integrated in the bony defects, and no chondrocyte transplant failure could be detected throughout the follow-up. Large and deep osteochondral defects of the knee joint can be treated successfully with bone augmentation and MACT. The treatment of shallow bony defects with cancellous bone grafting and deep bony defects with bone block augmentation shows promising results.

Suitability of the CellientTM cell block method for diagnosing soft tissue and bone tumors

PubMed Central

Song, W.; van Hemel, B. M.

2018-01-01

BACKGROUND The diagnosis of tumors of soft tissue and bone (STB) heavily relies on histological biopsies, whereas cytology is not widely used. CellientTM cell blocks often contain small tissue fragments. In addition to Hematoxylin and Eosin (H&E) interpretation of histological features, immunohistochemistry (IHC) can be applied after optimization of protocols. The objective of this retrospective study was to see whether this cytological technique allowed us to make a precise diagnosis of STB tumors. METHODS Our study cohort consisted of 20 consecutive STB tumors, 9 fine‐needle aspiration (FNAC) samples, and 11 endoscopic ultrasonography (EUS) FNACs and included 8 primary tumors and 12 recurrences or metastases of known STB tumors. RESULTS In all 20 cases, H&E stained sections revealed that diagnostically relevant histological and cytological features could be examined properly. In the group of 8 primary tumors, IHC performed on CellientTM material provided clinically important information in all cases. For instance, gastrointestinal stromal tumor (GIST) was positive for CD117 and DOG‐1 and a PEComa showed positive IHC for actin, desmin, and HMB‐45. In the group of 12 secondary tumors, SATB2 was visualized in metastatic osteosarcoma, whereas expression of S‐100 was present in 2 secondary chondrosarcomas. Metastatic chordoma could be confirmed by brachyury expression. Two metastatic alveolar rhabdomyosarcomas were myf4 positive, a metastasis of a gynecologic leiomyosarcoma was positive for actin and estrogen receptor (ER) and a recurrent dermatofibrosarcoma protuberans expressed CD34. CONCLUSION In the proper clinical context, including clinical presentation with imaging studies, the CellientTM cell block technique has great potential for the diagnosis of STB tumors. PMID:29318761

Experimental Analysis of Temperature Differences During Implant Site Preparation: Continuous Drilling Technique Versus Intermittent Drilling Technique.

PubMed

Di Fiore, Adolfo; Sivolella, Stefano; Stocco, Elena; Favero, Vittorio; Stellini, Edoardo

2018-02-01

Implant site preparation through drilling procedures may cause bone thermonecrosis. The aim of this in vitro study was to evaluate, using a thermal probe, overheating at implant sites during osteotomies through 2 different drilling methods (continuous drilling technique versus intermittent drilling technique) using irrigation at different temperatures. Five implant sites 13 mm in length were performed on 16 blocks (fresh bovine ribs), for a total of 80 implant sites. The PT-100 thermal probe was positioned 5 mm from each site. Two physiological refrigerant solutions were used: one at 23.7°C and one at 6.0°C. Four experimental groups were considered: group A (continuous drilling with physiological solution at 23.7°C), group B (intermittent drilling with physiological solution at 23.7°C), group C (continuous drilling with physiological solution at 6.0°C), and group D (intermittent drilling with physiological solution at 6.0°C). The Wilcoxon rank-sum test (2-tailed) was used to compare groups. While there was no difference between group A and group B (W = 86; P = .45), statistically significant differences were observed between experimental groups A and C (W = 0; P =.0001), B and D (W = 45; P =.0005), and C and D (W = 41; P = .003). Implant site preparation did not affect the overheating of the bone. Statistically significant differences were found with the refrigerant solutions. Using both irrigating solutions, bone temperature did not exceed 47°C.

Efficacy of ketamine hydrochloride administered as a basilar sesamoid nerve block in alleviating foot pain in horses caused by natural disease.

PubMed

Schumacher, J; DeGraves, F; Cesar, F; Duran, S

2014-09-01

A local anaesthetic agent capable of temporarily resolving lameness after being administered perineurally would be helpful because rapid return of lameness would allow for other analgesic techniques to be performed within a short period of time. To determine if a 3% solution of ketamine hydrochloride (HCl), administered around the palmar nerves at the level of the base of the proximal sesamoid bones, can improve naturally occurring lameness that can be improved or abolished with a basilar sesamoid nerve block performed using lidocaine HCl and to compare the change in gait produced using lidocaine to the change in gait produced using ketamine by using objective lameness assessment. Experimental trial using research horses with naturally occurring lameness. Seven horses, chronically lame on a thoracic limb, were chosen for the study. A wireless, inertial, sensor-based, motion analysis system was used to evaluate lameness before and after administration of 2% lidocaine and later, before and after administration of 3% ketamine over the palmar digital nerves at the base of the proximal sesamoid bones (a basilar sesamoid nerve block) at 5 min intervals for 30 min. Lameness scores obtained before and after administration of lidocaine and ketamine HCl were compared using repeated measures analysis. Gait significantly improved after basilar sesamoid nerve blocks using 2% lidocaine, but gait did not significantly improve after performing the same nerve block using 3% ketamine HCl. Ketamine (3%) administered perineurally for regional anaesthesia of the digit does not desensitise the digit to the same extent as does lidocaine and thus 3% ketamine appears to have no value as a local anaesthetic agent for diagnostic regional anaesthesia. © 2013 EVJ Ltd.

The effect of low-speed drilling without irrigation on heat generation: an experimental study.

PubMed

Oh, Ji-Hyeon; Fang, Yiqin; Jeong, Seung-Mi; Choi, Byung-Ho

2016-02-01

In this study we evaluated heat generation during the low-speed drilling procedure without irrigation. Ten artificial bone blocks that were similar to human D1 bone were used in this study. The baseline temperature was 37.0℃. We drilled into 5 artificial bone blocks 60 times at the speed of 50 rpm without irrigation. As a control group, we drilled into an additional 5 artificial bone blocks 60 times at the speed of 1,500 rpm with irrigation. The temperature changes during diameter 2 mm drilling were measured using thermocouples. The mean maximum temperatures during drilling were 40.9℃ in the test group and 39.7℃ in the control group. Even though a statistically significant difference existed between the two groups, the low-speed drilling did not produce overheating. These findings suggest that low-speed drilling without irrigation may not lead to overheating during drilling.

Evidence for a Role for Nanoporosity and Pyridinoline Content in Human Mild Osteogenesis Imperfecta.

PubMed

Paschalis, Eleftherios P; Gamsjaeger, Sonja; Fratzl-Zelman, Nadja; Roschger, Paul; Masic, Admir; Brozek, Wolfgang; Hassler, Norbert; Glorieux, Francis H; Rauch, Frank; Klaushofer, Klaus; Fratzl, Peter

2016-05-01

Osteogenesis imperfecta (OI) is a clinically and genetically heterogeneous connective tissue disorder characterized by bone fragility that arises from decreased bone mass and abnormalities in bone material quality. OI type I represents the milder form of the disease and according to the original Sillence classification is characterized by minimal skeletal deformities and near-normal stature. Raman microspectroscopy is a vibrational spectroscopic technique that allows the determination of bone material properties in bone biopsy blocks with a spatial resolution of ∼1 µm, as a function of tissue age. In the present study, we used Raman microspectroscopy to evaluate bone material quality in transiliac bone biopsies from children with a mild form of OI, either attributable to collagen haploinsufficiency OI type I (OI-Quant; n = 11) or aberrant collagen structure (OI-Qual; n = 5), as a function of tissue age, and compared it against the previously published values established in a cohort of biopsies from healthy children (n = 54, ages 1 to 23 years). The results indicated significant differences in bone material compositional characteristics between OI-Quant patients and healthy controls, whereas fewer were evident in the OI-Qual patients. Differences in both subgroups of OI compared with healthy children were evident for nanoporosity, mineral maturity/crystallinity as determined by maxima of the v1 PO4 Raman band, and pyridinoline (albeit in different direction) content. These alterations in bone material compositional properties most likely contribute to the bone fragility characterizing this disease. © 2016 American Society for Bone and Mineral Research. © 2016 American Society for Bone and Mineral Research.

CAD-CAM-generated hydroxyapatite scaffold to replace the mandibular condyle in sheep: preliminary results.

PubMed

Ciocca, Leonardo; Donati, Davide; Fantini, Massimiliano; Landi, Elena; Piattelli, Adriano; Iezzi, Giovanna; Tampieri, Anna; Spadari, Alessandro; Romagnoli, Noemi; Scotti, Roberto

2013-08-01

In this study, rapid CAD-CAM prototyping of pure hydroxyapatite to replace temporomandibular joint condyles was tested in sheep. Three adult animals were implanted with CAD-CAM-designed porous hydroxyapatite scaffolds as condyle substitutes. The desired scaffold shape was achieved by subtractive automated milling machining (block reduction). Custom-made surgical guides were created by direct metal laser sintering and were used to export the virtual planning of the bone cut lines into the surgical environment. Using the same technique, fixation plates were created and applied to the scaffold pre-operatively to firmly secure the condyles to the bone and to assure primary stability of the hydroxyapatite scaffolds during masticatory function. Four months post-surgery, the sheep were sacrificed. The hydroxyapatite scaffolds were explanted, and histological specimens were prepared. Different histological tissues penetrating the scaffold macropores, the sequence of bone remodeling, new apposition of bone and/or cartilage as a consequence of the different functional anatomic role, and osseointegration at the interface between the scaffold and bone were documented. This animal model was found to be appropriate for testing CAD-CAM customization and the biomechanical properties of porous, pure hydroxyapatite scaffolds used as joint prostheses.

Comparison of the Efficacy of Local Infiltration and Mandibular Block Anesthesia With Articaine for Harvesting Ramus Grafts.

PubMed

Göçmen, Gökhan; Özkan, Yaşar

2016-11-01

We compared the efficacy of local infiltrative anesthesia and regional mandibular block anesthesia using articaine to harvest ramus grafts and the postoperative sequelae. A total of 20 patients with alveolar bone deficiency participated in the present comparative, prospective, randomized study. The first group received regional anesthesia with the mandibular block technique (group A; n = 10), and those in the second group received local infiltration anesthesia (group B; n = 10). Intraoperative pain and bleeding were evaluated as the primary outcome variables. The visual analog scale (VAS) scores were compared at 0.5, 1, 2, and 4 hours postoperatively. The maximal interincisal mouth opening (MIO) (on days 3 and 7) and VAS scores (at 6, 12, 24, and 48 hours and on days 3 and 7) were compared as secondary outcome variables. The correlation between pain (VAS scores) and trismus (MIO) were also compared. A painless procedure was performed in both groups. The VAS score, MIO, and intraoperative bleeding were not significantly different between the 2 groups. Paresthesia was not observed in either group postoperatively. No statistically significant correlations were found between the VAS scores and MIO. Local infiltrative anesthesia preserves almost the same depth of anesthesia as mandibular block anesthesia. No differences were found between these techniques in terms of efficacy and postoperative sequelae during and after ramus graft harvest. Thus, using articaine with a local infiltration technique is an alternative to mandibular block anesthesia during ramus graft harvesting and results in a reduced risk of inferior alveolar nerve damage. Copyright © 2016 American Association of Oral and Maxillofacial Surgeons. Published by Elsevier Inc. All rights reserved.

Evaluation of the resolving potency of a novel reconstruction filter on periodontal ligament space with dental cone-beam CT: a quantitative phantom study

NASA Astrophysics Data System (ADS)

Houno, Yuuki; Hishikawa, Toshimitsu; Gotoh, Ken-ichi; Naitoh, Munetaka; Ariji, Eiichiro; Kodera, Yoshie

2014-03-01

Diagnosis of the alveolar bone condition is important for the treatment planning of periodontal disease. Especially the determination of periodontal ligament space is the most important remark because it represents the periodontal tissue support for tooth retention. However, owing to the image blur of the current cone-beam CT (CBCT) imaging technique, the periodontal ligament space is difficult to visualize. In this study, we developed an original periodontal ligament phantom (PLP) and evaluated the image quality of simulated periodontal ligament space using a novel reconstruction filter for CBCT that emphasized high frequency component. PLP was composed from two resin blocks of different materials, the bone equivalent block and the dentine equivalent block. They were assembled to make continuously changing space from 0.0 to 1.0 millimeter that mimics periodontal ligament space. PLP was placed in water and the image was obtained by using Alphard-3030 dental cone-beam CT (Asahi Roentgen Industry Co., Ltd.). Then we reconstructed the projection data with a novel reconstruction filter. The axial images were compared with conventional reconstructed images. In novel filter reconstruction images, 0.4 millimeter of the space width was steadily detected by calculation of pixel value, on the other hand 0.6 millimeter was in conventional images. With our method, the resolving potency of conebeam CT images was improved.

Influence of low-level laser therapy on the healing process of autogenous bone block grafts in the jaws of systemically nicotine-modified rats: A histomorphometric study.

PubMed

de Almeida, Juliano Milanezi; de Moraes, Ricardo Oliveira; Gusman, David Jonathan Rodrigues; Faleiros, Paula Lazilha; Nagata, Maria José Hitomi; Garcia, Valdir Gouveia; Theodoro, Letícia Helena; Bosco, Alvaro Francisco

2017-03-01

To analyze the influence of low-level laser therapy (LLLT) on the bone healing process of autogenous bone block grafts installed in nicotine systemically modified rats. Seventy-two rats (Wistar) were randomly assigned into 4 groups (n=18). SS-BG: saline application+bone graft. SS-BG/LLLT: saline application+bone graft+LLLT. NIC-BG: nicotine application+bone graft. NIC-BG/LLLT: nicotine application+bone graft+LLLT. After 30days of application of solutions, all animals received autogenous bone block graft in the jaw, with the donation from the parietal bone's calvarial area. Treatment with LLLT was in bed-graft interface, after accommodation of the graft. The animals in each group were sacrificed at 7, 14, and 28days after graft surgery. The histologic analyses of NIC-BG group depicted a delay of osteogenic activity in the recipient bed-graft interface and the irradiation of tissue with LLLT provided better bone healing. The histometric analysis revealed that SS-BG/LLLT and NIC-BG/LLLT groups showed increased bone formation compared to BG-SS and NIC-BG groups, after 14days (SS-BG 24.94%±13.06% versus SS-BG/LLLT 27.53%±19.07% and NIC-BG 14.27%±2.22% versus NIC-BG/LLLT 24.37%±11.93%) and 28days (SS-BG 50.31%±2.69% versus SS-BG/LLLT 58 19%±12.32% and NIC-BG 36.89%±8.40% versus NIC-BG/LLLT 45.81%±6.03%). Nicotine harms bone formation in the bed-graft interface and LLLT action can mitigate this. Copyright © 2016 Elsevier Ltd. All rights reserved.

Repair of Segmental Load-Bearing Bone Defect by Autologous Mesenchymal Stem Cells and Plasma-Derived Fibrin Impregnated Ceramic Block Results in Early Recovery of Limb Function

PubMed Central

Ng, Min Hwei; Duski, Suryasmi; Tan, Kok Keong; Yusof, Mohd Reusmaazran; Low, Kiat Cheong; Mohamed Rose, Isa; Mohamed, Zahiah; Bin Saim, Aminuddin; Idrus, Ruszymah Bt Hj

2014-01-01

Calcium phosphate-based bone substitutes have not been used to repair load-bearing bone defects due to their weak mechanical property. In this study, we reevaluated the functional outcomes of combining ceramic block with osteogenic-induced mesenchymal stem cells and platelet-rich plasma (TEB) to repair critical-sized segmental tibial defect. Comparisons were made with fresh marrow-impregnated ceramic block (MIC) and partially demineralized allogeneic bone block (ALLO). Six New Zealand White female rabbits were used in each study group and three rabbits with no implants were used as negative controls. By Day 90, 4/6 rabbits in TEB group and 2/6 in ALLO and MIC groups resumed normal gait pattern. Union was achieved significantly faster in TEB group with a radiological score of 4.50 ± 0.78 versus ALLO (1.06 ± 0.32), MIC (1.28 ± 0.24), and negative controls (0). Histologically, TEB group scored the highest percentage of new bone (82% ± 5.1%) compared to ALLO (5% ± 2.5%) and MIC (26% ± 5.2%). Biomechanically, TEB-treated tibiae achieved the highest compressive strength (43.50 ± 12.72 MPa) compared to those treated with ALLO (15.15 ± 3.57 MPa) and MIC (23.28 ± 6.14 MPa). In conclusion, TEB can repair critical-sized segmental load-bearing bone defects and restore limb function. PMID:25165699

Block Copolymer Directed Biomimetic Mineral Formation for Polymer Nanocomposites

NASA Astrophysics Data System (ADS)

Gleeson, Sarah; Yu, Tony; Chen, Xi; Marcolongo, Michele; Li, Christopher

Bone is a hierarchically structured biocomposite comprised of mineralized collagen fibrils. The mechanical properties of bone can be precisely tuned by the structure and morphology of the mineral nanocrystals as well as the organic collagen fibrils. Synthetic materials that can mimic the nanostructure of natural bone show promise to replicate bone's structural function, yet little is known about the mechanism of mineral formation. We previously have shown that hierarchically ordered polymer fibers control the distribution and orientation of hydroxyapatite, enhancing mechanical properties and biocompatibility. We demonstrate a new method for mineralization by forming block copolymer single crystal films of polycaprolactone-block-poly(acrylic acid) (PCL- b-PAA) so that lamellar anionic PAA nanodomains recruit mineral ions and provide one-dimensional confinement to induce orientation. The effect of the anionic domain dimensions on mineral content, orientation, and structure within the polymer matrix is shown. The mechanical properties of the nanocomposite are evaluated to determine the role of mineral orientation and crystallinity in composite strength. These results can be used to tailor the physical mineralization environment to create a more biomimetic bone material.

The effects and mechanisms of clinorotation on proliferation and differentiation in bone marrow mesenchymal stem cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yan, Ming; Wang, Yongchun; Yang, Min

Data from human and rodent studies have demonstrated that microgravity induces observed bone loss in real spaceflight or simulated experiments. The decrease of bone formation and block of maturation may play important roles in bone loss induced by microgravity. The aim of this study was to investigate the changes of proliferation and differentiation in bone marrow mesenchymal stem cells (BMSCs) induced by simulated microgravity and the mechanisms underlying it. We report here that clinorotation, a simulated model of microgravity, decreased proliferation and differentiation in BMSCs after exposure to 48 h simulated microgravity. The inhibited proliferation are related with blocking the cellmore » cycle in G2/M and enhancing the apoptosis. While alterations of the osteoblast differentiation due to the decreased SATB2 expression induced by simulated microgravity in BMSCs. - Highlights: • Simulated microgravity inhibited proliferation and differentiation in BMSCs. • The decreased proliferation due to blocked cell cycle and enhanced the apoptosis. • The inhibited differentiation accounts for alteration of SATB2, Hoxa2 and Cbfa1.« less

Full-Field Calcium K-Edge X-ray Absorption Near-Edge Structure Spectroscopy on Cortical Bone at the Micron-Scale: Polarization Effects Reveal Mineral Orientation.

PubMed

Hesse, Bernhard; Salome, Murielle; Castillo-Michel, Hiram; Cotte, Marine; Fayard, Barbara; Sahle, Christoph J; De Nolf, Wout; Hradilova, Jana; Masic, Admir; Kanngießer, Birgit; Bohner, Marc; Varga, Peter; Raum, Kay; Schrof, Susanne

2016-04-05

Here, we show results on X-ray absorption near edge structure spectroscopy in both transmission and X-ray fluorescence full-field mode (FF-XANES) at the calcium K-edge on human bone tissue in healthy and diseased conditions and for different tissue maturation stages. We observe that the dominating spectral differences originating from different tissue regions, which are well pronounced in the white line and postedge structures are associated with polarization effects. These polarization effects dominate the spectral variance and must be well understood and modeled before analyzing the very subtle spectral variations related to the bone tissue variations itself. However, these modulations in the fine structure of the spectra can potentially be of high interest to quantify orientations of the apatite crystals in highly structured tissue matrices such as bone. Due to the extremely short wavelengths of X-rays, FF-XANES overcomes the limited spatial resolution of other optical and spectroscopic techniques exploiting visible light. Since the field of view in FF-XANES is rather large the acquisition times for analyzing the same region are short compared to, for example, X-ray diffraction techniques. Our results on the angular absorption dependence were verified by both site-matched polarized Raman spectroscopy, which has been shown to be sensitive to the orientation of bone building blocks and by mathematical simulations of the angular absorbance dependence. As an outlook we further demonstrate the polarization based assessment of calcium-containing crystal orientation and specification of calcium in a beta-tricalcium phosphate (β-Ca3(PO4)2 scaffold implanted into ovine bone. Regarding the use of XANES to assess chemical properties of Ca in human bone tissue our data suggest that neither the anatomical site (tibia vs jaw) nor pathology (healthy vs necrotic jaw bone tissue) affected the averaged spectral shape of the XANES spectra.

Mastoid cortex plasty using bone pate.

PubMed

Yanagihara, Naoaki; Hinohira, Yasuyuki; Sato, Hidemitu

2002-07-01

To describe the surgical technique of mastoid cortex plasty using bone pate and its clinical significance. Retrospective. Tertiary medical center. Bone pate collected while drilling the mastoid cortex was mixed with fibrin glue to make a pate plate. The mastoid cortex defect was closed with a pate plate cut to the desired shape and size. Mastoid cortex plasty was included in the first-stage operation in 49 patients who underwent staged tympanoplasty. The second-stage operation was an inspection to see whether the mastoid cortex was reconstructed and the ingrowth of fibrous soft tissue was prevented. In 35 patients, the mastoid cortex was reconstructed completely, and soft tissue ingrowth into the mastoid cavity was blocked completely. In the remaining 14 patients, a defect of varying size occurred at the site of drainage-tube insertion. This defect was small enough to prevent soft tissue ingrowth into the mastoid cavity. Mastoid cortex plasty is a simple and rapid procedure for preventing postoperative deformity of the mastoid process and is valuable for restoring mastoid cavity function.

Decursin from Angelica gigas suppresses RANKL-induced osteoclast formation and bone loss.

PubMed

Wang, Xin; Zheng, Ting; Kang, Ju-Hee; Li, Hua; Cho, Hyewon; Jeon, Raok; Ryu, Jae-Ha; Yim, Mijung

2016-03-05

Osteoclasts are the only cells capable of breaking down bone matrix, and excessive activation of osteoclasts is responsible for bone-destructive diseases. In this study, we investigated the effects of decursin from extract of Angelica gigas root on receptor activator of nuclear factor kappa B ligand (RANKL)-induced osteoclast formation using mouse bone marrow-derived macrophages (BMMs). Decursin inhibited RANKL-induced osteoclast formation without cytotoxicity. In particular, decursin maintains the characteristics of macrophages by blocking osteoclast differentiation by RANKL. Furthermore, the RANKL-stimulated bone resorption was diminished by decursin. Mechanistically, decursin blocked the RANKL-triggered ERK mitogen-activated protein kinases (MAPK) phosphorylation, which results in suppression of c-Fos and the nuclear factor of activated T cells (NFATc1) expression. In accordance with the in vitro study, decursin reduced lipopolysaccharide (LPS)- or ovariectomy (OVX)-induced bone loss in vivo. Therefore, decursin exerted an inhibitory effect on osteoclast formation and bone loss in vitro and in vivo. Decursin could be useful for the treatment of bone diseases associated with excessive bone resorption. Copyright © 2016 Elsevier B.V. All rights reserved.

Accurate reconstruction of discontinuous mandible using a reverse engineering/computer-aided design/rapid prototyping technique: a preliminary clinical study.

PubMed

Zhou, Li-bin; Shang, Hong-tao; He, Li-sheng; Bo, Bin; Liu, Gui-cai; Liu, Yan-pu; Zhao, Jin-long

2010-09-01

To improve the reconstructive surgical outcome of a discontinuous mandibular defect, we used reverse engineering (RE), computer-aided design (CAD), and rapid prototyping (RP) technique to fabricate customized mandibular trays to precisely restore the mandibular defects. Autogenous bone grafting was also used to restore the bony continuity for occlusion rehabilitation. Six patients who had undergone block resection of the mandible underwent reconstruction using a custom titanium tray combining autogenous iliac grafts. The custom titanium tray was made using a RE/CAD/RP technique. A virtual 3-dimensional model was obtained by spiral computed tomography scanning. The opposite side of the mandible was mirrored to cover the defect area to restore excellent facial symmetry. A bone grafting tray was designed from the mirrored image and manufactured using RP processing and casting. The mandibular defects were restored using the trays in combination of autologous iliac grafting. An implant denture was made for 1 of the 6 patients at 24 weeks postoperatively for occlusion rehabilitation. The trays fabricated using this technique fit well in all 6 patients. The reconstructive procedures were easy and time saving. Satisfactory facial symmetry was restored. No severe complications occurred in the 5 patients without occlusion rehabilitation during a mean 50-month follow-up period. The reconstruction in the patient with occlusion lasted for only 1 year and failed eventually because of bone resorption and infection. Mandibular reconstruction was facilitated using the RE/CAD/RP technique. Satisfactory esthetic results were achieved. However, the rigidity of the cast tray could cause severe stress shielding to the grafts, which could lead to disuse atrophy. Therefore, some modification is needed for functional reconstruction. Copyright 2010 American Association of Oral and Maxillofacial Surgeons. Published by Elsevier Inc. All rights reserved.

Investigation of structural resorption behavior of biphasic bioceramics with help of gravimetry, μCT, SEM, and XRD.

PubMed

de Wild, Michael; Amacher, Fabienne; Bradbury, Christopher R; Molenberg, Aart

2016-04-01

Resorbable bone substitute materials are widely used for bone augmentation after tumor resection, parallel to implant placement, or in critical size bone defects. In this study, the structural dissolution of a biphasic calcium phosphate bone substitute material with a hydroxyapatite (HA)/tricalcium phosphate (β-TCP) ratio of 60/40 was investigated by repeatedly placing porous blocks in EDTA solution at 37 °C. At several time points, the blocks were investigated by SEM, µCT, and gravimetry. It was found that always complete 2-3 µm sized grains were removed from the structure and that the β-TCP is dissolved more rapidly. This selective dissolution of the β-TCP grains was confirmed by XRD measurements. The blocks were eroded from the outside toward the center. The structure remained mechanically stable because the central part showed a delayed degradation and because the slower dissolving HA grains preserved the integrity of the structure. © 2015 Wiley Periodicals, Inc.

A TNF receptor loop peptide mimic blocks RANK ligand–induced signaling, bone resorption, and bone loss

PubMed Central

Aoki, Kazuhiro; Saito, Hiroaki; Itzstein, Cecile; Ishiguro, Masaji; Shibata, Tatsuya; Blanque, Roland; Mian, Anower Hussain; Takahashi, Mariko; Suzuki, Yoshifumi; Yoshimatsu, Masako; Yamaguchi, Akira; Deprez, Pierre; Mollat, Patrick; Murali, Ramachandran; Ohya, Keiichi; Horne, William C.; Baron, Roland

2006-01-01

Activating receptor activator of NF-κB (RANK) and TNF receptor (TNFR) promote osteoclast differentiation. A critical ligand contact site on the TNFR is partly conserved in RANK. Surface plasmon resonance studies showed that a peptide (WP9QY) that mimics this TNFR contact site and inhibits TNF-α–induced activity bound to RANK ligand (RANKL). Changing a single residue predicted to play an important role in the interaction reduced the binding significantly. WP9QY, but not the altered control peptide, inhibited the RANKL-induced activation of RANK-dependent signaling in RAW 264.7 cells but had no effect on M-CSF–induced activation of some of the same signaling events. WP9QY but not the control peptide also prevented RANKL-induced bone resorption and osteoclastogenesis, even when TNFRs were absent or blocked. In vivo, where both RANKL and TNF-α promote osteoclastogenesis, osteoclast activity, and bone loss, WP9QY prevented the increased osteoclastogenesis and bone loss induced in mice by ovariectomy or low dietary calcium, in the latter case in both wild-type and TNFR double-knockout mice. These results suggest that a peptide that mimics a TNFR ligand contact site blocks bone resorption by interfering with recruitment and activation of osteoclasts by both RANKL and TNF. PMID:16680194

Implant treatment in atrophic posterior mandibles: vertical regeneration with block bone grafts versus implants with 5.5-mm intrabony length.

PubMed

Peñarrocha-Oltra, David; Aloy-Prósper, Amparo; Cervera-Ballester, Juan; Peñarrocha-Diago, Maria; Canullo, Luigi; Peñarrocha-Diago, Miguel

2014-01-01

To retrospectively compare the outcomes of implants placed in posterior mandibles vertically regenerated with onlay autogenous block bone grafts and short dental implants. Consecutive patients with vertical bone atrophy in edentulous mandibular posterior regions (7 to 8 mm of bone above the inferior alveolar nerve) were treated with either implants placed in regenerated bone using autologous block bone grafts (group 1) or short implants (with 5.5-mm intrabony length) in native bone (group 2) between 2005 and 2010 and followed for 12 months after loading. The procedure used was the established treatment protocol for this type of patient at the Oral Surgery Unit (University of Valencia, Spain) at the time of surgery. All grafts were obtained using piezosurgery. The outcomes assessed were: complications related to the procedure, implant survival, implant success, and peri-implant marginal bone loss. Statistical analysis was done using the Fisher exact test and the Mann-Whitney test. Thirty-seven patients were included, 20 (45 implants) in group 1 and 17 (35 implants) in group 2. In group 1, 13 implants were less than 10 mm long (2 were 7 mm and 11 were 8.5 mm), and 32 were 10 mm or longer; the diameter was 3.6 mm in 6 implants, 4.2 mm in 31, and 5.5 mm in 8. In group 2 all implants were 7 mm long; the diameter measured 4.2 mm in 14 implants and 5.5 mm in 21 implants. Complications related to the block bone grafting procedure were temporary hypoesthesia in one patient, wound dehiscence with graft exposure in three patients, and exposure of the osteosynthesis screw without bone graft exposure in one patient. After 12 months, implant survival rates were 95.6% in group 1 and 97.1 % in group 2; success rates were 91.1% and 97.1%, respectively. The average marginal bone loss was 0.7 ± 1.1 mm in group 1 and 0.6 ± 0.3 mm in group 2. When residual bone height over the mandibular canal is between 7 and 8 mm, short implants (with 5.5-mm intrabony length) might be a preferable treatment option over vertical augmentation, reducing chair time, expense, and morbidity.

Knotless anchors with sutures external to the anchor body may be at risk for suture cutting through osteopenic bone.

PubMed

Ono, Y; Woodmass, J M; Nelson, A A; Boorman, R S; Thornton, G M; Lo, I K Y

2016-06-01

This study evaluated the mechanical performance, under low-load cyclic loading, of two different knotless suture anchor designs: sutures completely internal to the anchor body (SpeedScrew) and sutures external to the anchor body and adjacent to bone (MultiFIX P). Using standard suture loops pulled in-line with the rotator cuff (approximately 60°), anchors were tested in cadaveric bone and foam blocks representing normal to osteopenic bone. Mechanical testing included preloading to 10 N and cyclic loading for 500 cycles from 10 N to 60 N at 60 mm/min. The parameters evaluated were initial displacement, cyclic displacement and number of cycles and load at 3 mm displacement relative to preload. Video recording throughout testing documented the predominant source of suture displacement and the distance of 'suture cutting through bone'. In cadaveric bone and foam blocks, MultiFIX P anchors had significantly greater initial displacement, and lower number of cycles and lower load at 3 mm displacement than SpeedScrew anchors. Video analysis revealed 'suture cutting through bone' as the predominant source of suture displacement in cadaveric bone (qualitative) and greater 'suture cutting through bone' comparing MultiFIX P with SpeedScrew anchors in foam blocks (quantitative). The greater suture displacement in MultiFIX P anchors was predominantly from suture cutting through bone, which was enhanced in an osteopenic bone model. Anchors with sutures external to the anchor body are at risk for suture cutting through bone since the suture eyelet is at the distal tip of the implant and the suture directly abrades against the bone edge during cyclic loading. Suture cutting through bone may be a significant source of fixation failure, particularly in osteopenic bone.Cite this article: Y. Ono, J. M. Woodmass, A. A. Nelson, R. S. Boorman, G. M. Thornton, I. K. Y. Lo. Knotless anchors with sutures external to the anchor body may be at risk for suture cutting through osteopenic bone. Bone Joint Res 2016;5:269-275. DOI: 10.1302/2046-3758.56.2000535. © 2016 Lo et al.

Correlation Between Bone Density and Instantaneous Torque at Implant Site Preparation: A Validation on Polyurethane Foam Blocks of a Device Assessing Density of Jawbones.

PubMed

Di Stefano, Danilo Alessio; Arosio, Paolo

2016-01-01

Bone density at implant placement sites is one of the key factors affecting implant primary stability, which is a determinant for implant osseointegration and rehabilitation success. Site-specific bone density assessment is, therefore, of paramount importance. Recently, an implant micromotor endowed with an instantaneous torque-measuring system has been introduced. The aim of this study was to assess the reliability of this system. Five blocks with different densities (0.16, 0.26, 0.33, 0.49, and 0.65 g/cm(3)) were used. A single trained operator measured the density of one of them (0.33 g/cm(3)), by means of five different devices (20 measurements/device). The five resulting datasets were analyzed through the analysis of variance (ANOVA) model to investigate interdevice variability. As differences were not significant (P = .41), the five devices were each assigned to a different operator, who collected 20 density measurements for each block, both under irrigation (I) and without irrigation (NI). Measurements were pooled and averaged for each block, and their correlation with the actual block-density values was investigated using linear regression analysis. The possible effect of irrigation on density measurement was additionally assessed. Different devices provided reproducible, homogenous results. No significant interoperator variability was observed. Within the physiologic range of densities (> 0.30 g/cm(3)), the linear regression analysis showed a significant linear correlation between the mean torque measurements and the actual bone densities under both drilling conditions (r = 0.990 [I], r = 0.999 [NI]). Calibration lines were drawn under both conditions. Values collected under irrigation were lower than those collected without irrigation at all densities. The NI/I mean torque ratio was shown to decrease linearly with density (r = 0.998). The mean error introduced by the device-operator system was less than 10% in the range of normal jawbone density. Measurements performed with the device were linearly correlated with the blocks' bone densities. The results validate the device as an objective intraoperative tool for bone-density assessment that may contribute to proper jawbone-density evaluation and implant-insertion planning.

Tibial Inlay Press-fit Fixation Versus Interference Screw in Posterior Cruciate Ligament Reconstruction.

PubMed

Ettinger, Max; Büermann, Sarah; Calliess, Tilman; Omar, Mohamed; Krettek, Christian; Hurschler, Christof; Jagodzinski, Michael; Petri, Maximilian

2013-01-01

Reconstruction of the posterior cruciate ligament (PCL) by a tibial press-fit fixation of the patellar tendon with an accessory bone plug is a promising approach because no foreign materials are required. Until today, there is no data about the biomechanical properties of such press-fit fixations. The aim of this study was to compare the biomechanical qualities of a bone plug tibial inlay technique with the commonly applied interference screw of patellar tendon PCL grafts. Twenty patellar tendons including a bone block were harvested from ten human cadavers. The grafts were implanted into twenty legs of adult German country pigs. In group P, the grafts were attached in a press-fit technique with accessory bone plug. In group S, the grafts were fixed with an interference screw. Each group consisted of 10 specimens. The constructs were biomechanically analyzed in cyclic loading between 60 and 250 N for 500 cycles recording elongation. Finally, ultimate failure load and failure mode were analyzed. Ultimate failure load was 598.6±36.3 N in group P and 653.7±39.8 N in group S (not significant, P>0.05). Elongation during cyclic loading between the 1(st) and the 20(th) cycle was 3.4±0.9 mm for group P and 3.1±1 mm for group S. Between the 20(th) and the 500(th) cycle, elongation was 4.2±2.3 mm in group P and 2.5±0.9 mm in group S (not significant, P>0.05). This is the first study investigating the biomechanical properties of tibial press-fit fixation of the patellar tendon with accessory bone plug in posterior cruciate ligament reconstruction. The implant-free tibial inlay technique shows equal biomechanical characteristics compared to an interference screw fixation. Further in vivo studies are desirable to compare the biological behavior and clinical relevance of this fixation device.

Vertical ridge augmentation using an equine bone and collagen block infused with recombinant human platelet-derived growth factor-BB: a randomized single-masked histologic study in non-human primates.

PubMed

Nevins, Myron; Al Hezaimi, Khalid; Schupbach, Peter; Karimbux, Nadeem; Kim, David M

2012-07-01

This study tests the effectiveness of hydroxyapatite and collagen bone blocks of equine origin (eHAC), infused with recombinant human platelet-derived growth factor-BB (rhPDGF-BB), to augment localized posterior mandibular defects in non-human primates (Papio hamadryas). Bilateral critical-sized defects simulating severe atrophy were created at the time of the posterior teeth extraction. Test and control blocks (without growth factor) were randomly grafted into the respective sites in each non-human primate. All sites exhibited vertical ridge augmentation, with physiologic hard- and soft-tissue integration of the blocks when clinical and histologic examinations were done at 4 months after the vertical ridge augmentation procedure. There was a clear, although non-significant, tendency to increased regeneration in the test sites. As in the first two preclinical studies in this series using canines, experimental eHAC blocks infused with rhPDGF-BB proved to be a predictable and technically viable method to predictably regenerate bone and soft tissue in critical-sized defects. This investigation supplies additional evidence that eHAC blocks infused with rhPDGF-BB growth factor is a predictable and technically feasible option for vertical augmentation of severely resorbed ridges.

Healing at the interface between recipient sites and autologous block bone grafts affixed by either position or lag screw methods: a histomorphometric study in rabbits.

PubMed

Caneva, Marco; Botticelli, Daniele; Carneiro Martins, Evandro Neto; Caneva, Martina; Lang, Niklaus P; Xavier, Samuel P

2017-12-01

To compare the sequential healing at the interface gap occurring between autologous bone grafts and recipient sites using two types of fixation techniques. Twenty-four adult male New Zealand white rabbits were used. Two bone grafts were collected from the calvaria and secured to the lateral aspect of the angle of mandible in each animal. Cortical perforations at the recipient sites were performed. However, no modifications were applied to the graft for its adaptation to the recipient site. Two types of fixation techniques by position or lag screws were applied. This was done by preparing osteotomy holes smaller or larger than the screw diameter, respectively. The animals were sacrificed after 3, 7, 20, and 40 days. After 3 days, the distance between the graft and the recipient site was similar between the two different fixations. Due to the anatomical shapes of the recipient sites and grafts, the distance between the two parts was lower in the central region (<0.1 mm) compared to the external regions of the graft (0.5-0.6 mm). The first evidence of small amounts of new (woven) bone was seen after 7 days, forming from the parent bone. The percentage increased after 20 and 40 days. After 40 days, the grafts were well incorporated within the recipient sites in both groups without any statistically significant difference. The present study did not show superiority of one method over another. A fixation to a recipient site with perforations may be sufficient for incorporating an autologous bone graft even if its adaptation is not perfect and irrespectively of the fixation method. Distances of approximately half millimeter were bridged with newly formed bone. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

[Treatment of metaphyseal fractures of shin bones by the method of blocking osteosynthesis].

PubMed

Neverov, V A; Khromov, A A; Cherniaev, S N; Egorov, K S; Shebarshov, A L

2008-01-01

The proposed method of reposition and polyaxial stabilization of fragments for intramedullary meallosynthesis of fractures of long tubular bones allows blocking osteosynthesis to be successfully used in treatment of complex metaphyseal fractures of shin bones. It results in strong fixation of the fragments, makes it possible to successfully eliminate residual deformities after introduction of the nail and to avoid the development of them in future under the influence of loading. The method provides early functioning of the interfacing joints, early axial loading, shorter period of disability, the absence of external immobilization.

Experimental verification of using nanostructured ceramic implants and osteograft

NASA Astrophysics Data System (ADS)

Rerikh, V. V.; Lastevskiy, A. D.; Sadovoy, M. A.; Zaidman, A. M.; Bataev, A. V.; Predein, Yu. A.; Avetisyan, A. R.; Romanenko, V. V.; Mamonova, E. V.; Nikulina, A. A.; Semantsova, E. S.; Smirnov, A. I.

2017-09-01

Ventral interbody fusion was carried out in 8 mini pigs in order to determine the effectiveness of anterior stabilization of the vertebral unit with implants made of nanostructured alumina ceramics using cellular technologies to form a bone block. A ceramic cage with a through cylindrical orifice in the center was implanted into the interbody gap; either cellular osteograft (group 1) or cellular autograft (group 2) was placed in it. The adjacent vertebrae were fixed anteriorly with a ceramic plate containing 4 screws. Bone block formation was studied radiographically, morphologically, and by MSCT. The signs of osteointegration of ceramic implants were observed in both groups after 90 days. MSCT and morphological analysis revealed the formation of the osteoceramic block and completed osteogenesis in the bone-graft contact region in group 1 compared to the control group (p < 0.05).

Evaluation of Efficacy of Bone Scan With SPECT/CT in the Management of Low Back Pain: A Study Supported by Differential Diagnostic Local Anesthetic Blocks.

PubMed

Jain, Anuj; Jain, Suruchi; Agarwal, Anil; Gambhir, Sanjay; Shamshery, Chetna; Agarwal, Amita

2015-12-01

Conventional radiologic modalities provide details only about the anatomic aspect of the various structures of the spine. Frequently the structures that show abnormal morphology may not be the cause of low back pain (LBP). Functional imaging in the form of bone scan along with single photon emission computerized tomography (SPECT/CT) may be helpful in identifying structures causing pain, whether morphologically normal or not. The objective of this study is to evaluate the role of bone scan with SPECT/CT in management of patients with LBP. This is randomized double-blinded controlled study performed on 80 patients with LBP aged 20 to 80 years, ASA physical status I to III. Patients were randomized into bone scan and control groups consisting of 40 patients each. On the basis of the clinical features and radiologic findings a clinical diagnosis was made. After making a clinical diagnosis, the patients in bone scan group were subjected to bone scan with SPECT/CT. On the basis of the finding of the bone scan and SPECT/CT, a new working diagnosis was made and intervention was performed according to the new working diagnosis. Diagnostic blocks in the control group were given based on clinical diagnosis. Controlled comparative diagnostic blocks were performed with local anesthetic. The pain score just after the diagnostic block and at the time of discharge (approximately 4 h later) was recorded; the pain relief was recorded in percentage. In both the groups, sacroilitis was the most common diagnosis followed by facet joint arthropathy. The number of patients obtaining pain relief of >50% was significantly higher in the bone scan-positive group as compared with the control group. Three new clinical conditions were identified in the bone scan group. These conditions were multiple myeloma, avascular necrosis of the femoral head, and ankylosing spondylitis. Bone scan with SPECT/CT was found to complement the clinical workup of patients with LBP. Inclusion of bone scan with SPECT/CT in LBP management protocol can help in making a correct diagnosis. At times it might bring out some new information that may be vital for further management of the patients with LBP.

Current concepts in periodontal bioengineering

PubMed Central

Taba, M.; Jin, Q.; Sugai, J.V.; Giannobile, W.V.

2008-01-01

Repair of tooth supporting alveolar bone defects caused by periodontal and peri-implant tissue destruction is a major goal of reconstructive therapy. Oral and craniofacial tissue engineering has been achieved with limited success by the utilization of a variety of approaches such as cell-occlusive barrier membranes, bone substitutes and autogenous block grafting techniques. Signaling molecules such as growth factors have been used to restore lost tooth support because of damage by periodontal disease or trauma. This paper will review emerging periodontal therapies in the areas of materials science, growth factor biology and cell/gene therapy. Several different polymer delivery systems that aid in the targeting of proteins, genes and cells to periodontal and peri-implant defects will be highlighted. Results from preclinical and clinical trials will be reviewed using the topical application of bone morphogenetic proteins (BMP-2 and BMP-7) and platelet-derived growth factor-BB (PDGF) for periodontal and peri-implant regeneration. The paper concludes with recent research on the use of ex vivo and in vivo gene delivery strategies via gene therapy vectors encoding growth promoting and inhibiting molecules (PDGF, BMP, noggin and others) to regenerate periodontal structures including bone, periodontal ligament and cementum. PMID:16238610

Inhibition of bone resorption in vitro by antisense RNA and DNA molecules targeted against carbonic anhydrase II or two subunits of vacuolar H(+)-ATPase.

PubMed Central

Laitala, T; Väänänen, H K

1994-01-01

The bone resorbing cells, osteoclasts, express high levels of carbonic anhydrase II (CA II) and vacuolar H(+)-ATPase (V-ATPase) during bone resorption. We have used antisense RNA and DNA molecules targeted against CA II, and against 16- and 60-kD subunits of vacuolar H(+)-ATPase (V-ATPase), to block the expression of these proteins in vitro. Osteoclastic bone resorption was studied in two in vitro culture systems: release of 45Calcium from prelabeled newborn mouse calvaria cultures, and resorption pit assays performed with rat osteoclasts cultured on bovine bone slices. Both antisense RNA and DNA against CA II and the V-ATPase were used to compare their specificities as regards inhibiting bone resorption in vitro. The antisense molecules inhibited the synthesis of these proteins by decreasing the amounts of mRNA in the cells in a highly specific manner. In osteoclast cultures treated with the 16-kD V-ATPase antisense RNA, acidification of an unknown population of intracellular vesicles was highly stimulated. The acidification of these vesicles was not sensitive to amiloride or bafilomycin A1. This suggests the existence of a back-up system for acidification of intracellular vesicles, when the expression of the V-ATPase is blocked. Our results further indicate that blocking the expression of CA II and V-ATPase with antisense RNA or DNA leads to decreased bone resorption. Images PMID:8200964

Experimental analysis of insertion torques and forces of threaded and press-fit acetabular cups by means of ex vivo and in vivo measurements.

PubMed

Vogel, Danny; Rathay, Andreas; Teufel, Stephanie; Ellenrieder, Martin; Zietz, Carmen; Sander, Manuela; Bader, Rainer

2017-01-01

In THA a sufficient primary implant stability is the precondition for successful secondary stability. Industrial foams of different densities have been used for primary stability investigations. The aim of this study was to analyse and compare the insertion behaviour of threaded and press-fit cups in vivo and ex vivo using bone substitutes with various densities. Two threaded (Bicon Plus®, Trident® TC) and one press-fit cup (Trident PSL®) were inserted by orthopaedic surgeons (S1, S2) into 10, 20 and 31 pcf blocks, using modified surgical instruments allowing measurements of the insertion forces and torques. Furthermore, the insertion behaviour of two cups were analysed intraoperatively. Torques for the threaded cups increased while bone substitute density increased. Maximum insertion torques were observed for S2 with 102 Nm for the Bicon Plus® in 20 pcf blocks and 77 Nm for the Trident® TC in 31 pcf blocks, which compares to the in vivo measurement (85 Nm). The average insertion forces for the press-fit cup varied from 5.2 to 6.8 kN (S1) and 7.2-11.5 kN (S2) ex vivo. Intraoperatively an average insertion force of 8.0 kN was determined. Implantation behaviour was influenced by acetabular cup design, bone substitute and experience of the surgeon. No specific density of bone substitute could be favoured for ex vivo investigations on the implantation behaviour of acetabular cups. The use synthetic bone blocks of high density (31 pcf) led to problems regarding cup orientation and seating. Therefore, bone substitutes used should be critically scrutinized in terms of the comparability to the in vivo situation.

Experimental and numeric stress analysis of titanium and zirconia one-piece dental implants.

PubMed

Mobilio, Nicola; Stefanoni, Filippo; Contiero, Paolo; Mollica, Francesco; Catapano, Santo

2013-01-01

To compare the stress in bone around zirconia and titanium implants under loading. A one-piece zirconia implant and a replica of the same implant made of commercially pure titanium were embedded in two self-curing acrylic resin blocks. To measure strain, a strain gauge was applied on the surface of the two samples. Loads of 50, 100, and 150 N, with orientations of 30, 45, and 60 degrees with respect to the implant axis were applied on the implant. Strain under all loading conditions on both samples was measured. Three-dimensional virtual replicas of both the implants were reproduced using the finite element method and inserted into a virtual acrylic resin block. All the materials were considered isotropic, linear, and elastic. The same geometry and loading conditions of the experimental setup were used to realize two new models, with the implants embedded within a virtual bone block. Very close values of strain in the two implants embedded in acrylic resin were obtained both experimentally and numerically. The stress states generated by the implants embedded in virtual bone were also very similar, even if the two implants moved differently. Moreover, the stress levels were higher on cortical bone than on trabecular bone. The stress levels in bone, generated by the two implants, appeared to be very similar. From a mechanical point of view, zirconia is a feasible substitute for titanium.

Enhancement of tissue engineered bone formation by a low pressure system improving cell seeding and medium perfusion into a porous scaffold.

PubMed

Wang, Juyong; Asou, Yoshinori; Sekiya, Ichiro; Sotome, Shinichi; Orii, Hisaya; Shinomiya, Kenichi

2006-05-01

To obtain more extensive bone formation in composites of porous ceramics and bone marrow stromal cells (BMSCs), we hypothesized that a low-pressure system would serve to facilitate the perfusion of larger number of BMSCs into the porous scaffold, enhancing bone formation within the composites. After culturing BMSCs in osteogenic medium, porous blocks of beta-tricalcium phosphate (beta-TCP) were soaked in the cell suspension. Composites of the block and BMSCs were put immediately into a vacuum desiccator. Low pressure was applied to the low pressure group, while controls were left at atmospheric pressure. Composites were incubated in vitro or subcutaneously implanted into syngeneic rats, then analyzed biologically and histologically. In the in vitro group, cell suspension volume, cell seeding efficiency, alkaline phosphatase (ALP) activity, and DNA content in the beta-TCP blocks were significantly higher in low pressure group than in the controls. Scanning electron microscopy (SEM) demonstrated that a greater number of cells covered the central parts of the composites in the low pressure group. ALP activity in the composites was increased at 3 and 6 weeks after implantation into rats. Histomorphometric analysis revealed more uniform and extensive bone formation in the low pressure group than in the controls. The application of low pressure during the seeding of BMSCs in perfusing medium into a porous scaffold is useful for tissue-engineered bone formation.

Knotless anchors with sutures external to the anchor body may be at risk for suture cutting through osteopenic bone

PubMed Central

Ono, Y.; Woodmass, J. M.; Nelson, A. A.; Boorman, R. S.; Thornton, G. M.

2016-01-01

Objectives This study evaluated the mechanical performance, under low-load cyclic loading, of two different knotless suture anchor designs: sutures completely internal to the anchor body (SpeedScrew) and sutures external to the anchor body and adjacent to bone (MultiFIX P). Methods Using standard suture loops pulled in-line with the rotator cuff (approximately 60°), anchors were tested in cadaveric bone and foam blocks representing normal to osteopenic bone. Mechanical testing included preloading to 10 N and cyclic loading for 500 cycles from 10 N to 60 N at 60 mm/min. The parameters evaluated were initial displacement, cyclic displacement and number of cycles and load at 3 mm displacement relative to preload. Video recording throughout testing documented the predominant source of suture displacement and the distance of ‘suture cutting through bone’. Results In cadaveric bone and foam blocks, MultiFIX P anchors had significantly greater initial displacement, and lower number of cycles and lower load at 3 mm displacement than SpeedScrew anchors. Video analysis revealed ‘suture cutting through bone’ as the predominant source of suture displacement in cadaveric bone (qualitative) and greater ‘suture cutting through bone’ comparing MultiFIX P with SpeedScrew anchors in foam blocks (quantitative). The greater suture displacement in MultiFIX P anchors was predominantly from suture cutting through bone, which was enhanced in an osteopenic bone model. Conclusions Anchors with sutures external to the anchor body are at risk for suture cutting through bone since the suture eyelet is at the distal tip of the implant and the suture directly abrades against the bone edge during cyclic loading. Suture cutting through bone may be a significant source of fixation failure, particularly in osteopenic bone. Cite this article: Y. Ono, J. M. Woodmass, A. A. Nelson, R. S. Boorman, G. M. Thornton, I. K. Y. Lo. Knotless anchors with sutures external to the anchor body may be at risk for suture cutting through osteopenic bone. Bone Joint Res 2016;5:269–275. DOI: 10.1302/2046-3758.56.2000535. PMID:27357383

Thermoluminescence dosimetry applied to in vivo dose measurements for total body irradiation techniques.

PubMed

Duch, M A; Ginjaume, M; Chakkor, H; Ortega, X; Jornet, N; Ribas, M

1998-06-01

In total body irradiation (TBI) treatments in vivo dosimetry is recommended because it makes it possible to ensure the accuracy and quality control of dose delivery. The aim of this work is to set up an in vivo thermoluminescence dosimetry (TLD) system to measure the dose distribution during the TBI technique used prior to bone marrow transplant. Some technical problems due to the presence of lung shielding blocks are discussed. Irradiations were performed in the Hospital de la Santa Creu i Sant Pau by means of a Varian Clinac-1800 linear accelerator with 18 MV X-ray beams. Different TLD calibration experiments were set up to optimize in vivo dose assessment and to analyze the influence on dose measurement of shielding blocks. An algorithm to estimate midplane doses from entrance and exit doses is proposed and the estimated dose in critical organs is compared to internal dose measurements performed in an Alderson anthropomorphic phantom. The predictions of the dose algorithm, even in heterogeneous zones of the body such as the lungs, are in good agreement with the experimental results obtained with and without shielding blocks. The differences between measured and predicted values are in all cases lower than 2%. The TLD system described in this work has been proven to be appropriate for in vivo dosimetry in TBI irradiations. The described calibration experiments point out the difficulty of calibrating an in vivo dosimetry system when lung shielding blocks are used.

Biomaterial shell bending with 3D-printed templates in vertical and alveolar ridge augmentation: a technical note.

PubMed

Draenert, Florian G; Gebhart, Florian; Mitov, Gergo; Neff, Andreas

2017-06-01

Alveolar ridge and vertical augmentations are challenging procedures in dental implantology. Even material blocks with an interconnecting porous system are never completely resorbed. Shell techniques combined with autologous bone chips are therefore the gold standard. Using biopolymers for these techniques is well documented. We applied three-dimensional (3-D) techniques to create an individualized bending model for the adjustment of a plane biopolymer membrane made of polylactide. Two cases with a vertical alveolar ridge defect in the maxilla were chosen. The cone beam computed tomography data were processed with a 3-D slicer and the Autodesk Meshmixer to generate data about the desired augmentation result. STL data were used to print a bending model. A 0.2-mm poly-D, L-lactic acid membrane (KLS Matin Inc., Tuttlingen, Germany) was bended accordingly and placed into the defect via a tunnel approach in both cases. A mesh graft of autologous bone chips and hydroxylapatite material was augmented beneath the shell, which was fixed with osteosynthesis screws. The operative procedure was fast and without peri- or postoperative complications or complaints. The panoramic x-ray showed correct fitting of the material in the location. Bone quality at the time of implant placement was type II, resulting in good primary stability. A custom-made 3-D model for bending confectioned biomaterial pieces is an appropriate method for individualized adjustment in shell techniques. The advantages over direct printing of the biomaterial shell and products on the market, such as the Xyoss shell (Reoss Inc., Germany), include cost-efficiency and avoidance of regulatory issues. Copyright © 2016 Elsevier Inc. All rights reserved.

Vitamin D

MedlinePlus

... body needs to grow and develop normally. Vitamin D helps your body absorb calcium. Calcium is one ... building blocks of bone. A lack of vitamin D can lead to bone diseases such as osteoporosis ...

Evaluation of the presence of VEGF, BMP2 and CBFA1 proteins in autogenous bone graft: histometric and immunohistochemical analysis.

PubMed

Guskuma, Marcos Heidy; Hochuli-Vieira, Eduardo; Pereira, Flávia Priscila; Rangel-Garcia, Idelmo; Okamoto, Roberta; Okamoto, Tetuo; Filho, Osvaldo Magro

2014-06-01

The purpose of this study was to evaluate the expression of proteins that participate in the osteoinduction stage (VEGF, BMP2 and CBFA1) of the process of bone regeneration of defects created in rat calvariae and filled with autogenous bone block grafts. 10 adult male rats (Rattus norvegicus albinus, Wistar) were used, who received two bone defects measuring 5 mm each in the calvariae. The bone defects constituted two experimental groups (n = 10): Control Group (CONT) (defects filled with a coagulum); Graft Group (GR) (defects filled with autogenous bone removed from the contralateral defect). The animals were submitted to euthanasia at 7 and 30 days post-operatively. Quantitative analysis demonstrated significantly greater bone formation in Group GR, but the presence of the studied proteins was significantly greater in the CONT Group in both time intervals of observation. It was not possible in this study in cortical bone block groups to detect the osteoinductive proteins in a significant amount during the repair process. Copyright © 2013 European Association for Cranio-Maxillo-Facial Surgery. Published by Elsevier Ltd. All rights reserved.

Influence of Screw Length and Bone Thickness on the Stability of Temporary Implants

PubMed Central

Fernandes, Daniel Jogaib; Elias, Carlos Nelson; Ruellas, Antônio Carlos de Oliveira

2015-01-01

The purpose of this work was to study the influence of screw length and bone thickness on the stability of temporary implants. A total of 96 self-drilling temporary screws with two different lengths were inserted into polyurethane blocks (n = 66), bovine femurs (n = 18) and rabbit tibia (n = 12) with different cortical thicknesses (1 to 8 mm). Screws insertion in polyurethane blocks was assisted by a universal testing machine, torque peaks were collected by a digital torquemeter and bone thickness was monitored by micro-CT. The results showed that the insertion torque was significantly increased with the thickness of cortical bone from polyurethane (p < 0.0001), bovine (p = 0.0035) and rabbit (p < 0.05) sources. Cancellous bone improved significantly the mechanical implant stability. Insertion torque and insertion strength was successfully moduled by equations, based on the cortical/cancellous bone behavior. Based on the results, insertion torque and bone strength can be estimate in order to prevent failure of the cortical layer during temporary screw placement. The stability provided by a cortical thickness of 2 or 1 mm coupled to cancellous bone was deemed sufficient for temporary implants stability. PMID:28793582

Can CT-based patient-matched instrumentation achieve consistent rotational alignment in knee arthroplasty?

PubMed

Tibesku, C O; Innocenti, B; Wong, P; Salehi, A; Labey, L

2012-02-01

Long-term success of contemporary total knee replacements relies to a large extent on proper implant alignment. This study was undertaken to test whether specimen-matched cutting blocks based on computed axial tomography (CT) scans could provide accurate rotational alignment of the femoral component. CT scans of five fresh frozen full leg cadaver specimens, equipped with infrared reflective markers, were used to produce a specimen-matched femoral cutting block. Using those blocks, the bone cuts were made to implant a bi-compartmental femoral component. Rotational alignment of the components in the horizontal plane was determined using an optical measurement system and compared with all relevant rotational reference axes identified on the CT scans. Average rotational alignment for the bi-compartmental component in the horizontal plane was 1.9° (range 0°-6.3°; standard deviation 2.6°). One specimen that showed the highest deviation from the planned alignment also featured a completely degraded medial articular surface. The CT-based specimen-matched cutting blocks achieved good rotational alignment accuracy except for one specimen with badly damaged cartilage. In such cases, imaging techniques that visualize the cartilage layer might be more suitable to design cutting blocks, as they will provide a better fit and increased surface support.

Vertical augmentation with interpositional blocks of anorganic bovine bone vs. 7-mm-long implants in posterior mandibles: 1-year results of a randomized clinical trial.

PubMed

Felice, Pietro; Pellegrino, Gerardo; Checchi, Luigi; Pistilli, Roberto; Esposito, Marco

2010-12-01

To evaluate whether 7-mm-long implants could be an alternative to longer implants placed in vertically augmented posterior mandibles. Sixty patients with posterior mandibular edentulism with 7-8 mm bone height above the mandibular canal were randomized to either vertical augmentation with anorganic bovine bone blocks and delayed 5-month placement of ≥10 mm implants or to receive 7-mm-long implants. Four months after implant placement, provisional prostheses were delivered, replaced after 4 months, by definitive prostheses. The outcome measures were prosthesis and implant failures, any complications and peri-implant marginal bone levels. All patients were followed to 1 year after loading. One patient dropped out from the short implant group. In two augmented mandibles, there was not sufficient bone to place 10-mm-long implants possibly because the blocks had broken apart during insertion. One prosthesis could not be placed when planned in the 7 mm group vs. three prostheses in the augmented group, because of early failure of one implant in each patient. Four complications (wound dehiscence) occurred during graft healing in the augmented group vs. none in the 7 mm group. No complications occurred after implant placement. These differences were not statistically significant. One year after loading, patients of both groups lost an average of 1 mm of peri-implant bone. There no statistically significant differences in bone loss between groups. When residual bone height over the mandibular canal is between 7 and 8 mm, 7 mm short implants might be a preferable choice than vertical augmentation, reducing the chair time, expenses and morbidity. These 1-year preliminary results need to be confirmed by follow-up of at least 5 years. © 2010 John Wiley & Sons A/S.

Insertion torque in different bone models with different screw pitch: an in vitro study.

PubMed

Orlando, Bruno; Barone, Antonio; Giorno, Thierry M; Giacomelli, Luca; Tonelli, Paolo; Covani, Ugo

2010-01-01

Orthopedic surgeons use different types of screws for bone fixation. Whereas hard cortical bone requires a screw with a fine pitch, in softer cancellous bone a wider pitch might help prevent micromotion and eventually lead to greater implant stability. The aim of this study was to validate the assumption that fine-pitch implants are appropriate for cortical bone and wide-pitch implants are appropriate for cancellous bone. Wide-pitch and fine-pitch implants were inserted in both hard (D1 and D2) bone and soft (D3 and D4) bone, which was simulated by separate experimental blocks of cellular rigid polyurethane foam. A series of insertion sites in D1-D2 and D3-D4 experimental blocks were prepared using 1.5-mm and 2.5-mm drills. The final torque required to insert each implant was recorded. Wide-pitch implants displayed greater insertion torque (20% more than the fine-pitch implants) in cancellous bone and were therefore more suitable than fine-pitch implants. It is more appropriate to use a fine pitch design for implants, in conjunction with a 2.5-mm osteotomy site, in dense cortical bone (D1 or D2), whereas it is recommended to choose a wide-pitch design for implants, in conjunction with a 1.5-mm osteotomy site, in softer bone (D3 or D4).

Fabrication and evaluation of interconnected porous carbonate apatite from alpha tricalcium phosphate spheres.

PubMed

Ishikawa, Kunio; Arifta, Tya Indah; Hayashi, Koichiro; Tsuru, Kanji

2018-03-26

Carbonate apatite (CO 3 Ap) blocks have attracted considerable attention as an artificial bone substitute material because CO 3 Ap is a component of and shares properties with bone, including high osteoconductivity and replacement by bone similar to autografts. In this study, we fabricated an interconnected porous CO 3 Ap block using α-tricalcium phosphate (TCP) spheres and evaluated the tissue response to this material in a rabbit tibial bone defect model. Interconnected porous α-TCP, the precursor of interconnected porous CO 3 Ap, could not be fabricated directly by sintering α-TCP spheres. It was therefore made via a setting reaction with α-TCP spheres, yielding interconnected porous calcium-deficient hydroxyapatite that was subjected to heat treatment. Immersing the interconnected porous α-TCP in Na-CO 3 -PO 4 solution produced CO 3 Ap, which retained the interconnected porous structure after the dissolution-precipitation reaction. The diametral tensile strength and porosity of the porous CO 3 Ap were 1.8 ± 0.4 MPa and 55% ± 3.2%, respectively. Both porous and dense (control) CO 3 Ap showed excellent tissue response and good osteoconductivity. At 4 weeks after surgery, approximately 15% ± 4.9% of the tibial bone defect was filled with new bone when reconstruction was performed using porous CO 3 Ap; this amount was five times greater than that obtained with dense CO 3 Ap. At 12 weeks after surgery, for porous CO 3 Ap, approximately 47% of the defect was filled with new bone as compared to 16% for dense CO 3 Ap. Thus, the interconnected porous CO 3 Ap block is a promising artificial bone substitute material for the treatment of bone defects caused by large fractures or bone tumor resection. © 2018 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2018. © 2018 Wiley Periodicals, Inc.

Fabrication of B-type carbonate apatite blocks by the phosphorization of free-molding gypsum-calcite composite.

PubMed

Zaman, Chowdury Tanira; Takeuchi, Akari; Matsuya, Shigeki; Zaman, Q H M Shawket; Ishikawa, Kunio

2008-09-01

B-type carbonate apatite (CO3Ap) block may be an ideal artificial bone substitute because it is closer in chemical composition to bone mineral. In the present study, the feasibility to fabricate CO3Ap blocks was investigated using compositional transformation, which was based on the dissolution-precipitation reaction of a gypsum-calcite composite with free-molding behavior. For the compositional change, or phosphorization, gypsum-calcite composites of varying CaCO3 contents were immersed in 1 mol/L (NH4)3PO4 aqueous solution at 100 degrees C for 24 hours. No macroscopic changes were found after the treatment, whereas microscopic change was observed at SEM level. X-ray diffraction, Fourier transform infrared spectroscopy and CHN analysis indicated that the composites were B-type CO3Ap containing approximately 6-7 wt% of CO3, a value similar to that of biological bone apatite. Diametral tensile strength of the CO3Ap block was approximately 1-3 MPa. Based on the results obtained, it was therefore concluded that gypsum-calcite was a good candidate for the fabrication of CO3Ap blocks, coupled with the advantage that the composite can be molded to any shape by virtue of the setting property of gypsum.

78 FR 36241 - Notice of Inventory Completion: University of Oregon Museum of Natural and Cultural History...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-06-17

... 13 points, 9 scrapers, 1 blade, 1 bone awl, 1 pumice block, and 1 lot of pigment samples. In 1946... objects are 1 scraper fragment, 1 copper pendant, 1 pipe in fragments, 2 worked tuff, 1 worked bone, 1 dentalium shell, 1 bird bone, 1 pestle, 1 worked chert, and 2 bone fragments. In 1951, human remains...

Hydrogel-embedded nanocrystalline hydroxyapatite granules (elastic blocks) based on a cross-linked polyvinylpyrrolidone as bone grafting substitute in a rat tibia model.

PubMed

Dau, Michael; Ganz, Cornelia; Zaage, Franziska; Frerich, Bernhard; Gerber, Thomas

2017-01-01

The aim of this study was to examine the in vivo characteristics and levels of integration and degradation of a ready-to-use bone grafting block with elastic properties (elastic block) for the use in surgery. Thirty-six male Wistar rats underwent surgical creation of a well-defined bone defect in the tibia. All created defects - one per animal - were filled with an unsintered nanocrystalline hydroxyapatite embedded either with a non-cross-linked hydrogel carrier (CONT, n=18) or a cross-linked hydrogel carrier (elastic block [EB], n=18) based on polyvinylpyrrolidone (PVP) and silica sol, respectively. The animals were killed after 12 (n=12), 21 (n=12) and 63 days (n=12). The bone formation and defect healing were quantified by histomorphometric measurements made in paraffin sections. Additionally, immunohistochemical (tartrate-resistant acid phosphatase [TRAP] and alkaline phosphatase [aP]), antibody-based examinations (CD68) and energy-dispersive x-ray scattering measurements of silica atom concentration were carried out. A larger remaining bone defect area overall was observed in EB after 12 days and 21 days. After 63 days, similar areas of remaining bone defects were found. The amount of the remaining carrier material in EB overall was higher at all times. In CONT no residual carrier material was found at 12 days and later. CD68 analyses showed significantly lower level of CD68-positive marked cells after 21 days in CONT, and nonsignificant differences at 12 and 63 days, respectively. Additionally, a significantly higher level of aP-positive marked cells was observed in CONT after 12 days. Later on, the levels of aP-positive marked cells were slightly higher in EB (21 and 63 days). Furthermore, no significant differences regarding the level of TRAP-positive marked cells in each group were observed. The bone substitute (EB) with the cross-linked PVP-based hydrogel carrier leads at the beginning to a higher amount of remaining carrier material and remaining bone substitute. This delayed degradation is supposed to be the reason for the observed lower level of bone remodeling and is caused by the irradiation changes (cross links) in the structure in PVP.

Hydrogel-embedded nanocrystalline hydroxyapatite granules (elastic blocks) based on a cross-linked polyvinylpyrrolidone as bone grafting substitute in a rat tibia model

PubMed Central

Dau, Michael; Ganz, Cornelia; Zaage, Franziska; Frerich, Bernhard; Gerber, Thomas

2017-01-01

Purpose The aim of this study was to examine the in vivo characteristics and levels of integration and degradation of a ready-to-use bone grafting block with elastic properties (elastic block) for the use in surgery. Materials and methods Thirty-six male Wistar rats underwent surgical creation of a well-defined bone defect in the tibia. All created defects – one per animal – were filled with an unsintered nanocrystalline hydroxyapatite embedded either with a non-cross-linked hydrogel carrier (CONT, n=18) or a cross-linked hydrogel carrier (elastic block [EB], n=18) based on polyvinylpyrrolidone (PVP) and silica sol, respectively. The animals were killed after 12 (n=12), 21 (n=12) and 63 days (n=12). The bone formation and defect healing were quantified by histomorphometric measurements made in paraffin sections. Additionally, immunohistochemical (tartrate-resistant acid phosphatase [TRAP] and alkaline phosphatase [aP]), antibody-based examinations (CD68) and energy-dispersive x-ray scattering measurements of silica atom concentration were carried out. Results A larger remaining bone defect area overall was observed in EB after 12 days and 21 days. After 63 days, similar areas of remaining bone defects were found. The amount of the remaining carrier material in EB overall was higher at all times. In CONT no residual carrier material was found at 12 days and later. CD68 analyses showed significantly lower level of CD68-positive marked cells after 21 days in CONT, and nonsignificant differences at 12 and 63 days, respectively. Additionally, a significantly higher level of aP-positive marked cells was observed in CONT after 12 days. Later on, the levels of aP-positive marked cells were slightly higher in EB (21 and 63 days). Furthermore, no significant differences regarding the level of TRAP-positive marked cells in each group were observed. Conclusion The bone substitute (EB) with the cross-linked PVP-based hydrogel carrier leads at the beginning to a higher amount of remaining carrier material and remaining bone substitute. This delayed degradation is supposed to be the reason for the observed lower level of bone remodeling and is caused by the irradiation changes (cross links) in the structure in PVP. PMID:29066890

Bone loss from Wnt inhibition mitigated by concurrent alendronate therapy.

PubMed

Madan, Babita; McDonald, Mitchell J; Foxa, Gabrielle E; Diegel, Cassandra R; Williams, Bart O; Virshup, David M

2018-01-01

Dysregulated Wnt signaling is associated with the pathogenesis of cancers, fibrosis, and vascular diseases. Inhibition of Wnt signaling has shown efficacy in various pre-clinical models of these disorders. One of the key challenges in developing targeted anti-cancer drugs is to balance efficacy with on-target toxicity. Given the crucial role Wnts play in the differentiation of osteoblasts and osteoclasts, acute inhibition of Wnt signaling is likely to affect bone homeostasis. In this study, we evaluated the skeletal effect of small molecule inhibitor of an o-acyl transferase porcupine (PORCN) that prevents Wnt signaling by blocking the secretion of all Wnts. Micro-computed tomography and histomorphometric evaluation revealed that the bones of mice treated with two structurally distinct PORCN inhibitors LGK974 and ETC-1922159 (ETC-159) had loss-of-bone volume and density within 4 weeks of exposure. This decreased bone mass was associated with a significant increase in adipocytes within the bone marrow. Notably, simultaneous administration of a clinically approved anti-resorptive, alendronate, a member of the bisphosphonate family, mitigated loss-of-bone mass seen upon ETC-159 treatment by regulating activity of osteoclasts and blocking accumulation of bone marrow adipocytes. Our results support the addition of bone protective agents when treating patients with PORCN inhibitors. Mitigation of bone toxicity can extend the therapeutic utility of Wnt pathway inhibitors.

Zoledronate promotes bone formation by blocking osteocyte-osteoblast communication during bone defect healing.

PubMed

Cui, Pingping; Liu, Hongrui; Sun, Jing; Amizuka, Norio; Sun, Qinfeng; Li, Minqi

2018-01-01

Nitrogen-containing bisphosphonates (N-BPs) are potent antiresorptive drugs and their actions on osteoclasts have been studied extensively. Recent studies have suggested that N-BPs also target bone-forming cells. However, the precise mechanism of N-BPs in osteoblasts is paradoxical, and the specific role of osteocytes is worthy of in-depth study. Here, we investigated the cellular mechanisms of N-BPs regulating bone defect healing by zoledronate (ZA). Bone histomorphometry confirmed an increase in new bone formation by systemic ZA administration. ZA induced more alkaline phosphatase-positive osteoblasts and tartrate-resistant acid phosphatase-positive osteoclasts residing on the bone surface. Inexplicably, ZA increased SOST expression in osteocytes embedded in the bone matrix, which was not compatible with the intense osteoblast activity on the bone surface. ZA induced heterogeneous osteocytes and disturbed the distribution of the osteocytic-canalicular system (OLCS). Furthermore, according to the degree of OLCS regularity, dentin matrix protein 1 reactivity had accumulated around osteocytes in the ZA group, but it was distributed evenly in the OLCS of the control group. The control group showed a dense array of the gap junction protein connexin 43. However, connexin 43 was extremely sparse after ZA administration. In summary, ZA treatment reduces gap junction connections and blocks cellular communication between osteocytes and osteoblasts. Retaining SOST expression in osteocytes leads to activation of the Wnt signaling pathway and subsequent bone formation.

Evaluation of demineralized bone and bone transplants in vitro and in vivo with cone beam computed tomography imaging.

PubMed

Draenert, F G; Gebhart, F; Berthold, M; Gosau, M; Wagner, W

2010-07-01

The objective of this study was to determine the ability of two flat panel cone beam CT (CBCT) devices to identify demineralized bone and bone transplants in vivo and in vitro. Datasets from patients with autologous bone grafts (n = 9, KaVo 3DeXam (KaVo, Biberach, Germany); n = 38, Accuitomo 40 (Morita, Osaka, Japan)) were retrospectively evaluated. Demineralized and non-demineralized porcine cancellous bone blocks were examined with the two CBCT devices. A SawBone skull (Pacific Research Laboratories, Vashon, WA) was used as a positioning tool for the bone blocks. Descriptive evaluation and image quality assessment were conducted on the KaVo 3DeXam data (voxel size 0.3 mm) using the OsiriX viewer as well as on the Morita Accuitomo data (voxel size 0.25 mm) using proprietary viewer software. Both in vivo and in vitro, the descriptive analysis of the images of the two devices showed well-visualized bone transplants with clearly defined cancellous bones and well-defined single bone trabeculae in all cross-sections. In vitro, demineralized samples showed lower radiographic opacity but no significant loss of quality compared with fresh bone (P = 0.070). Single cancellous bone trabeculae were significantly better visualized with the Morita 3D Accuitomo device than with the KaVo 3DeXam device (P = 0.038). Both the KaVo 3DeXam and Morita 3D Accuitomo devices produce good-quality images of cancellous bones in in vivo remodelling as well as after in vitro demineralization.

Loss of the hematopoietic stem cell factor GATA2 in the osteogenic lineage impairs trabecularization and mechanical strength of bone.

PubMed

Tolkachov, Alexander; Fischer, Cornelius; Ambrosi, Thomas H; Bothe, Melissa; Han, Chung-Ting; Muenzner, Matthias; Mathia, Susanne; Salminen, Marjo; Seifert, Georg; Thiele, Mario; Duda, Georg N; Meijsing, Sebastiaan H; Sauer, Sascha; Schulz, Tim J; Schupp, Michael

2018-03-26

The transcription factor GATA2 is required for expansion and differentiation of hematopoietic stem cells (HSCs). In mesenchymal stem cells (MSCs) GATA2 blocks adipogenesis, but its biological relevance and underlying genomic events are unknown. We report a dual function of GATA2 in bone homeostasis. GATA2 in MSCs binds near genes involved in skeletal system development and co-localizes with motifs for FOX and HOX transcription factors, known regulators of skeletal development. Ectopic GATA2 blocks osteoblastogenesis by interfering with SMAD1/5/8 activation. MSC-specific deletion of GATA2 in mice increases numbers and differentiation capacity of bone-derived precursors, resulting in elevated bone formation. Surprisingly, MSC-specific GATA2 deficiency impairs trabecularization and mechanical strength of bone, involving reduced MSC expression of the osteoclast inhibitor osteoprotegerin and increased osteoclast numbers. Thus, GATA2 affects bone turnover via MSC-autonomous and indirect effects. By regulating bone trabecularization, GATA2 expression in the osteogenic lineage may contribute to the anatomical and cellular microenvironment of the HSC niche required for hematopoiesis. Copyright © 2018 American Society for Microbiology.

Temperature Values Variability in Piezoelectric Implant Site Preparation: Differences between Cortical and Corticocancellous Bovine Bone.

PubMed

Lamazza, Luca; Garreffa, Girolamo; Laurito, Domenica; Lollobrigida, Marco; Palmieri, Luigi; De Biase, Alberto

2016-01-01

Various parameters can influence temperature rise and detection during implant site preparation. The aim of this study is to investigate local temperature values in cortical and corticocancellous bovine bone during early stages of piezoelectric implant site preparation. 20 osteotomies were performed using a diamond tip (IM1s, Mectron Medical Technology, Carasco, Italy) on two different types of bovine bone samples, cortical and corticocancellous, respectively. A standardized protocol was designed to provide constant working conditions. Temperatures were measured in real time at a fixed position by a fiber optic thermometer. Significantly higher drilling time (154.90 sec versus 99.00 sec; p < 0.0001) and temperatures (39.26°C versus 34.73°C; p = 0.043) were observed in the cortical group compared to the corticocancellous group. A remarkable variability of results characterized the corticocancellous blocks as compared to the blocks of pure cortical bone. Bone samples can influence heat generation during in vitro implant site preparation. When compared to cortical bone, corticocancellous samples present more variability in temperature values. Even controlling most experimental factors, the impact of bone samples still remains one of the main causes of temperature variability.

A biomechanical study comparing a raft of 3.5 mm cortical screws with 6.5 mm cancellous screws in depressed tibial plateau fractures.

PubMed

Patil, Sunit; Mahon, Andrew; Green, Sarah; McMurtry, Ian; Port, Andrew

2006-06-01

There has been a recent trend towards using a raft of small diameter 3.5mm cortical screws for supporting depressed tibial plateau fractures (Schatzker type III). Our aim was to compare the biomechanical properties of a raft of 3.5 mm cortical screws with that of 6.5 mm cancellous screws in a synthetic bone model. Ten rigid polyurethane foam (sawbone) blocks, with a density simulating osteoporotic bone and ten blocks with a density simulating normal density bone were obtained. A Schatzker type III fracture was created in each block. The fracture fragments were then elevated and supported using two 6.5 mm cancellous screws in ten blocks and four 3.5 mm cortical screws in the remaining. The fractures were loaded using a Lloyd testing machine. The mean force needed to produce a depression of 5 mm was 700.8 N with the four-screw construct and 512.4 N with the two-screw construct in the osteoporotic model. This difference was highly statistically significant (p = 0.009). The mean force required to produce the same depression was 1878.2 N with the two-screw construct and 1938.2 N with the four-screw construct in the non-osteoporotic model. Though the difference was not statistically significant (p = 0.42), an increased fragmentation of the synthetic bone fragments was noticed with the two-screw construct but not with the four-screw construct. A raft of four 3.5 mm cortical screws is biomechanically stronger than two 6.5 mm cancellous screws in resisting axial compression in osteoporotic bone.

[Progress of Masquelet technique to repair bone defect].

PubMed

Yin, Qudong; Sun, Zhenzhong; Gu, Sanjun

2013-10-01

To summarize the progress of Masquelet technique to repair bone defect. The recent literature concerning the application of Masquelet technique to repair bone defect was extensively reviewed and summarized. Masquelet technique involves a two-step procedure. First, bone cement is used to fill the bone defect after a thorough debridement, and an induced membrane structure surrounding the spacer formed; then the bone cement is removed after 6-8 weeks, and rich cancellous bone is implanted into the induced membrane. Massive cortical bone defect is repaired by new bone forming and consolidation. Experiments show that the induced membrane has vascular system and is also rich in vascular endothelial growth factor, transforming growth factor beta1, bone morphogenetic protein 2, and bone progenitor cells, so it has osteoinductive property; satisfactory results have been achieved in clinical application of almost all parts of defects, various types of bone defect and massive defect up to 25 cm long. Compared with other repair methods, Masquelet technique has the advantages of reliable effect, easy to operate, few complications, low requirements for recipient site, and wide application. Masquelet technique is an effective method to repair bone defect and is suitable for various types of bone defect, especially for bone defects caused by infection and tumor resection.

Synthetic Bone Substitute Engineered with Amniotic Epithelial Cells Enhances Bone Regeneration after Maxillary Sinus Augmentation

PubMed Central

Barboni, Barbara; Mangano, Carlo; Valbonetti, Luca; Marruchella, Giuseppe; Berardinelli, Paolo; Martelli, Alessandra; Muttini, Aurelio; Mauro, Annunziata; Bedini, Rossella; Turriani, Maura; Pecci, Raffaella; Nardinocchi, Delia; Zizzari, Vincenzo Luca; Tetè, Stefano; Piattelli, Adriano; Mattioli, Mauro

2013-01-01

Background Evidence has been provided that a cell-based therapy combined with the use of bioactive materials may significantly improve bone regeneration prior to dental implant, although the identification of an ideal source of progenitor/stem cells remains to be determined. Aim In the present research, the bone regenerative property of an emerging source of progenitor cells, the amniotic epithelial cells (AEC), loaded on a calcium-phosphate synthetic bone substitute, made by direct rapid prototyping (rPT) technique, was evaluated in an animal study. Material And Methods Two blocks of synthetic bone substitute (∼0.14 cm3), alone or engineered with 1×106 ovine AEC (oAEC), were grafted bilaterally into maxillary sinuses of six adult sheep, an animal model chosen for its high translational value in dentistry. The sheep were then randomly divided into two groups and sacrificed at 45 and 90 days post implantation (p.i.). Tissue regeneration was evaluated in the sinus explants by micro-computer tomography (micro-CT), morphological, morphometric and biochemical analyses. Results And Conclusions The obtained data suggest that scaffold integration and bone deposition are positively influenced by allotransplantated oAEC. Sinus explants derived from sheep grafted with oAEC engineered scaffolds displayed a reduced fibrotic reaction, a limited inflammatory response and an accelerated process of angiogenesis. In addition, the presence of oAEC significantly stimulated osteogenesis either by enhancing bone deposition or making more extent the foci of bone nucleation. Besides the modulatory role played by oAEC in the crucial events successfully guiding tissue regeneration (angiogenesis, vascular endothelial growth factor expression and inflammation), data provided herein show that oAEC were also able to directly participate in the process of bone deposition, as suggested by the presence of oAEC entrapped within the newly deposited osteoid matrix and by their ability to switch-on the expression of a specific bone-related protein (osteocalcin, OCN) when transplanted into host tissues. PMID:23696804

2-(trimethylammonium) ethyl (R)-3-methoxy-3-oxo-2-stearamidopropyl phosphate suppresses osteoclast maturation and bone resorption by targeting macrophage-colony stimulating factor signaling.

PubMed

Park, So Jeong; Park, Doo Ri; Bhattarai, Deepak; Lee, Kyeong; Kim, Jaesang; Bae, Yun Soo; Lee, Soo Young

2014-08-01

2-(Trimethylammonium) ethyl (R)-3-methoxy-3-oxo-2-stearamidopropyl phosphate [(R)-TEMOSPho], a derivative of an organic chemical identified from a natural product library, promotes highly efficient megakaryopoiesis. Here, we show that (R)-TEMOSPho blocks osteoclast maturation from progenitor cells of hematopoietic origin, as well as blocking the resorptive function of mature osteoclasts. The inhibitory effect of (R)-TEMOSPho on osteoclasts was due to a disruption of the actin cytoskeleton, resulting from impaired downstream signaling of c-Fms, a receptor for macrophage-colony stimulating factor linked to c-Cbl, phosphoinositol-3-kinase (PI3K), Vav3, and Rac1. In addition, (R)-TEMOSPho blocked inflammation-induced bone destruction by reducing the numbers of osteoclasts produced in mice. Thus, (R)-TEMOSPho may represent a promising new class of antiresorptive drugs for the treatment of bone loss associated with increased osteoclast maturation and activity.

[Development of computer aided forming techniques in manufacturing scaffolds for bone tissue engineering].

PubMed

Wei, Xuelei; Dong, Fuhui

2011-12-01

To review recent advance in the research and application of computer aided forming techniques for constructing bone tissue engineering scaffolds. The literature concerning computer aided forming techniques for constructing bone tissue engineering scaffolds in recent years was reviewed extensively and summarized. Several studies over last decade have focused on computer aided forming techniques for bone scaffold construction using various scaffold materials, which is based on computer aided design (CAD) and bone scaffold rapid prototyping (RP). CAD include medical CAD, STL, and reverse design. Reverse design can fully simulate normal bone tissue and could be very useful for the CAD. RP techniques include fused deposition modeling, three dimensional printing, selected laser sintering, three dimensional bioplotting, and low-temperature deposition manufacturing. These techniques provide a new way to construct bone tissue engineering scaffolds with complex internal structures. With rapid development of molding and forming techniques, computer aided forming techniques are expected to provide ideal bone tissue engineering scaffolds.

Comparative study of open and arthroscopic coracoid transfer for shoulder anterior instability (Latarjet)-computed tomography evaluation at a short term follow-up. Part II.

PubMed

Kordasiewicz, Bartłomiej; Kicinski, Maciej; Małachowski, Konrad; Wieczorek, Janusz; Chaberek, Sławomir; Pomianowski, Stanisław

2018-05-01

The aim of this study was to evaluate and to compare the radiological parameters after arthroscopic and open Latarjet technique via evaluation of computed tomography (CT) scans. Our hypothesis was that the radiological results after arthroscopic stabilisation remained in the proximity of those results achieved after open stabilisation. CT scan evaluation results of patients after primary Latarjet procedure were analysed. Patients operated on between 2006 and 2011 using an open technique composed the OPEN group and patients operated on arthroscopically between 2011 and 2013 composed the ARTHRO group. Forty-three out of 55 shoulders (78.2%) in OPEN and 62 out of 64 shoulders (95.3%) in ARTHRO were available for CT scan evaluation. The average age at surgery was 28 years in OPEN and 26 years in ARTHRO. The mean follow-up was 54.2 months in OPEN and 23.4 months in ARTHRO. CT scan evaluation was used to assess graft fusion and osteolysis. Bone block position and screw orientation were assessed in the axial and the sagittal views. The subscapularis muscle fatty infiltration was evaluated according to Goutallier classification. The non-union rate was significantly higher in OPEN than in ARTHRO: 5 (11.9%) versus 1 (1.7%) (p < 0.05). The total graft osteolysis was significantly higher in the OPEN group: five cases (11.9%) versus zero in ARTHRO (p < 0.05). Graft fracture incidence was comparable in both groups: in two patients in ARTHRO (3.3%) and one case (2.4%) in the OPEN group (p > 0.05). These results should be evaluated very carefully due to significant difference in the follow-up of both groups. A significantly higher rate of partial graft osteolysis at the level of the superior screw was reported in ARTHRO with 32 patients (53.3%) versus 10 (23.8%) in OPEN (p < 0.05). In the axial view, 78.4% of patients in ARTHRO and 80.5% in OPEN had the coracoid bone block in an acceptable position (between 4 mm medially and 2 mm laterally). In the sagittal plane, the bone block was in an acceptable position between 2 and 5 o'clock in 86.7% of patients in ARTHRO and 90.2% in OPEN (p > 0.05). However, in the position between 3 and 5 o'clock there were 56.7% of the grafts in ARTHRO versus 87.8% in OPEN (p < 0.05). The screws were more parallel to the glenoid surface in ARTHRO-the angles were 12.3° for the inferior screw and 12.6° for the superior one. These angles in the OPEN group were respectively 15° and 17° (p < 0.05 and for the superior screw). There was no significant difference in the presence of fatty infiltration of the subscapularis muscle. Arthroscopic Latarjet stabilisation showed satisfactory radiographic results, comparable to the open procedure, however the short-term follow-up can bias this evaluation. Graft healing rate was very high in the arthroscopic technique, but yet osteolysis of the superior part of the graft and more superior graft position in the sagittal view were significantly different when compared to the open technique. The screw position was slightly more parallel to the glenoid via the arthroscopic technique. We recommend both further investigation and development of the arthroscopic technique. III.

Leukemia inhibitory factor: a novel bone-active cytokine.

PubMed

Reid, L R; Lowe, C; Cornish, J; Skinner, S J; Hilton, D J; Willson, T A; Gearing, D P; Martin, T J

1990-03-01

A number of cytokines have been found to be potent regulators of bone resorption and to share the properties originally attributed to osteoclast-activating factor. One such activity, differentiation-inducing factor (DIF, D-factor) from mouse spleen cells, shares a number of biological and biochemical properties with the recently characterized and cloned leukemia inhibitory factor (LIF). We have assessed the effects of recombinant LIF on bone resorption and other parameters in neonatal mouse calvaria. Both recombinant murine and human (h) LIFs stimulated 45Ca release from prelabeled calvaria in a dose-dependent manner. The increase in bone resorption was associated with an increase in the number of osteoclasts per mm2 bone. The osteolytic effect of hLIF were blocked by 10(-7) M indomethacin. hLIF also stimulated incorporation of [3H] thymidine into calvaria, but the dose-response relationship was distinct from that for bone resorption, and this effect was not blocked by indomethacin. Similarly, hLIF increased [3H]phenylalanine incorporation into calvaria, and this was also not inhibited by indomethacin. It is concluded that LIF stimulates bone resorption by a mechanism involving prostaglandin production, but that a distinct mechanism is responsible for its stimulation of DNA and protein synthesis. The primary structure of LIF differs from that of other fully characterized, bone-active cytokines, and it, thus, represents a novel factor which may be involved in the normal regulation of bone cell function.

Periodontal healing in one-wall intra-bony defects in dogs following implantation of autogenous bone or a coral-derived biomaterial.

PubMed

Kim, Chang-Sung; Choi, Seong-Ho; Cho, Kyoo-Sung; Chai, Jung-Kiu; Wikesjö, Ulf M E; Kim, Chong-Kwan

2005-06-01

Autogenous bone grafts and bone biomaterials are being used as part of protocols aiming at reconstruction of periodontal defects. There is a limited biologic information on the effect of such materials on periodontal healing, in particular aberrant healing events that may prevent their general use. The objective of this study was, using histological techniques, to evaluate periodontal healing with focus on root resorption and ankylosis following implantation of autogenous bone and a coral-derived biomaterial into intra-bony defects in dogs. One-wall intra-bony periodontal defects were surgically created at the distal aspect of the second and the mesial aspect of the fourth mandibular premolars in either right or left jaw quadrants in four Beagle dogs. Each animal received particulated autogenous bone and the resorbable calcium carbonate biomaterial into discrete one-wall intra-bony defects. The mucoperiosteal flaps were positioned and sutured to their pre-surgery position. The animals were euthanized 8 weeks post-surgery when block sections of the defect sites were collected and prepared for qualitative histological analysis. There were no significant differences in periodontal healing between sites receiving autograft bone and the coral-derived biomaterial. A well-organized periodontal ligament bridging new bone and cementum regeneration was observed extending coronal to a notch prepared to delineate the apical extent of the defect. Osteoid and bone with enclosed osteocytes were formed onto the surface of both autograft and coral particles. Although small resorption pits were evident in most teeth, importantly none of the biomaterials provoked marked root resorption. Ankylosis was not observed. Particulated autogenous bone and the coral-derived biomaterial may be implanted into periodontal defects without significant healing aberrations such as root resorption and ankylosis. The histopathological evaluation suggests that the autogenous bone graft has a limited osteogenic potential as demonstrated in this study model.

Ventral cervical fusion at multiple levels using free vascularized double-islanded fibula - a technical report and review of the relevant literature.

PubMed

Krishnan, Kartik G; Müller, Adolf

2002-04-01

Reconstruction of the cervical spine using free vascularized bone flaps has been described in the literature. The reports involve either one level or, when multiple levels, they describe en bloc resection and reconstruction. Stabilization of different levels with a preserved intermediate segment with a single vascularized flap has not been described. We report on the case of a 55-year-old man, who had been operated several times using conventional techniques for cervical myelopathy and instability, who presented to us with severe neck pain. Diagnostic procedures showed pseudarthrosis of C3/4 and stress-overload of the C3/4 and C5/6 segments. The C4/5 fusion was adequately rigid, but avascular. We performed anterior cervical fusion at the C3/4 and C5/6 levels with a vascularized fibula flap modified as a double island. The rigidly fused C4/5 block was preserved and vascularized with the periosteum bridging the two fibular islands. The method and technique are described in detail. Fusion was adequate. Donor site morbidity was minimal and temporary. The patient is symptom free to date (25 months). The suggested method provides the possibility of vertebral fusion at different levels using a single vascularized flap. The indications for this procedure are (1) repeated failure of conventional methods, (2) established poor bone healing and bone non-union with avascular grafts and (3) a well-fused or preserved intermediate segment. The relevant literature is reviewed.

Validation of value of actual micromotion as a direct measure of implant micromobility after healing (secondary implant stability). An in vivo histologic and biomechanical study.

PubMed

Trisi, Paolo; Berardini, Marco; Falco, Antonello; Podaliri Vulpiani, Michele

2016-11-01

The osseointegration process replaces the surgically damaged bone with newly formed bone in contact to the implant surface. This involves some loss of primary stability, which will continue until new bone is formed providing a new stability, known as "secondary stability." A direct measurement of secondary implant stability appears fundamental to determine the period and modalities for implant loading. The aim of this study was to validate the measurement of the implant micromotion to test secondary implant stability. Twenty-four 3.8 × 11.5 mm implants (Dynamix, Cortex, Shlomi, Israel) were inserted in sheep iliac crests. The animals were sacrificed after 2 months, and the freshly retrieved bone blocks were immediately fixed on a customized device to calculate the value of actual micromotion (VAM) according to a previously described technique. Implant stability quotient (ISQ) values, reverse torque value (RTV), %bone-to-implant contact (%BIC), bone volume percentage (%BV) and crestal bone loss (CBL) were also calculated for each implant. Statistical correlations between VAM and the other parameters were calculated. Data correlation analysis between the examined parameters showed that VAM significantly correlates (P < 0.05) to RTV, %BIC, ISQ and CBL. As VAM showed to be statistical correlated to the other parameters of osseointegration, it may be used to clinically check the amount of implant osseointegration, secondary stability and CBL. Future studies are needed to confirm these results moreover. An instrument to measure VAM in the oral cavity still needs to be developed. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Effect of low level laser and low intensity pulsed ultrasound therapy on bone remodeling during orthodontic tooth movement in rats.

PubMed

Alazzawi, Mohammed Mahmood Jawad; Husein, Adam; Alam, Mohammad Khursheed; Hassan, Rozita; Shaari, Rumaizi; Azlina, Ahmad; Salzihan, M S

2018-04-16

Quality bone regeneration, which leads to the improvement of bone remodeling, is essential for orthodontic treatment. In order to improve bone regeneration and increase the amount of tooth movement, different techniques have been implemented. The object of this study is to compare the effects of low-level laser therapy (LLLT), low-intensity pulsed ultrasound (LIPUS), and their combination on bone remodeling during orthodontic tooth movement. Eighty (80) male, 6-week-old Sprague Dawley rats were grouped in to four groups, the first group was irradiated with (940 nm) diode laser, second group with LIPUS, and third group with combination of both LLLT and LIPUS. A forth group used was a control group in an incomplete block split-mouth design. The LLLT and LIPUS were used to treat the area around the moving tooth once a day on days 0-7, then the experiment was ended in each experimental endpoint (1, 3, 7, 14, and 21 days). For amount of tooth movement, models were imaged and analyzed. Histological examination was performed after staining with (hematoxylin and eosin) and (alizarin red and Alcian Blue) stain. One step reverse transcription-polymerase chain reaction RT-PCR was also performed to elucidate the gene expression of RANK, RANKL, OPG, and RUNX-2. The amount of tooth movement, the histological bone remodeling, and the RT-PCR were significantly greater in the treatment groups than that in the control group. Among the treatment groups, the combination group was the highest and the LIPUS group was the lowest. These findings suggest that LLLT and LIPUS can enhance the velocity of tooth movement and improve the quality of bone remodeling during orthodontic tooth movement.

Biomechanical evaluation of oversized drilling technique on primary implant stability measured by insertion torque and resonance frequency analysis

PubMed Central

Santamaría-Arrieta, Gorka; Brizuela-Velasco, Aritza; Fernández-González, Felipe J.; Chávarri-Prado, David; Chento-Valiente, Yelko; Solaberrieta, Eneko; Diéguez-Pereira, Markel; Yurrebaso-Asúa, Jaime

2016-01-01

Background This study evaluated the influence of implant site preparation depth on primary stability measured by insertion torque and resonance frequency analysis (RFA). Material and Methods Thirty-two implant sites were prepared in eight veal rib blocks. Sixteen sites were prepared using the conventional drilling sequence recommended by the manufacturer to a working depth of 10mm. The remaining 16 sites were prepared using an oversize drilling technique (overpreparation) to a working depth of 12mm. Bone density was determined using cone beam computerized tomography (CBCT). The implants were placed and primary stability was measured by two methods: insertion torque (Ncm), and RFA (implant stability quotient [ISQ]). Results The highest torque values were achieved by the conventional drilling technique (10mm). The ANOVA test confirmed that there was a significant correlation between torque and drilling depth (p<0.05). However, no statistically significant differences were obtained between ISQ values at 10 or 12 mm drilling depths (p>0.05) at either measurement direction (cortical and medullar). No statistical relation between torque and ISQ values was identified, or between bone density and primary stability (p >0.05). Conclusions Vertical overpreparation of the implant bed will obtain lower insertion torque values, but does not produce statistically significant differences in ISQ values. Key words:Implant stability quotient, overdrilling, primary stability, resonance frequency analysis, torque. PMID:27398182

Fabrication of porous low crystalline calcite block by carbonation of calcium hydroxide compact.

PubMed

Matsuya, Shigeki; Lin, Xin; Udoh, Koh-ichi; Nakagawa, Masaharu; Shimogoryo, Ryoji; Terada, Yoshihiro; Ishikawa, Kunio

2007-07-01

Calcium carbonate (CaCO(3)) has been widely used as a bone substitute material because of its excellent tissue response and good resorbability. In this experimental study, we propose a new method obtaining porous CaCO(3) monolith for an artificial bone substitute. In the method, calcium hydroxide compacts were exposed to carbon dioxide saturated with water vapor at room temperature. Carbonation completed within 3 days and calcite was the only product. The mechanical strength of CaCO(3) monolith increased with carbonation period and molding pressure. Development of mechanical strength proceeded through two steps; the first rapid increase by bonding with calcite layer formed at the surface of calcium hydroxide particles and the latter increase by the full conversion of calcium hydroxide to calcite. The latter process was thought to be controlled by the diffusion of CO(2) through micropores in the surface calcite layer. Porosity of calcite blocks thus prepared had 36.8-48.1% depending on molding pressure between 1 MPa and 5 MPa. We concluded that the present method may be useful for the preparation of bone substitutes or the preparation of source material for bone substitutes since this method succeeded in fabricating a low-crystalline, and thus a highly reactive, porous calcite block.

Annulus Fibrosus Can Strip Hyaline Cartilage End Plate from Subchondral Bone: A Study of the Intervertebral Disk in Tension.

PubMed

Balkovec, Christian; Adams, Michael A; Dolan, Patricia; McGill, Stuart M

2015-10-01

Study Design Biomechanical study on cadaveric spines. Objective Spinal bending causes the annulus to pull vertically (axially) on the end plate, but failure mechanisms in response to this type of loading are poorly understood. Therefore, the objective of this study was to identify the weak point of the intervertebral disk in tension. Methods Cadaveric motion segments (aged 79 to 88 years) were dissected to create midsagittal blocks of tissue, with ∼10 mm of bone superior and inferior to the disk. From these blocks, 14 bone-disk-bone slices (average 4.8 mm thick) were cut in the frontal plane. Each slice was gripped by its bony ends and stretched to failure at 1 mm/s. Mode of failure was recorded using a digital camera. Results Of the 14 slices, 10 failed by the hyaline cartilage being peeled off the subchondral bone, with the failure starting opposite the lateral annulus and proceeding medially. Two slices failed by rupturing of the trabecular bone, and a further two failed in the annulus. Conclusions The hyaline cartilage-bone junction is the disk's weak link in tension. These findings provide a plausible mechanism for the appearance of bone and cartilage fragments in herniated material. Stripping cartilage from the bony end plate would result in the herniated mass containing relatively stiff cartilage that does not easily resorb.

Compression and contact area of anterior strut grafts in spinal instrumentation: a biomechanical study.

PubMed

Pizanis, Antonius; Holstein, Jörg H; Vossen, Felix; Burkhardt, Markus; Pohlemann, Tim

2013-08-26

Anterior bone grafts are used as struts to reconstruct the anterior column of the spine in kyphosis or following injury. An incomplete fusion can lead to later correction losses and compromise further healing. Despite the different stabilizing techniques that have evolved, from posterior or anterior fixating implants to combined anterior/posterior instrumentation, graft pseudarthrosis rates remain an important concern. Furthermore, the need for additional anterior implant fixation is still controversial. In this bench-top study, we focused on the graft-bone interface under various conditions, using two simulated spinal injury models and common surgical fixation techniques to investigate the effect of implant-mediated compression and contact on the anterior graft. Calf spines were stabilised with posterior internal fixators. The wooden blocks as substitutes for strut grafts were impacted using a "pressfit" technique and pressure-sensitive films placed at the interface between the vertebral bone and the graft to record the compression force and the contact area with various stabilization techniques. Compression was achieved either with posterior internal fixator alone or with an additional anterior implant. The importance of concomitant ligament damage was also considered using two simulated injury models: pure compression Magerl/AO fracture type A or rotation/translation fracture type C models. In type A injury models, 1 mm-oversized grafts for impaction grafting provided good compression and fair contact areas that were both markedly increased by the use of additional compressing anterior rods or by shortening the posterior fixator construct. Anterior instrumentation by itself had similar effects. For type C injuries, dramatic differences were observed between the techniques, as there was a net decrease in compression and an inadequate contact on the graft occurred in this model. Under these circumstances, both compression and the contact area on graft could only be maintained at high levels with the use of additional anterior rods. Under experimental conditions, we observed that ligamentous injury following type C fracture has a negative influence on the compression and contact area of anterior interbody bone grafts when only an internal fixator is used for stabilization. Because of the loss of tension banding effects in type C injuries, an additional anterior compressing implant can be beneficial to restore both compression to and contact on the strut graft.

Internal bone transport using a cannulated screw as a mounting device in the treatment of a post-infective ulnar defect.

PubMed

Tsitskaris, Konstantinos; Havard, Heledd; Bijlsma, Paulien; Hill, Robert A

2016-04-01

Bone transport techniques can be used to address the segmental bone loss occurring after debridement for infection. Secure fixation of the bone transport construct to the bone transport segment can be challenging, particularly if the bone is small and osteopenic. We report a case of a segmental ulnar bone defect in a young child treated with internal bone transport using a cannulated screw as the mounting device. We found this technique particularly useful in the treatment of bone loss secondary to infection, where previous treatment and prolonged immobilisation had led to osteopenia. This technique has not been previously reported.

Cell culture-based tissue engineering as an alternative to bone grafts in implant dentistry: a literature review.

PubMed

Boeckel, Daniel Gonçalves; Shinkai, Rosemary Sadami Arai; Grossi, Márcio Lima; Teixeira, Eduardo Rolim

2012-09-01

Several biomaterials and techniques for bone grafting have been described in the literature for atresic bone tissue replacement caused by edentulism, surgical resectioning, and traumas. A new technique involves tissue engineering, a promising option to replace bone tissue and solve problems associated with morbidity of autogenous grafting. This literature review aims to describe tissue-engineering techniques using ex vivo cell culture as an alternative to repair bone maxillary atresias and discuss the concepts and potentials of bone regeneration through cell culture techniques as an option for restorative maxillofacial surgery.

Coracoid process x-ray investigation before Latarjet procedure: a radioanatomic study.

PubMed

Bachy, Manon; Lapner, Peter L C; Goutallier, Daniel; Allain, Jérôme; Hernigou, Phillipe; Bénichou, Jacques; Zilber, Sébastien

2013-12-01

The purpose of this study was to determine whether a preoperative radiologic assessment of the coracoid process is predictive of the amount of bone available for coracoid transfer by the Latarjet procedure. Thirty-five patients with anterior instability undergoing a Latarjet procedure were included. A preoperative radiologic assessment was performed with the Bernageau and true anteroposterior (true AP) views. The length of the coracoid process was measured on both radiographic views and the values were compared with the length of the bone block during surgery. Statistical analysis was carried out by ANOVA and Wilcoxon tests (P < .05). On radiologic examination, the mean coracoid process length was 29 ± 4 and 33 ± 4 mm on the Bernageau and true AP views, respectively. The mean bone block length during surgery was 21.6 ± 2.7 mm. A significant correlation was found (P = .032) between the coracoid process length on the true AP view and the intraoperative bone block length. Preoperative planning for the Latarjet procedure, including graft orientation and screw placement, requires knowledge of the length of coracoid bone available for transfer. This can be facilitated with the use of preoperative standard radiographs, thus avoiding computed tomography. This planning allows the detection of coracoid process anatomic variations or the analysis of the remaining part of the coracoid process after failure of a first Latarjet procedure to avoid an iliac bone graft. Radiologic preoperative coracoid process measurement is an easy, reliable method to aid preoperative planning of the Latarjet procedure in primary surgery and reoperations. Copyright © 2013 Journal of Shoulder and Elbow Surgery Board of Trustees. All rights reserved.

Missile war injuries of the face.

PubMed

Kummoona, Raja K

2011-11-01

In a society struggling to rebuild its country after 3 decades of years of dictatorships and wars, Iraqi maxillofacial and craniofacial surgeons play a critical role in treatment of many most serious terrorist missile injuries of the face by ongoing conflict in Iraq. This study reflects our surgical techniques of treating explosive missile injuries and other combat- and terrorism-related injuries and also evaluates the immediate and secondary phase managements of patients with missile injuries. This study includes 235 patients with missile war injuries of the face during a period of 4 years; all injured patients were treated in the Maxillofacial Unit of Surgical Specialties Hospital, Medical City, Baghdad. There were 195 men and 40 women; their ages ranged from 1 to 70 years (mean, 39.5 years). Posttraumatic missile facial deformities were classified as follows: 95 patients (40.43%) had bone loss; 72 patients (30.64%) had soft tissue loss; 33 patients (14.05%) had orbital injuries; and 35 patients (14.90%) had other deformities of scar contracture, fistula, and sinus formation. Two techniques were used for reconstruction of the bony defect, either by bone chips carried by osteomesh tray harvested from the iliac crest or by free block of corticocancellous bone graft from the iliac crest. Soft tissue reconstruction was done by local flaps and regional flaps such as lateral cervical and cervicofacial flaps, and the orbit was reconstructed by bone graft, lyophilized dura, and sialastic implant. Scar contracture was treated by scar revision and sinus tract excised at the same time of scar revision. In conclusion, the primary phase required an urgent airway management, controlling an active bleeding by surgical intervention; most entrance and exit wounds as well as retained missiles were located in the cheek, chin, and mandibular body, with few cases of mortality due to complications related to head injuries. The secondary phase management of deformities of the face as a complication of missile injuries was classified as bone loss, soft tissue loss, combined bone and soft tissue loss, and others (sinus tracts and poor scars).

The effectiveness of the bone bridge transtibial amputation technique: A systematic review of high-quality evidence.

PubMed

Kahle, Jason T; Highsmith, M Jason; Kenney, John; Ruth, Tim; Lunseth, Paul A; Ertl, Janos

2017-06-01

This literature review was undertaken to determine if commonly held views about the benefits of a bone bridge technique are supported by the literature. Four databases were searched for articles pertaining to surgical strategies specific to a bone bridge technique of the transtibial amputee. A total of 35 articles were identified as potential articles. Authors included methodology that was applied to separate topics. Following identification, articles were excluded if they were determined to be low quality evidence or not pertinent. Nine articles were identified to be pertinent to one of the topics: Perioperative Care, Acute Care, Subjective Analysis and Function. Two articles sorted into multiple topics. Two articles were sorted into the Perioperative Care topic, 4 articles sorted into the Acute Care topic, 2 articles into the Subjective Analysis topic and 5 articles into the Function topic. There are no high quality (level one or two) clinical trials reporting comparisons of the bone bridge technique to traditional methods. There is limited evidence supporting the clinical outcomes of the bone bridge technique. There is no agreement supporting or discouraging the perioperative and acute care aspects of the bone bridge technique. There is no evidence defining an interventional comparison of the bone bridge technique. Current level III evidence supports a bone bridge technique as an equivalent option to the non-bone bridge transtibial amputation technique. Formal level I and II clinical trials will need to be considered in the future to guide clinical practice. Clinical relevance Clinical Practice Guidelines are evidence based. This systematic literature review identifies the highest quality evidence to date which reports a consensus of outcomes agreeing bone bridge is as safe and effective as alternatives. The clinical relevance is understanding bone bridge could additionally provide a mechanistic advantage for the transtibial amputee.

Biologic therapies and bone loss in rheumatoid arthritis.

PubMed

Zerbini, C A F; Clark, P; Mendez-Sanchez, L; Pereira, R M R; Messina, O D; Uña, C R; Adachi, J D; Lems, W F; Cooper, C; Lane, N E

2017-02-01

Rheumatoid arthritis (RA) is a common systemic autoimmune disease of unknown cause, characterized by a chronic, symmetric, and progressive inflammatory polyarthritis. One of the most deleterious effects induced by the chronic inflammation of RA is bone loss. During the last 15 years, the better knowledge of the cytokine network involved in RA allowed the development of potent inhibitors of the inflammatory process classified as biological DMARDs. These new drugs are very effective in the inhibition of inflammation, but there are only few studies regarding their role in bone protection. The principal aim of this review was to show the evidence of the principal biologic therapies and bone loss in RA, focusing on their effects on bone mineral density, bone turnover markers, and fragility fractures. Using the PICOST methodology, two coauthors (PC, LM-S) conducted the search using the following MESH terms: rheumatoid arthritis, osteoporosis, clinical trials, TNF- antagonists, infliximab, adalimumab, etanercept, certolizumab, golimumab, IL-6 antagonists, IL-1 antagonists, abatacept, tocilizumab, rituximab, bone mineral density, bone markers, and fractures. The search was conducted electronically and manually from the following databases: Medline and Science Direct. The search period included articles from 2003 to 2015. The selection included only original adult human research written in English. Titles were retrieved and the same two authors independently selected the relevant studies for a full text. The retrieved selected studies were also reviewed completing the search for relevant articles. The first search included 904 titles from which 253 titles were selected. The agreement on the selection among researchers resulted in a Kappa statistic of 0.95 (p < 0.000). Only 248 abstracts evaluated were included in the acronym PICOST. The final selection included only 28 studies, derived from the systematic search. Additionally, a manual search in the bibliography of the selected articles was made and included into the text and into the section of "small molecules of new agents." Treatment with biologic drugs is associated with the decrease in bone loss. Studies with anti-TNF blocking agents show preservation or increase in spine and hip BMD and also a better profile of bone markers. Most of these studies were performed with infliximab. Only three epidemiological studies analyzed the effect on fractures after anti-TNF blocking agent's treatment. IL-6 blocking agents also showed improvement in localized bone loss not seen with anti-TNF agents. There are a few studies with rituximab and abatacept. Although several studies reported favorable actions of biologic therapies on bone protection, there are still unmet needs for studies regarding their actions on the risk of bone fractures.

Surface modification of biodegradable porous Mg bone scaffold using polycaprolactone/bioactive glass composite.

PubMed

Yazdimamaghani, Mostafa; Razavi, Mehdi; Vashaee, Daryoosh; Tayebi, Lobat

2015-04-01

A reduction in the degradation rate of magnesium (Mg) and its alloys is in high demand to enable these materials to be used in orthopedic applications. For this purpose, in this paper, a biocompatible polymeric layer reinforced with a bioactive ceramic made of polycaprolactone (PCL) and bioactive glass (BG) was applied on the surface of Mg scaffolds using dip-coating technique under low vacuum. The results indicated that the PCL-BG coated Mg scaffolds exhibited noticeably enhanced bioactivity compared to the uncoated scaffold. Moreover, the mechanical integrity of the Mg scaffolds was improved using the PCL-BG coating on the surface. The stable barrier property of the coatings effectively delayed the degradation activity of Mg scaffold substrates. Moreover, the coatings induced the formation of apatite layer on their surface after immersion in the SBF, which can enhance the biological bone in-growth and block the microcracks and pore channels in the coatings, thus prolonging their protective effect. Furthermore, it was shown that a three times increase in the concentration of PCL-BG noticeably improved the characteristics of scaffolds including their degradation resistance and mechanical stability. Since bioactivity, degradation resistance and mechanical integrity of a bone substitute are the key factors for repairing and healing fractured bones, we suggest that PCL-BG is a suitable coating material for surface modification of Mg scaffolds. Published by Elsevier B.V.

Advanced tissue engineering scaffold design for regeneration of the complex hierarchical periodontal structure.

PubMed

Costa, Pedro F; Vaquette, Cédryck; Zhang, Qiyi; Reis, Rui L; Ivanovski, Saso; Hutmacher, Dietmar W

2014-03-01

This study investigated the ability of an osteoconductive biphasic scaffold to simultaneously regenerate alveolar bone, periodontal ligament and cementum. A biphasic scaffold was built by attaching a fused deposition modelled bone compartment to a melt electrospun periodontal compartment. The bone compartment was coated with a calcium phosphate (CaP) layer for increasing osteoconductivity, seeded with osteoblasts and cultured in vitro for 6 weeks. The resulting constructs were then complemented with the placement of PDL cell sheets on the periodontal compartment, attached to a dentin block and subcutaneously implanted into athymic rats for 8 weeks. Scanning electron microscopy, X-ray diffraction, alkaline phosphatase and DNA content quantification, confocal laser microscopy, micro computerized tomography and histological analysis were employed to evaluate the scaffold's performance. The in vitro study showed that alkaline phosphatase activity was significantly increased in the CaP-coated samples and they also displayed enhanced mineralization. In the in vivo study, significantly more bone formation was observed in the coated scaffolds. Histological analysis revealed that the large pore size of the periodontal compartment permitted vascularization of the cell sheets, and periodontal attachment was achieved at the dentin interface. This work demonstrates that the combination of cell sheet technology together with an osteoconductive biphasic scaffold could be utilized to address the limitations of current periodontal regeneration techniques. © 2013 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

The biomechanical effect of artificial and human bone density on stopping and stripping torque during screw insertion.

PubMed

Tsuji, Matthew; Crookshank, Meghan; Olsen, Michael; Schemitsch, Emil H; Zdero, Rad

2013-06-01

Orthopedic surgeons apply torque to metal screws manually by "subjective feel" to obtain adequate fracture fixation, i.e. stopping torque, and attempt to avoid accidental over-tightening that leads to screw-bone interface failure, i.e. stripping torque. Few studies have quantified stripping torque in human bone, and only one older study from 1980 reported stopping/ stripping torque ratio. The present aim was to measure stopping and stripping torque of cortical and cancellous screws in artificial and human bone over a wide range of densities. Sawbone blocks were obtained having densities from 0.08 to 0.80g/cm(3). Sixteen fresh-frozen human femurs of known standardized bone mineral density (sBMD) were also used. Using a torque screwdriver, 3.5-mm diameter cortical screws and 6.5-mm diameter cancellous screws were inserted for adequate tightening as determined subjectively by an orthopedic surgeon, i.e. stopping torque, and then further tightened until failure of the screw-bone interface, i.e. stripping torque. There were weak (R=0.25) to strong (R=0.99) linear correlations of absolute and normalized torque vs. density or sBMD. Maximum stopping torques normalized by screw thread area engaged by the host material were 15.2N/mm (cortical screws) and 13.4N/mm (cancellous screws) in sawbone blocks and 20.9N/mm (cortical screws) and 6.1N/mm (cancellous screws) in human femurs. Maximum stripping torques normalized by screw thread area engaged by the host material were 23.4N/mm (cortical screws) and 16.8N/mm (cancellous screws) in sawbone blocks and 29.3N/mm (cortical screws) and 8.3N/mm (cancellous screws) in human femurs. Combined average stopping/ stripping torque ratios were 80.8% (cortical screws) and 76.8% (cancellous screws) in sawbone blocks, as well as 66.6% (cortical screws) and 84.5% (cancellous screws) in human femurs. Surgeons should be aware of stripping torque limits for human femurs and monitor stopping torque during surgery. This is the first study of the effect of sawbone density or human bone sBMD on stopping and stripping torque. Copyright © 2013 Elsevier Ltd. All rights reserved.

IL-18 Contributes to Bone Cancer Pain by Regulating Glia Cells and Neuron Interaction.

PubMed

Liu, Su; Liu, Yue-Peng; Lv, You; Yao, Jun-Li; Yue, Dong-Mei; Zhang, Mao-Yin; Qi, Dun-Yi; Liu, Gong-Jian

2018-02-01

Glial cell hyperactivity has been proposed to be responsible for chronic pain, however, the mechanisms remain unclear. Interleukin (IL)-18, released from glial cells, has been reported to be involved in neuropathic pain. In this study, we investigated the role of IL-18 in bone cancer pain. Bone cancer pain was mimicked by injecting Walker-256 mammary gland carcinoma cells into the intramedullary space of the tibia in rats. Expression and location of IL-18 and the IL-18 receptor were tested. To investigate the contribution of IL-18 signaling to bone cancer pain, IL-18 binding protein and recombinant IL-18 were used. To investigate the mechanisms of glial cells effects, MK801, N-methyl-D-aspartate (NMDA) receptor inhibitor, and Src kinase-specific inhibitor PP1 were used. Tumor cell implantation (TCI) treatment increased expression of IL-18 and IL-18 receptor in spinal cord. The time course of IL-18 upregulation was correlated with TCI-induced pain behaviors. Blocking the IL-18 signaling pathway prevented and reversed bone cancer-related pain behaviors. Meanwhile, blocking IL-18 signaling also suppressed TCI-induced glial cell hyperactivity, as well as activation of GluN2B and subsequent Ca 2+ -dependent signaling. Spinal administration of recombinant IL-18 in naive rat induced significant mechanical allodynia, as well as GluN2B activation. However, intrathecal injection of MK801 failed to suppress recombinant IL-18-induced GluN2B phosphorylation, whereas Src kinase inhibitor PP1 significantly inhibited IL-18-induced GluN2B activation. IL-18-mediated glial-glia and glial-neuron interaction may facilitate bone cancer pain. Blocking IL-18 signaling may effectively prevent and/or suppress bone cancer pain. IL-18 signaling may be a new target for cancer pain therapy. Copyright © 2017 The American Pain Society. Published by Elsevier Inc. All rights reserved.

Hydrophilicity, Viscoelastic, and Physicochemical Properties Variations in Dental Bone Grafting Substitutes.

PubMed

Trajkovski, Branko; Jaunich, Matthias; Müller, Wolf-Dieter; Beuer, Florian; Zafiropoulos, Gregory-George; Houshmand, Alireza

2018-01-30

The indication-oriented Dental Bone Graft Substitutes (DBGS) selection, the correct bone defects classification, and appropriate treatment planning are very crucial for obtaining successful clinical results. However, hydrophilic, viscoelastic, and physicochemical properties' influence on the DBGS regenerative potential has poorly been studied. For that reason, we investigated the dimensional changes and molecular mobility by Dynamic Mechanical Analysis (DMA) of xenograft (cerabone ® ), synthetic (maxresorb ® ), and allograft (maxgraft ® , Puros ® ) blocks in a wet and dry state. While no significant differences could be seen in dry state, cerabone ® and maxresorb ® blocks showed a slight height decrease in wet state, whereas both maxgraft ® and Puros ® had an almost identical height increase. In addition, cerabone ® and maxresorb ® blocks remained highly rigid and their damping behaviour was not influenced by the water. On the other hand, both maxgraft ® and Puros ® had a strong increase in their molecular mobility with different damping behaviour profiles during the wet state. A high-speed microscopical imaging system was used to analyze the hydrophilicity in several naturally derived (cerabone ® , Bio-Oss ® , NuOss ® , SIC ® nature graft) and synthetic DBGS granules (maxresorb ® , BoneCeramic ® , NanoBone ® , Ceros ® ). The highest level of hydrophilicity was detected in cerabone ® and maxresorb ® , while Bio-Oss ® and BoneCeramic ® had the lowest level of hydrophilicity among both naturally derived and synthetic DBGS groups. Deviations among the DBGS were also addressed via physicochemical differences recorded by Micro Computed Tomography, Scanning Electron Microscopy, Fourier Transform Infrared Spectroscopy, X-ray powder Diffractometry, and Thermogravimetric Analysis. Such DBGS variations could influence the volume stability at the grafting site, handling as well as the speed of vascularization and bone regeneration. Therefore, this study initiates a new insight into the DBGS differences and their importance for successful clinical results.

Hydrophilicity, Viscoelastic, and Physicochemical Properties Variations in Dental Bone Grafting Substitutes

PubMed Central

Müller, Wolf-Dieter; Beuer, Florian; Zafiropoulos, Gregory-George; Houshmand, Alireza

2018-01-01

The indication-oriented Dental Bone Graft Substitutes (DBGS) selection, the correct bone defects classification, and appropriate treatment planning are very crucial for obtaining successful clinical results. However, hydrophilic, viscoelastic, and physicochemical properties’ influence on the DBGS regenerative potential has poorly been studied. For that reason, we investigated the dimensional changes and molecular mobility by Dynamic Mechanical Analysis (DMA) of xenograft (cerabone®), synthetic (maxresorb®), and allograft (maxgraft®, Puros®) blocks in a wet and dry state. While no significant differences could be seen in dry state, cerabone® and maxresorb® blocks showed a slight height decrease in wet state, whereas both maxgraft® and Puros® had an almost identical height increase. In addition, cerabone® and maxresorb® blocks remained highly rigid and their damping behaviour was not influenced by the water. On the other hand, both maxgraft® and Puros® had a strong increase in their molecular mobility with different damping behaviour profiles during the wet state. A high-speed microscopical imaging system was used to analyze the hydrophilicity in several naturally derived (cerabone®, Bio-Oss®, NuOss®, SIC® nature graft) and synthetic DBGS granules (maxresorb®, BoneCeramic®, NanoBone®, Ceros®). The highest level of hydrophilicity was detected in cerabone® and maxresorb®, while Bio-Oss® and BoneCeramic® had the lowest level of hydrophilicity among both naturally derived and synthetic DBGS groups. Deviations among the DBGS were also addressed via physicochemical differences recorded by Micro Computed Tomography, Scanning Electron Microscopy, Fourier Transform Infrared Spectroscopy, X-ray powder Diffractometry, and Thermogravimetric Analysis. Such DBGS variations could influence the volume stability at the grafting site, handling as well as the speed of vascularization and bone regeneration. Therefore, this study initiates a new insight into the DBGS differences and their importance for successful clinical results. PMID:29385747

Methods of reconstruction for bone defect after tumor excision: a review of alternatives.

PubMed

Nishida, Jun; Shimamura, Tadashi

2008-08-01

Bone defect is a common problem encountered in the treatment of musculoskeletal tumor surgery. Allograft is a commonly used technique to reconstruct a large osseous defect following tumor excision in the United States and some European countries, and relatively good results have been reported because of its biologic nature. However, with the use of an allograft, there are concerns of transmission of infectious diseases, immunological reactions, and social or religious refusal in some regions in the world. Under these circumstances, vascularized autogenous fibular or iliac bone grafts are commonly used techniques and bone lengthening techniques using external fixation have been reported recently. These procedures utilize viable bone. In addition to these procedures, some biological reconstructive techniques utilizing nonviable bone have been performed as surgical alternatives for allografts using treated recycling bone including irradiated or pasteurized resected bone graft and reconstruction using an autograft containing tumor treated by liquid nitrogen. Although each technique has its proper advantages and disadvantages, the clinical results are similar to the allograft, and numerous techniques are now available as reasonable alternatives for allografts.

The conclusiveness of less-invasive imaging techniques (computer tomography, X-ray) with regard to their identification of bone diseases in a primate model (Callithrix jacchus).

PubMed

Grohmann, J; Taetzner, S; Theuss, T; Kuehnel, F; Buchwald, U; Einspanier, A

2012-04-01

Although common marmosets seem to be appropriate animal models to examine bone diseases, no data about the conclusiveness of less-invasive techniques are available. Therefore, the aim was to combine different techniques to analyse changes in bone metabolism of common marmosets with bone diseases. Five monkeys were examined by X-ray, computer tomography (CT), histology and immunohistochemistry (IHC). Monkeys with lowest bone mineral density (BMD) showed increased bone marrow, decreased cancellous bone and decreased contrast in X-ray. Highest alkaline phosphatase (AP)-levels were detected in bones with low elastic modulus. Expression of osteopontin (OPN), osteocalcin (OC) and runt-related transcriptions factor 2 (RUNX 2) was detected in bones with high modulus. No expression was present in bones with lower modulus. Collagen type I and V were found in every bone. In conclusion, CT, X-ray and AP are useful techniques to detect bone diseases in common marmosets. These observations could be confirmed by IHC. © 2012 John Wiley & Sons A/S.

Evaluation of the treatment modalities for neurosensory disturbances of the inferior alveolar nerve following retromolar bone harvesting for bone augmentation.

PubMed

Nogami, Shinnosuke; Yamauchi, Kensuke; Shiiba, Shunji; Kataoka, Yoshihiro; Hirayama, Bunichi; Takahashi, Tetsu

2015-03-01

The purpose of this study was to evaluate the treatment modalities for neurosensory disturbances (NSDs) of the inferior alveolar nerve occurring after retromolar bone harvesting for bone augmentation procedures before implant placement. One hundred four patients, of which 49 and 55 exhibited vertical or horizontal alveolar ridge defects in the mandible and maxilla, respectively, were enrolled. Nineteen patients underwent block bone grafting, 38 underwent guided bone generation or autogenous bone grafting combined with titanium mesh reconstruction, and 47 underwent sinus floor augmentation. Using a visual analog scale, we examined subjective symptoms and discomfort related to sensory alteration within the area of the NSDs in these patients. NSDs were clinically investigated using a two-point discrimination test with blunt-tipped calipers. In addition, neurometry was used for evaluation of trigeminal nerve injury. We tested three treatment modalities for NSDs: follow-up observation (no treatment), medication, and stellate ganglion block (SGB). A week after surgery, 26 patients (25.0%) experienced NSDs. Five patients received no treatment, 10 patients received medication, and 11 patients received SGB. Three months after surgery, patients in the medication and SGB group achieved complete recovery. Current perception threshold values recovered to near-baseline values at 3 months: recovery was much earlier in this group than in the other two groups. SGB can accelerate recovery from NSDs. Our results justify SGB as a reasonable treatment modality for NSDs occurring after the harvesting of retromolar bone grafts. Wiley Periodicals, Inc.

A novel pyrazole derivative protects from ovariectomy-induced osteoporosis through the inhibition of NADPH oxidase

PubMed Central

Joo, Jung Hee; Huh, Jeong-Eun; Lee, Jee Hyun; Park, Doo Ri; Lee, Yoonji; Lee, Seul Gee; Choi, Sun; Lee, Hwa Jeong; Song, Seong-Won; Jeong, Yongmi; Goo, Ja-Il; Choi, Yongseok; Baek, Hye Kyung; Yi, Sun Shin; Park, Soo Jin; Lee, Ji Eun; Ku, Sae Kwang; Lee, Won Jae; Lee, Kee-In; Lee, Soo Young; Bae, Yun Soo

2016-01-01

Osteoclast cells (OCs) are differentiated from bone marrow-derived macrophages (BMMs) by activation of receptor activator of nuclear factor κB (NF-κB) ligand (RANKL). Activation of NADPH oxidase (Nox) isozymes is involved in RANKL-dependent OC differentiation, implicating Nox isozymes as therapeutic targets for treatment of osteoporosis. Here, we show that a novel pyrazole derivative, Ewha-18278 has high inhibitory potency on Nox isozymes. Blocking the activity of Nox with Ewha-18278 inhibited the responses of BMMs to RANKL, including reactive oxygen species (ROS) generation, activation of mitogen-activated protein (MAP) kinases and NF-κB, and OC differentiation. To evaluate the anti-osteoporotic function of Ewha-18278, the derivative was applied to estrogen-deficient ovariectomized (OVX) ddY mice. Oral administration of Ewha-18278 (10 mg/kg/daily, 4 weeks) into the mice recovered bone mineral density, trabecular bone volume, trabecular bone length, number and thickness, compared to control OVX ddY mice. Moreover, treatment of OVX ddY mice with Ewha-18278 increased bone strength by increasing cortical bone thickness. We provide that Ewha-18278 displayed Nox inhibition and blocked the RANKL-dependent cell signaling cascade leading to reduced differentiation of OCs. Our results implicate Ewha-18278 as a novel therapeutic agent for the treatment of osteoporosis. PMID:26975635

Betulinic acid, a bioactive pentacyclic triterpenoid, inhibits skeletal-related events induced by breast cancer bone metastases and treatment

DOE Office of Scientific and Technical Information (OSTI.GOV)

Park, Se Young; Kim, Hyun-Jeong; Kim, Ki Rim

Many breast cancer patients experience bone metastases and suffer skeletal complications. The present study provides evidence on the protective and therapeutic potential of betulinic acid on cancer-associated bone diseases. Betulinic acid is a naturally occurring triterpenoid with the beneficial activity to limit the progression and severity of cancer, diabetes, cardiovascular diseases, atherosclerosis, and obesity. We first investigated its effect on breast cancer cells, osteoblastic cells, and osteoclasts in the vicious cycle of osteolytic bone metastasis. Betulinic acid reduced cell viability and the production of parathyroid hormone-related protein (PTHrP), a major osteolytic factor, in MDA-MB-231 human metastatic breast cancer cells stimulatedmore » with or without tumor growth factor-β. Betulinic acid blocked an increase in the receptor activator of nuclear factor-kappa B ligand (RANKL)/osteoprotegerin ratio by downregulating RANKL protein expression in PTHrP-treated human osteoblastic cells. In addition, betulinic acid inhibited RANKL-induced osteoclastogenesis in murine bone marrow macrophages and decreased the production of resorbed area in plates with a bone biomimetic synthetic surface by suppressing the secretion of matrix metalloproteinase (MMP)-2, MMP-9, and cathepsin K in RANKL-induced osteoclasts. Furthermore, oral administration of betulinic acid inhibited bone loss in mice intra-tibially inoculated with breast cancer cells and in ovariectomized mice causing estrogen deprivation, as supported by the restored bone morphometric parameters and serum bone turnover markers. Taken together, these findings suggest that betulinic acid may have the potential to prevent bone loss in patients with bone metastases and cancer treatment-induced estrogen deficiency. - Highlights: • Betulinic acid reduced PTHrP production in human metastatic breast cancer cells. • Betulinic acid blocked RANKL/OPG ratio in PTHrP-stimulated human osteoblastic cells. • Betulinic acid inhibited RANKL-induced osteoclastogenesis in bone marrow macrophages. • Betulinic acid decreased bone resorption by suppressing osteoclast activity. • Orally administered betulinic acid inhibited cancer-associated bone diseases in mice.« less

Blocking the expression of both bone sialoprotein (BSP) and osteopontin (OPN) impairs the anabolic action of PTH in mouse calvaria bone.

PubMed

Bouleftour, Wafa; Bouet, Guenaelle; Granito, Renata Neves; Thomas, Mireille; Linossier, Marie-Thérèse; Vanden-Bossche, Arnaud; Aubin, Jane E; Lafage-Proust, Marie-Hélène; Vico, Laurence; Malaval, Luc

2015-03-01

Osteopontin (OPN) and bone sialoprotein (BSP) are coexpressed in osteoblasts and osteoclasts, and display overlapping properties. We used daily injection of parathyroid hormone 1-84 (iPTH) over the calvaria of BSP knockout (-/-) mice to investigate further their functional specificity and redundancy. iPTH stimulated bone formation in both +/+ and -/- mice, increasing to the same degree periosteum, osteoid and total bone thickness. Expression of OPN, osterix, osteocalcin (OCN) and DMP1 was also increased by iPTH in both genotypes. In contrast to +/+, calvaria cell cultures from -/- mice revealed few osteoblast colonies, no mineralization and little expression of OCN, MEPE or DMP1. In contrast, OPN levels were 5× higher in -/- versus +/+ cultures. iPTH increased alkaline phosphatase (ALP) activity in cell cultures of both genotypes, with higher OCN and the induction of mineralization in -/- cultures. siRNA blocking of OPN expression did not alter the anabolic action of the hormone in BSP +/+ calvaria, while it blunted iPTH effects in -/- mice, reduced to a modest increase in periosteum thickness. In -/- (not +/+) cell cultures, siOPN blocked the stimulation by iPTH of ALP activity and OCN expression, as well as the induction of mineralization. Thus, full expression of either OPN or BSP is necessary for the anabolic effect of PTH at least in the ectopic calvaria injection model. This suggests that OPN may compensate for the lack of BSP in the response to this hormonal challenge, and provides evidence of functional overlap between these cognate proteins. © 2014 Wiley Periodicals, Inc., A Wiley Company.

Treatment of The Posterior Unstable Shoulder

PubMed Central

Alepuz, Eduardo Sánchez

2017-01-01

Background: It is estimated that approximately 5% of glenohumeral instabilities are posterior. There are a number of controversies regarding therapeutic approaches for these patients. Methods: We analyse the main surgery alternatives for the treatment of the posterior shoulder instability. We did a research of the publications related with posterior glenohumeral instability. Results: There are conservative and surgical treatment options. Conservative treatment has positive results in most patients, with around 65 to 80% of cases showing recurrent posterior dislocation. There are multiple surgical techniques, both open and arthroscopic, for the treatment of posterior glenohumeral instability. There are procedures that aim to repair bone defects and others that aim to repair soft tissues and capsulolabral injuries. The treatment should be planned according to each case on an individual basis according to the patient characteristics and the injury type. Surgical treatment is indicated in patients with functional limitations arising from instability and/or pain that have not improved with rehabilitation treatment. The indications for arthroscopic treatment are recurrent posterior subluxation caused by injury of the labrum or the capsulolabral complex; recurrent posterior subluxation caused by capsuloligamentous laxity or capsular redundancy; and multidirectional instability with posterior instability as a primary component. Arthroscopic assessment will help identify potential injuries associated with posterior instability such as bone lesions or defects and lesions or defects of soft tissues. The main indications for open surgery would be in cases of Hill Sachs lesions or broad reverse Bankart lesions not accessible by arthroscopy. We indicated non-anatomical techniques (McLaughlin or its modifications) for reverse Hill-Sachs lesions with impairment of the articular surface between 20% and 50%. Disimpaction of the fracture and placement of bone graft (allograft or autograft) is a suitable treatment for acute lesions that do not exceed 50% of the articular surface and with articular cartilage in good condition. Reconstruction with allograft may be useful in lesions affecting up to 50% of the humeral surface and should be considered when there is a situation of non-viable cartilage at the fracture site. For defects greater than 50% of the articular surface or in the case of dislocations over 6 months in duration where there is poor bone quality, some authors advocate substitution techniques as a treatment of choice. The main techniques for treating glenoid bone defects are posterior bone block and posterior opening osteotomy of the glenoid. Conclusions: The treatment of the posterior glenohumeral instability has to be individualized based on the patient´s injuries, medical history, clinical exam and goals. The most important complications in the treatment of posterior glenohumeral instability are recurrent instability, avascular necrosis and osteoarthritis. PMID:28979596

[Lumbosacral facet joint stabilization: Mc Bride technique].

PubMed

Martínez, Ernesto De León; García, J Antonio Vázquez; Castillo, Pablo Atlitec

2008-01-01

We carried out a retrospective study of the clinical results of lumbosacral decompression with Mc Bride technique, in treatment of degenerative unstable lumbar stenosis. Three hundred and forty patients (180 male) were treated during May 1996 to May 2003. Mean age at surgery was 47 years old (22-85) with 3 to 8 years of follow up. All patients fulfilled clinical and image criteria for chronic lumbar pain due to degenerative lumbar stenosis and segmental instability that did not improve with conservative treatment. We found very good results in 114 patients (33.5%), good in 203 patients (59.7%), regular in 16 patients (4.7%), and poor in 6 patients (2%). The Mc Bride technique is based in interlaminar distraction and permits managing lumbar stenosis and arthrodesis of an unstable segment simultaneously. It diminishes compression in the foramen, maintains a position in extension, reduces facet joints subluxation and eliminates the strategic point of intervertebral mobility in facet joints. It allows immediate stabilization and later fusion by placing a bone block.

Development of laminated fiber-reinforced nanocomposites for bone regeneration

NASA Astrophysics Data System (ADS)

Xu, Weijie

There have been numerous efforts to develop synthetic and/or natural tissue engineering scaffolds that are suitable for bone regeneration applications to replace autograft and allograft bones. Current biomaterials as a scaffold for bone regeneration are limited by the extent of degradation concurrent with bone formation, mechanical strength, and the extent of osteogenic differentiation of marrow stromal cells migrating from the surrounding tissues. In this project, a novel laminated nanocomposite scaffold is fabricated, consisting of poly (L-lactide ethylene oxide fumarate) (PLEOF) hydrogel reinforced with poly (L-lactic acid) (PLLA) electrospun nanofibers and hydroxyapatite (HA) nanoparticles. PLEOF is a novel in situ crosslinkable macromer synthesized from biocompatible building units which can be functionalized with bioactive peptides like the cell-adhesive Arg--Gly--Asp (RGD) amino acid sequence. The hydrophilicity and degradation rate of the macromer can be tailored to a particular application by controlling the ratio of PEG to PLA blocks in the macromer and the unsaturated fumarate units can be used for in-situ crosslinking. The PLLA nanofibers were electrospun from high molecular weight PLLA. The laminated nanocomposites were fabricated by dry-hand lay up technique followed by compression molding and thermal crosslinking. The laminated nanocomposites were evaluated with respect to degradation, water uptake, mechanical strength, and the extent of osteogenic differentiation of bone marrow stromal (BMS) cells. Laminates with or without HA nanoparticles showed modulus values much higher than that of trabecular bone (50-100 MPa). The effect of laminated nanocomposites on osteogenic differentiation of BMS cells was determined in terms of cell number, ALPase activity and calcium content. Our results demonstrate that grafting RGD peptide and HA nanoparticles to a PLEOF hydrogel reinforced with PLLA nanofibers synergistically enhance osteogenic differentiation of BMS cells. In conclusion, the laminated nanocomposite with controllable degradation characteristics and robust mechanical properties is attractive as a synthetic bone-mimetic matrix for skeletal tissue regeneration.

Evaluation and Management of Failed Shoulder Instability Surgery.

PubMed

Cartucho, António; Moura, Nuno; Sarmento, Marco

2017-01-01

Failed shoulder instability surgery is mostly considered to be the recurrence of shoulder dislocation but subluxation, painful or non-reliable shoulder are also reasons for patient dissatisfaction and should be considered in the notion. The authors performed a revision of the literature and online contents on evaluation and management of failed shoulder instability surgery. When we look at the reasons for failure of shoulder instability surgery we point the finger at poor patient selection, technical error and an additional traumatic event. More than 80% of surgical failures, for shoulder instability, are associated with bone loss. Quantification of glenoid bone loss and investigation of an engaging Hill-Sachs lesion are determining facts. Adequate imaging studies are determinant to assess labrum and capsular lesions and to rule out associated pathology as rotator cuff tears. CT-scan is the method of choice to diagnose and quantify bone loss. Arthroscopic soft tissue procedures are indicated in patients with minimal bone loss and no contact sports. Open soft tissue procedures should be performed in patients with small bone defects, with hiperlaxity and practicing contact sports. Soft tissue techniques, as postero-inferior capsular plication and remplissage, may be used in patients with less than 25% of glenoid bone loss and Hill-Sachs lesions. Bone block procedures should be used for glenoid larger bone defects in the presence of an engaging Hill-Sachs lesion or in the presence of poor soft tissue quality. A tricortical iliac crest graft may be used as a primary procedure or as a salvage procedure after failure of a Bristow or a Latarjet procedure. Less frequently, the surgeon has to address the Hill-Sachs lesion. When a 30% loss of humeral head circumference is present a filling graft should be used. Reasons for failure are multifactorial. In order to address this entity, surgeons must correctly identify the causes and tailor the right solution.

Simultaneous Impacted Third Molar Extraction and Lateral Ramus Block Graft Harvest for Horizontal Ridge Augmentation: A Case Series.

PubMed

Deeb, George R; Laskin, Daniel M; Deeb, Janina Golob

2017-03-01

The purpose of this study was to confirm the efficiency of using a lateral ramus block graft taken at the time of impacted mandibular third molar removal for horizontal ridge augmentation and implant placement. Ten patients had grafts obtained from the lateral aspect of the mandible during impacted third molar removal and placed in areas of horizontal ridge deficiency. Measurements made on cone-beam computerized tomograms after 4 months showed gains of 2.7 to 3.5 mm and 16 implants were placed successfully. In patients with impacted third molars requiring dental implants, simultaneous harvest of a lateral block bone graft is an efficient way of obtaining bone for horizontal ridge augmentation. Copyright © 2016 American Association of Oral and Maxillofacial Surgeons. Published by Elsevier Inc. All rights reserved.

Zebrafish skeleton development: High resolution micro-CT and FIB-SEM block surface serial imaging for phenotype identification

PubMed Central

Silvent, Jeremie; Akiva, Anat; Brumfeld, Vlad; Reznikov, Natalie; Rechav, Katya; Yaniv, Karina; Addadi, Lia; Weiner, Steve

2017-01-01

Although bone is one of the most studied living materials, many questions about the manner in which bones form remain unresolved, including fine details of the skeletal structure during development. In this study, we monitored skeleton development of zebrafish larvae, using calcein fluorescence, high-resolution micro-CT 3D images and FIB-SEM in the block surface serial imaging mode. We compared calcein staining of the skeletons of the wild type and nacre mutants, which are transparent zebrafish, with micro-CT for the first 30 days post fertilization embryos, and identified significant differences. We quantified the bone volumes and mineral contents of bones, including otoliths, during development, and showed that such developmental differences, including otolith development, could be helpful in identifying phenotypes. In addition, high-resolution imaging revealed the presence of mineralized aggregates in the notochord, before the formation of the first bone in the axial skeleton. These structures might play a role in the storage of the mineral. Our results highlight the potential of these high-resolution 3D approaches to characterize the zebrafish skeleton, which in turn could prove invaluable information for better understanding the development and the characterization of skeletal phenotypes. PMID:29220379

Association with replication between estrogen-related receptor gamma (ESRRgamma) polymorphisms and bone phenotypes in women of European ancestry.

PubMed

Elfassihi, Latifa; Giroux, Sylvie; Bureau, Alexandre; Laflamme, Nathalie; Cole, David Ec; Rousseau, François

2010-04-01

Osteoporosis is a bone disease characterized by low bone mineral density (BMD), a highly heritable polygenic trait. Women are more prone than men to develop osteoporosis owing to a lower peak bone mass and accelerated bone loss at menopause. Lack of estrogen thus is a major risk factor for osteoporosis. In addition to having strong similarity to the estrogen receptor 1 (ESR1), the orphan nuclear estrogen-related receptor gamma (ESRRgamma) is widely expressed and shows overlap with ESR1 expression in tissues where estrogen has important physiologic functions. For these reasons, we have undertaken a study of ESRRgamma sequence variants in association with bone measurements [heel quantitative ultrasound (QUS) by measurements of broadband ultrasound attenuation (BUA), speed of sound (SOS), and stiffness index (SI) and dual-energy X-ray absorptiometry (DXA) at the femoral neck (FN) and lumbar spine (LS)]. A silent variant was found to be associated with multiple bone measurements (LS, BUA, SOS, and SI), the p values ranging from .006 to .04 in a sample of 5144 Quebec women. The region of this variant was analyzed using the HapMap database and the Gabriel method to define a block of 20 kb. Using the Tagger method, eight TagSNPs were identified and genotyped in a sample of 1335 women. Four of these SNPs capture the five major block haplotypes. One SNP (rs2818964) and one haplotype were significantly associated with multiple bone measures. All SNPs involved in the associations were analyzed in two other sample sets with significant results in the same direction. These results suggest involvement of ESRRgamma in the determination of bone density in women. Copyright 2010 American Society for Bone and Mineral Research.

Temperature and time variations during osteotomies performed with different piezosurgical devices: an in vitro study.

PubMed

Delgado-Ruiz, R A; Sacks, D; Palermo, A; Calvo-Guirado, J L; Perez-Albacete, C; Romanos, G E

2016-09-01

The aim of this experimental in vitro study was to evaluate the effects of the piezoelectric device in temperature and time variations in standardized osteotomies performed with similar tip inserts in bovine bone blocks. Two different piezosurgical devices were used the OE-F15(®) (Osada Inc., Los Angeles, California, USA) and the Surgybone(®) (Silfradent Inc., Sofia, Forli Cesena, Italy). Serrated inserts with similar geometry were coupled with each device (ST94 insert/test A and P0700 insert/test B). Osteotomies 10 mm long and 3 mm deep were performed in bone blocks resembling type II (dense) and type IV (soft) bone densities with and without irrigation. Thermal changes and time variations were recorded. The effects of bone density, irrigation, and device on temperature changes and time necessary to accomplish the osteotomies were analyzed. Thermal analysis showed significant higher temperatures during piezosurgery osteotomies in hard bone without irrigation (P < 0.05). The type of piezosurgical device did not influence thermal variations (P > 0.05). Time analysis showed that the mean time values necessary to perform osteotomies were shorter in soft bone than in dense bone (P < 0.05). Within the limitations of this in vitro study, it may be concluded that the temperature increases more in piezosurgery osteotomies in dense bone without irrigation; the time to perform the osteotomy with piezosurgery is shorter in soft bone compared to hard bone; and the piezosurgical device have a minimal influence in the temperature and time variations when a similar tip design is used during piezosurgery osteotomies. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Lymphatic Endothelial Cells Produce M-CSF, Causing Massive Bone Loss in Mice.

PubMed

Wang, Wensheng; Wang, Hua; Zhou, Xichao; Li, Xing; Sun, Wen; Dellinger, Michael; Boyce, Brendan F; Xing, Lianping

2017-05-01

Gorham-Stout disease (GSD) is a rare bone disorder characterized by aggressive osteolysis associated with lymphatic vessel invasion within bone marrow cavities. The etiology of GSD is not known, and there is no effective therapy or animal model for the disease. Here, we investigated if lymphatic endothelial cells (LECs) affect osteoclasts (OCs) to cause a GSD osteolytic phenotype in mice. We examined the effect of a mouse LEC line on osteoclastogenesis in co-cultures. LECs significantly increased receptor activator of NF-κB ligand (RANKL)-mediated OC formation and bone resorption. LECs expressed high levels of macrophage colony-stimulating factor (M-CSF), but not RANKL, interleukin-6 (IL-6), and tumor necrosis factor (TNF). LEC-mediated OC formation and bone resorption were blocked by an M-CSF neutralizing antibody or Ki20227, an inhibitor of the M-CSF receptor, c-Fms. We injected LECs into the tibias of wild-type (WT) mice and observed massive osteolysis on X-ray and micro-CT scans. Histology showed that LEC-injected tibias had significant trabecular and cortical bone loss and increased OC numbers. M-CSF protein levels were significantly higher in serum and bone marrow plasma of mice given intra-tibial LEC injections. Immunofluorescence staining showed extensive replacement of bone and marrow by podoplanin+ LECs. Treatment of LEC-injected mice with Ki20227 significantly decreased tibial bone destruction. In addition, lymphatic vessels in a GSD bone sample were stained positively for M-CSF. Thus, LECs cause bone destruction in vivo in mice by secreting M-CSF, which promotes OC formation and activation. Blocking M-CSF signaling may represent a new therapeutic approach for treatment of patients with GSD. Furthermore, tibial injection of LECs is a useful mouse model to study GSD. © 2017 American Society for Bone and Mineral Research. © 2017 American Society for Bone and Mineral Research.

Intercomparison of techniques for the non-invasive measurement of bone mass

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cohn, S.H.

1981-01-01

A variety of methods are presently available for the non-invasive measurement of bone mass of both normal individuals and patients with metabolic disorders. Chief among these methods are radiographic techniques such as radiogrammetry, photon absorptiometry, computer tomography, Compton scattering and neutron activation analysis. In this review, the salient features of the bone measurement techniques are discussed along with their accuracy and precision. The advantages and disadvantages of the various techniques for measuring bone mass are summarized. Where possible, intercomparisons are made of the various techniques.

Characterization of controlled bone defects using 2D and 3D ultrasound imaging techniques.

PubMed

Parmar, Biren J; Longsine, Whitney; Sabonghy, Eric P; Han, Arum; Tasciotti, Ennio; Weiner, Bradley K; Ferrari, Mauro; Righetti, Raffaella

2010-08-21

Ultrasound is emerging as an attractive alternative modality to standard x-ray and CT methods for bone assessment applications. As of today, however, there is a lack of systematic studies that investigate the performance of diagnostic ultrasound techniques in bone imaging applications. This study aims at understanding the performance limitations of new ultrasound techniques for imaging bones in controlled experiments in vitro. Experiments are performed on samples of mammalian and non-mammalian bones with controlled defects with size ranging from 400 microm to 5 mm. Ultrasound findings are statistically compared with those obtained from the same samples using standard x-ray imaging modalities and optical microscopy. The results of this study demonstrate that it is feasible to use diagnostic ultrasound imaging techniques to assess sub-millimeter bone defects in real time and with high accuracy and precision. These results also demonstrate that ultrasound imaging techniques perform comparably better than x-ray imaging and optical imaging methods, in the assessment of a wide range of controlled defects both in mammalian and non-mammalian bones. In the future, ultrasound imaging techniques might provide a cost-effective, real-time, safe and portable diagnostic tool for bone imaging applications.

Primary Stability of Zirconium vs Titanium Implants: An In Vitro Comparison

DTIC Science & Technology

2015-06-05

Zirconia implant and 4x11.5 Titanium implant placed in artificial bone ( polyurethane foam ) at .08 rotations /sec…………………………………28   viii...measurements as they relate to primary Implant Stability. Artificial Bone made of solid ridged polyurethane foam was used as an alternative test...30 pound per cubic foot solid rigid polyurethane blocks used to substitute human cancellous bone

Evaluation of the 3D spatial distribution of the Calcium/Phosphorus ratio in bone using computed-tomography dual-energy analysis.

PubMed

Hadjipanteli, A; Kourkoumelis, N; Fromme, P; Huang, J; Speller, R D

2016-01-01

The Calcium/Phosphorus (Ca/P) ratio was shown to vary between healthy bones and bones with osteoporotic symptoms. The relation of the Ca/P ratio to bone quality remains under investigation. To study this relation and determine if the ratio can be used to predict bone fractures, a non-invasive 3D imaging technique is required. The first aim of this study was to test the effectiveness of a computed-tomography dual-energy analysis (CT-DEA) technique developed to assess the Ca/P ratio in bone apatite (collagen-free bone) in identifying differences between healthy and inflammation-mediated osteoporotic (IMO) bones. The second aim was to extend the above technique for its application to a more complex structure, intact bone, that could potentially lead to clinical use. For the first aim, healthy and IMO rabbit cortical bone apatite samples were assessed. For the second aim, some changes were made to the technique, which was applied to healthy and IMO intact bone samples. Statistically significant differences between healthy and IMO bone apatite were found for the bulk Ca/P ratio, low Ca/P ratio proportion and interconnected low Ca/P ratio proportion. For the intact bone samples, the bulk Ca/P ratio was found to be significantly different between healthy and IMO. Results show that the CT-DEA technique can be used to identify differences in the Ca/P ratio between healthy and osteoporotic, in both bone apatite and intact bone. With quantitative imaging becoming an increasingly important advancement in medical imaging, CT-DEA for bone decomposition could potentially have several applications. Copyright © 2015. Published by Elsevier Ltd.

A Prospective Comparative Study of Arthroscopic Versus Mini-Open Latarjet Procedure With a Minimum 2-Year Follow-up.

PubMed

Marion, Blandine; Klouche, Shahnaz; Deranlot, Julien; Bauer, Thomas; Nourissat, Geoffroy; Hardy, Philippe

2017-02-01

To compare postoperative pain during the first postoperative week and the position of the coracoid bone block at the anterior aspect of the glenoid after the arthroscopic and the mini-open Latarjet procedure. The secondary purpose was to assess functional results and recurrence after at least 2 years of follow-up. This comparative prospective study included patients who underwent a Latarjet-Bristow procedure for anterior shoulder instability in 2012. The Latarjet procedure was performed by a mini-open approach (G1) in one center and by an arthroscopic approach (G2) in the other. The main evaluation criterion was average shoulder pain during the first postoperative week assessed by the patient on a standard 10-cm visual analog scale (0-10). Secondary criteria were consumption of analgesics during the first week, the position of the coracoid bone block on radiograph and computed tomography scan at the 3-month follow-up and clinical outcomes (Western Ontario Score Index and new surgery) after at least 2 years of follow-up. Fifty-eight patients were included, 22 G1 and 36 G2, 13 women and 45 men, mean age 26.9 ± 7.7 years. The mean follow-up was 29.8 ± 4.4 months. There was significantly less pain in the arthroscopic Latarjet group than in the mini-open group during the first postoperative week (2.5 ± 1.4 vs 1.2 ± 1.2, P = .002) with comparable consumption of analgesics (P > .05). The arthroscopic Latarjet procedure resulted in a more lateral coracoid bone block (P = .04) and a better equatorial position than the mini-open technique (P = .02). Three patients underwent revision surgery (1 recurrence [2.8%], 1 block fracture, 1 screw ablation) in the arthroscopic group, none in the mini-open group (P = .54). At the final follow-up, the Western Ontario Score Index score was good in all patients (G1: 78.5 ± 7.5% vs G2: 82.3 ± 7%, P = .03). This prospective comparative study showed that the arthroscopic Latarjet procedure was significantly less painful than the mini-open procedure during the first postoperative week. The clinical outcomes were comparable after at least 2 years of follow-up. Level II, prospective comparative study. Copyright © 2016 Arthroscopy Association of North America. Published by Elsevier Inc. All rights reserved.

Lysophosphatidic Acid Receptor Type 1 (LPA1) Plays a Functional Role in Osteoclast Differentiation and Bone Resorption Activity*

PubMed Central

David, Marion; Machuca-Gayet, Irma; Kikuta, Junichi; Ottewell, Penelope; Mima, Fuka; Leblanc, Raphael; Bonnelye, Edith; Ribeiro, Johnny; Holen, Ingunn; Vales, Rùben Lopez; Jurdic, Pierre; Chun, Jerold; Clézardin, Philippe; Ishii, Masaru; Peyruchaud, Olivier

2014-01-01

Lysophosphatidic acid (LPA) is a natural bioactive lipid that acts through six different G protein-coupled receptors (LPA1–6) with pleiotropic activities on multiple cell types. We have previously demonstrated that LPA is necessary for successful in vitro osteoclastogenesis of bone marrow cells. Bone cells controlling bone remodeling (i.e. osteoblasts, osteoclasts, and osteocytes) express LPA1, but delineating the role of this receptor in bone remodeling is still pending. Despite Lpar1−/− mice displaying a low bone mass phenotype, we demonstrated that bone marrow cell-induced osteoclastogenesis was reduced in Lpar1−/− mice but not in Lpar2−/− and Lpar3−/− animals. Expression of LPA1 was up-regulated during osteoclastogenesis, and LPA1 antagonists (Ki16425, Debio0719, and VPC12249) inhibited osteoclast differentiation. Blocking LPA1 activity with Ki16425 inhibited expression of nuclear factor of activated T-cell cytoplasmic 1 (NFATc1) and dendritic cell-specific transmembrane protein and interfered with the fusion but not the proliferation of osteoclast precursors. Similar to wild type osteoclasts treated with Ki16425, mature Lpar1−/− osteoclasts had reduced podosome belt and sealing zone resulting in reduced mineralized matrix resorption. Additionally, LPA1 expression markedly increased in the bone of ovariectomized mice, which was blocked by bisphosphonate treatment. Conversely, systemic treatment with Debio0719 prevented ovariectomy-induced cancellous bone loss. Moreover, intravital multiphoton microscopy revealed that Debio0719 reduced the retention of CX3CR1-EGFP+ osteoclast precursors in bone by increasing their mobility in the bone marrow cavity. Overall, our results demonstrate that LPA1 is essential for in vitro and in vivo osteoclast activities. Therefore, LPA1 emerges as a new target for the treatment of diseases associated with excess bone loss. PMID:24429286

Measurement of the normalized broadband ultrasound attenuation in trabecular bone by using a bidirectional transverse transmission technique

NASA Astrophysics Data System (ADS)

Lee, Kang Il

2015-01-01

A new method for measuring the normalized broadband ultrasound attenuation (nBUA) in trabecular bone by using a bidirectional transverse transmission technique was proposed and validated with measurements obtained by using the conventional transverse transmission technique. There was no significant difference between the nBUA measurements obtained for 14 bovine femoral trabecular bone samples by using the bidirectional and the conventional transverse transmission techniques. The nBUA measured by using the two transverse transmission techniques showed strong positive correlations of r = 0.87 to 0.88 with the apparent bone density, consistent with the behavior in human trabecular bone invitro. We expect that the new method can be usefully applied for improved accuracy and precision in clinical measurements.

Bone Tissue Engineering Under Xenogeneic-Free Conditions in a Large Animal Model as a Basis for Early Clinical Applicability.

PubMed

Weigand, Annika; Beier, Justus P; Schmid, Rafael; Knorr, Tobias; Kilian, David; Götzl, Rebekka; Gerber, Thomas; Horch, Raymund E; Boos, Anja M

2017-03-01

For decades, researchers have been developing a range of promising strategies in bone tissue engineering with the aim of producing a significant clinical benefit over existing therapies. However, a major problem concerns the traditional use of xenogeneic substances for the expansion of cells, which complicates direct clinical transfer. The study's aim was to establish a totally autologous sheep model as a basis for further preclinical studies and future clinical application. Ovine mesenchymal stromal cells (MSC) were cultivated in different concentrations (0%, 2%, 5%, 10%, and 25%) of either autologous serum (AS) or fetal calf serum (FCS). With an increase of serum concentration, enhanced metabolic activity and proliferation could be observed. There were minor differences between MSC cultivated in AS or FCS, comparing gene and protein expression of osteogenic and stem cell markers, morphology, and osteogenic differentiation. MSC implanted subcutaneously in the sheep model, together with a nanostructured bone substitute, either in stable block or moldable putty form, induced similar vascularization and remodeling of the bone substitute irrespective of cultivation of MSC in AS or FCS and osteogenic differentiation. The bone substitute in block form together with MSC proved particularly advantageous in the induction of ectopic bone formation compared to the cell-free control and putty form. It could be demonstrated that AS is suitable for replacement of FCS for cultivation of ovine MSC for bone tissue engineering purposes. Substantial progress has been made in the development of a strictly xenogeneic-free preclinical animal model to bring future clinical application of bone tissue engineering strategies within reach.

Medium-Term Function of a 3D Printed TCP/HA Structure as a New Osteoconductive Scaffold for Vertical Bone Augmentation: A Simulation by BMP-2 Activation

PubMed Central

Moussa, Mira; Carrel, Jean-Pierre; Scherrer, Susanne; Cattani-Lorente, Maria; Wiskott, Anselm; Durual, Stéphane

2015-01-01

Introduction: A 3D-printed construct made of orthogonally layered strands of tricalcium phosphate (TCP) and hydroxyapatite has recently become available. The material provides excellent osteoconductivity. We simulated a medium-term experiment in a sheep calvarial model by priming the blocks with BMP-2. Vertical bone growth/maturation and material resorption were evaluated. Materials and methods: Titanium hemispherical caps were filled with either bare- or BMP-2 primed constructs and placed onto the calvaria of adult sheep (n = 8). Histomorphometry was performed after 8 and 16 weeks. Results: After 8 weeks, relative to bare constructs, BMP-2 stimulation led to a two-fold increase in bone volume (Bare: 22% ± 2.1%; BMP-2 primed: 50% ± 3%) and a 3-fold decrease in substitute volume (Bare: 47% ± 5%; BMP-2 primed: 18% ± 2%). These rates were still observed at 16 weeks. The new bone grew and matured to a haversian-like structure while the substitute material resorbed via cell- and chemical-mediation. Conclusion: By priming the 3D construct with BMP-2, bone metabolism was physiologically accelerated, that is, enhancing vertical bone growth and maturation as well as material bioresorption. The scaffolding function of the block was maintained, leaving time for the bone to grow and mature to a haversian-like structure. In parallel, the material resorbed via cell-mediated and chemical processes. These promising results must be confirmed in clinical tests.

Bone Marrow Matters

ERIC Educational Resources Information Center

Dunne, Mark; Maklad, Rania; Heaney, Emma

2014-01-01

As a final-year student teacher specialising in primary science, Emma Heaney faced the challenge of having to plan, organise, and conduct a small-scale, classroom-based research project. She had to teach about bones in the final block practice session and thought it would be a good idea to bring in some biological specimens obtained from the local…

Synthesis of nitric oxide in human osteoblasts in response to physiologic stimulation of electrotherapy.

PubMed

Hamed, Ayman; Kim, Paul; Cho, Michael

2006-12-01

Electrotherapy for bone healing, remodeling and wound healing may be mediated by modulation of nitric oxide (NO). Using NO-specific fluorophore (DAF-2), we report here that application of non-invasive, physiologic electrical stimulation induces NO synthesis in human osteoblasts, and that such NO generation is comparable to that induced by estrogen treatment. For example, application of a sinusoidal 1 Hz, 2 V/cm (peak to peak) electrical stimulation (ES) increases NO-bound DAF-2 fluorescence intensity by a 2-fold within 60 min exposure by activating nitric oxide synthase (NOS). Increase in the NO level is found to depend critically on the frequency and strength of ES. While the frequency of 1 Hz ES seems optimal, the ES strength >0.5 V/cm is required to induce significant NO increase, however. Nitric oxide synthesis in response to ES is completely prevented by blocking estrogen receptors using a competitive inhibitor, suggesting that NO generation is likely initiated by activation of estrogen receptors at the cell surface. Based on these findings, physiologic stimulation of electrotherapy appears to represent a potential non-invasive, non-genomic, and novel physical technique that could be used to regulate NO-mediated bone density and facilitate bone remodeling without adverse effects associated with hormone therapy.

High resolution bone mineral densitometry with a gamma camera

NASA Technical Reports Server (NTRS)

Leblanc, A.; Evans, H.; Jhingran, S.; Johnson, P.

1983-01-01

A technique by which the regional distribution of bone mineral can be determined in bone samples from small animals is described. The technique employs an Anger camera interfaced to a medical computer. High resolution imaging is possible by producing magnified images of the bone samples. Regional densitometry of femurs from oophorectomised and bone mineral loss.

Effect of molding pressure on fabrication of low-crystalline calcite block.

PubMed

Lin, Xin; Matsuya, Shigeki; Nakagawa, Masaharu; Terada, Yoshihiro; Ishikawa, Kunio

2008-02-01

We have reported that low-crystalline porous calcite block, which is useful as a bone substitute or a source material to prepare apatite-type bone fillers could be fabricated by exposing calcium hydroxide compact to carbon dioxide gas saturated with water vapor. In the present study, we investigated the effect of molding pressure on the transformation of calcium hydroxide into calcite and the mechanical strength of the carbonated compact. Transformation into calcite was almost completed within 72 h, however, a small amount of Ca(OH)(2) still remained unreacted at higher molding pressure because of incomplete penetration of CO(2) gas into the interparticle space due to dense packing of Ca(OH)(2) particles. On the other hand, high molding pressure resulted in an increase in diametral tensile strength (DTS) of the calcite compact formed. Critical porosity of the calcite block was calculated as approximately 68%.

Fabrication of porous calcite using chopped nylon fiber and its evaluation using rats.

PubMed

Ishikawa, Kunio; Tram, Nguyen Xuan Thanh; Tsuru, Kanji; Toita, Riki

2015-02-01

Although porous calcite has attracted attention as bone substitutes, limited studies have been made so far. In the present study, porous calcite block was fabricated by introducing chopped nylon fiber as porogen. Ca(OH)2 powder containing 10 wt% chopped nylon fiber was compacted at 150 MPa, and sintered to burn out the fiber and to carbonate the Ca(OH)2 under stream of 1:2 O2-CO2. Sintering of Ca(OH)2 at 750 °C or lower temperature resulted in incomplete burning out of the fiber whereas sintering at 800 °C or higher temperature resulted in the formation of CaO due to the thermal decomposition of Ca(OH)2. However, sintering at 770 °C resulted in complete burning out of the fiber and complete carbonation of Ca(OH)2 to calcite without forming CaO. Macro- and micro-porosities of the porous calcite were approximately 23 and 16%, respectively. Diameter of the macropores was approximately 100 μm which is suitable for bone tissue penetration. Porous calcite block fabricated by this method exhibited good tissue response when implanted in the bone defect in femur of 12-weeks-old rat. Four weeks after implantation, bone bonded on the surface of calcite. Furthermore, bone tissue penetrated interior to the macropore at 8 weeks. These results demonstrated the good potential value of porous calcite as artificial bone substitutes.

Bone tissue engineering scaffolding: computer-aided scaffolding techniques.

PubMed

Thavornyutikarn, Boonlom; Chantarapanich, Nattapon; Sitthiseripratip, Kriskrai; Thouas, George A; Chen, Qizhi

Tissue engineering is essentially a technique for imitating nature. Natural tissues consist of three components: cells, signalling systems (e.g. growth factors) and extracellular matrix (ECM). The ECM forms a scaffold for its cells. Hence, the engineered tissue construct is an artificial scaffold populated with living cells and signalling molecules. A huge effort has been invested in bone tissue engineering, in which a highly porous scaffold plays a critical role in guiding bone and vascular tissue growth and regeneration in three dimensions. In the last two decades, numerous scaffolding techniques have been developed to fabricate highly interconnective, porous scaffolds for bone tissue engineering applications. This review provides an update on the progress of foaming technology of biomaterials, with a special attention being focused on computer-aided manufacturing (Andrade et al. 2002) techniques. This article starts with a brief introduction of tissue engineering (Bone tissue engineering and scaffolds) and scaffolding materials (Biomaterials used in bone tissue engineering). After a brief reviews on conventional scaffolding techniques (Conventional scaffolding techniques), a number of CAM techniques are reviewed in great detail. For each technique, the structure and mechanical integrity of fabricated scaffolds are discussed in detail. Finally, the advantaged and disadvantage of these techniques are compared (Comparison of scaffolding techniques) and summarised (Summary).

Evaluation of bone marrow specimens with acute myelogenous leukemia for CD34, CD15, CD117, and myeloperoxidase.

PubMed

Dunphy, C H; Polski, J M; Evans, H L; Gardner, L J

2001-08-01

Immunophenotyping of bone marrow (BM) specimens with acute myelogenous leukemia (AML) may be performed by flow cytometric (FC) or immunohistochemical (IH) techniques. Some markers (CD34, CD15, and CD117) are available for both techniques. Myeloperoxidase (MPO) analysis may be performed by enzyme cytochemical (EC) or IH techniques. To determine the reliability of these markers and MPO by these techniques, we designed a study to compare the results of analyses of these markers and MPO by FC (CD34, CD15, and CD117), EC (MPO), and IH (CD34, CD15, CD117, and MPO) techniques. Twenty-nine AMLs formed the basis of the study. These AMLs all had been immunophenotyped previously by FC analysis; 27 also had had EC analysis performed. Of the AMLs, 29 had BM core biopsies and 26 had BM clots that could be evaluated. The paraffin blocks of the 29 BM core biopsies and 26 BM clots were stained for CD34, CD117, MPO, and CD15. These results were compared with results by FC analysis (CD34, CD15, and CD117) and EC analysis (MPO). Immunodetection of CD34 expression in AML had a similar sensitivity by FC and IH techniques. Immunodetection of CD15 and CD117 had a higher sensitivity by FC analysis than by IH analysis. Detection of MPO by IH analysis was more sensitive than by EC analysis. There was no correlation of French-American-British (FAB) subtype of AML with CD34 or CD117 expression. Expression of CD15 was associated with AMLs with a monocytic component. Myeloperoxidase reactivity by IH analysis was observed in AMLs originally FAB subtyped as M0. CD34 can be equally detected by FC and IH techniques. CD15 and CD117 are better detected by FC analysis and MPO is better detected by IH analysis.

Microporous pure beta-tricalcium phosphate implants for press-fit fixation of anterior cruciate ligament grafts: strength and healing in a sheep model.

PubMed

Mayr, Hermann O; Dietrich, Markwart; Fraedrich, Franz; Hube, Robert; Nerlich, Andreas; von Eisenhart-Rothe, Rüdiger; Hein, Werner; Bernstein, Anke

2009-09-01

A sheep study was conducted to test a press-fit technique using microporous pure beta-tricalcium phosphate (beta-TCP) dowels for fixation of the anterior cruciate ligament (ACL) graft. Microporous (5 mum) cylindrical plugs of beta-TCP (diameter, 7 mm; length, 25 mm) with interconnecting pores were used. The material featured a novel configuration of structure and surface geometry. Implants were tested by use of press-fit fixation of ACL grafts with and without bone blocks in 42 sheep over a period of 24 weeks. Biomechanical, radiologic, histologic, and immunohistochemical evaluations were performed. In load-to-failure tests at 6, 12, and 24 weeks after surgery, the intra-articular graft always failed, not the fixation. Grafts showed bony fixation in the tunnel at 6 weeks and primary healing at the junction of the tunnel and joint after 24 weeks. Tricalcium phosphate was resorbed and simultaneously replaced by bone. Remodeling was still incomplete at 24 weeks. In the sheep model microporous beta-TCP implants used with press-fit fixation of ACL grafts permit early functional rehabilitation. After 6 weeks, the graft is fixed by woven bone or bony integration. Implanted microporous tricalcium phosphate is resorbed and replaced by bone. In a sheep model we showed that primary healing of ACL grafts with resorption and bony replacement of the fixating implant can be achieved by means of press-fit fixation with pure beta-TCP.

Inorganic-organic shape memory polymers and foams for bone defect repairs

NASA Astrophysics Data System (ADS)

Zhang, Dawei

The ultimate goal of this research was to develop a "self-fitting" shape memory polymer (SMP) scaffold for the repair of craniomaxillofacial (CMF) bone defects. CMF defects may be caused by trauma, tumor removal or congenital abnormalities and represent a major class of bone defects. Their repair with autografts is limited by availability, donor site morbidity and complex surgical procedures. In addition, shaping and positioning of these rigid grafts into irregular defects is difficult. Herein, we have developed SMP scaffolds which soften at T > ˜56 °C, allowing them to conformally fit into a bone defect. Upon cooling to body temperature, the scaffold becomes rigid and mechanically locks in place. This research was comprised of four major studies. In the first study, photocrosslinkable acrylated (AcO) SMP macromers containing a poly(epsilon-caprolactone) (PCL) segment and polydimethylsiloxane (PDMS) segments were synthesized with the general formula: AcO-PCL40-block-PDMS m-block-PCL40-OAc. By varying the PDMS segment length (m), solid SMPs with highly tunable mechanical properties and excellent shape memory abilities were prepared. In the second study, porous SMP scaffolds were fabricated based on AcO-PCL 40-block-PDMS37-block-PCL 40-OAc via a revised solvent casting particulate leaching (SCPL) method. By tailoring scaffold parameters including salt fusion, macromer concentration and salt size, scaffold properties (e.g. pore features, compressive modulus and shape memory behavior) were tuned. In the third study, porous SMP scaffolds were produced from macromers with variable PDMS segment lengths (m = 0 -- 130) via an optimized SCPL method. The impact on pore features, thermal, mechanical, and shape memory properties as well as degradation rates were investigated. In the final study, a bioactive polydopamine coating was applied onto pore surfaces of the SMP scaffold prepared from PCL diacrylate. The thin coating did not affect intrinsic bulk properties of the scaffold. However, the coating significantly increased its bioactivity, giving rise to the formation of "bone-bonding" hydroxyapatite (HAp) when exposed to simulated body fluid (SBF). It was also shown that the coating largely enhanced the scaffold's capacities to support osteoblasts adhesion, proliferation and osteogenesis. Thus, the polydopamine coating should enhance the performance of the "self-fitting" SMP scaffolds for the repair of bone defects.

Papineau debridement, Ilizarov bone transport, and negative-pressure wound closure for septic bone defects of the tibia.

PubMed

Karargyris, Orestis; Polyzois, Vasilios D; Karabinas, Panayiotis; Mavrogenis, Andreas F; Pneumaticos, Spyros G

2014-08-01

Ilizarov pioneered bone transport using a circular external fixator. Papineau described a staged technique for the treatment for infected pseudarthrosis of the long bones. This article presents a single-stage Papineau technique and Ilizarov bone transport, and postoperative negative-pressure wound dressing changes for septic bone defects of the tibia. We studied the files of seven patients (mean age, 32 years) with septic bone defects of the tibia treated with a Papineau technique and Ilizarov bone transport in a single stage, followed by postoperative negative-pressure wound dressing changes. All patients had septic pseudarthrosis and skin necrosis of the tibia. The technique included a single-stage extensive surgical debridement of necrotic bone, open bone grafting with cancellous bone autograft and bone transport, and postoperative negative-pressure wound dressing changes for wound closure. The mean time from the initial injury was 6 months (range, 4-8 months). The mean follow-up was 14 months (range, 10-17 months). All patients experienced successful wound healing at a mean of 29 days. Six patients experienced successful bone regeneration and union at the docking side at a mean of 6 months. One patient experienced delayed union at the docking site, which was treated with autologous cancellous bone grafting. Two patients experienced pin track infection, which was successfully treated with antibiotics and pin site dressing changes. All patients were able to return to their work and previous levels of activity, except one patient who had a stiff ankle joint and had to change his job. No patient experienced recurrence of infection, or fracture of the regenerated or transported bone segment until the period of this study. The combined Papineau and Ilizarov bone transport technique with negative-pressure wound closure provides for successful eradication of the infection, reconstruction of the bone defect, and soft-tissue closure. A single-stage surgical treatment is feasible, without any complications.

Bone surface enhancement in ultrasound images using a new Doppler-based acquisition/processing method.

PubMed

Yang, Xu; Tang, Songyuan; Tasciotti, Ennio; Righetti, Raffaella

2018-01-17

Ultrasound (US) imaging has long been considered as a potential aid in orthopedic surgeries. US technologies are safe, portable and do not use radiations. This would make them a desirable tool for real-time assessment of fractures and to monitor fracture healing. However, image quality of US imaging methods in bone applications is limited by speckle, attenuation, shadow, multiple reflections and other imaging artifacts. While bone surfaces typically appear in US images as somewhat 'brighter' than soft tissue, they are often not easily distinguishable from the surrounding tissue. Therefore, US imaging methods aimed at segmenting bone surfaces need enhancement in image contrast prior to segmentation to improve the quality of the detected bone surface. In this paper, we present a novel acquisition/processing technique for bone surface enhancement in US images. Inspired by elastography and Doppler imaging methods, this technique takes advantage of the difference between the mechanical and acoustic properties of bones and those of soft tissues to make the bone surface more easily distinguishable in US images. The objective of this technique is to facilitate US-based bone segmentation methods and improve the accuracy of their outcomes. The newly proposed technique is tested both in in vitro and in vivo experiments. The results of these preliminary experiments suggest that the use of the proposed technique has the potential to significantly enhance the detectability of bone surfaces in noisy ultrasound images.

Bone surface enhancement in ultrasound images using a new Doppler-based acquisition/processing method

NASA Astrophysics Data System (ADS)

Yang, Xu; Tang, Songyuan; Tasciotti, Ennio; Righetti, Raffaella

2018-01-01

Ultrasound (US) imaging has long been considered as a potential aid in orthopedic surgeries. US technologies are safe, portable and do not use radiations. This would make them a desirable tool for real-time assessment of fractures and to monitor fracture healing. However, image quality of US imaging methods in bone applications is limited by speckle, attenuation, shadow, multiple reflections and other imaging artifacts. While bone surfaces typically appear in US images as somewhat ‘brighter’ than soft tissue, they are often not easily distinguishable from the surrounding tissue. Therefore, US imaging methods aimed at segmenting bone surfaces need enhancement in image contrast prior to segmentation to improve the quality of the detected bone surface. In this paper, we present a novel acquisition/processing technique for bone surface enhancement in US images. Inspired by elastography and Doppler imaging methods, this technique takes advantage of the difference between the mechanical and acoustic properties of bones and those of soft tissues to make the bone surface more easily distinguishable in US images. The objective of this technique is to facilitate US-based bone segmentation methods and improve the accuracy of their outcomes. The newly proposed technique is tested both in in vitro and in vivo experiments. The results of these preliminary experiments suggest that the use of the proposed technique has the potential to significantly enhance the detectability of bone surfaces in noisy ultrasound images.

Fabrication of carbonate apatite blocks from set gypsum based on dissolution-precipitation reaction in phosphate-carbonate mixed solution.

PubMed

Nomura, Shunsuke; Tsuru, Kanji; Maruta, Michito; Matsuya, Shigeki; Takahashi, Ichiro; Ishikawa, Kunio

2014-01-01

Carbonate apatite (CO3Ap), fabricated by dissolution-precipitation reaction based on an appropriate precursor, is expected to be replaced by bone according to bone remodeling cycle. One of the precursor candidates is gypsum because it shows self-setting ability, which then enables it to be shaped and molded. The aim of this study, therefore, was to fabricate CO3Ap blocks from set gypsum. Set gypsum was immersed in a mixed solution of 0.4 mol/L disodium hydrogen phosphate (Na2HPO4) and 0.4 mol/L sodium hydrogen carbonate (NaHCO3) at 80-200°C for 6-48 h. Powder X-ray diffraction patterns and Fourier transform infrared spectra showed that CO3Ap block was fabricated by dissolution-precipitation reaction in Na2HPO4-NaHCO3 solution using set gypsum in 48 h when the temperature was 100°C or higher. Conversion rate to CO3Ap increased with treatment temperature. CO3Ap block containing a larger amount of carbonate was obtained when treated at lower temperature.

LIM mineralization protein-1 potentiates bone morphogenetic protein responsiveness via a novel interaction with Smurf1 resulting in decreased ubiquitination of Smads.

PubMed

Sangadala, Sreedhara; Boden, Scott D; Viggeswarapu, Manjula; Liu, Yunshan; Titus, Louisa

2006-06-23

Development and repair of the skeletal system and other organs is highly dependent on precise regulation of bone morphogenetic proteins (BMPs), their receptors, and their intracellular signaling proteins known as Smads. The use of BMPs clinically to induce bone formation has been limited in part by the requirement of much higher doses of recombinant proteins in primates than were needed in cell culture or rodents. Therefore, control of cellular responsiveness to BMPs is now a critical area that is poorly understood. We determined that LMP-1, a LIM domain protein capable of inducing de novo bone formation, interacts with Smurf1 (Smad ubiquitin regulatory factor 1) and prevents ubiquitination of Smads. In the region of LMP responsible for bone formation, there is a motif that directly interacts with the Smurf1 WW2 domain and can effectively compete with Smad1 and Smad5 for binding. We have shown that small peptides containing this motif can mimic the ability to block Smurf1 from binding Smads. This novel interaction of LMP-1 with the WW2 domain of Smurf1 to block Smad binding results in increased cellular responsiveness to exogenous BMP and demonstrates a novel regulatory mechanism for the BMP signaling pathway.

Improvement of Implant Placement after Bone Augmentation of Severely Resorbed Maxillary Sinuses with 'Tent-Pole' Grafting Technique in Combination with rhBMP-2.

PubMed

Zhang, Qiao; Zhang, Li Li; Yang, Yang; Lin, Yi Zhen; Miron, Richard J; Zhang, Yu Feng

To study the clinical effect of short implant placement using osteotome sinus floor elevation technique and tent-pole grafting technique with recombinant human bone morphogenetic protein 2 (rhBMP-2) in severely resorbed maxillary area. Eleven patients with insufficient bone height in the posterior maxillary area were included. According to the native bone height and crown height space (CHS), the patients were divided into two groups: immediate placement of short implants with simultaneous bone augmentation (group A, 5 patients) and delayed dental implant placement (4 to 6 months) after bone augmentation. The rhBMP-2 was added into a deproteinised bovine bone mineral (DBBM) bone grafting material to shorten the treatment procedure and enhance the final effect of bone augmentation in both groups. Tent-pole grafting technique was applied for vertical bone augmentation in group B (6 patients). The success rate of the implants placed was 100% in both groups. In group A, the short implants treatment was successful, with a vertical gain of 1.5 to 6.4 mm in bone height after 4 to 6 months. In group B, the tent-pole grafting procedure in combination with DBBM and rhBMP-2 increased vertical bone height between 3.1 and 8.1 mm, an optimistic and adequate increase for implant placement. This bone increase was maintained following implant placement and final crown placement in the maxillary region (3.5 to 7.3 mm). The tent-pole grafting technique was a viable alternative choice to lateral sinus floor elevation in cases with excessive CHS. The application of rhBMP-2 with a shortened treatment time demonstrated positive outcomes in sinus floor augmentation procedures.

A Comparison of Jump Height, Takeoff Velocities, and Blocking Coverage in the Swing and Traditional Volleyball Blocking Techniques

PubMed Central

Ficklin, Travis; Lund, Robin; Schipper, Megan

2014-01-01

The purpose of this study was to compare traditional and swing blocking techniques on center of mass (COM) projectile motion and effective blocking area in nine healthy Division I female volleyball players. Two high-definition (1080 p) video cameras (60 Hz) were used to collect two-dimensional variables from two separate views. One was placed perpendicular to the plane of the net and the other was directed along the top of the net, and were used to estimate COM locations and blocking area in a plane parallel to the net and hand penetration through the plane of the net respectively. Video of both the traditional and swing techniques were digitized and kinematic variables were calculated. Paired samples t-tests indicated that the swing technique resulted in greater (p < 0.05) vertical and horizontal takeoff velocities (vy and vx), jump height (H), duration of the block (tBLOCK), blocking coverage during the block (C) as well as hand penetration above and through the net’s plane (YPEN, ZPEN). The traditional technique had significantly greater approach time (tAPP). The results of this study suggest that the swing technique results in both greater jump height and effective blocking area. However, the shorter tAPP that occurs with swing is associated with longer times in the air during the block which may reduce the ability of the athlete to make adjustments to attacks designed to misdirect the defense. Key Points Swing blocking technique has greater jump height, effective blocking area, hand penetration, horizontal and vertical takeoff velocity, and has a shorter time of approach. Despite these advantages, there may be more potential for mistiming blocks and having erratic deflections of the ball after contact when using the swing technique. Coaches should take more than simple jump height and hand penetration into account when deciding which technique to employ. PMID:24570609

A comparison of jump height, takeoff velocities, and blocking coverage in the swing and traditional volleyball blocking techniques.

PubMed

Ficklin, Travis; Lund, Robin; Schipper, Megan

2014-01-01

The purpose of this study was to compare traditional and swing blocking techniques on center of mass (COM) projectile motion and effective blocking area in nine healthy Division I female volleyball players. Two high-definition (1080 p) video cameras (60 Hz) were used to collect two-dimensional variables from two separate views. One was placed perpendicular to the plane of the net and the other was directed along the top of the net, and were used to estimate COM locations and blocking area in a plane parallel to the net and hand penetration through the plane of the net respectively. Video of both the traditional and swing techniques were digitized and kinematic variables were calculated. Paired samples t-tests indicated that the swing technique resulted in greater (p < 0.05) vertical and horizontal takeoff velocities (vy and vx), jump height (H), duration of the block (tBLOCK), blocking coverage during the block (C) as well as hand penetration above and through the net's plane (YPEN, ZPEN). The traditional technique had significantly greater approach time (tAPP). The results of this study suggest that the swing technique results in both greater jump height and effective blocking area. However, the shorter tAPP that occurs with swing is associated with longer times in the air during the block which may reduce the ability of the athlete to make adjustments to attacks designed to misdirect the defense. Key PointsSwing blocking technique has greater jump height, effective blocking area, hand penetration, horizontal and vertical takeoff velocity, and has a shorter time of approach.Despite these advantages, there may be more potential for mistiming blocks and having erratic deflections of the ball after contact when using the swing technique.Coaches should take more than simple jump height and hand penetration into account when deciding which technique to employ.

Gaussian curvature analysis allows for automatic block placement in multi-block hexahedral meshing.

PubMed

Ramme, Austin J; Shivanna, Kiran H; Magnotta, Vincent A; Grosland, Nicole M

2011-10-01

Musculoskeletal finite element analysis (FEA) has been essential to research in orthopaedic biomechanics. The generation of a volumetric mesh is often the most challenging step in a FEA. Hexahedral meshing tools that are based on a multi-block approach rely on the manual placement of building blocks for their mesh generation scheme. We hypothesise that Gaussian curvature analysis could be used to automatically develop a building block structure for multi-block hexahedral mesh generation. The Automated Building Block Algorithm incorporates principles from differential geometry, combinatorics, statistical analysis and computer science to automatically generate a building block structure to represent a given surface without prior information. We have applied this algorithm to 29 bones of varying geometries and successfully generated a usable mesh in all cases. This work represents a significant advancement in automating the definition of building blocks.

Bone Replacement Materials and Techniques Used for Achieving Vertical Alveolar Bone Augmentation

PubMed Central

Sheikh, Zeeshan; Sima, Corneliu; Glogauer, Michael

2015-01-01

Alveolar bone augmentation in vertical dimension remains the holy grail of periodontal tissue engineering. Successful dental implant placement for restoration of edentulous sites depends on the quality and quantity of alveolar bone available in all spatial dimensions. There are several surgical techniques used alone or in combination with natural or synthetic graft materials to achieve vertical alveolar bone augmentation. While continuously improving surgical techniques combined with the use of auto- or allografts provide the most predictable clinical outcomes, their success often depends on the status of recipient tissues. The morbidity associated with donor sites for auto-grafts makes these techniques less appealing to both patients and clinicians. New developments in material sciences offer a range of synthetic replacements for natural grafts to address the shortcoming of a second surgical site and relatively high resorption rates. This narrative review focuses on existing techniques, natural tissues and synthetic biomaterials commonly used to achieve vertical bone height gain in order to successfully restore edentulous ridges with implant-supported prostheses.

The type 1 lysophosphatidic acid receptor is a target for therapy in bone metastases

PubMed Central

Boucharaba, Ahmed; Serre, Claire-Marie; Guglielmi, Julien; Bordet, Jean-Claude; Clézardin, Philippe; Peyruchaud, Olivier

2006-01-01

Platelet-derived lysophosphatidic acid (LPA) supports the progression of breast and ovarian cancer metastasis to bone. The mechanisms through which LPA promotes bone metastasis formation are, however, unknown. Here we report that silencing of the type 1 LPA receptor (LPA1) in cancer cells blocks the production of tumor-derived cytokines that are potent activators of osteoclast-mediated bone destruction and significantly reduces the progression of osteolytic bone metastases. Moreover, functional blockade of LPA action on its cognate receptor LPA1 using a pharmacological antagonist mimics the effects of silencing LPA1 in tumor cells in vitro and substantially reduces bone metastasis progression in animals. Overall, these results suggest that inhibition of platelet-derived LPA action on LPA1 expressed by tumor cells may be a promising therapeutic target for patients with bone metastases. PMID:16769891

DOE Office of Scientific and Technical Information (OSTI.GOV)

Paudel, M; currently at University of Toronto, Sunnybrook Health Sciences Center, Toronto, ON; MacKenzie, M

Purpose: To evaluate the metal artifacts in diagnostic kVCT images of patients that are corrected using a normalized metal artifact reduction method with MVCT prior images, MVCT-NMAR. Methods: An MVCTNMAR algorithm was developed and applied to five patients: three with bilateral hip prostheses, one with unilateral hip prosthesis and one with dental fillings. The corrected images were evaluated for visualization of tissue structures and their interfaces, and for radiotherapy dose calculations. They were also compared against the corresponding images corrected by a commercial metal artifact reduction technique, O-MAR, on a Phillips™ CT scanner. Results: The use of MVCT images formore » correcting kVCT images in the MVCT-NMAR technique greatly reduces metal artifacts, avoids secondary artifacts, and makes patient images more useful for correct dose calculation in radiotherapy. These improvements are significant over the commercial correction method, provided the MVCT and kVCT images are correctly registered. The remaining and the secondary artifacts (soft tissue blurring, eroded bones, false bones or air pockets, CT number cupping within the metal) present in O-MAR corrected images are removed in the MVCT-NMAR corrected images. Large dose reduction is possible outside the planning target volume (e.g., 59.2 Gy in comparison to 52.5 Gy in pubic bone) when these MVCT-NMAR corrected images are used in TomoTherapy™ treatment plans, as the corrected images no longer require directional blocks for prostate plans in order to avoid the image artifact regions. Conclusion: The use of MVCT-NMAR corrected images in radiotherapy treatment planning could improve the treatment plan quality for cancer patients with metallic implants. Moti Raj Paudel is supported by the Vanier Canada Graduate Scholarship, the Endowed Graduate Scholarship in Oncology and the Dissertation Fellowship at the University of Alberta. The authors acknowledge the CIHR operating grant number MOP 53254.« less

Temperature changes induced by 809-nm GaAlAs laser at the implant-bone interface during simulated surface decontamination.

PubMed

Kreisler, Matthias; Al Haj, Haitham; D'Hoedt, Bernd

2003-02-01

The aim of the study was to investigate temperature changes at the implant-bone interface during simulated implant surface decontamination with a 809-nm gallium-aluminium-arsenid (GaAlAs) semiconductor laser. Stepped cylinder implants with a diameter of 3.8 mm and a length of 11 mm with two different surfaces (sand-blasted and acid etched, and hydroxyapatite-coated) were inserted into bone blocks cut from freshly resected pig femurs. Access holes of 0.5 mm were drilled into the bone, to allow K-type thermocouples to contact periimplant bone in different parts of the cavity. An artificial periimplant bone defect provided access for laser irradiation in the coronal third. A 600-micrometer optic fiber was used at a distance of 0.5 mm from the implant surface. Power output varied between 0.5 and 2.5 W in the continuous wave mode. The bone block was placed into a 37 degrees C water bath in order to simulate in vivo thermal conductivity and diffusitivity of heat. Temperature elevations during irradiation were registered for a period of 120 s. In mean, the critical threshold of 47 degrees C was exceeded after 9.0 s at 2.5 W, 12.5 s at 2.0 W, 18.0 s at 1.5 W and 30.5 s at 1.0 W. Surface characteristics did not have a significant effect on temperature elevations. In an energy-dependent manner, implant surface decontamination with an 809-nm GaAlAs laser must be limited in time to allow the implant and bone to cool down. Clinical guidelines are presented to avoid tissue damage.

Inhibition of estrogen biosynthesis with a potent aromatase inhibitor increases predicted adult height in boys with idiopathic short stature: a randomized controlled trial.

PubMed

Hero, Matti; Norjavaara, Ensio; Dunkel, Leo

2005-12-01

In males as well as in females, estrogen is an essential regulator of bone maturation, growth plate fusion, and cessation of longitudinal growth. Therefore, an increase in predicted adult height (PAH) may be achieved in short boys by blocking estrogen biosynthesis. We tested the hypothesis that a decrease in the rate of bone maturation and an increase in PAH can be achieved in boys with idiopathic short stature (ISS) by the method of blocking estrogen biosynthesis with an aromatase inhibitor. Secondarily, we investigated the effects of aromatase inhibition on bone mineralization. This was a prospective, double-blind, randomized, placebo (Pl)-controlled clinical study. The study was performed at a university hospital out-patient clinic. Thirty-one boys, aged 9.0-14.5 yr, with ISS were studied. The boys were treated with the aromatase inhibitor letrozole (Lz; 2.5 mg/d) or Pl for 2 yr. The main outcome measure was the change in PAH after 24 months of treatment. PAH increased by 5.9 cm (P < 0.0001), and height SD score for bone age increased by 0.7 SD score (P < 0.0001) in the Lz-treated boys, whereas no changes occurred in the respective measures in Pl-treated boys. Areal bone mineral density of the lumbar spine and femoral neck, assessed by dual-energy x-ray absorptiometry, increased in a similar fashion in both groups during the treatment, whereas bone mineral apparent density increased only in those taking Lz (median increase, 4.3%; P = 0.009). Treatment with the aromatase inhibitor Lz delays bone maturation and improves PAH in boys with ISS. No adverse effects on bone mineralization were evident after 2 yr of treatment.

Oral Rehabilitation of a Patient With Ectodermal Dysplasia Treated With Fresh-Frozen Bone Allografts and Computer-Guided Implant Placement: A Clinical Case Report.

PubMed

Maiorana, Carlo; Poli, Pier Paolo; Poggio, Carlo; Barbieri, Paola; Beretta, Mario

2017-05-01

Ectodermal dysplasia (ED) is an inherited disorder characterized by abnormality of ectodermally derived structures. A recurrent oral finding is oligodontia, which in turn leads to a severely hypotrophic alveolar process with typical knife-edge morphology and adverse ridge contours. This unfavorable anatomy can seriously hamper proper implant placement. Fresh-frozen bone (FFB) allografts recently have been proposed to augment the residual bone volume for implant placement purposes; however, scientific evidence concerning the use of FFB to treat ED patients is absent. Similarly, data reporting computer-aided template-guided implant placement in medically compromised patients are limited. Thus the purpose of this report is to illustrate the oral rehabilitation of a female patient affected by ED and treated with appositional FFB block grafts and consecutive computer-guided flapless implant placement in a 2-stage procedure. Fixed implant-supported dental prostheses were finally delivered to the patient, which improved her self-esteem and quality of life. During the follow-up recall 1 year after the prosthetic loading, the clinical examination showed healthy peri-implant soft tissues with no signs of bleeding on probing or pathologic probing depths. The panoramic radiograph confirmed the clinical stability of the result. Peri-implant marginal bone levels were radiographically stable with neither pathologic bone loss at the mesial and distal aspects of each implant nor peri-implant radiolucency. Within the limitations of this report, the use of FFB allografts in association with computer-aided flapless implant surgery might be considered a useful technique in patients affected by ED. Copyright © 2017 American Association of Oral and Maxillofacial Surgeons. Published by Elsevier Inc. All rights reserved.

Smad4 is required to inhibit osteoclastogenesis and maintain bone mass.

PubMed

Morita, Mayu; Yoshida, Shigeyuki; Iwasaki, Ryotaro; Yasui, Tetsuro; Sato, Yuiko; Kobayashi, Tami; Watanabe, Ryuichi; Oike, Takatsugu; Miyamoto, Kana; Takami, Masamichi; Ozato, Keiko; Deng, Chu-Xia; Aburatani, Hiroyuki; Tanaka, Sakae; Yoshimura, Akihiko; Toyama, Yoshiaki; Matsumoto, Morio; Nakamura, Masaya; Kawana, Hiromasa; Nakagawa, Taneaki; Miyamoto, Takeshi

2016-10-12

Bone homeostasis is maintained as a delicate balance between bone-resorption and bone-formation, which are coupled to maintain appropriate bone mass. A critical question is how bone-resorption is terminated to allow bone-formation to occur. Here, we show that TGFβs inhibit osteoclastogenesis and maintain bone-mass through Smad4 activity in osteoclasts. We found that latent-TGFβ1 was activated by osteoclasts to inhibit osteoclastogenesis. Osteoclast-specific Smad4 conditional knockout mice (Smad4-cKO) exhibited significantly reduced bone-mass and elevated osteoclast formation relative to controls. TGFβ1-activation induced expression of Irf8 and Bcl6, both of which encode factors inhibiting osteoclastogenesis, by blocking their negative regulator, Prdm1, in osteoclasts in a Smad4-dependent manner. Reduced bone-mass and accelerated osteoclastogenesis seen in Smad4-cKO were abrogated by Prdm1 deletion. Administration of latent-TGFβ1-Fc to wild-type mice antagonized LPS-induced bone destruction in a model of activated osteoclast-mediated bone destruction. Thus, latent-TGFβ1-Fc could serve as a promising new therapeutic agent in bone diseases marked by excessive resorption.

Island custom blocking technique

DOE Office of Scientific and Technical Information (OSTI.GOV)

Carabetta, R.J.

The technique of Island blocking is being used more frequently since the advent of our new head and neck blocking techniques and the implementation of a newly devised lung protocol. The system presented affords the mould room personnel a quick and accurate means of island block fabrication without the constant remeasuring or subtle shifting to approximate correct placement. The cookie cutter is easily implemented into any department's existing block cutting techniques. The device is easily and inexpensively made either in a machine shop or acquired by contacting the author.

Technical errors in planar bone scanning.

PubMed

Naddaf, Sleiman Y; Collier, B David; Elgazzar, Abdelhamid H; Khalil, Magdy M

2004-09-01

Optimal technique for planar bone scanning improves image quality, which in turn improves diagnostic efficacy. Because planar bone scanning is one of the most frequently performed nuclear medicine examinations, maintaining high standards for this examination is a daily concern for most nuclear medicine departments. Although some problems such as patient motion are frequently encountered, the degraded images produced by many other deviations from optimal technique are rarely seen in clinical practice and therefore may be difficult to recognize. The objectives of this article are to list optimal techniques for 3-phase and whole-body bone scanning, to describe and illustrate a selection of deviations from these optimal techniques for planar bone scanning, and to explain how to minimize or avoid such technical errors.

Hominid cranial bone structure: a histological study of Omo 1 specimens from Ethiopia using different microscopic techniques.

PubMed

Bartsiokas, Antonis

2002-05-01

The microstructure of a hominid cranial vault has not previously been studied to determine its tissue histology, and differences in comparison with that of modern humans. We selected the parietals of Omo-Kibish 1, regarded as one of the oldest (about 130,000 years old) anatomically modern humans, and Omo 1 (Howell), which is a very recent human (about 2,000 years old)-both from the same area of Ethiopia. A combination of macrophotography, polarizing microscopy in the incident and transmission illumination mode, and confocal laser scanning microscopy (CLSM) was employed to examine thin sections, as well as polished and unpolished block faces of unembedded bone fragments, to minimize specimen destruction as much as possible. The methods enabled remarkably detailed information on bone microstructure and remodeling to be gleaned from tiny fragments of bone. The best method for examining fossilized human bones was shown to be that of incident light microscopy, which was the least destructive while producing the most amount of information. Unless the above methods are used, bone-filling minerals, such as calcite, can cause erroneous estimations of bone thickness, as observations with the naked eye or even a magnifying glass cannot determine the limit between the cortex and the diploe. This is particularly important for sciences such as paleoanthropology, in which, for instance, a thick cranial bone of Homo erectus may be confused with a pathological one of H. sapiens and vice versa. Cross sections of parietal bones revealed differences between Omo-Kibish 1 and Omo 1 (Howell) in diploic histology and in the relative thickness between the cortex and diploe, with the former specimen having an H. erectus ratio despite its H. sapiens gross anatomy. Omo-Kibish 1 may still retain some affinities with H. erectus despite its being classified as H. sapiens. Newly described histological structures, such as the reverse type II osteons, the multicanalled osteons, and the osteocytomata are presented here. A modern human skeletal anatomy does not necessarily imply a modern human cranial bone histology. The outer circumferential lamellae of cranial bones are in essence growth lines. Cranial histology of hominids may provide useful information concerning their taxonomy and life history, including such factors as growth rate, developmental stress, and diet. Copyright 2002 Wiley-Liss, Inc.

MR-Based Assessment of Bone Marrow Fat in Osteoporosis, Diabetes, and Obesity

PubMed Central

Cordes, Christian; Baum, Thomas; Dieckmeyer, Michael; Ruschke, Stefan; Diefenbach, Maximilian N.; Hauner, Hans; Kirschke, Jan S.; Karampinos, Dimitrios C.

2016-01-01

Bone consists of the mineralized component (i.e., cortex and trabeculae) and the non-mineralized component (i.e., bone marrow). Most of the routine clinical bone imaging uses X-ray-based techniques and focuses on the mineralized component. However, bone marrow adiposity has been also shown to have a strong linkage with bone health. Specifically, multiple previous studies have demonstrated a negative association between bone marrow fat fraction (BMFF) and bone mineral density. Magnetic resonance imaging (MRI) and magnetic resonance spectroscopy (MRS) are ideal imaging techniques for non-invasively investigating the properties of bone marrow fat. In the present work, we first review the most important MRI and MRS methods for assessing properties of bone marrow fat, including methodologies for measuring BMFF and bone marrow fatty acid composition parameters. Previous MRI and MRS studies measuring BMFF and fat unsaturation in the context of osteoporosis are then reviewed. Finally, previous studies investigating the relationship between bone marrow fat, other fat depots, and bone health in patients with obesity and type 2 diabetes are presented. In summary, MRI and MRS are powerful non-invasive techniques for measuring properties of bone marrow fat in osteoporosis, obesity, and type 2 diabetes and can assist in future studies investigating the pathophysiology of bone changes in the above clinical scenarios. PMID:27445977

Osteoporosis Imaging: State of the Art and Advanced Imaging

PubMed Central

2012-01-01

Osteoporosis is becoming an increasingly important public health issue, and effective treatments to prevent fragility fractures are available. Osteoporosis imaging is of critical importance in identifying individuals at risk for fractures who would require pharmacotherapy to reduce fracture risk and also in monitoring response to treatment. Dual x-ray absorptiometry is currently the state-of-the-art technique to measure bone mineral density and to diagnose osteoporosis according to the World Health Organization guidelines. Motivated by a 2000 National Institutes of Health consensus conference, substantial research efforts have focused on assessing bone quality by using advanced imaging techniques. Among these techniques aimed at better characterizing fracture risk and treatment effects, high-resolution peripheral quantitative computed tomography (CT) currently plays a central role, and a large number of recent studies have used this technique to study trabecular and cortical bone architecture. Other techniques to analyze bone quality include multidetector CT, magnetic resonance imaging, and quantitative ultrasonography. In addition to quantitative imaging techniques measuring bone density and quality, imaging needs to be used to diagnose prevalent osteoporotic fractures, such as spine fractures on chest radiographs and sagittal multidetector CT reconstructions. Radiologists need to be sensitized to the fact that the presence of fragility fractures will alter patient care, and these fractures need to be described in the report. This review article covers state-of-the-art imaging techniques to measure bone mineral density, describes novel techniques to study bone quality, and focuses on how standard imaging techniques should be used to diagnose prevalent osteoporotic fractures. © RSNA, 2012 PMID:22438439

Weakening Pin Bone Attachment in Fish Fillets Using High-Intensity Focused Ultrasound.

PubMed

Skjelvareid, Martin H; Stormo, Svein Kristian; Þórarinsdóttir, Kristín Anna; Heia, Karsten

2017-09-18

High Intensity Focused Ultrasound (HIFU) can be used for the localized heating of biological tissue through the conversion of sound waves into heat. Although originally developed for human medicine, HIFU may also be used to weaken the attachment of pin bones in fish fillets to enable easier removal of such bones. This was shown in the present study, where a series of experiments were performed on HIFU phantoms and fillets of cod and salmon. In thin objects such as fish fillets, the heat is mainly dissipated at the surfaces. However, bones inside the fillet absorb ultrasound energy more efficiently than the surrounding tissue, resulting in a "self-focusing" heating of the bones. Salmon skin was found to effectively block the ultrasound, resulting in a significantly lower heating effect in fillets with skin. Cod skin partly blocked the ultrasound, but only to a small degree, enabling HIFU treatment through the skin. The treatment of fillets to reduce the pin bone attachment yielded an average reduction in the required pulling force by 50% in cod fillets with skin, with little muscle denaturation, and 72% in skinned fillets, with significant muscle denaturation. Salmon fillets were treated from the muscle side of the fillet to circumvent the need for penetration through skin. The treatment resulted in a 30% reduction in the peak pulling force and 10% reduction in the total pulling work, with a slight denaturation of the fillet surface.

Weakening Pin Bone Attachment in Fish Fillets Using High-Intensity Focused Ultrasound

PubMed Central

Stormo, Svein Kristian; Þórarinsdóttir, Kristín Anna; Heia, Karsten

2017-01-01

High Intensity Focused Ultrasound (HIFU) can be used for the localized heating of biological tissue through the conversion of sound waves into heat. Although originally developed for human medicine, HIFU may also be used to weaken the attachment of pin bones in fish fillets to enable easier removal of such bones. This was shown in the present study, where a series of experiments were performed on HIFU phantoms and fillets of cod and salmon. In thin objects such as fish fillets, the heat is mainly dissipated at the surfaces. However, bones inside the fillet absorb ultrasound energy more efficiently than the surrounding tissue, resulting in a “self-focusing” heating of the bones. Salmon skin was found to effectively block the ultrasound, resulting in a significantly lower heating effect in fillets with skin. Cod skin partly blocked the ultrasound, but only to a small degree, enabling HIFU treatment through the skin. The treatment of fillets to reduce the pin bone attachment yielded an average reduction in the required pulling force by 50% in cod fillets with skin, with little muscle denaturation, and 72% in skinned fillets, with significant muscle denaturation. Salmon fillets were treated from the muscle side of the fillet to circumvent the need for penetration through skin. The treatment resulted in a 30% reduction in the peak pulling force and 10% reduction in the total pulling work, with a slight denaturation of the fillet surface. PMID:28926968

A peptide that blocks the interaction of NF-κB p65 subunit with Smad4 enhances BMP2-induced osteogenesis.

PubMed

Urata, Mariko; Kokabu, Shoichiro; Matsubara, Takuma; Sugiyama, Goro; Nakatomi, Chihiro; Takeuchi, Hiroshi; Hirata-Tsuchiya, Shizu; Aoki, Kazuhiro; Tamura, Yukihiko; Moriyama, Yasuko; Ayukawa, Yasunori; Matsuda, Miho; Zhang, Min; Koyano, Kiyoshi; Kitamura, Chiaki; Jimi, Eijiro

2018-09-01

Bone morphogenetic protein (BMP) potentiates bone formation through the Smad signaling pathway in vitro and in vivo. The transcription factor nuclear factor κB (NF-κB) suppresses BMP-induced osteoblast differentiation. Recently, we identified that the transactivation (TA) 2 domain of p65, a main subunit of NF-κB, interacts with the mad homology (MH) 1 domain of Smad4 to inhibit BMP signaling. Therefore, we further attempted to identify the interacting regions of these two molecules at the amino acid level. We identified a region that we term the Smad4-binding domain (SBD), an amino-terminal region of TA2 that associates with the MH1 domain of Smad4. Cell-permeable SBD peptide blocked the association of p65 with Smad4 and enhanced BMP2-induced osteoblast differentiation and mineralization without affecting the phosphorylation of Smad1/5 or the activation of NF-κB signaling. SBD peptide enhanced the binding of the BMP2-inudced phosphorylated Smad1/5 on the promoter region of inhibitor of DNA binding 1 (Id-1) compared with control peptide. Although SBD peptide did not affect BMP2-induced chondrogenesis during ectopic bone formation, the peptide enhanced BMP2-induced ectopic bone formation in subcortical bone. Thus, the SBD peptide is useful for enabling BMP2-induced bone regeneration without inhibiting NF-κB activity. © 2018 Wiley Periodicals, Inc.

The Effect of Different Bone Marrow Stimulation Techniques on Human Talar Subchondral Bone: A Micro-Computed Tomography Evaluation.

PubMed

Gianakos, Arianna L; Yasui, Youichi; Fraser, Ethan J; Ross, Keir A; Prado, Marcelo P; Fortier, Lisa A; Kennedy, John G

2016-10-01

To evaluate morphological alterations, microarchitectural disturbances, and the extent of bone marrow access to the subchondral bone marrow compartment using micro-computed tomography analysis in different bone marrow stimulation (BMS) techniques. Nine zones in a 3 × 3 grid pattern were assigned to 5 cadaveric talar dome articular surfaces. A 1.00-mm microfracture awl (s.MFX), a 2.00-mm standard microfracture awl (l.MFX), or a 1.25-mm Kirschner wire (K-wire) drill hole was used to penetrate the subchondral bone in each grid zone. Subchondral bone holes and adjacent tissue areas were assessed by micro-computed tomography to analyze adjacent bone area destruction and communicating channels to the bone marrow. Grades 1 to 3 were assigned, where 1 = minimal compression/sclerosis; 2 = moderate compression/sclerosis; 3 = severe compression/sclerosis. Bone volume/total tissue volume, bone surface area/bone volume, trabecular thickness, and trabecular number were calculated in the region of interest. Visual assessment revealed that the s.MFX had significantly more grade 1 holes (P < .001) and that the l.MFX had significantly more poor/grade 3 holes (P = .002). Bone marrow channel assessment showed a statistically significant increase in the number of channels in the s.MFX when compared with both K-wire and l.MFX holes (P < .001). Bone volume fraction for the s.MFX was significantly less than that of the l.MFX (P = .029). BMS techniques using instruments with larger diameters resulted in increased trabecular compaction and sclerosis in areas adjacent to the defect. K-wire and l.MFX techniques resulted in less open communicating bone marrow channels, denoting a reduction in bone marrow access. The results of this study indicate that BMS using larger diameter devices results in greater microarchitecture disturbances. The current study suggests that the choice of a BMS technique should be carefully considered as the results indicate that smaller diameter hole sizes may diminish the amount of microarchitectural disturbances in the subchondral bone. Copyright © 2016 Arthroscopy Association of North America. Published by Elsevier Inc. All rights reserved.

[Arthroscopic reconstruction of anterior cruciate ligament with press-fit technique].

PubMed

Halder, A M

2010-08-01

Problems related to the use of interference screws for fixation of bone-patellar tendon-bone grafts for anterior cruciate ligament (ACL) replacement have led to increasing interest in press-fit techniques. Most of the described techniques use press-fit fixation on either the femoral or tibial side. Therefore an arthroscopic technique was developed which achieves bone-patellar tendon-bone graft fixation by press-fit on both sides without the need for supplemental fixation material. The first consecutive 40 patients were examined clinically with a KT-1000 arthrometer and radiologically after a mean of 28.7 months (range 20-40 months) postoperatively. The mean difference in side-to-side laxity was 1.3 mm (SD 2.2 mm) and the results according to the International Knee Documentation Committee (IKDC) score were as follows: 7 A, 28 B, 5 C, 0 D. The presented press-fit technique avoids all complications related to the use of interference screws. It achieves primary stable fixation of the bone-patellar tendon-bone graft thereby allowing early functional rehabilitation. However, fixation strength depends on bone quality and the arthroscopic procedure is demanding. The results showed reliable stabilization of the operated knees.

Effects of Low-Dose Total-Body Irradiation on Canine Bone Marrow Function and Canine Lymphoma

DTIC Science & Technology

1981-11-01

SCIENTIFIC REPORT Effects of low-dose total-body irradiation on canine bone marrow function and canine lymphoma cc ca D. E. Cowal! 7. J. MacVittie G... CANINE BONE MARROW FUNCTION AND CANINE LYMPHOMA 6. PERFORMING O1G. REPORT NUMBER 7. AUTHO1R(s) 8. CONTRACT OR GRANT NUMBER(s) Dt E. Cowall*, T. J...ott it e r .f00 !(1414011V byt block tumbv,) canine , I’M, bone marrow, GM-CFC 20 A US TR AC y t (𔃺t 104#0 00 ,r ,. @#PS#0 It Ml 0 le~ 9 ncj0 dd0 19

Meniscus-force-mediated layer transfer technique using single-crystalline silicon films with midair cavity: Application to fabrication of CMOS transistors on plastic substrates

NASA Astrophysics Data System (ADS)

Sakaike, Kohei; Akazawa, Muneki; Nakagawa, Akitoshi; Higashi, Seiichiro

2015-04-01

A novel low-temperature technique for transferring a silicon-on-insulator (SOI) layer with a midair cavity (supported by narrow SiO2 columns) by meniscus force has been proposed, and a single-crystalline Si (c-Si) film with a midair cavity formed in dog-bone shape was successfully transferred to a poly(ethylene terephthalate) (PET) substrate at its heatproof temperature or lower. By applying this proposed transfer technique, high-performance c-Si-based complementary metal-oxide-semiconductor (CMOS) transistors were successfully fabricated on the PET substrate. The key processes are the thermal oxidation and subsequent hydrogen annealing of the SOI layer on the midair cavity. These processes ensure a good MOS interface, and the SiO2 layer works as a “blocking” layer that blocks contamination from PET. The fabricated n- and p-channel c-Si thin-film transistors (TFTs) on the PET substrate showed field-effect mobilities of 568 and 103 cm2 V-1 s-1, respectively.

Towards optical brain imaging: getting light through a bone

NASA Astrophysics Data System (ADS)

Thompson, J. V.; Hokr, B. H.; Nodurft, D. T.; Yakovlev, V. V.

2018-06-01

Optical imaging and detection in biological samples is severely limited by scattering effects. In particular, optical techniques for measuring conditions beneath the skull and within the bone marrow hold significant promise when it comes to speed, sensitivity and specificity. However, the strong optical scattering due to bone hinders the realization of these methods. In this article, we propose a technique to enhance the transmittance of light through bone. This is achieved by injecting light below the top surface of the bone and utilizing multiple scattering to increase transmittance. This technique suggests that enhancements of 2-6 times may be realized by injection of light 1 mm below the surface of the bone. By enhancing the transmittance of light through bone, we will greatly improve our ability to utilize optical methods to better understand and diagnose conditions within biological media.

Prostate Cancer and Bone: The Elective Affinities

PubMed Central

2014-01-01

The onset of metastases dramatically changes the prognosis of prostate cancer patients, determining increased morbidity and a drastic fall in survival expectancy. Bone is a common site of metastases in few types of cancer, and it represents the most frequent metastatic site in prostate cancer. Of note, the prevalence of tumor relapse to the bone appears to be increasing over the years, likely due to a longer overall survival of prostate cancer patients. Bone tropism represents an intriguing challenge for researchers also because the preference of prostate cancer cells for the bone is the result of a sequential series of targetable molecular events. Many factors have been associated with the peculiar ability of prostate cancer cells to migrate in bone marrow and to determine mixed osteoblastic/osteolytic lesions. As anticipated by the success of current targeted therapy aimed to block bone resorption, a better understanding of molecular affinity between prostate cancer and bone microenvironment will permit us to cure bone metastasis and to improve prognosis of prostate cancer patients. PMID:24971315

A basic review on the inferior alveolar nerve block techniques.

PubMed

Khalil, Hesham

2014-01-01

The inferior alveolar nerve block is the most common injection technique used in dentistry and many modifications of the conventional nerve block have been recently described in the literature. Selecting the best technique by the dentist or surgeon depends on many factors including the success rate and complications related to the selected technique. Dentists should be aware of the available current modifications of the inferior alveolar nerve block techniques in order to effectively choose between these modifications. Some operators may encounter difficulty in identifying the anatomical landmarks which are useful in applying the inferior alveolar nerve block and rely instead on assumptions as to where the needle should be positioned. Such assumptions can lead to failure and the failure rate of inferior alveolar nerve block has been reported to be 20-25% which is considered very high. In this basic review, the anatomical details of the inferior alveolar nerve will be given together with a description of its both conventional and modified blocking techniques; in addition, an overview of the complications which may result from the application of this important technique will be mentioned.

A basic review on the inferior alveolar nerve block techniques

PubMed Central

Khalil, Hesham

2014-01-01

The inferior alveolar nerve block is the most common injection technique used in dentistry and many modifications of the conventional nerve block have been recently described in the literature. Selecting the best technique by the dentist or surgeon depends on many factors including the success rate and complications related to the selected technique. Dentists should be aware of the available current modifications of the inferior alveolar nerve block techniques in order to effectively choose between these modifications. Some operators may encounter difficulty in identifying the anatomical landmarks which are useful in applying the inferior alveolar nerve block and rely instead on assumptions as to where the needle should be positioned. Such assumptions can lead to failure and the failure rate of inferior alveolar nerve block has been reported to be 20-25% which is considered very high. In this basic review, the anatomical details of the inferior alveolar nerve will be given together with a description of its both conventional and modified blocking techniques; in addition, an overview of the complications which may result from the application of this important technique will be mentioned. PMID:25886095

Determinants of bone density among athletes engaged in weight-bearing and non-weight-bearing activity

NASA Technical Reports Server (NTRS)

Block, Jon E.; Friedlander, Anne L.; Brooks, George A.; Steiger, Peter; Stubbs, Harrison A.

1989-01-01

The effect of weight bearing activity on the bone density was investigated in athletes by comparing the measures of bone density of athletes engaged in weight-training programs with those of polo players and nonexercising subjects. All subjects had measurements of spinal trabecular and integral bone density by quantitative tomography, as well as determinations of hip bone density by dual photon absorptiometry. Results confirmed previous findings by Block et al. (1987) of significantly greater bone density among highly trained athletes compared with nonexercising subjects of similar age. Results also indicated that athletes engaged in non-weight-bearing forms of rigorous exercise had greater levels of bone density. However, as the participants in this study were exceptional athletes, engaged in a strenuous sport with both aerobic and heavy resistance components, a confirmation of these data is needed, using larger samples of individuals.

Improved accuracy of markerless motion tracking on bone suppression images: preliminary study for image-guided radiation therapy (IGRT)

NASA Astrophysics Data System (ADS)

Tanaka, Rie; Sanada, Shigeru; Sakuta, Keita; Kawashima, Hiroki

2015-05-01

The bone suppression technique based on advanced image processing can suppress the conspicuity of bones on chest radiographs, creating soft tissue images obtained by the dual-energy subtraction technique. This study was performed to evaluate the usefulness of bone suppression image processing in image-guided radiation therapy. We demonstrated the improved accuracy of markerless motion tracking on bone suppression images. Chest fluoroscopic images of nine patients with lung nodules during respiration were obtained using a flat-panel detector system (120 kV, 0.1 mAs/pulse, 5 fps). Commercial bone suppression image processing software was applied to the fluoroscopic images to create corresponding bone suppression images. Regions of interest were manually located on lung nodules and automatic target tracking was conducted based on the template matching technique. To evaluate the accuracy of target tracking, the maximum tracking error in the resulting images was compared with that of conventional fluoroscopic images. The tracking errors were decreased by half in eight of nine cases. The average maximum tracking errors in bone suppression and conventional fluoroscopic images were 1.3   ±   1.0 and 3.3   ±   3.3 mm, respectively. The bone suppression technique was especially effective in the lower lung area where pulmonary vessels, bronchi, and ribs showed complex movements. The bone suppression technique improved tracking accuracy without special equipment and implantation of fiducial markers, and with only additional small dose to the patient. Bone suppression fluoroscopy is a potential measure for respiratory displacement of the target. This paper was presented at RSNA 2013 and was carried out at Kanazawa University, JAPAN.

Fracture of the proximal tibia after revision total knee arthroplasty with an extensor mechanism allograft.

PubMed

Klein, Gregg R; Levine, Harlan B; Sporer, Scott M; Hartzband, Mark A

2013-02-01

Extensor mechanism reconstruction with an extensor mechanism allograft (EMA) remains one of the most reliable methods for treating the extensor mechanism deficient total knee arthroplasty. We report 3 patients who were treated with an EMA who sustained a proximal tibial shaft fracture. In all 3 cases, a short tibial component was present that ended close to the level of the distal extent of the bone block. When performing an EMA, it is important to recognize that the tibial bone block creates a stress riser and revision to a long-stemmed tibial component should be strongly considered to bypass this point to minimize the risk of fracture. Copyright © 2013 Elsevier Inc. All rights reserved.

Blockage of hemichannels alters gene expression in osteocytes in a high magneto-gravitational environment

PubMed Central

Xu, Huiyun; Ning, Dandan; Zhao, Dezhi; Chen, Yunhe; Zhao, Dongdong; Gu, Sumin; Jiang, Jean X.; Shang, Peng

2017-01-01

Osteocytes, the most abundant cells in bone, are highly responsive to external environmental changes. We tested how Cx43 hemichannels which mediate the exchange of small molecules between cells and extracellular environment impact genome wide gene expression under conditions of abnormal gravity and magnetic field. To this end, we subjected osteocytic MLO-Y4 cells to a high magneto-gravitational environment and used microarray to examine global gene expression and a specific blocking antibody was used to assess the role of Cx43 hemichannels. While 3 hr exposure to abnormal gravity and magnetic field had relatively minor effects on global gene expression, blocking hemichannels significantly impacted the expression of a number of genes which are involved in cell viability, apoptosis, mineral absorption, protein absorption and digestion, and focal adhesion. Also, blocking of hemichannels enriched genes in multiple signaling pathways which are enaged by TGF-beta, Jak-STAT and VEGF. These results show the role of connexin hemichannels in bone cells in high magneto-gravitational environments. PMID:27814646

Technique for systematic bone reduction for fixed implant-supported prosthesis in the edentulous maxilla.

PubMed

Bidra, Avinash S

2015-06-01

Bone reduction for maxillary fixed implant-supported prosthodontic treatment is often necessary to either gain prosthetic space or to conceal the prosthesis-tissue junction in patients with excessive gingival display (gummy smile). Inadequate bone reduction is often a cause of prosthetic failure due to material fractures, poor esthetics, or inability to perform oral hygiene procedures due to unfavorable ridge lap prosthetic contours. Various instruments and techniques are available for bone reduction. It would be helpful to have an accurate and efficient method for bone reduction at the time of surgery and subsequently create a smooth bony platform. This article presents a straightforward technique for systematic bone reduction by transferring the patient's maximum smile line, recorded clinically, to a clear radiographic smile guide for treatment planning using cone beam computed tomography (CBCT). The patient's smile line and the amount of required bone reduction are transferred clinically by marking bone with a sterile stationery graphite wood pencil at the time of surgery. This technique can help clinicians to accurately achieve the desired bone reduction during surgery, and provide confidence that the diagnostic and treatment planning goals have been achieved. Copyright © 2015 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.

Optimization of tyrosine-derived polycarbonate terpolymers for bone regeneration scaffolds

NASA Astrophysics Data System (ADS)

Resurreccion-Magno, Maria Hanshella C.

Tyrosine-derived polycarbonates (TyrPC) are a versatile class of polymers highly suitable for bone tissue engineering. Among the tyrosine-derived polycarbonates, poly(DTE carbonate) has an FDA masterfile that documents its biocompatibility and non-toxicity and has shown potential utility in orthopedics due to its osteoconductive properties and strength. DTE stands for desaminotyrosyl-tyrosine ethyl ester and is the most commonly used tyrosine-derived monomer. However, in vitro degradation studies showed that poly(DTE carbonate) did not completely resorb even after four years of incubation in phosphate buffered saline. Thus for bone regeneration, which only requires a temporary implant until the bone heals, poly(DTE carbonate) would not be the best choice. The goal of the present research was to optimize a scaffold composition for bone regeneration that is based on desaminotyrosyl-tyrosine alkyl ester (DTR), desaminotyrosyl-tyrosine (DT) and poly(ethylene glycol) (PEG). Five areas of research were presented: (1) synthesis and characterization of a focused library of TyrPC terpolymers; (2) evaluation of the effects of how small changes on the composition affected the mechanism and kinetics of polymer degradation and erosion; (3) fabrication of bioactive three-dimensional porous scaffold constructs for bone regeneration; (4) assessment of osteogenic properties in vitro using pre-osteoblasts; and (5) evaluation of bone regeneration potential, with or without recombinant human bone morphogenetic protein-2 (rhBMP-2), in vivo using a critical sized defect (CSD) rabbit calvaria (cranium) model. Small changes in the composition, such as changing the R group of DTR from ethyl to methyl, varying the mole percentages of DT and PEG, and using a different PEG block length, affected the overall properties of these polymers. Porous scaffolds were prepared by a combination of solvent casting, porogen leaching and phase separation techniques. Calcium phosphate was coated on the surface post-fabrication. The scaffolds displayed (i) a bimodal pore architecture with micropores (< 20 mum) and macropores (200 -- 400 mum), (ii) a highly interconnected and open pore structure, and (iii) a highly organized microstructure. These scaffolds supported robust cell attachment and promoted osteogenic differentiation of pre-osteoblasts. This is the first report that a synthetic polymeric scaffold either without a biological supplement or with a minimal dose of rhBMP-2 induced comparable bone regeneration to a commercially available bone substitute in a non-rodent CSD animal model.

[Treatment effects of magnetic Twin-block appliance for class II cases].

PubMed

Wu, Jian-Yong; Liu, Jian; Li, Qi-Shun; Xu, Tian-Min; Lin, Jiu-Xiang

2007-09-01

To evaluate the effects of magnetic Twin-block appliance in the treatment of skeletal class II cases. The magnetic Twin-block appliance was embedded with two pairs of neodymium-iron-boron (Nd(2)Fe(14)B) rare earth permanent magnets in the upper and lower inclined planes of Twin-block appliance. The sample comprised of 13 skeletal class II patients in the late mixed or early permanent dentition treated by magnetic Twin-block appliance. Cephalometric films were taken before and after treatment. Helix CT images of the temporomandibular joint (TMJ) in all patients were examined before treatment (T1), during treatment (4 months after appliance placement, T2), after treatment (T3) and one year after treatment (T4). A double contour image was detected in the superior posterior part of the condylar head on the pseudo-sagittal reconstruction plane pictures of T2 in 11 patients. The double contour image could be observed in most patients as well. This image also exhibited on the pictures of T3 in several patients. On the pictures of T2 and T3 in some patients, interruption of cortical bone and "bifurcation phenomenon" of condyles were shown. Pictures of T1 and T4 were similar and no signs of remodeling of TMJ were observed. Cephalometric analysis revealed significant changes in the maxillofacial structure after treatment. The profile of patients improved. Bone remodeling of condyle occurred during the magnetic Twin-block treatment in class II patients. Magnetic Twin-block appliance was effective in the treatment of the growing skeletal class II patients.

Tactile and bone-conduction auditory brain computer interface for vision and hearing impaired users.

PubMed

Rutkowski, Tomasz M; Mori, Hiromu

2015-04-15

The paper presents a report on the recently developed BCI alternative for users suffering from impaired vision (lack of focus or eye-movements) or from the so-called "ear-blocking-syndrome" (limited hearing). We report on our recent studies of the extents to which vibrotactile stimuli delivered to the head of a user can serve as a platform for a brain computer interface (BCI) paradigm. In the proposed tactile and bone-conduction auditory BCI novel multiple head positions are used to evoke combined somatosensory and auditory (via the bone conduction effect) P300 brain responses, in order to define a multimodal tactile and bone-conduction auditory brain computer interface (tbcaBCI). In order to further remove EEG interferences and to improve P300 response classification synchrosqueezing transform (SST) is applied. SST outperforms the classical time-frequency analysis methods of the non-linear and non-stationary signals such as EEG. The proposed method is also computationally more effective comparing to the empirical mode decomposition. The SST filtering allows for online EEG preprocessing application which is essential in the case of BCI. Experimental results with healthy BCI-naive users performing online tbcaBCI, validate the paradigm, while the feasibility of the concept is illuminated through information transfer rate case studies. We present a comparison of the proposed SST-based preprocessing method, combined with a logistic regression (LR) classifier, together with classical preprocessing and LDA-based classification BCI techniques. The proposed tbcaBCI paradigm together with data-driven preprocessing methods are a step forward in robust BCI applications research. Copyright © 2014 Elsevier B.V. All rights reserved.

Four osteotomy methods with piezosurgery to remove complicated mandibular third molars: a retrospective study.

PubMed

Ge, Jing; Yang, Chi; Zheng, Jia-Wei; He, Dong-Mei; Zheng, Ling-Yan; Hu, Ying-Kai

2014-11-01

Piezosurgery has been used widely in oral and maxillofacial surgery, but there has been no report systematically describing an osteotomy method with piezosurgery for complicated mandibular third molar removal. The aim of this study was to introduce 4 osteotomy methods using piezosurgery and evaluate their effects. A retrospective study was conducted of patients with a complicated impacted mandibular third molar requiring extraction. The predictor variable was the extraction technique. Four osteotomy methods using piezosurgery were tested according to different impaction types: method 1 involved complete bone removal; method 2 involved segmental bone removal; method 3 involved bone removal combined with tooth splitting; and method 4 involved block bone removal. Outcome variables were success rate, operative time, major complications (including nerve injury, mandible fracture, severe hematoma, or severe edema), and serious pyogenic infection. Data were analyzed using descriptive statistics. The study was composed of 55 patients with 74 complicated impacted mandibular third molars. All impacted mandibular third molars were removed successfully. The average surgical time was 15 minutes (range, 8 to 26 minutes). Thirty-eight molars (51.4%) were extracted by method 1, 18 molars (24.3%) by method 2, 12 molars (16.2%) by method 3, and 6 molars (8.1%) by method 4. Two cases (2.7%) developed postoperative infections and recovered within 1 week using drainage and antibiotic administration. The 4 osteotomy methods with piezosurgery provide effective ways of removing complicated impacted mandibular third molars. Copyright © 2014 American Association of Oral and Maxillofacial Surgeons. Published by Elsevier Inc. All rights reserved.

Periodontal ligament and intraosseous anesthetic injection techniques: alternatives to mandibular nerve blocks.

PubMed

Moore, Paul A; Cuddy, Michael A; Cooke, Matthew R; Sokolowski, Chester J

2011-09-01

and Overview. The provision of mandibular anesthesia traditionally has relied on nerve block anesthetic techniques such as the Halsted, the Gow-Gates and the Akinosi-Vazirani methods. The authors present two alternative techniques to provide local anesthesia in mandibular teeth: the periodontal ligament (PDL) injection and the intraosseous (IO) injection. The authors also present indications for and complications associated with these techniques. The PDL injection and the IO injection are effective anesthetic techniques for managing nerve block failures and for providing localized anesthesia in the mandible. Dentists may find these techniques to be useful alternatives to nerve block anesthesia.

Bone augmentation in dental implantology using press-fit bone cylinders and twin-principle diamond hollow drills: a case series.

PubMed

Draenert, Florian Guy; Huetzen, Dominic; Kämmerer, Peer; Wagner, Wilfried

2011-09-01

Bone transplants are mostly prepared with cutting drills, chisels, and rasps. These techniques are difficult for unexperienced surgeons, and the implant interface is less precise due to unstandardized preparation. Cylindrical bone transplants are a known alternative. Current techniques include fixation methods with osteosynthesis screws or the dental implant. A new bone cylinder transplant technique is presented using a twin-drill principle resulting in a customized pressfit of the transplant without fixation devices and combining this with the superior grinding properties of a diamond coating. New cylindrical diamond hollow drills are used for customized press fit bone transplants in a case series of five patients for socket reconstruction in the front and molar region of maxilla and mandibula with and without simultaneous implant placement. The technical approach was successful without intra or postoperative complications during the acute healing phase. The customized press fit completes a technological trias of bone cylinder transplant techniques adding to the assisted press fit with either osteosynthesis screws or the dental implant itself. © 2009 Wiley Periodicals, Inc.

Arthroscopic Latarjet Techniques: Graft and Fixation Positioning Assessed With 2-Dimensional Computed Tomography Is Not Equivalent With Standard Open Technique.

PubMed

Neyton, Lionel; Barth, Johannes; Nourissat, Geoffroy; Métais, Pierre; Boileau, Pascal; Walch, Gilles; Lafosse, Laurent

2018-05-19

To analyze graft and fixation (screw and EndoButton) positioning after the arthroscopic Latarjet technique with 2-dimensional computed tomography (CT) and to compare it with the open technique. We performed a retrospective multicenter study (March 2013 to June 2014). The inclusion criteria included patients with recurrent anterior instability treated with the Latarjet procedure. The exclusion criterion was the absence of a postoperative CT scan. The positions of the hardware, the positions of the grafts in the axial and sagittal planes, and the dispersion of values (variability) were compared. The study included 208 patients (79 treated with open technique, 87 treated with arthroscopic Latarjet technique with screw fixation [arthro-screw], and 42 treated with arthroscopic Latarjet technique with EndoButton fixation [arthro-EndoButton]). The angulation of the screws was different in the open group versus the arthro-screw group (superior, 10.3° ± 0.7° vs 16.9° ± 1.0° [P < .001]; inferior, 10.3° ± 0.8° vs 15.7° ± 0.9° [P < .0001]). The angulation of the EndoButtons was 5.7° ± 0.5°; this was different from that of open inferior screws (P = .003). In the axial plane (level of equator), the arthroscopic techniques resulted in lateral positions (arthro-screw, 1.5 ± 0.3 mm lateral [P < .001]; arthro-EndoButton, 0 ± 0.3 mm lateral [P < .0001]) versus the open technique (0.9 ± 0.2 mm medial). At the level of 25% of the glenoid height, the arthroscopic techniques resulted in lateral positions (arthro-screw, 0.3 ± 0.3 mm lateral [P < .001]); (arthro-EndoButton, 0.7 ± 0.3 mm lateral [P < .0001]) versus the open technique (1.0 ± 0.2 mm medial). Higher variability was observed in the arthro-screw group. In the sagittal plane, the arthro-screw technique resulted in higher positions (55% ± 3% of graft below equator) and the arthro-EndoButton technique resulted in lower positions (82% ± 3%, P < .0001) versus the open technique (71% ± 2%). Variability was not different. This study shows that the position of the fixation devices and position of the bone graft with the arthroscopic techniques are statistically significantly different from those with the open technique with 2-dimensional CT assessment. In the sagittal plane, the arthro-screw technique provides the highest positions, and the arthro-EndoButton technique, the lowest. Overall, the mean position of the bone block with the open Latarjet technique in the axial plane is slightly medial to the joint line, as recommended. Conversely, with the arthroscopic techniques, the bone grafts are more lateral with a slight overhang. The main differences are observed in the dispersion of the values (more extreme positions) with the arthro-screw technique, given the acknowledged limitations. Despite the statistical significance, the clinical significance of these differences is yet unknown. Level III, retrospective comparative study. Copyright © 2018 Arthroscopy Association of North America. Published by Elsevier Inc. All rights reserved.

Actual and Simulated Weightlessness Inhibit Osteogenesis in Long Bone Metaphysis by Different Mechanisms

NASA Technical Reports Server (NTRS)

Roberts, W. E.

1985-01-01

Weightlessness and simulated weightlessness inhibit the rate of periosteal bone formation in long bones. Formation of preosteoblasts is suppressed in periodontal ligament (PDL) of maxillary molars, which suggests a generalized block in osteoblast histogenesis. Growth in length of long bones is decreased by simulated weightlessness, but there are no reliable data on the influence of actual weightlessness on metaphyseal growth. The nuclear size assay for assessing relative numbers of osteoblast precursor cells was utilized in the primary spongiosa of growing long bones subjected to actual and simulated weightlessness. It is found that: (1) Actual weightlessness decreases total number of osteogenic cells and inhibits differentiation of osteoblast precursor cells, (2) Simulated weightlessness suppresses only osteoblast differentation; and (3) The nuclear morphometric assay is an effective means of assessing osteogenic activity in the growing metaphysis or long bones.

Coralline hydroxyapatite bone graft substitutes.

PubMed

Elsinger, E C; Leal, L

1996-01-01

The authors present a review of the various bone grafts currently available with special attention to coral bone grafts. Several of the benefits of coralline hydroxyapatite bone graft substitutes, such as safety and biocompatibility, will be addressed in this article, part of an ongoing investigation of coral bone grafts used in triple arthrodesis procedures. To date, eight cases have been performed. In seven cases, granular chips were employed to pack the subtalar joint. The final case, presented in this article, represents a 26-year-old male who, 2 years previously, sustained a calcaneal fracture with resultant shortening along the lateral column. A coralline hydroxyapatite block was used at the calcaneocuboid joint to achieve distraction. Clinically, the patient is progressing well at 10 months postoperatively. Radiographically, one can still clearly appreciate the margins of the bone graft at 5 months.

Solid Free-form Fabrication Technology and Its Application to Bone Tissue Engineering

PubMed Central

Lee, Jin Woo; Kim, Jong Young; Cho, Dong-Woo

2010-01-01

The development of scaffolds for use in cell-based therapies to repair damaged bone tissue has become a critical component in the field of bone tissue engineering. However, design of scaffolds using conventional fabrication techniques has limited further advancement, due to a lack of the required precision and reproducibility. To overcome these constraints, bone tissue engineers have focused on solid free-form fabrication (SFF) techniques to generate porous, fully interconnected scaffolds for bone tissue engineering applications. This paper reviews the potential application of SFF fabrication technologies for bone tissue engineering with respect to scaffold fabrication. In the near future, bone scaffolds made using SFF apparatus should become effective therapies for bone defects. PMID:24855546

Reconstruction of Long Bone Infections Using the Induced Membrane Technique: Tips and Tricks.

PubMed

Mauffrey, Cyril; Hake, Mark E; Chadayammuri, Vivek; Masquelet, Alain-Charles

2016-06-01

The management of posttraumatic long bone osteomyelitis remains a challenging clinical problem. A systematic approach is necessary, beginning with eradication of the infected bone and soft tissue. There are a number of options for reconstruction of the remaining bone defect, including the induced membrane technique developed by Masquelet. We describe our technique for the 2-stage treatment of long bone osteomyelitis. The first stage involves a radical debridement, stabilization of the bone with either external fixation or an antibiotic-coated intramedullary nail, and placement of a polymethylmethacrylate spacer. The second stage includes excision of the spacer and placement of autologous bone graft. Various resection methods, fixation strategies, antibiotic additives, and types of bone grafts or substitutes can be used. The purpose of our technical article is to share our personal experience and describe several nuances that are critical for the success of this treatment strategy. Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Thermal evaluation by infrared measurement of implant site preparation between single and gradual drilling in artificial bone blocks of different densities.

PubMed

Möhlhenrich, S C; Abouridouane, M; Heussen, N; Hölzle, F; Klocke, F; Modabber, A

2016-11-01

The aim of this study was to investigate the influence of bone density and drilling protocol on heat generation during implant bed preparation. Ten single and 10 gradual implant sites with diameters of 2.8, 3.5, and 4.2mm were prepared in four artificial bone blocks (density types I-IV; D1-D4). Drilling was done at constant speed (1500rpm) and with external irrigation (50ml/min); vertical speed was set at 2mm/s. An infrared camera was used for temperature measurements. Significantly higher temperatures for single drilling were found between 2.8-mm drills in D1 (P=0.0014) and D4 (P<0.0001) and between 3.5-mm drills in D3 (P=0.0087) and D4 (P<0.0001), as well as between 4.2-mm drills in D1 (P<0.0001) and D4 (P=0.0014). Low bone density led to a thermal decrease after single drilling and a thermal increase after gradual drilling. Burs with a large diameter always showed a higher temperature generation. In comparisons between 2.8- and 4.2-mm diameters for both single and gradual drills, significant differences (P<0.001) were noted for bone types II, III, and IV. Single drilling could generate more heat than traditional sequential drilling, and bone density, as well as drill diameter, influenced thermal increases. Particularly in lower-density bone, conventional sequential drilling seems to raise the temperature less. Copyright © 2016 International Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.

Augmentation of autologous hamstring graft during anterior cruciate ligament reconstruction using the bone chip technique.

PubMed

Nha, Kyung Wook; Shetty, Gautam M; Ahn, Jin Hwan; Lee, Yong Seuk; Chae, Dong Ju; Nam, Hyok Woo; Lee, Dae Hee

2010-01-01

The use of autologous quadrupled hamstring tendon graft is a well-known technique for anterior cruciate ligament reconstruction. In cases where the diameter of the graft is inadequate, the stability of graft fixation and subsequent bone to tendon healing may be compromised. We describe a new technique to augment the autologous double looped hamstring tendon graft during anterior cruciate ligament reconstruction using cancellous bone chips. This simple technique effectively enhances graft fixation and stability.

Endothelial Barrier and Metabolism: New Kids on the Block Regulating Bone Marrow Vascular Niches.

PubMed

Harjes, Ulrike; Verfaillie, Catherine; Carmeliet, Peter

2016-05-09

The vasculature of the bone marrow remains poorly characterized, yet crucial to maintain hematopoiesis and retain stem cells in a quiescent state. A recent study by Itkin et al. (2016) in Nature reports how vascular barrier integrity and endothelial cell metabolism regulate hematopoietic stem cell quiescence and leukocyte trafficking. Copyright © 2016 Elsevier Inc. All rights reserved.

Reproducibility of techniques using Archimedes' principle in measuring cancellous bone volume.

PubMed

Zou, L; Bloebaum, R D; Bachus, K N

1997-01-01

Researchers have been interested in developing techniques to accurately and reproducibly measure the volume fraction of cancellous bone. Historically bone researchers have used Archimedes' principle with water to measure the volume fraction of cancellous bone. Preliminary results in our lab suggested that the calibrated water technique did not provide reproducible results. Because of this difficulty, it was decided to compare the conventional water method to a water with surfactant and a helium method using a micropycnometer. The water/surfactant and the helium methods were attempts to improve the fluid penetration into the small voids present in the cancellous bone structure. In order to compare the reproducibility of the new methods with the conventional water method, 16 cancellous bone specimens were obtained from femoral condyles of human and greyhound dog femora. The volume fraction measurements on each specimen were repeated three times with all three techniques. The results showed that the helium displacement method was more than an order of magnitudes more reproducible than the two other water methods (p < 0.05). Statistical analysis also showed that the conventional water method produced the lowest reproducibility (p < 0.05). The data from this study indicate that the helium displacement technique is a very useful, rapid and reproducible tool for quantitatively characterizing anisotropic porous tissue structures such as cancellous bone.

Quantitative analysis of rib movement based on dynamic chest bone images: preliminary results

NASA Astrophysics Data System (ADS)

Tanaka, R.; Sanada, S.; Oda, M.; Mitsutaka, M.; Suzuki, K.; Sakuta, K.; Kawashima, H.

2014-03-01

Rib movement during respiration is one of the diagnostic criteria in pulmonary impairments. In general, the rib movement is assessed in fluoroscopy. However, the shadows of lung vessels and bronchi overlapping ribs prevent accurate quantitative analysis of rib movement. Recently, an image-processing technique for separating bones from soft tissue in static chest radiographs, called "bone suppression technique", has been developed. Our purpose in this study was to evaluate the usefulness of dynamic bone images created by the bone suppression technique in quantitative analysis of rib movement. Dynamic chest radiographs of 10 patients were obtained using a dynamic flat-panel detector (FPD). Bone suppression technique based on a massive-training artificial neural network (MTANN) was applied to the dynamic chest images to create bone images. Velocity vectors were measured in local areas on the dynamic bone images, which formed a map. The velocity maps obtained with bone and original images for scoliosis and normal cases were compared to assess the advantages of bone images. With dynamic bone images, we were able to quantify and distinguish movements of ribs from those of other lung structures accurately. Limited rib movements of scoliosis patients appeared as reduced rib velocity vectors. Vector maps in all normal cases exhibited left-right symmetric distributions, whereas those in abnormal cases showed nonuniform distributions. In conclusion, dynamic bone images were useful for accurate quantitative analysis of rib movements: Limited rib movements were indicated as a reduction of rib movement and left-right asymmetric distribution on vector maps. Thus, dynamic bone images can be a new diagnostic tool for quantitative analysis of rib movements without additional radiation dose.

Interventional radiology in bone metastases.

PubMed

Chiras, J; Shotar, E; Cormier, E; Clarençon, F

2017-11-01

Interventional radiology plays a significant role in the treatment of bone metastases by various techniques, percutaneous or endovascular. Vertebroplasty is the most well-studied technique for stabilisation of spine metastases as it induces satisfactory stabilisation of the vertebra and offers clear improvement of the quality of life. Due to the success of this technique cementoplasty of other bones, mainly pelvic girdle, has been largely developed. The development of reinforced cementoplasty allows treatment of pre-fractural osteolysis of some long bones. The heat due to the polymerisation of the cement induces carcinolytic effect but this effect is not as important as that which results from radiofrequency destruction. This last technique appears currently as the most important development to definitively destroy bone metastases and is progressively replacing percutaneous alcoholic destruction of such lesions. Angiographic techniques, such as endovascular embolisation, can also be very useful to reduce the risk of surgical treatment of hyper vascular metastases. Chemoembolisation is currently developed to associate pain relief induced by Endovascular embolisation and the carcinolytic effect obtained by local endovascular chemotherapy. All these techniques should develop largely during the next years. © 2017 John Wiley & Sons Ltd.

Evaluation of primary stability of self-tapping and non-self-tapping dental implants. A 12-week clinical study.

PubMed

Marković, Aleksa; Calvo-Guirado, José Luís; Lazić, Zoran; Gómez-Moreno, Gerardo; Ćalasan, Dejan; Guardia, Javier; Čolic, Snježana; Aguilar-Salvatierra, Antonio; Gačić, Bojan; Delgado-Ruiz, Rafael; Janjić, Bojan; Mišić, Tijana

2013-06-01

The aim of this study was to investigate the relationship between surgical techniques and implant macro-design (self-tapping/non-self-tapping) for the optimization of implant stability in the low-density bone present in the posterior maxilla using resonance frequency analysis (RFA). A total of 102 implants were studied. Fifty-six self-tapping BlueSkyBredent® (Bredent GmbH&Co.Kg®, Senden, Germany) and 56 non-self-tapping Standard Plus Straumann® (Institut Straumann AG®, Waldenburg, Switzerland) were placed in the posterior segment of the maxilla. Implants of both types were placed in sites prepared with either lateral bone-condensing or with bone-drilling techniques. Implant stability measurements were performed using RFA immediately after implant placement and weekly during a 12-week follow-up period. Both types of implants placed after bone condensing achieved significantly higher stability immediately after surgery, as well as during the entire 12-week observation period compared with those placed following bone drilling. After bone condensation, there were no significant differences in primary stability or in implant stability after the first week between both implant types. From 2 to 12 postoperative weeks, significantly higher stability was shown by self-tapping implants. After bone drilling, self-tapping implants achieved significantly higher stability than non-self-tapping implants during the entire follow-up period. The outcomes of the present study indicate that bone drilling is not an effective technique for improving implant stability and, following this technique, the use of self-tapping implants is highly recommended. Implant stability optimization in the soft bone can be achieved by lateral bone-condensing technique, regardless of implant macro-design. © 2011 Wiley Periodicals, Inc.

Comparative study for surface topography of bone drilling using conventional drilling and loose abrasive machining.

PubMed

Singh, Gurmeet; Jain, Vivek; Gupta, Dheeraj

2015-03-01

Drilling through the bone is a complicated process in orthopaedic surgery. It involves human as a part of the work so it needs better perfection and quality which leads to the sustainability. Different studies were carried out on this curious topic and some interesting results were obtained, which help the orthopaedic surgeon on the operation table. Major problems faced during bone drilling were crack initiation, thermal necrosis and burr formation. The surface topography of the bone is an indirect indication for the sustainability of bone joint. In this study, a comparison is made between conventional and a loose abrasive unconventional drilling technique for the surface characterization of the bone. The attempt has been made to show the feasibility of bone drilling with non-conventional technique and its aftereffect on the bone structure. The burr formation during conventional bone drilling was found to be more which leads to problems such as crack initiation and thermal necrosis. Scanning electrode microscope and surface roughness tester were used to characterize the surface of the fine drilled bone specimen and the results testified quite better surface finish and least crack formation while drilling with loose abrasive unconventional technique. © IMechE 2015.

Image processing, geometric modeling and data management for development of a virtual bone surgery system.

PubMed

Niu, Qiang; Chi, Xiaoyi; Leu, Ming C; Ochoa, Jorge

2008-01-01

This paper describes image processing, geometric modeling and data management techniques for the development of a virtual bone surgery system. Image segmentation is used to divide CT scan data into different segments representing various regions of the bone. A region-growing algorithm is used to extract cortical bone and trabecular bone structures systematically and efficiently. Volume modeling is then used to represent the bone geometry based on the CT scan data. Material removal simulation is achieved by continuously performing Boolean subtraction of the surgical tool model from the bone model. A quadtree-based adaptive subdivision technique is developed to handle the large set of data in order to achieve the real-time simulation and visualization required for virtual bone surgery. A Marching Cubes algorithm is used to generate polygonal faces from the volumetric data. Rendering of the generated polygons is performed with the publicly available VTK (Visualization Tool Kit) software. Implementation of the developed techniques consists of developing a virtual bone-drilling software program, which allows the user to manipulate a virtual drill to make holes with the use of a PHANToM device on a bone model derived from real CT scan data.

Clinical and Histomorphometric Assessment of Lateral Alveolar Ridge Augmentation Using a Corticocancellous Freeze-Dried Allograft Bone Block.

PubMed

Ahmadi, Roya Shariatmadar; Sayar, Ferena; Rakhshan, Vahid; Iranpour, Babak; Jahanbani, Jahanfar; Toumaj, Ahmad; Akhoondi, Nasrin

2017-06-01

Horizontal ridge augmentation with allografts has attracted notable attention because of its proper success rate and the lack of disadvantages of autografts. Corticocancellous block allografts have not been adequately studied in humans. Therefore, this study clinically and histomorphometrically evaluated the increase in ridge width after horizontal ridge augmentation using corticocancellous block allografts as well as implant success after 12 to 18 months after implantation. In 10 patients receiving implants (3 women, 7 men; mean age = 45 years), defective maxillary alveolar ridges were horizontally augmented using freeze-dried bone allograft blocks. Ridge widths were measured before augmentation, immediately after augmentation, and ∼6 months later in the reentry surgery for implantation. This was done at points 2 mm (A) and 5 mm (B) apically to the crest. Biopsy cores were acquired from the implantation site. Implant success was assessed 15.1 ± 2.7 months after implantation (range = 12-18 months). Data were analyzed using Friedman and Dunn tests (α = 0.05). At point A, ridge widths were 2.77 ± 0.37, 8.02 ± 0.87, and 6.40 ± 0.66 mm, respectively, before surgery, immediately after surgery, and before implantation. At point B, ridge widths were 3.40 ± 0.39, 9.35 ± 1.16, and 7.40 ± 1.10 mm, respectively, before surgery, immediately after surgery, and before implantation. The Friedman test showed significant increases in ridge widths, both at point A and point B (both P = .0000). Postaugmentation resorption was about 1.5-2 mm and was statistically significant at points A and B (P < .05, Dunn). The percentage of newly formed bone, residual graft material, and soft tissue were 33.0% ± 11.35% (95% confidence interval [CI] = 24.88%-41.12%), 37.50% ± 19.04% (95% CI = 23.88%-51.12%), and 29.5%, respectively. The inflammation was limited to grades 1 or zero. Twelve to 18 months after implantation, no implants caused pain or showed exudates or pockets. Radiographic bone loss was 2.0 ± 0.7 mm (range = 1-3). It can be concluded that lateral ridge augmentation with corticocancellous allograft blocks might be successful both clinically and histologically. Implants might have a proper clinical success after a minimum of 12 months.

The ABC7 regimen: a new approach to metastatic breast cancer using seven common drugs to inhibit epithelial-to-mesenchymal transition and augment capecitabine efficacy.

PubMed

Kast, Richard E; Skuli, Nicolas; Cos, Samuel; Karpel-Massler, Georg; Shiozawa, Yusuke; Goshen, Ran; Halatsch, Marc-Eric

2017-01-01

Breast cancer metastatic to bone has a poor prognosis despite recent advances in our understanding of the biology of both bone and breast cancer. This article presents a new approach, the ABC7 regimen (Adjuvant for Breast Cancer treatment using seven repurposed drugs), to metastatic breast cancer. ABC7 aims to defeat aspects of epithelial-to-mesenchymal transition (EMT) that lead to dissemination of breast cancer to bone. As add-on to current standard treatment with capecitabine, ABC7 uses ancillary attributes of seven already-marketed noncancer treatment drugs to stop both the natural EMT process inherent to breast cancer and the added EMT occurring as a response to current treatment modalities. Chemotherapy, radiation, and surgery provoke EMT in cancer generally and in breast cancer specifically. ABC7 uses standard doses of capecitabine as used in treating breast cancer today. In addition, ABC7 uses 1) an older psychiatric drug, quetiapine, to block RANK signaling; 2) pirfenidone, an anti-fibrosis drug to block TGF-beta signaling; 3) rifabutin, an antibiotic to block beta-catenin signaling; 4) metformin, a first-line antidiabetic drug to stimulate AMPK and inhibit mammalian target of rapamycin, (mTOR); 5) propranolol, a beta-blocker to block beta-adrenergic signaling; 6) agomelatine, a melatonergic antidepressant to stimulate M1 and M2 melatonergic receptors; and 7) ribavirin, an antiviral drug to prevent eIF4E phosphorylation. All these block the signaling pathways - RANK, TGF-beta, mTOR, beta-adrenergic receptors, and phosphorylated eIF4E - that have been shown to trigger EMT and enhance breast cancer growth and so are worthwhile targets to inhibit. Agonism at MT1 and MT2 melatonergic receptors has been shown to inhibit both breast cancer EMT and growth. This ensemble was designed to be safe and augment capecitabine efficacy. Given the expected outcome of metastatic breast cancer as it stands today, ABC7 warrants a cautious trial.

Development and application of a direct method to observe the implant/bone interface using simulated bone.

PubMed

Yamaguchi, Yoko; Shiota, Makoto; FuJii, Masaki; Sekiya, Michi; Ozeki, Masahiko

2016-01-01

Primary stability after implant placement is essential for osseointegration. It is important to understand the bone/implant interface for analyzing the influence of implant design on primary stability. In this study rigid polyurethane foam is used as artificial bone to evaluate the bone-implant interface and to identify where the torque is being generated during placement. Five implant systems-Straumann-Standard (ST), Straumann-Bone Level (BL), Straumann-Tapered Effect (TE), Nobel Biocare-Brånemark MKIII (MK3), and Nobel Biocare-Brånemark MKIV (MK4)-were used for this experiment. Artificial bone blocks were prepared and the implant was installed. After placement, a metal jig and one side artificial bone block were removed and then the implant embedded in the artificial bone was exposed for observing the bone-implant interface. A digital micro-analyzer was used for observing the contact interface. The insertion torque values were 39.35, 23.78, 12.53, 26.35, and 17.79 N cm for MK4, BL, ST, TE, and MK3, respectively. In ST, MK3, TE, MK4, and BL the white layer areas were 61 × 103 μm(2), 37 × 103 μm(2), 103 × 103 μm(2) in the tapered portion and 84 × 03 μm(2) in the parallel portion, 134 × 103 μm(2), and 98 × 103 μm(2) in the tapered portion and 87 × 103 μm(2) in the parallel portion, respectively. The direct observation method of the implant/artificial bone interface is a simple and useful method that enables the identification of the area where implant retention occurs. A white layer at the site of stress concentration during implant placement was identified and the magnitude of the stress was quantitatively estimated. The site where the highest torque occurred was the area from the thread crest to the thread root and the under and lateral aspect of the platform. The artificial bone debris created by the self-tapping blade accumulated in both the cutting chamber and in the space between the threads and artificial bone.

Fixation of Hydroxyapatite-Coated Revision Implants Is Improved by the Surgical Technique of Cracking the Sclerotic Bone Rim

PubMed Central

Elmengaard, Brian; Bechtold, Joan E.; Chen, Xinqian; Søballe, Kjeld

2013-01-01

Revision joint replacement has poorer outcomes that have been associated with poorer mechanical fixation. We investigate a new bone-sparing surgical technique that locally cracks the sclerotic bone rim formed during aseptic loosening. We inserted 16 hydroxyapatite-coated implants bilaterally in the distal femur of eight dogs, using a controlled weight-bearing experimental model that replicates important features of a typical revision setting. At 8 weeks, a control revision procedure and a crack revision procedure were performed on contralateral implants. The crack procedure used a splined tool to perform a systematic local perforation of the sclerotic bone rim of the revision cavity. After 4 weeks, the hydroxyapatite-coated implants were evaluated for mechanical fixation by a push-out test and for tissue distribution by histomorphometry. The cracking revision procedure resulted in significantly improved mechanical fixation, significantly more bone ongrowth and bone volume in the gap, and reduced fibrous tissue compared to the control revision procedure. The study demonstrates that the sclerotic bone rim prevents bone ingrowth and promotes fixation by fibrous tissue. The effect of the cracking technique may be due to improved access to the vascular compartment of the bone. The cracking technique is a simple surgical method that potentially can improve the fixation of revision implants in sclerotic regions important for obtaining the fixation critical for overall implant stability. PMID:19148940

Atlas of computerized blood flow analysis in bone disease.

PubMed

Gandsman, E J; Deutsch, S D; Tyson, I B

1983-11-01

The role of computerized blood flow analysis in routine bone scanning is reviewed. Cases illustrating the technique include proven diagnoses of toxic synovitis, Legg-Perthes disease, arthritis, avascular necrosis of the hip, fractures, benign and malignant tumors, Paget's disease, cellulitis, osteomyelitis, and shin splints. Several examples also show the use of the technique in monitoring treatment. The use of quantitative data from the blood flow, bone uptake phase, and static images suggests specific diagnostic patterns for each of the diseases presented in this atlas. Thus, this technique enables increased accuracy in the interpretation of the radionuclide bone scan.

Reconstruction of large diaphyseal bone defect by simplified bone transport over nail technique: A 7-case series.

PubMed

Ferchaud, F; Rony, L; Ducellier, F; Cronier, P; Steiger, V; Hubert, L

2017-11-01

Reconstruction of large diaphyseal bone defect is complex and the complications rate is high. This study aimed to assess a simplified technique of segmental bone transport by monorail external fixator over an intramedullary nail.A prospective study included 7 patients: 2 femoral and 5 tibial defects. Mean age was 31years (range: 16-61years). Mean follow-up was 62 months (range: 46-84months). Defects were post-traumatic, with a mean length of 7.2cm (range: 4 to 9.5cm). For 3 patients, reconstruction followed primary failure. In 4 cases, a covering flap was necessary. Transport used an external fixator guided by an intramedullary nail, at a rate of 1mm per day. One pin was implanted on either side of the distraction zone. The external fixator was removed 1 month after bone contact at the docking site. Mean bone transport time was 11 weeks (range: 7-15 weeks). Mean external fixation time was 5.1months (range: 3.5 to 8months). Full weight-bearing was allowed 5.7months (range: 3.5-13months) after initiation of transport. In one patient, a pin had to be repositioned. In 3 patients, the transported segment re-ascended after external fixatorablation, requiring repeat external fixation and resumption of transport. There was just 1 case of superficial pin infection. Reconstruction quality was considered "excellent" on the Paley-Marr criteria in 6 cases. The present technique provided excellent reconstruction quality in 6 of the 7 cases. External fixation time was shorter and resumption of weight-bearing earlier than with other reconstruction techniques, notably including bone autograft, vascularized bone graft or the induced membrane technique. Nailing facilitated control of limb axis and length. The complications rate was 50%, comparable to other techniques. This study raises the question of systematic internal fixation of the docking site, to avoid any mobilization of the transported segment. The bone quality, axial control and rapidity shown by the present technique make it well-adapted to reconstruction of diaphyseal bone defect. Four-case series. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

Keratinocyte expression of inflammatory mediators plays a crucial role in substance P-induced acute and chronic pain

PubMed Central

2012-01-01

Tibia fracture in rats followed by cast immobilization leads to nociceptive, trophic, vascular and bone-related changes similar to those seen in Complex Regional Pain Syndrome (CRPS). Substance P (SP) mediated neurogenic inflammation may be responsible for some of the signs of CRPS in humans. We therefore hypothesized that SP acting through the SP receptor (NK1) leads to the CRPS-like changes found in the rat model. In the present study, we intradermally injected rats with SP and monitored hindpaw mechanical allodynia, temperature, and thickness as well as tissue levels of tumor necrosis factor-α (TNF-α), interleukin 1β (IL-1β), interleukin 6 (IL-6), and nerve growth factor-β (NGF) for 72 h. Anti-NGF antibody was utilized to block the effects of SP-induced NGF up-regulation. Fracture rats treated with the selective NK1 receptor antagonist LY303870 prior to cast removal were assessed for BrdU, a DNA synthesis marker, incorporation in skin cells to examine cellular proliferation. Bone microarchitecture was measured using micro computed tomography (μCT). We observed that: (1) SP intraplantar injection induced mechanical allodynia, warmth and edema as well as the expression of nociceptive mediators in the hindpaw skin of normal rats, (2) LY303870 administered intraperitoneally after fracture attenuated allodynia, hindpaw unweighting, warmth, and edema, as well as cytokine and NGF expression, (3) LY303870 blocked fracture-induced epidermal thickening and BrdU incorporation after fracture, (4) anti-NGF antibody blocked SP-induced allodynia but not warmth or edema, and (5) LY303870 had no effect on bone microarchitecture. Collectively our data indicate that SP acting through NK1 receptors supports the nociceptive and vascular components of CRPS, but not the bone-related changes. PMID:22824437

The use of cancellous block allograft for sinus floor augmentation with simultaneous implant placement in the posterior atrophic maxilla.

PubMed

Chaushu, Gavriel; Mardinger, Ofer; Calderon, Shlomo; Moses, Ofer; Nissan, Joseph

2009-03-01

The simultaneous placement of dental implants during sinus augmentation is advocated in cases in which >or=4 to 5 mm of alveolar bone exists coronally to the sinus floor. The aim of the present study was to assess the survival rate of dental implants placed during sinus augmentation and stabilized by the use of cancellous freeze-dried block allograft. Residual alveolar ridge height

Comprehensive Review of Adipose Stem Cells and Their Implication in Distraction Osteogenesis and Bone Regeneration

PubMed Central

Morcos, Mina W.; Al-Jallad, Hadil; Hamdy, Reggie

2015-01-01

Bone is one of the most dynamic tissues in the human body that can heal following injury without leaving a scar. However, in instances of extensive bone loss, this intrinsic capacity of bone to heal may not be sufficient and external intervention becomes necessary. Several techniques are available to address this problem, including autogenous bone grafts and allografts. However, all these techniques have their own limitations. An alternative method is the technique of distraction osteogenesis, where gradual and controlled distraction of two bony segments after osteotomy leads to induction of new bone formation. Although distraction osteogenesis usually gives satisfactory results, its major limitation is the prolonged duration of time required before the external fixator is removed, which may lead to numerous complications. Numerous methods to accelerate bone formation in the context of distraction osteogenesis have been reported. A viable alternative to autogenous bone grafts for a source of osteogenic cells is mesenchymal stem cells from bone marrow. However, there are certain problems with bone marrow aspirate. Hence, scientists have investigated other sources for mesenchymal stem cells, specifically adipose tissue, which has been shown to be an excellent source of mesenchymal stem cells. In this paper, the potential use of adipose stem cells to stimulate bone formation is discussed. PMID:26448947

True Color Image Analysis For Determination Of Bone Growth In Fluorochromic Biopsies

NASA Astrophysics Data System (ADS)

Madachy, Raymond J.; Chotivichit, Lee; Huang, H. K.; Johnson, Eric E.

1989-05-01

A true color imaging technique has been developed for analysis of microscopic fluorochromic bone biopsy images to quantify new bone growth. The technique searches for specified colors in a medical image for quantification of areas of interest. Based on a user supplied training set, a multispectral classification of pixel values is performed and used for segmenting the image. Good results were obtained when compared to manual tracings of new bone growth performed by an orthopedic surgeon. At a 95% confidence level, the hypothesis that there is no difference between the two methods can be accepted. Work is in progress to test bone biopsies with different colored stains and further optimize the analysis process using three-dimensional spectral ordering techniques.

Lipid Osteoclastokines Regulate Breast Cancer Bone Metastasis

PubMed Central

Krzeszinski, Jing Y.; Schwaid, Adam G.; Cheng, Wing Yin; Jin, Zixue; Gallegos, Zachary R.; Saghatelian, Alan

2017-01-01

Bone metastasis is a deadly consequence of cancers, in which osteoclast forms a vicious cycle with tumor cells. Bone metastasis attenuation by clinical usage of osteoclast inhibitors and in our osteopetrotic mouse genetic models with β-catenin constitutive activation or peroxisome proliferator-activated receptor γ deficiency fully support the important role of osteoclast in driving the bone metastatic niche. However, the mechanisms for this “partnership in crime” are underexplored. Here we show that osteoclasts reprogram their lipid secretion to support cancer cells. Metabolomic profiling reveals elevated prometastatic arachidonic acid (AA) but reduced antimetastatic lysophosphatidylcholines (LPCs). This shift in lipid osteoclastokines synergistically stimulates tumor cell proliferation, migration, survival, and expression of prometastatic genes. Pharmacologically, combined treatment with LPCs and BW-755C, an inhibitor of AA signaling via blocking lipoxygenase and cyclooxygenase, impedes breast cancer bone metastasis. Our findings elucidate key paracrine mechanisms for the osteoclast-cancer vicious cycle and uncover important therapeutic targets for bone metastasis. PMID:27967239

Awake Fibreoptic Intubation for Forearm Injury in a Patient with Occipito-Cervical Fixator

PubMed Central

Akkaya, Akcan; Yıldız, İsa; Demirhan, Abdullah; Tekelioğlu, Ümit Yaşar; Koçoğlu, Hasan

2013-01-01

A 23-year-old male patient with occipitocervical fixator was scheduled for surgery due to injury to the right forearm. The patient’s thyromental distance was 5 cm, mouth opening grade II, sternomental distance 10 cm and Mallampati score 4. Loss of extension and rotation movements of the head was assessed as difficult intubation criteria. Anaesthetic procedures are almost always difficult in patients with occipitocervical fixation; the limited cervical extension complicated both intubation and ventilation. In this report, application of general anaesthesia using awake fibreoptic bronchoscopic intubation (FOB) is described. After routine monitoring of vital signs and premedication, hypopharyngeal topical anaesthesia was accomplished by instilling 10% lidocaine spray twice via the appropriate nostril. Superior laryngeal nerve block was performed with local anaesthetic infiltration of tissues 1 cm below the greater horns of the hyoid bone. Lingual and pharyngeal branches of the glossopharyngeal nerve were blocked. Transtracheal block was performed. Following completion of local anaesthesia, the patient was intubated using the awake FOB technique, on 5 L min−1 of 100% O2. After muscle relaxation, the patient underwent a microsurgical operation to repair eight tendons, one artery, and one nerve. Surgery lasted for 5 hours. When the extubation criteria were met, the patient was extubated. In cases of occipitocervical fixation, which causes severe limitation of neck movements, the use of awake fibreoptic intubation should be considered. PMID:27366367

Osteogenesis imperfecta

MedlinePlus

... defect in the gene that produces type 1 collagen, an important building block of bone. There are ... fractures Early hearing loss ( deafness ) Because type I collagen is also found in ligaments, people with OI ...

Ruxolitinib

MedlinePlus

... by scar tissue and causes decreased blood cell production). Ruxolitinib is in a class of medications called kinase inhibitors. It works by blocking an enzyme that causes scar tissue to form in the bone marrow.

[Bone graft reconstruction for posterior mandibular segment using the formwork technique].

PubMed

Pascual, D; Roig, R; Chossegros, C

2014-04-01

Pre-implant bone graft in posterior mandibular segments is difficult because of masticatory and lingual mechanical constraints, because of the limited bone vascularization, and because of the difficulty to cover it with the mucosa. The formwork technique is especially well adapted to this topography. The recipient site is abraded with a drill. Grooves are created to receive and stabilize the grafts. The bone grafts were harvested from the ramus. The thinned cortices are assembled in a formwork and synthesized by mini-plates. The gaps are filled by bone powder collected during bone harvesting. The bone volume reconstructed with the formwork technique allows anchoring implants more than 8mm long. The proximity of the inferior alveolar nerve does not contra indicate this technique. The formwork size and its positioning on the alveolar crest can be adapted to prosthetic requirements by using osteosynthesis plates. The lateral implant walls are supported by the formwork cortices; the implant apex is anchored on the native alveolar crest. The primary stability of implants is high, and the torque is important. The ramus harvesting decreases operative risks. Copyright © 2014 Elsevier Masson SAS. All rights reserved.

Topology Optimization of Lightweight Lattice Structural Composites Inspired by Cuttlefish Bone

NASA Astrophysics Data System (ADS)

Hu, Zhong; Gadipudi, Varun Kumar; Salem, David R.

2018-03-01

Lattice structural composites are of great interest to various industries where lightweight multifunctionality is important, especially aerospace. However, strong coupling among the composition, microstructure, porous topology, and fabrication of such materials impedes conventional trial-and-error experimental development. In this work, a discontinuous carbon fiber reinforced polymer matrix composite was adopted for structural design. A reliable and robust design approach for developing lightweight multifunctional lattice structural composites was proposed, inspired by biomimetics and based on topology optimization. Three-dimensional periodic lattice blocks were initially designed, inspired by the cuttlefish bone microstructure. The topologies of the three-dimensional periodic blocks were further optimized by computer modeling, and the mechanical properties of the topology optimized lightweight lattice structures were characterized by computer modeling. The lattice structures with optimal performance were identified.

Optical absorption coefficient, time of thermal relaxation, time of surface threshold, and time of heat incubation for PMMA samples at the CO2 laser-beam wavelength of 10.6 microm.

PubMed

Canestri, Franco

2006-10-01

This paper discusses in detail the mathematical identification of the optical absorption alpha (cm(1)) of Beer's law, a crucial parameter to study the development of laser beam craters into dry poly(methyl methacrylate) (PMMA) samples exposed to steady CO(2) laser beams emitting radiation at lambda = 10.6 microm in continuous- wave (CW) mode. Three additional time-dependent coefficients have been determined as well. In clinical applications, these results are important in order to precisely quantify and forecast the ablation capabilities of the CO(2) laser beam, to optimize its usage in the operating room, and to address the safety issues related to surgical interventions on human tissue. Currently, the data available in the literature do not allow the identification of the numerical value of alpha (cm(1)) for PMMA at lambda = 10.6 microm with enough, and therefore satisfactory, accuracy. Additionally, the correct identification of the optical absorption of PMMA would allow the isolation, with better accuracy, of other key time-dependent coefficients, such as relaxation time, surface threshold time, and heat incubation time, which are all described in the literature in a qualitative rather than quantitative fashion. Correct bone cement preparation depends on the value of alpha (cm(1)) of the PMMA in order to avoid unwanted complications in patients during cement removal via laser techniques. The laser in use was configured in different combinations with the following parameters: transverse electromagnetic modes (TEMnm), output power (I0), exposure times (te), and focal lengths (fk). Several PMMA blocks (1 cm x 4 cm x 4 cm) were exposed to CW radiation of three commercially available CO(2) medical laser devices showing a TEM11 mode. Each block was exposed to the beam on a horizontal and well-polished surface of each sample. Four focal lengths (2.5", 5", 7.5", and 15.75" [400 mm]) were used to focus the beam on the well-polished and dry surface of the PMMA samples. The resulting dimensions of the craters were measured after each exposure, which has been kept at a 10-Watt CW beam. Exposure time ranged from 0.5 to 2 sec. The value of alpha = 502 (cm(1)) for PMMAat 10.6 microm was identified, matching other results reported in the literature for similar compact media in the absence of water content, such as PMMA. The time of thermal relaxation was 9.358 x 10(4) sec, the time of surface threshold was 9.365 x 10(4) sec, and the time of heat incubation was 3.6 x 10(7) sec (all three for PMMAat 10.6 microm for any exposure). Using the calculated value of alpha, one of the practical clinical recommendations would be, for instance, to reduce or to abolish the utilization of colorant dopants in the preparation of the bone cement mixture and therefore reduce the danger of bone damage possible during the removal of bone cement via laser techniques. Other examples refer to other clinical bone and dental treatments.

Targeted Therapies for Myeloma and Metastatic Bone Cancers

DTIC Science & Technology

2010-09-01

to produce NPs for in-vivo studies compatible with the short half life of Tc99m. (Fig 6,7) Developed methods to radiolabel polymer nanoparticles...fully characterize PLA-b-PEG-Maleimide block Polymer (PLA-b-PEG-MAL) Propose: To synthesize Maleimide modified PLGA-b-PEG 2000 for NPs bone-targeted... polymer was synthesized and characterized by H-NMR. (Appendix 2) Improved lyostability of polymer nanoparticles, with and without PEG modification

Prefabrication of axial vascularized tissue engineering coral bone by an arteriovenous loop: a better model.

PubMed

Dong, Qing-shan; Shang, Hong-tao; Wu, Wei; Chen, Fu-lin; Zhang, Jun-rui; Guo, Jia-ping; Mao, Tian-qiu

2012-08-01

The most important problem for the survival of thick 3-dimensional tissues is the lack of vascularization in the context of bone tissue engineering. In this study, a modified arteriovenous loop (AVL) was developed to prefabricate an axial vascularized tissue engineering coral bone in rabbit, with comparison of the arteriovenous bundle (AVB) model. An arteriovenous fistula between rabbit femoral artery and vein was anastomosed to form an AVL. It was placed in a circular side groove of the coral block. The complex was wrapped with an expanded-polytetrafluoroethylene membrane and implanted beneath inguinal skin. After 2, 4, 6 and 8 weeks, the degree of vascularization was evaluated by India ink perfusion, histological examination, vascular casts, and scanning electron microscopy images of vascular endangium. Newly formed fibrous tissues and vasculature extended over the surfaces and invaded the interspaces of entire coral block. The new blood vessels robustly sprouted from the AVL. Those invaginated cavities in the vascular endangium from scanning electron microscopy indicated vessel's sprouted pores. Above indexes in AVL model are all superior to that in AVB model, indicating that the modified AVL model could more effectively develop vascularization in larger tissue engineering bone. Copyright © 2012 Elsevier B.V. All rights reserved.

Success rate and risk factors of failure of the induced membrane technique in children: a systematic review.

PubMed

Aurégan, Jean-Charles; Bégué, Thierry; Rigoulot, Guillaume; Glorion, Christophe; Pannier, Stéphanie

2016-12-01

The induced membrane technique was designed by Masquelet et al. to address segmental bone defects of critical size in adults. It has been used after bone defects of traumatic, infectious and tumoral origin with satisfactory results. Recently, it has been used in children but, after an initial enthusiasm, several cases of failure have been reported. The purpose of this study was to assess the success rate and the risk factors of failure of the induced membrane for children. We conducted a systematic review of all the studies reporting the results of the induced membrane technique to address bone defects of critical size in children. Our primary outcome was the success rate of the technique defined as a bone union before any iterative surgery. Our secondary outcomes were the complications and the risk factors of failure. We searched Medline via Pubmed, EMBASE and the Cochrane Library. Twelve studies, including 69 patients, met the inclusion criteria. There were 41 boys and 28 girls. Mean age at surgery was 10 years. Mean size of resection was 12.38 cm and the mean time between the two stages was 5.86 months. Mean rate of bone union after the two stages of the induced membrane technique was 58% (40/69) but this rate increased to 87% after revision surgeries (60/69). Main complications were non-unions (19/69), lysis of the graft (6/69) and fractures of the bone graft (6/69). Only 1/69 deep infection was reported. Other non specific complications were regularly reported such limb length discrepancies, joint stiffness and protruding wires. Risk factor of failure that could be suspected comprised the resection of a malignant tumour, a bone defect located at the femur, a wide resection, a long time between the two stages, an unstable osteosynthesis and a bone graft associating autograft to other graft materials. The induced membrane technique is suitable for bone defects of critical size in children. It is a reliable technique with no need of micro vascular surgery. However, we found several risk factors of failure for the use of the induced membrane technique to address segmental bone defect of critical size in children. Copyright © 2016 Elsevier Ltd. All rights reserved.

Novel Radiomitigator for Radiation-Induced Bone Loss

NASA Technical Reports Server (NTRS)

Schreurs, A-S; Shirazi-fard, Y.; Terada, M.; Alwood, J. S.; Steczina, S.; Medina, C.; Tahimic, C. G. T.; Globus, R. K.

2016-01-01

Radiation-induced bone loss can occur with radiotherapy patients, accidental radiation exposure and during long-term spaceflight. Bone loss due to radiation is due to an early increase in oxidative stress, inflammation and bone resorption, resulting in an imbalance in bone remodeling. Furthermore, exposure to high-Linear Energy Transfer (LET) radiation will impair the bone forming progenitors and reduce bone formation. Radiation can be classified as high-LET or low-LET based on the amount of energy released. Dried Plum (DP) diet prevents bone loss in mice exposed to total body irradiation with both low-LET and high-LET radiation. DP prevents the early radiation-induced bone resorption, but furthermore, we show that DP protects the bone forming osteoblast progenitors from high-LET radiation. These results provide insight that DP re-balances the bone remodeling by preventing resorption and protecting the bone formation capacity. This data is important considering that most of the current osteoporosis treatments only block the bone resorption but do not protect bone formation. In addition, DP seems to act on both the oxidative stress and inflammation pathways. Finally, we have preliminary data showing the potential of DP to be radio-protective at a systemic effect and could possible protect other tissues at risk of total body-irradiation such as skin, brain and heart.

Osteoclast TGF-β Receptor Signaling Induces Wnt1 Secretion and Couples Bone Resorption to Bone Formation

PubMed Central

Weivoda, Megan M; Ruan, Ming; Pederson, Larry; Hachfeld, Christine; Davey, Rachel A; Zajac, Jeffrey D; Westendorf, Jennifer J; Khosla, Sundeep; Oursler, Merry Jo

2016-01-01

Osteoblast-mediated bone formation is coupled to osteoclast-mediated bone resorption. These processes become uncoupled with age, leading to increased risk for debilitating fractures. Therefore, understanding how osteoblasts are recruited to sites of resorption is vital to treating age-related bone loss. Osteoclasts release and activate TGF-β from the bone matrix. Here we show that osteoclastspecific inhibition of TGF-β receptor signaling in mice results in osteopenia due to reduced osteoblast numbers with no significant impact on osteoclast numbers or activity. TGF-β induced osteoclast expression of Wnt1, a protein crucial to normal bone formation, and this response was blocked by impaired TGF-β receptor signaling. Osteoclasts in aged murine bones had lower TGF-β signaling and Wnt1 expression in vivo. Ex vivo stimulation of osteoclasts derived from young or old mouse bone marrow macrophages showed no difference in TGF-β–induced Wnt1 expression. However, young osteoclasts expressed reduced Wnt1 when cultured on aged mouse bone chips compared to young mouse bone chips, consistent with decreased skeletal TGF-β availability with age. Therefore, osteoclast responses to TGF-β are essential for coupling bone resorption to bone formation, and modulating this pathway may provide opportunities to treat age-related bone loss. PMID:26108893

Effects of polycaprolactone-tricalcium phosphate, recombinant human bone morphogenetic protein-2 and dog mesenchymal stem cells on bone formation: pilot study in dogs.

PubMed

Kim, Sun-Jong; Kim, Myung-Rae; Oh, Jin-Sub; Han, Inho; Shin, Sang-Wan

2009-12-31

The aim of this study was to evaluate the survival, proliferation, and bone formation of dog mesenchymal stem cells (dMSCs) in the graft material by using Polycaprolactone-tricalcium phosphate (PCL-TCP), auto-fibrin glue (AFG), recombinant human bone morphogenetic protein-2 (rhBMP-2), and dMSCs after a transplantation to the scapula of adult beagle dogs. The subjects were two beagle dogs. Total dose of rhBMP-2 on each block was 10 microg with 50 microg/mg concentration. The cortical bone of the scapula of the dog was removed which was the same size of PCL-TCP block (Osteopore International Pte, Singapore; 5.0x5.0x8.0 mm in size), and the following graft material then was fixed with orthodontic mini-implant, Dual-top (Titanium alloy, Jeil Co. Seoul, Korea). Four experimental groups were prepared for this study, Group 1: PCL-TCP + aFG; Group 2: PCL-TCP + aFG + dMSCs; Group 3: PCL-TCP + aFG + dMSCs + rhBMP-2; Group 4: PCL-TCP + aFG + dMSCs + rhBMP-2 + PCL membrane. The survival or proliferation of dMSCs cells was identified with an extracted tissue through a fluorescence microscope, H-E staining and Von-Kossa staining in two weeks and four weeks after the transplantation. The survival and proliferation of dMSCs were identified through a fluorescence microscope from both Group 1 and Group 2 in two weeks and four weeks after the transplantation. Histological observation also found that the injected cells were proliferating well in the G2, G3, and G4 scaffolds. This study concluded that bone ingrowth occurred in PCL-TCP scaffold which was transplanted with rhBMP-2, and MSCs did not affect bone growth. More sufficient healing time would be needed to recognize effects of dMSCs on bone formation.

Application of a 3-dimensional printed navigation template in Bernese periacetabular osteotomies: A cadaveric study.

PubMed

Zhou, You; Kang, Xiaopeng; Li, Chuan; Xu, Xiaoshan; Li, Rong; Wang, Jun; Li, Wei; Luo, Haotian; Lu, Sheng

2016-12-01

The aim of the present study was to describe the application of 3D printed templates for intraoperative navigation and simulation of periacetabular osteotomies (PAOs) in a cadaveric model.Five cadaveric specimens (10 sides) underwent thin-slice computed tomographic scans of the ala of ilium downwards to the proximal end of femoral shaft. Bernese PAO was performed. Using Mimics v10.1 software (Materialise, Leuven, Belgium), 3D computed tomographic reconstructions were created and the 4 standard PAO bone cuts-ischial, pubic, anterior, and posterior aspects of the ilium-as well as rotation of the dislocated acetabular bone blocks were simulated for each specimen. Using these data, custom 3D printed bone-drilling templates of the pelvis were manufactured, to guide surgical placement of the PAO bone cuts. An angle fix wedge was designed and printed, to help accurately achieve the predetermined rotation angle of the acetabular bone block. Each specimen underwent a conventional PAO. Preoperative, postsimulation, and postoperative lateral center-edge angles, acetabular indices, extrusion indices, and femoral head coverage were measured and compared; P and t values were calculated for above-mentioned measurements while comparing preoperative and postoperative data, and also in postsimulation and postoperative data comparison.All 10 PAO osteotomies were successfully completed using the 3D printed bone-drilling template and angle fix wedge. No osteotomy entered the hip joint and a single posterior column fracture was observed. Comparison of preoperative and postoperative measurements of the 10 sides showed statistically significant changes, whereas no statistically significant differences between postsimulation and postoperative values were noted, demonstrating the accuracy and utility of the 3D printed templates.The application of patient-specific 3D printed bone-drilling and rotation templates in PAO is feasible and may facilitate improved clinical outcomes, through the use of precise presurgical planning and reduced surgical complications with the precisely guided bone drilling.

[The Léon [correction of Laurent] Guedj implant concept: simplification of the surgical phase in implantology].

PubMed

Fabie, L; Guedj, L; Pichaud, Ch; Fabie, M

2002-11-01

We present a new self-drilling self-tapping dental implant that simplifies the operative technique and optimizes osseointegration. The implant, the instrumentation, and the operative technique are described. An experimental study was conducted in a sheep with pathological and histomorphological analysis at three months. A clinical evaluation was also conducted in 18 patients who had 27 implants. The experimental study demonstrated good quality osseointegration, without bone necrosis. Three sectors were identified. Histomorphometric analysis demonstrated that mean bone contact reached 40% on cancellous bone and 65% on cortical bone. In the clinical series, one implant had to be removed due to a problem with gum healing. All the other implants were well tolerated. The advantage of this new technique is the use of the implant as the drilling instrument. Much time is saved. In addition, the bone-implant contact is better since the bone cavity is exactly adapted to the implant. The risk of bone lesion is reduced due to the smaller number of drillings.

Haplotype-based gene-gene interaction of bone morphogenetic protein 4 and interferon regulatory factor 6 in the etiology of non-syndromic cleft lip with or without cleft palate in a Chilean population.

PubMed

Blanco, Rafael; Colombo, Alicia; Pardo, Rosa; Suazo, José

2017-04-01

Non-syndromic cleft lip with or without cleft palate (NSCL/P) is the most common craniofacial birth defect in humans, the etiology of which can be dependent on the interactions of multiple genes. We previously reported haplotype associations for polymorphic variants of interferon regulatory factor 6 (IRF6), msh homeobox 1 (MSX1), bone morphogenetic protein 4 (BMP4), and transforming growth factor beta 3 (TGFB3) in Chile. Here, we analyzed the haplotype-based gene-gene interaction for markers of these genes and NSCL/P risk in the Chilean population. We genotyped 15 single nucleoptide polymorphisms (SNPs) in 152 Chilean patients and 164 controls. Linkage disequilibrium (LD) blocks were determined using the Haploview software, and phase reconstruction was performed by the Phase program. Haplotype-based interactions were evaluated using the multifactor dimensionality reduction (MDR) method. We detected two LD blocks composed of two SNPs from BMP4 (Block 1) and three SNPs from IRF6 (Block 2). Although MDR showed no statistical significance for the global interaction model involving these blocks, we found four combinations conferring a statistically significantly increased NSCL/P risk (Block 1-Block 2): T-T/T-G C-G-T/G-A-T; T-T/T-G C-G-C/C-G-C; T-T/T-G G-A-T/G-A-T; and T-T/C-G G-A-T/G-A-T. These findings may reflect the presence of a genomic region containing potential causal variants interacting in the etiology of NSCL/P and may contribute to disentangling the complex etiology of this birth defect. © 2017 Eur J Oral Sci.

Alveolar Ridge Augmentation with Three-Dimensional Printed Hydroxyapatite Devices: A Preclinical Study.

PubMed

Fiorellini, Joseph P; Norton, Michael R; Luan, Kevin WanXin; Kim, David Minjoon; Wada, Kei; Sarmiento, Hector L

2018-02-14

The objective of this study was to evaluate the effectiveness of precise three-dimensional hydroxyapatite printed micro- and macrochannel devices for alveolar ridge augmentation in a canine model. All grafts induced minimal inflammatory and fibrotic reactions. Examination of undecalcified sections revealed that both types of grafts demonstrated bone ingrowth. The majority of the bone growth into the block graft was into the channels, though a portion grew directly into the construct in the form of small bony spicules. In conclusion, bone ingrowth was readily demonstrated in the middle of the implanted printed devices.

A review of the physiological and histological effects of laser osteotomy.

PubMed

Rajitha Gunaratne, G D; Khan, Riaz; Fick, Daniel; Robertson, Brett; Dahotre, Narendra; Ironside, Charlie

2017-01-01

Osteotomy is the surgical cutting of bone. Some obstacles to laser osteotomy have been melting, carbonisation and subsequent delayed healing. New cooled scanning techniques have resulted in effective bone cuts without the strong thermal side effects, which were observed by inappropriate irradiation techniques with continuous wave and long pulsed lasers. With these new techniques, osteotomy gaps histologically healed with new bone formation without any noticeable or minimum thermal damage. No significant cellular differences in bone healing between laser and mechanical osteotomies were noticed. Some studies even suggest that the healing rate may be enhanced following laser osteotomy compared to conventional mechanical osteotomy. Additional research is necessary to evaluate different laser types with appropriate laser setting variables to increase ablation rates, with control of depth, change in bone type and damage to adjacent soft tissue. Laser osteotomy has the potential to become incorporated into the armamentarium of bone surgery.

Osteotomy and fracture fixation in children and teenagers.

PubMed

de Billy, B; Gindraux, F; Langlais, J

2014-02-01

Significant changes have occurred recently in fixation methods following fracture or osteotomy in children and teenagers. Children have benefited the most from these advances. A child's growth is anatomically and physiologically ensured by the growth plate and periosteum. The need to keep the periosteum intact during trauma cases has led to the introduction of flexible intramedullary nailing. We will review the basic principles of this safe, universally adopted technique, and also describe available material, length and diameter options. The problems and the limitations of this method will be discussed extensively. In orthopedics, the desire to preserve the periosteum has led to the use of locking compression plates. Because of their low profile and high stability, they allow the micromovements essential for bone union. These new methods reduce the immobilization period and allow autonomy to be regained more quickly, which is especially important in children with neurological impairment. The need to preserve the growth plate, which is well known in pediatric surgery, is reviewed with the goal of summarizing current experimental data on standard fracture and osteotomy fixation methods. Adjustable block stop wires provide better control over compression. These provide an alternate means of fixation between K-wires and screws (now cannulated) and have contributed to the development of minimally invasive surgical techniques. The aim of this lecture is to provide a rationale for the distinct technical features of pediatric surgery, while emphasizing the close relationship between the physiology of growth, bone healing and technical advances. Copyright © 2013 Elsevier Masson SAS. All rights reserved.

Development of an acoustic measurement protocol to monitor acetabular implant fixation in cementless total hip Arthroplasty: A preliminary study.

PubMed

Goossens, Quentin; Leuridan, Steven; Henyš, Petr; Roosen, Jorg; Pastrav, Leonard; Mulier, Michiel; Desmet, Wim; Denis, Kathleen; Vander Sloten, Jos

2017-11-01

In cementless total hip arthroplasty (THA), the initial stability is obtained by press-fitting the implant in the bone to allow osseointegration for a long term secondary stability. However, finding the insertion endpoint that corresponds to a proper initial stability is currently based on the tactile and auditory experiences of the orthopedic surgeon, which can be challenging. This study presents a novel real-time method based on acoustic signals to monitor the acetabular implant fixation in cementless total hip arthroplasty. Twelve acoustic in vitro experiments were performed on three types of bone models; a simple bone block model, an artificial pelvic model and a cadaveric model. A custom made beam was screwed onto the implant which functioned as a sound enhancer and insertor. At each insertion step an acoustic measurement was performed. A significant acoustic resonance frequency shift was observed during the insertion process for the different bone models; 250 Hz (35%, second bending mode) to 180 Hz (13%, fourth bending mode) for the artificial bone block models and 120 Hz (11%, eighth bending mode) for the artificial pelvis model. No significant frequency shift was observed during the cadaveric experiment due to a lack of implant fixation in this model. This novel diagnostic method shows the potential of using acoustic signals to monitor the implant seating during insertion. Copyright © 2017 IPEM. Published by Elsevier Ltd. All rights reserved.

[Interventional radiology for bone metastases].

PubMed

Iannessi, Antoine; Garnon, Julien; Cormier, Évelyne; Clarencon, Frédéric; Chiras, Jacques

2013-11-01

The management of bone metastases requires a multidisciplinary staff to include systemic and local treatments like radiotherapy, surgery or interventional radiology (IR). Patients are often fragile. Imaging allows safe guidance to create "mini-invasive" procedures under adequate anesthesia. Patients' selection is important. If the goal is pain relief, cementoplasty provides a very effective bone consolidation and pain control. Simple and low-risk, vertebroplasty is the technique of choice in case of lytic bone metastases with spinal fracture risk or after failure of analgesic radiotherapy. If the medical project is curative, the tumor ablation procedures are realised through thermic or embolic techniques. After 60°C, the heat induces a coagulative necrose. Under -20°C, the cold leads to destroy the tissues. The major advantage of the cryotherapy is the predictibility of the ablation zone due to the well-visualized ice ball on perprocedural images. This technique is much more adapted to spare the nervous structures closed to the metastasis. The development of these new techniques of IR will treat bone metastases earlier, sometimes asymptomatic and thus improves the quality of life in patients with bone metastases.

Personalized models of bones based on radiographic photogrammetry.

PubMed

Berthonnaud, E; Hilmi, R; Dimnet, J

2009-07-01

The radiographic photogrammetry is applied, for locating anatomical landmarks in space, from their two projected images. The goal of this paper is to define a personalized geometric model of bones, based uniquely on photogrammetric reconstructions. The personalized models of bones are obtained from two successive steps: their functional frameworks are first determined experimentally, then, the 3D bone representation results from modeling techniques. Each bone functional framework is issued from direct measurements upon two radiographic images. These images may be obtained using either perpendicular (spine and sacrum) or oblique incidences (pelvis and lower limb). Frameworks link together their functional axes and punctual landmarks. Each global bone volume is decomposed in several elementary components. Each volumic component is represented by simple geometric shapes. Volumic shapes are articulated to the patient's bone structure. The volumic personalization is obtained by best fitting the geometric model projections to their real images, using adjustable articulations. Examples are presented to illustrating the technique of personalization of bone volumes, directly issued from the treatment of only two radiographic images. The chosen techniques for treating data are then discussed. The 3D representation of bones completes, for clinical users, the information brought by radiographic images.

Prostate Cancer Cell–Stromal Cell Cross-Talk via FGFR1 Mediates Antitumor Activity of Dovitinib in Bone Metastases

PubMed Central

Wan, Xinhai; Corn, Paul G.; Yang, Jun; Palanisamy, Nallasivam; Starbuck, Michael W.; Efstathiou, Eleni; Li-Ning Tapia, Elsa M.; Zurita, Amado J.; Aparicio, Ana; Ravoori, Murali K.; Vazquez, Elba S.; Robinson, Dan R.; Wu, Yi-Mi; Cao, Xuhong; Iyer, Matthew K.; McKeehan, Wallace; Kundra, Vikas; Wang, Fen; Troncoso, Patricia; Chinnaiyan, Arul M.; Logothetis, Christopher J.; Navone, Nora M.

2015-01-01

Bone is the most common site of prostate cancer (PCa) progression to a therapy-resistant, lethal phenotype. We found that blockade of fibroblast growth factor receptors (FGFRs) with the receptor tyrosine kinase inhibitor dovitinib has clinical activity in a subset of men with castration-resistant PCa and bone metastases. Our integrated analyses suggest that FGF signaling mediates a positive feedback loop between PCa cells and bone cells and that blockade of FGFR1 in osteoblasts partially mediates the antitumor activity of dovitinib by improving bone quality and by blocking PCa cell–bone cell interaction. These findings account for clinical observations such as reductions in lesion size and intensity on bone scans, lymph node size, and tumor-specific symptoms without proportional declines in prostate-specific antigen concentration. Our findings suggest that targeting FGFR has therapeutic activity in advanced PCa and provide direction for the development of therapies with FGFR inhibitors. PMID:25186177

Prostate cancer cell-stromal cell crosstalk via FGFR1 mediates antitumor activity of dovitinib in bone metastases.

PubMed

Wan, Xinhai; Corn, Paul G; Yang, Jun; Palanisamy, Nallasivam; Starbuck, Michael W; Efstathiou, Eleni; Li Ning Tapia, Elsa M; Tapia, Elsa M Li-Ning; Zurita, Amado J; Aparicio, Ana; Ravoori, Murali K; Vazquez, Elba S; Robinson, Dan R; Wu, Yi-Mi; Cao, Xuhong; Iyer, Matthew K; McKeehan, Wallace; Kundra, Vikas; Wang, Fen; Troncoso, Patricia; Chinnaiyan, Arul M; Logothetis, Christopher J; Navone, Nora M

2014-09-03

Bone is the most common site of prostate cancer (PCa) progression to a therapy-resistant, lethal phenotype. We found that blockade of fibroblast growth factor receptors (FGFRs) with the receptor tyrosine kinase inhibitor dovitinib has clinical activity in a subset of men with castration-resistant PCa and bone metastases. Our integrated analyses suggest that FGF signaling mediates a positive feedback loop between PCa cells and bone cells and that blockade of FGFR1 in osteoblasts partially mediates the antitumor activity of dovitinib by improving bone quality and by blocking PCa cell-bone cell interaction. These findings account for clinical observations such as reductions in lesion size and intensity on bone scans, lymph node size, and tumor-specific symptoms without proportional declines in serum prostate-specific antigen concentration. Our findings suggest that targeting FGFR has therapeutic activity in advanced PCa and provide direction for the development of therapies with FGFR inhibitors. Copyright © 2014, American Association for the Advancement of Science.

Experimental rotator cuff repair. A preliminary study.

PubMed

Gerber, C; Schneeberger, A G; Perren, S M; Nyffeler, R W

1999-09-01

The repair of chronic, massive rotator cuff tears is associated with a high rate of failure. Prospective studies comparing different repair techniques are difficult to design and carry out because of the many factors that influence structural and clinical outcomes. The objective of this study was to develop a suitable animal model for evaluation of the efficacy of different repair techniques for massive rotator cuff tears and to use this model to compare a new repair technique, tested in vitro, with the conventional technique. We compared two techniques of rotator cuff repair in vivo using the left shoulders of forty-seven sheep. With the conventional technique, simple stitches were used and both suture ends were passed transosseously and tied over the greater tuberosity of the humerus. With the other technique, the modified Mason-Allen stitch was used and both suture ends were passed transosseously and tied over a cortical-bone-augmentation device. This device consisted of a poly(L/D-lactide) plate that was fifteen millimeters long, ten millimeters wide, and two millimeters thick. Number-3 braided polyester suture material was used in all of the experiments. In pilot studies (without prevention of full weight-bearing), most repairs failed regardless of the technique that was used. The simple stitch always failed by the suture pulling through the tendon or the bone; the suture material did not break or tear. The modified Mason-Allen stitch failed in only two of seventeen shoulders. In ten shoulders, the suture material failed even though the stitches were intact. Thus, we concluded that the modified Mason-Allen stitch is a more secure method of achieving suture purchase in the tendon. In eight of sixteen shoulders, the nonaugmented double transosseous bone-fixation technique failed by the suture pulling through the bone. The cortical-bone-augmentation technique never failed. In definite studies, prevention of full weight-bearing was achieved by fixation of a ten-centimeter-diameter ball under the hoof of the sheep. This led to healing in eight of ten shoulders repaired with the modified Mason-Allen stitch and cortical-bone augmentation. On histological analysis, both the simple-stitch and the modified Mason-Allen technique caused similar degrees of transient localized tissue damage. Mechanical pullout tests of repairs with the new technique showed a failure strength that was approximately 30 percent of that of an intact infraspinatus tendon at six weeks, 52 percent of that of an intact tendon at three months, and 81 percent of that of an intact tendon at six months. The repair technique with a modified Mason-Allen stitch with number-3 braided polyester suture material and cortical-bone augmentation was superior to the conventional repair technique. Use of the modified Mason-Allen stitch and the cortical-bone-augmentation device transferred the weakest point of the repair to the suture material rather than to the bone or the tendon. Failure to protect the rotator cuff post-operatively was associated with an exceedingly high rate of failure, even if optimum repair technique was used. Different techniques for rotator cuff repair substantially influence the rate of failure. A modified Mason-Allen stitch does not cause tendon necrosis, and use of this stitch with cortical-bone augmentation yields a repair that is biologically well tolerated and stronger in vivo than a repair with the conventional technique. Unprotected repairs, however, have an exceedingly high rate of failure even if optimum repair technique is used. Postoperative protection from tension overload, such as with an abduction splint, may be necessary for successful healing of massive rotator cuff tears.

[Significance of bone mineral density and modern cementing technique for in vitro cement penetration in total shoulder arthroplasty].

PubMed

Pape, G; Raiss, P; Kleinschmidt, K; Schuld, C; Mohr, G; Loew, M; Rickert, M

2010-12-01

Loosening of the glenoid component is one of the major causes of failure in total shoulder arthroplasty. Possible risk factors for loosening of cemented components include an eccentric loading, poor bone quality, inadequate cementing technique and insufficient cement penetration. The application of a modern cementing technique has become an established procedure in total hip arthroplasty. The goal of modern cementing techniques in general is to improve the cement-penetration into the cancellous bone. Modern cementing techniques include the cement vacuum-mixing technique, retrograde filling of the cement under pressurisation and the use of a pulsatile lavage system. The main purpose of this study was to analyse cement penetration into the glenoid bone by using modern cement techniques and to investigate the relationship between the bone mineral density (BMD) and the cement penetration. Furthermore we measured the temperature at the glenoid surface before and after jet-lavage of different patients during total shoulder arthroplasty. It is known that the surrounding temperature of the bone has an effect on the polymerisation of the cement. Data from this experiment provide the temperature setting for the in-vitro study. The glenoid surface temperature was measured in 10 patients with a hand-held non-contact temperature measurement device. The bone mineral density was measured by DEXA. Eight paired cadaver scapulae were allocated (n = 16). Each pair comprised two scapulae from one donor (matched-pair design). Two different glenoid components were used, one with pegs and the other with a keel. The glenoids for the in-vitro study were prepared with the bone compaction technique by the same surgeon in all cases. Pulsatile lavage was used to clean the glenoid of blood and bone fragments. Low viscosity bone cement was applied retrogradely into the glenoid by using a syringe. A constant pressure was applied with a modified force sensor impactor. Micro-computed tomography scans were applied to analyse the cement penetration into the cancellous bone. The mean temperature during the in-vivo arthroplasty of the glenoid was 29.4 °C (27.2-31 °C) before and 26.2 °C (25-27.5 °C) after jet-lavage. The overall peak BMD was 0.59 (range 0.33-0.99) g/cm (2). Mean cement penetration was 107.9 (range 67.6-142.3) mm (2) in the peg group and 128.3 (range 102.6-170.8) mm (2) in the keel group. The thickness of the cement layer varied from 0 to 2.1 mm in the pegged group and from 0 to 2.4 mm in the keeled group. A strong negative correlation between BMD and mean cement penetration was found for the peg group (r (2) = -0.834; p < 0.01) and for the keel group (r (2) = -0.727; p < 0.041). Micro-CT shows an inhomogenous dispersion of the cement into the cancellous bone. Data from the in-vivo temperature measurement indicate that the temperature at the glenohumeral surface under operation differs from the body core temperature and should be considered in further in-vitro studies with human specimens. Bone mineral density is negatively correlated to cement penetration in the glenoid. The application of a modern cementing technique in the glenoid provides sufficient cementing penetration although there is an inhomogenous dispersion of the cement. The findings of this study should be considered in further discussions about cementing technique and cement penetration into the cancellous bone of the glenoid. © Georg Thieme Verlag KG Stuttgart · New York.

Combining Ultrasound Pulse-Echo and Transmission Computed Tomography for Quantitative Imaging the Cortical Shell of Long Bone Replicas

NASA Astrophysics Data System (ADS)

Shortell, Matthew P.; Althomali, Marwan A. M.; Wille, Marie-Luise; Langton, Christian M.

2017-11-01

We demonstrate a simple technique for quantitative ultrasound imaging of the cortical shell of long bone replicas. Traditional ultrasound computed tomography instruments use the transmitted or reflected waves for separate reconstructions but suffer from strong refraction artefacts in highly heterogenous samples such as bones in soft tissue. The technique described here simplifies the long bone to a two-component composite and uses both the transmitted and reflected waves for reconstructions, allowing the speed of sound and thickness of the cortical shell to be calculated accurately. The technique is simple to implement, computationally inexpensive and sample positioning errors are minimal.

Computational modelling of the mechanics of trabecular bone and marrow using fluid structure interaction techniques.

PubMed

Birmingham, E; Grogan, J A; Niebur, G L; McNamara, L M; McHugh, P E

2013-04-01

Bone marrow found within the porous structure of trabecular bone provides a specialized environment for numerous cell types, including mesenchymal stem cells (MSCs). Studies have sought to characterize the mechanical environment imposed on MSCs, however, a particular challenge is that marrow displays the characteristics of a fluid, while surrounded by bone that is subject to deformation, and previous experimental and computational studies have been unable to fully capture the resulting complex mechanical environment. The objective of this study was to develop a fluid structure interaction (FSI) model of trabecular bone and marrow to predict the mechanical environment of MSCs in vivo and to examine how this environment changes during osteoporosis. An idealized repeating unit was used to compare FSI techniques to a computational fluid dynamics only approach. These techniques were used to determine the effect of lower bone mass and different marrow viscosities, representative of osteoporosis, on the shear stress generated within bone marrow. Results report that shear stresses generated within bone marrow under physiological loading conditions are within the range known to stimulate a mechanobiological response in MSCs in vitro. Additionally, lower bone mass leads to an increase in the shear stress generated within the marrow, while a decrease in bone marrow viscosity reduces this generated shear stress.

X-ray (image)

MedlinePlus

X-rays are a form of electromagnetic radiation, just like visible light. Structures that are dense (such as bone) will block most of the x-ray particles, and will appear white. Metal and contrast media ( ...

Multiple Small Diameter Drillings Increase Femoral Neck Stability Compared with Single Large Diameter Femoral Head Core Decompression Technique for Avascular Necrosis of the Femoral Head.

PubMed

Brown, Philip J; Mannava, Sandeep; Seyler, Thorsten M; Plate, Johannes F; Van Sikes, Charles; Stitzel, Joel D; Lang, Jason E

2016-10-26

Femoral head core decompression is an efficacious joint-preserving procedure for treatment of early stage avascular necrosis. However, postoperative fractures have been described which may be related to the decompression technique used. Femoral head decompressions were performed on 12 matched human cadaveric femora comparing large 8mm single bore versus multiple 3mm small drilling techniques. Ultimate failure strength of the femora was tested using a servo-hydraulic material testing system. Ultimate load to failure was compared between the different decompression techniques using two paired ANCOVA linear regression models. Prior to biomechanical testing and after the intervention, volumetric bone mineral density was determined using quantitative computed tomography to account for variation between cadaveric samples and to assess the amount of bone disruption by the core decompression. Core decompression, using the small diameter bore and multiple drilling technique, withstood significantly greater load prior to failure compared with the single large bore technique after adjustment for bone mineral density (p< 0.05). The 8mm single bore technique removed a significantly larger volume of bone compared to the 3mm multiple drilling technique (p< 0.001). However, total fracture energy was similar between the two core decompression techniques. When considering core decompression for the treatment of early stage avascular necrosis, the multiple small bore technique removed less bone volume, thereby potentially leading to higher load to failure.

Unicameral bone cysts: general characteristics and management controversies.

PubMed

Pretell-Mazzini, Juan; Murphy, Robert Francis; Kushare, Indranil; Dormans, John P

2014-05-01

Unicameral bone cysts are benign bone lesions that are often asymptomatic and commonly develop in the proximal humerus and femur of skeletally immature patients. The etiology of these lesions remains unknown. Most patients present with a pathologic fracture, but these cysts can be discovered incidentally, as well. Radiographically, a unicameral bone cyst appears as a radiolucent lesion with cortical thinning and is centrally located within the metaphysis. Although diagnosis is frequently straightforward, management remains controversial. Because the results of various management methods are heterogeneous, no single method has emerged as the standard of care. New minimally invasive techniques involve cyst decompression with bone grafting and instrumentation. These techniques have yielded promising results, with low rates of complications and recurrence reported; however, prospective clinical trials are needed to compare these techniques with current evidence-based treatments.

Bone preserving techniques for explanting the well-fixed cemented acetabular component.

PubMed

Stevens, Jarrad; Macpherson, Gavin; Howie, Colin

2018-06-01

Removal of a well-fixed, cemented acetabular component at the time of revision hip surgery can be complex. It is essential to remove the implant and cement mantle in a timely fashion while preserving bone stock and osseous integrity. The biomechanical properties of polymethylmethacrylate cement and polyethylene can be utilised to aid with the removal of well cemented implants which are often harder than the surrounding bone. While removal of loose components may be relatively straightforward, the challenge for the revision arthroplasty surgeon often involves the removal of well-fixed implants. Here, we present three established techniques for the removal of a well-fixed cemented acetabular component and one novel modification we have described before. We collate and review four techniques for removing well-fixed cemented acetabular implants that utilise the different biomechanical properties of bone cement and polyethylene. These techniques are illustrated with a photographic series utilising saw bones. A step-by-step approach to our new technique is shown in photographs, both in the clinical setting and with a "Sawbone". This is accompanied by a clinical video that details the surgical technique in its entirety. These techniques utilise different biomechanical principles to extract the acetabular component. Each technique has advantages and disadvantages. Our new technique is a simplification of a previously published extraction manoeuvre that utilises tensile force between cement and the implant to remove the polyethylene cup. This is a safe and reproducible technique in patients with a well-fixed cemented acetabular implant. Understanding the biomechanical properties of polymethylmethacrylate bone cement and polyethylene can aid in the safe removal of a well-fixed cemented acetabular component in revision hip surgery. The optimal technique for removal of a cemented acetabular component varies depending on a number of patient and implant factors. This summary of the available techniques will be of interest to revision arthroplasty surgeons.

Variations in Urine Calcium Isotope: Composition Reflect Changes in Bone Mineral Balance in Humans

NASA Technical Reports Server (NTRS)

Skulan, Joseph; Anbar, Ariel; Bullen, Thomas; Puzas, J. Edward; Shackelford, Linda; Smith, Scott M.

2004-01-01

Changes in bone mineral balance cause rapid and systematic changes in the calcium isotope composition of human urine. Urine from subjects in a 17 week bed rest study was analyzed for calcium isotopic composition. Comparison of isotopic data with measurements of bone mineral density and metabolic markers of bone metabolism indicates the calcium isotope composition of urine reflects changes in bone mineral balance. Urine calcium isotope composition probably is affected by both bone metabolism and renal processes. Calcium isotope. analysis of urine and other tissues may provide information on bone mineral balance that is in important respects better than that available from other techniques, and illustrates the usefulness of applying geochemical techniques to biomedical problems.

Bone biosensors: knowing the present and predicting the future

NASA Astrophysics Data System (ADS)

Khashayar, Patricia; Amoabediny, Ghassem; Larijani, Bagher; Vanfleteren, Jan

2016-02-01

Bone is an active organ with the capacity of continuous remodeling throughout adult life. In view of the fact that the current gold standard to assess bone remodeling, bone mineral density, suffers from certain limitations, newer techniques are being developed. Currently enzyme-linked immunosorbent assay is commonly used to assess bone turnover markers; the technique, however, is expensive, time consuming and needs trained personnel. Thus, there is a growing demand to fabricate different types of biosensors to provide low cost miniaturized platforms to assess the bone remodeling process more accurately. This review focuses on the latest advancements in the field of bone biosensing technologies. Its results might help provide possible solutions for translation of this technology for point-of-care diagnostic applications.

Ontogeny, morphology and mechanics of the tessellated skeleton of cartilaginous fishes

NASA Astrophysics Data System (ADS)

Dean, Mason N.

2009-12-01

The members of the successful and diverse lineage of elasmobranch fishes (sharks, rays and relatives) possess endoskeletons fashioned entirely of cartilage. This is counterintuitive because cartilage, unlike bone, lacks a major blood supply and has limited capacity for repair; yet these fishes exhibit particularly dynamic lifestyles and high levels of performance. The functionality of this skeletal tissue is likely due to its mineralization: in most skeletal elements, the soft cartilage core is tiled (tessellated) with an outer rind of abutting hydroxyapatite blocks called tesserae, joined together by intertesseral fibers and overlain by the fibrous perichondrium. This basic composite arrangement of tissues has been appreciated for over a century, but available techniques have limited the ability to examine elasmobranch cartilage adequately---without artifacts, in 3-dimensions and at high resolution---so that its development, mechanics and phylogeny might be contextualized among vertebrate skeletal tissues. I summarize the history, nomenclature and challenges relating to study of tessellated cartilage (Chapter 1) and present a low temperature microscopy technique to facilitate visualization of all tissue components in situ (Chapter 2). I use that technique in tandem with synchrotron microtomography to examine the ultrastructure of tesserae (Chapter 3) and the development of tessellated cartilage across ontogeny (Chapter 4). Finally, I examine the ways in which selection acts on skeletal morphology by examining cranial anatomy across 40 species of batoid fishes (rays and relatives) in the contexts of ecology and phylogeny (Chapter 5). There are some similarities between mineralizing bone and elasmobranch cartilage (e.g. the flattening of peripheral cells in the unmineralized phase, decreases in cellular density with mineralization, the presence of canaliculi connecting entombed cells). However, the ability for tessellated cartilage to grow (through enlargement of tesserae during ontogeny) and meet diverse functional demands (e.g. the range of diets exhibited by batoid fishes), albeit without remodeling, characterizes it as a functional alternative to endochondral bone, rather than simply a retention of an embryonic tissue. Material testing of tessellated cartilage may clarify the selective pressures that led to the nearly simultaneous evolutions of these two tissues and may also demonstrate unappreciated and novel structural designs to engineers.

Teaching alternatives to the standard inferior alveolar nerve block in dental education: outcomes in clinical practice.

PubMed

Johnson, Thomas M; Badovinac, Rachel; Shaefer, Jeffry

2007-09-01

Surveys were sent to Harvard School of Dental Medicine students and graduates from the classes of 2000 through 2006 to determine their current primary means of achieving mandibular anesthesia. Orthodontists and orthodontic residents were excluded. All subjects received clinical training in the conventional inferior alveolar nerve block and two alternative techniques (the Akinosi mandibular block and the Gow-Gates mandibular block) during their predoctoral dental education. This study tests the hypothesis that students and graduates who received training in the conventional inferior alveolar nerve block, the Akinosi mandibular block, and the Gow-Gates mandibular block will report more frequent current utilization of alternatives to the conventional inferior alveolar nerve block than clinicians trained in the conventional technique only. At the 95 percent confidence level, we estimated that between 3.7 percent and 16.1 percent (mean=8.5 percent) of clinicians trained in using the Gow-Gates technique use this injection technique primarily, and between 35.4 percent and 56.3 percent (mean=47.5 percent) of those trained in the Gow-Gates method never use this technique. At the same confidence level, between 0.0 percent and 3.8 percent (mean=0.0 percent) of clinicians trained in using the Akinosi technique use this injection clinical technique primarily, and between 62.2 percent and 81.1 percent (mean=72.3 percent) of those trained in the Akinosi method never use this technique. No control group that was completely untrained in the Gow-Gates or Akinosi techniques was available for comparison. However, we presume that zero percent of clinicians who have not been trained in a given technique will use the technique in clinical practice. The confidence interval for the Gow-Gates method excludes this value, while the confidence interval for the Akinosi technique includes zero percent. We conclude that, in the study population, formal clinical training in the Gow-Gates and Akinosi injection techniques lead to a small but significant increase in current primary utilization of the Gow-Gates technique. No significant increase in current primary utilization of the Akinosi technique was found.

[Strontium and calcium metabolism. Interaction of strontium and vitamin D].

PubMed

Rousselet, F; El Solh, N; Maurat, J P; Gruson, M; Girard, M L

1975-01-01

Oral administration of strontium to calcium wellfed rats blocks the intestinal absorption of calcium. When high doses of vitamine D are given over long period, the inhibition of calcium intestinal absorption disapears. Under these conditions the absorption of strontium is increased. It is suggested that there is only one absorption mechanism for these two cations. An overdose of the vitamine D increases the renal elimination of strontium but under these conditions the plasma concentration of the strontium is unchanged. Vitamine D brings about the some action on the bone fixation of the strontium as it does on the bone fixation of calcium. The bone fixation is increased with low dosages. The bone fixation is decreased with high dosages.

International conference on bone mineral measurement, October 12--13, 1973, Chicago, Illinois

DOE Office of Scientific and Technical Information (OSTI.GOV)

None

1973-12-31

From international conference on bone mineral measurement; Chicago, Illinois, USA (12 Oct 1973). Abstracts of papers presented at the international conference on bone mineral measurement are presented. The papers were grouped into two sessions: a physical session including papers on measuring techniques, errors, interpretation and correlations, dual photon techniques, and data handling and exchange; a biomedical session including papers on bone disease, osteoporosis, normative data, non-disease influences, renal, and activity and inactivity. (ERB)

Fabrication of hydroxyapatite block from gypsum block based on (NH4)2HPO4 treatment.

PubMed

Suzuki, Yumiko; Matsuya, Shigeki; Udoh, Koh-ichi; Nakagawa, Masaharu; Tsukiyama, Yoshihiro; Koyano, Kiyoshi; Ishikawa, Kunio

2005-12-01

The aim of this study was to evaluate the feasibility of fabricating low-crystalline, porous apatite block using set gypsum as a precursor based on the fact that apatite is thermodynamically more stable than gypsum. When the set gypsum was immersed in 1 mol/L diammonium hydrogen phosphate aqueous solution at 100 degrees C, it transformed to low-crystalline porous apatite retaining its original shape. The transformation reaction caused a release of sulfate ions due to an ion exchange with phosphate ions, thus leading to a decrease in the pH of the solution. Then, due to decreased pH, dicalcium phosphate anhydrous--which has similar thermodynamic stability at lower pH--was also produced as a by-product. Apatite formed in the present method was low-crystalline, porous B-type carbonate apatite that contained approximately 0.5 wt% CO3, even though no carbonate sources--except carbon dioxide from air--were added to the reaction system. We concluded therefore that this is a useful bone filler fabrication method since B-type carbonate apatite is the biological apatite contained in bone.

Technique for bone volume measurement from human femur head samples by classification of micro-CT image histograms.

PubMed

Marinozzi, Franco; Bini, Fabiano; Marinozzi, Andrea; Zuppante, Francesca; De Paolis, Annalisa; Pecci, Raffaella; Bedini, Rossella

2013-01-01

Micro-CT analysis is a powerful technique for a non-invasive evaluation of the morphometric parameters of trabecular bone samples. This elaboration requires a previous binarization of the images. A problem which arises from the binarization process is the partial volume artifact. Voxels at the external surface of the sample can contain both bone and air so thresholding operates an incorrect estimation of volume occupied by the two materials. The aim of this study is the extraction of bone volumetric information directly from the image histograms, by fitting them with a suitable set of functions. Nineteen trabecular bone samples were extracted from femoral heads of eight patients subject to a hip arthroplasty surgery. Trabecular bone samples were acquired using micro-CT Scanner. Hystograms of the acquired images were computed and fitted by Gaussian-like functions accounting for: a) gray levels produced by the bone x-ray absorption, b) the portions of the image occupied by air and c) voxels that contain a mixture of bone and air. This latter contribution can be considered such as an estimation of the partial volume effect. The comparison of the proposed technique to the bone volumes measured by a reference instrument such as by a helium pycnometer show the method as a good way for an accurate bone volume calculation of trabecular bone samples.

TU-CD-BRA-11: Application of Bone Suppression Technique to Inspiratory/expiratory Chest Radiography

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tanaka, R; Sanada, S; Sakuta, K

Purpose: The bone suppression technique based on advanced image processing can suppress the conspicuity of bones on chest radiographs, creating soft tissue images normally obtained by the dual-energy subtraction technique. This study was performed to investigate the usefulness of bone suppression technique in quantitative analysis of pulmonary function in inspiratory/expiratory chest radiography. Methods: Commercial bone suppression image processing software (ClearRead; Riverain Technologies) was applied to paired inspiratory/expiratory chest radiographs of 107 patients (normal, 33; abnormal, 74) to create corresponding bone suppression images. The abnormal subjects had been diagnosed with pulmonary diseases, such as pneumothorax, pneumonia, emphysema, asthma, and lung cancer.more » After recognition of the lung area, the vectors of respiratory displacement were measured in all local lung areas using a cross-correlation technique. The measured displacement in each area was visualized as displacement color maps. The distribution pattern of respiratory displacement was assessed by comparison with the findings of lung scintigraphy. Results: Respiratory displacement of pulmonary markings (soft tissues) was able to be quantified separately from the rib movements on bone suppression images. The resulting displacement map showed a left-right symmetric distribution increasing from the lung apex to the bottom region of the lung in many cases. However, patients with ventilatory impairments showed a nonuniform distribution caused by decreased displacement of pulmonary markings, which were confirmed to correspond to area with ventilatory impairments found on the lung scintigrams. Conclusion: The bone suppression technique was useful for quantitative analysis of respiratory displacement of pulmonary markings without any interruption of the rib shadows. Abnormal areas could be detected as decreased displacement of pulmonary markings. Inspiratory/expiratory chest radiography combined with the bone suppression technique has potential for predicting local lung function on the basis of dynamic analysis of pulmonary markings. This work was partially supported by Nakatani Foundation, Grant-in-aid for Scientific Research (C) of Ministry of Education, Culture, Sports, Science and Technology, JAPAN (Grant number : 24601007), and Nakatani Foundation, Mitsubishi Foundation, and the he Mitani Foundation for Research and Development. Yasushi Kishitani is a staff of TOYO corporation.« less

The Role of Hedgehog Signaling in Tumor Induced Bone Disease

PubMed Central

Cannonier, Shellese A.; Sterling, Julie A.

2015-01-01

Despite significant progress in cancer treatments, tumor induced bone disease continues to cause significant morbidities. While tumors show distinct mutations and clinical characteristics, they behave similarly once they establish in bone. Tumors can metastasize to bone from distant sites (breast, prostate, lung), directly invade into bone (head and neck) or originate from the bone (melanoma, chondrosarcoma) where they cause pain, fractures, hypercalcemia, and ultimately, poor prognoses and outcomes. Tumors in bone secrete factors (interleukins and parathyroid hormone-related protein) that induce RANKL expression from osteoblasts, causing an increase in osteoclast mediated bone resorption. While the mechanisms involved varies slightly between tumor types, many tumors display an increase in Hedgehog signaling components that lead to increased tumor growth, therapy failure, and metastasis. The work of multiple laboratories has detailed Hh signaling in several tumor types and revealed that tumor establishment in bone can be controlled by both canonical and non-canonical Hh signaling in a cell type specific manner. This review will explore the role of Hh signaling in the modulation of tumor induced bone disease, and will shed insight into possible therapeutic interventions for blocking Hh signaling in these tumors. PMID:26343726

Adapted preparation technique for screw-type implants: explorative in vitro pilot study in a porcine bone model.

PubMed

Beer, Andreas; Gahleitner, André; Holm, Anders; Birkfellner, Wolfgang; Homolka, Peter

2007-02-01

The aim of this study was to quantify the effect of adapted preparation on the insertion torque of self-tapping implants in cancellous bone. In adapted preparation, bone condensation - and thus, insertion torque - is controlled by changing the diameter of the drilling. After preparation of cancellous porcine vertebral bone with drills of 2.85, 3, 3.15 or 3.35 mm final diameters, Brånemark sytem Mk III implants (3.75 x 11.5 mm) were inserted in 141 sites. During implantation, the insertion torque was recorded. Prior to implant insertion, bone mineralization (bone mineral density (BMD)) was measured with dental quantative computed tomography. The BMD values measured at the implant position were correlated with insertion torque for varying bone condensation. Based on the average torque recorded during implant insertion into the pre-drilled canals with a diameter of 3 mm, torque increased by approximately 17% on reducing the diameter of the drill by 5% (to 2.85 mm). On increasing the diameter of the osteotomy to 3.15 mm (5%) or 3.35 mm (12%), torque values decreased by approximately 21% and 50%, respectively. The results demonstrate a correlation between primary stability (average insertion torque) and the diameter of the implant bed on using a screw-shaped implant. Thus, using an individualized bone mineralization-dependent drilling technique, optimized torque values could be achieved in all tested bone qualities with BMDs ranging from 330 to 500 mg/cm(3). The results indicate that using a bone-dependent drilling technique, higher torque values can also be achieved in poor bone using an individualized drilling resulting in higher bone condensation. As immediate function is dependent on primary stability (high insertion torque), this indicates that primary stability can be increased using a modified drilling technique in lesser mineralized bone.

The Comparative Efficiency of Four Types of Endodontic Files and Reamers.

DTIC Science & Technology

1981-12-29

an reveree aide Ii neceeary end Identify by block number) Comparative efficiency of endodontic files; endodontic instrumentation ; instrumentation ...sections of bovine bone. Each canal was instrumented to a size 80 using four types of endodontic instruments : Hedstrom S files; K-files; reamers; and the...bovine bone. Each canal was instrumented to a size 80 using four types of endodontic instruments : Hedstrom files; K-files; reamers; and the new Unifile

A Coaxial Dual-element Focused Ultrasound Probe for Guidance of Epidural Catheterization: An Experimental Study.

PubMed

Dong, Guo-Chung; Chiu, Li-Chen; Ting, Chien-Kun; Hsu, Jia-Ruei; Huang, Chih-Chung; Chang, Yin; Chen, Gin-Shin

2017-09-01

Ultrasound guidance for epidural block has improved clinical blind-trial problems but the design of present ultrasonic probes poses operating difficulty of ultrasound-guided catheterization, increasing the failure rate. The purpose of this study was to develop a novel ultrasonic probe to avoid needle contact with vertebral bone during epidural catheterization. The probe has a central circular passage for needle insertion. Two focused annular transducers are deployed around the passage for on-axis guidance. A 17-gauge insulated Tuohy needle containing the self-developed fiber-optic-modified stylet was inserted into the back of the anesthetized pig, in the lumbar region under the guidance of our ultrasonic probe. The inner transducer of the probe detected the shallow echo signals of the peak-peak amplitude of 2.8 V over L3 at the depth of 2.4 cm, and the amplitude was decreased to 0.8 V directly over the L3 to L4 interspace. The outer transducer could detect the echoes from the deeper bone at the depth of 4.5 cm, which did not appear for the inner transducer. The operator tilted the probe slightly in left-right and cranial-caudal directions until the echoes at the depth of 4.5 cm disappeared, and the epidural needle was inserted through the central passage of the probe. The needle was advanced and stopped when the epidural space was identified by optical technique. The needle passed without bone contact. Designs of the hollow probe for needle pass and dual transducers with different focal lengths for detection of shallow and deep vertebrae may benefit operation, bone/nonbone identification, and cost.

Cold-spray coating of hydroxyapatite on a three-dimensional polyetheretherketone implant and its biocompatibility evaluated by in vitro and in vivo minipig model.

PubMed

Lee, Jae Hyup; Jang, Hae Lin; Lee, Kyung Mee; Baek, Hae-Ri; Jin, Kyoungsuk; Noh, Jun Hong

2017-04-01

PEEK is a bioinert material that does not chemically bind to native bone tissue and thus formation of natural bone-like hydroxyapatite (HA) coating layer on PEEK has been an important challenge to improve biocompatibility and to preserve mechanical property of PEEK. Among various coating techniques, cold-spray coating method is suitable to form stable HA coating layer on PEEK while maintaining their chemical properties, because it can be conducted in relatively low-temperature range. Therefore, in this research, we used cold-spray coating method to form a thick layer of HA on the topographically complex PEEK substrates with periodic ridges on the surface and implanted in iliac bone defects of minipigs which is known to be similar with human body system. In addition, PEEK cage for clinical usage was coated with HA and inserted in the lumbar intervertebral disc space of minipig. We observed higher ALP activity, calcium production, and BSP production of human bone marrow mesenchymal stem cells on the HA-coated PEEK implants than the bare PEEK group in in vitro test. In addition, two-dimensional histological analysis and three-dimensional micro CT analysis demonstrated that implantation of complex shape of HA-PEEK hybrid implant in in vivo minipig model resulted sufficient biocompatibility and osseointegration for further clinical applications. Notably, due to the enhanced stability of PEEK cage induced from HA coating layer, osseointegration rate of the small HA blocks loaded inside the PEEK cage was also significantly improved which indicates overall increased fusion rate and adherence of the HA-coated PEEK cage. © 2015 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 105B: 647-657, 2017. © 2015 Wiley Periodicals, Inc.

Imaging the Material Properties of Bone Specimens using Reflection-Based Infrared Microspectroscopy

PubMed Central

Acerbo, Alvin S.; Carr, G. Lawrence; Judex, Stefan; Miller, Lisa M.

2012-01-01

Fourier Transform InfraRed Microspectroscopy (FTIRM) is a widely used method for mapping the material properties of bone and other mineralized tissues, including mineralization, crystallinity, carbonate substitution, and collagen cross-linking. This technique is traditionally performed in a transmission-based geometry, which requires the preparation of plastic-embedded thin sections, limiting its functionality. Here, we theoretically and empirically demonstrate the development of reflection-based FTIRM as an alternative to the widely adopted transmission-based FTIRM, which reduces specimen preparation time and broadens the range of specimens that can be imaged. In this study, mature mouse femurs were plastic-embedded and longitudinal sections were cut at a thickness of 4 μm for transmission-based FTIRM measurements. The remaining bone blocks were polished for specular reflectance-based FTIRM measurements on regions immediately adjacent to the transmission sections. Kramers-Kronig analysis of the reflectance data yielded the dielectric response from which the absorption coefficients were directly determined. The reflectance-derived absorbance was validated empirically using the transmission spectra from the thin sections. The spectral assignments for mineralization, carbonate substitution, and collagen cross-linking were indistinguishable in transmission and reflection geometries, while the stoichiometric/non-stoichiometric apatite crystallinity parameter shifted from 1032 / 1021 cm−1 in transmission-based to 1035 / 1025 cm−1 in reflection-based data. This theoretical demonstration and empirical validation of reflection-based FTIRM eliminates the need for thin sections of bone and more readily facilitates direct correlations with other methods such nanoindentation and quantitative backscatter electron imaging (qBSE) from the same specimen. It provides a unique framework for correlating bone’s material and mechanical properties. PMID:22455306

[Surgical Techniques for Patella Replacement in Cases of Deficient Bone Stock in Revision TKA].

PubMed

Ritschl, P; Machacek, F; Strehn, L; Kloiber, J

2015-06-01

The patella replacement in revision surgery is a challenge especially in cases of unsufficient bone stock. Depending on the extent of the bone defect, the following videos demonstrate different approaches: Video 1: bone sparing removal of the patella implant: onlay-type patella implants. Video 2: complete cortical bone rim of the patella, residual thickness between 6 to 10 mm: biconvex patella implant. Video 3 and 4: small defects of the cortical bone rim of the patella, residual thickness 1 to 5 mm (patella shell): gull-wing osteotomy, patella bone grafting techniques. Video 5: partial necrosis/defect of the patella shell with incomplete cortical bone rim: porous tantalum patella prosthesis. On account of the various surgical options for different bone defects of the patella, patellectomy and pure patelloplasty should be avoided to prevent functional shortcomings. Georg Thieme Verlag KG Stuttgart · New York.

A Modified Suture Bridge Technique for Application With Bone Anchors in Foot and Ankle Surgery.

PubMed

Walters, Jeremy; Correa, Christopher; Moss, Mark

2015-01-01

We present a suture bridge technique for reattachment of tendon or ligament to bone for use in foot and ankle surgery. The method is a simple, strong, and reproducible technique that could decrease the risk of irritation of the overlying cutaneous barrier and minimizes the likelihood of tendon strangulation when combined with soft tissue bone anchors. The present report serves as a guide to the use of this suture technique for reattachment of the Achilles tendon. Copyright © 2015 American College of Foot and Ankle Surgeons. Published by Elsevier Inc. All rights reserved.

Osteoprotegerin inhibits bone resorption and prevents tumor development in a xenogenic model of Ewing's sarcoma by inhibiting RANKL

PubMed Central

Picarda, Gaëlle; Matous, Etienne; Amiaud, Jérôme; Charrier, Céline; Lamoureux, François; Heymann, Marie-Françoise; Tirode, Franck; Pitard, Bruno; Trichet, Valérie; Heymann, Dominique; Redini, Françoise

2013-01-01

Ewing's sarcoma (ES) associated with high osyeolytic lesions typically arises in the bones of children and adolescents. The development of multi-disciplinary therapy has increased current long-term survival rates to greater than 50% but only 20% for high risk group patients (relapse, metastases, etc.). Among new therapeutic approaches, osteoprotegerin (OPG), an anti-bone resorption molecule may represent a promising candidate to inhibit RANKL-mediated osteolytic component of ES and consequently to limit the tumor development. Xenogenic orthotopic models of Ewing's sarcoma were induced by intra-osseous injection of human TC-71 ES cells. OPG was administered in vivo by non-viral gene transfer using an amphiphilic non ionic block copolymer. ES bearing mice were assigned to controls (no treatment, synthetic vector alone or F68/empty pcDNA3.1 plasmid) and hOPG treated groups. A substantial but not significant inhibition of tumor development was observed in the hOPG group as compared to control groups. Marked bone lesions were revealed by micro-computed tomography analyses in control groups whereas a normal bone micro-architecture was preserved in the hOPG treated group. RANKL over-expressed in ES animal model was expressed by tumor cells rather than by host cells. However, TRAIL present in the tumor microenvironment may interfere with OPG effect on tumor development and bone remodeling via RANKL inhibition. In conclusion, the use of a xenogenic model of Ewing's sarcoma allowed discriminating between the tumor and host cells responsible for the elevation of RANKL production observed in this tumor and demonstrated the relevance of blocking RANKL by OPG as a promising therapy in ES. PMID:26909278

Morphological and ultrastructural comparative analysis of bone tissue after Er:YAG laser and surgical drill osteotomy.

PubMed

Panduric, Dragana Gabric; Juric, Ivona Bago; Music, Svetozar; Molčanov, Krešimir; Sušic, Mato; Anic, Ivica

2014-07-01

The purpose of this study was to analyze morphological, chemical, and crystallographic changes of bone tissue after osteotomy performed with an erbium:yttrium-aluminium-garnet (Er:YAG) laser and a low speed pilot drill. Bone blocks were prepared from porcine ribs, and on each block, two tunnel preparations were performed using the Er:YAG laser (pulse energy: 1000 mJ, pulse duration: 300 μs, pulse repetition rate: 20 Hz) or the low-speed surgical pilot drill. The morphological changes of the cortical and the spongious surface of the tunnel preparations were analyzed under the field emission scanning electron microscopy (FE-SEM) at low and high resolution. The distribution and the level of chemical elements in the treated surfaces were evaluated by qualitative and semiquantitative energy dispersive x-ray analysis (SEM-EDX). Diffraction x-ray analysis was used to detect any differences and thermally induced modifications of hydroxyapatite crystals. FE-SEM revealed sharp edges of the Er:YAG preparations, with empty intertrabecular spaces and no signs of carbonization. In the drill group, the surface of the preparations was smooth, completely covered with smear layer and microcracks, and with hairy-like irregularities on the edges. SEM-EDX analysis did not reveal any differences in the number of specific chemical elements between the laser and the drill group. There were no thermally induced modifications of hydroxyapatite crystal structure in the bone tissue in either group. The Er:YAG laser ablation did not cause any chemical or crystallographic changes of the bone tissue. Compared with the drill, Er:YAG laser created well-defined edges of the preparations, and cortical bone had no smear layer.

Reversible conduction block in peripheral nerve using electrical waveforms.

PubMed

Bhadra, Niloy; Vrabec, Tina L; Bhadra, Narendra; Kilgore, Kevin L

2018-01-01

Electrical nerve block uses electrical waveforms to block action potential propagation. Two key features that distinguish electrical nerve block from other nonelectrical means of nerve block: block occurs instantly, typically within 1 s; and block is fully and rapidly reversible (within seconds). Approaches for achieving electrical nerve block are reviewed, including kilohertz frequency alternating current and charge-balanced polarizing current. We conclude with a discussion of the future directions of electrical nerve block. Electrical nerve block is an emerging technique that has many significant advantages over other methods of nerve block. This field is still in its infancy, but a significant expansion in the clinical application of this technique is expected in the coming years.

Alveolar bone repair with strontium- containing nanostructured carbonated hydroxyapatite.

PubMed

Carmo, André Boziki Xavier do; Sartoretto, Suelen Cristina; Alves, Adriana Terezinha Neves Novellino; Granjeiro, José Mauro; Miguel, Fúlvio Borges; Calasans-Maia, Jose; Calasans-Maia, Monica Diuana

2018-01-18

This study aimed to evaluate bone repair in rat dental sockets after implanting nanostructured carbonated hydroxyapatite/sodium alginate (CHA) and nanostructured carbonated hydroxyapatite/sodium alginate containing 5% strontium microspheres (SrCHA) as bone substitute materials. Twenty male Wistar rats were randomly divided into two experimental groups: CHA and SrCHA (n=5/period/group). After one and 6 weeks of extraction of the right maxillary central incisor and biomaterial implantation, 5 μm bone blocks were obtained for histomorphometric evaluation. The parameters evaluated were remaining biomaterial, loose connective tissue and newly formed bone in a standard area. Statistical analysis was performed by Mann-Withney and and Wilcoxon tests at 95% level of significance. The histomorphometric results showed that the microspheres showed similar fragmentation and bio-absorbation (p>0.05). We observed the formation of new bones in both groups during the same experimental periods; however, the new bone formation differed significantly between the weeks 1 and 6 (p=0.0039) in both groups. The CHA and SrCHA biomaterials were biocompatible, osteoconductive and bioabsorbable, indicating their great potential for clinical use as bone substitutes.

Osteopenia and osteoporosis in people living with HIV: multiprofessional approach

PubMed Central

Lima, Ana Lucia Lei Munhoz; de Oliveira, Priscila Rosalba D; Plapler, Perola Grimberg; Marcolino, Flora Maria D Andrea; de Souza Meirelles, Eduardo; Sugawara, André; Gobbi, Riccardo Gomes; dos Santos, Alexandre Leme Godoy; Camanho, Gilberto Luis

2011-01-01

Increasing bone mineralization abnormalities observed among people living with HIV (PLWHIV) result from various factors relating to the host, the virus, and the antiretrovirals used. Today, HIV infection is considered to be a risk factor for bone mineralization disorders. The test most recommended for diagnosing osteoporosis is measurement of bone mineral density by means of dual energy X-ray absorptiometry at two sites. Osteoporosis treatment has the aims of bone mass improvement and fracture control. A combination of calcium and vitamin D supplementation may reduce the risk of fractures. Antiresorptive drugs act by blocking osteoclastic activity and reducing bone remodeling. On the other hand, bone-forming drugs stimulate osteoblastogenesis, thereby stimulating the formation of bone matrix. Mixed-action medications are those that are capable of both stimulating bone formation and inhibiting reabsorption. Antiresorptive drugs form the group of medications with the greatest quantity of scientific evidence confirming their efficacy in osteoporosis treatment. Physical activity is a health promotion strategy for the general population, but only preliminary data on its real value and benefit among PLWHIV are available, especially in relation to osteoporosis. PMID:22267944

Osteopenia and osteoporosis in people living with HIV: multiprofessional approach.

PubMed

Lima, Ana Lucia Lei Munhoz; de Oliveira, Priscila Rosalba D; Plapler, Perola Grimberg; Marcolino, Flora Maria D Andrea; de Souza Meirelles, Eduardo; Sugawara, André; Gobbi, Riccardo Gomes; Dos Santos, Alexandre Leme Godoy; Camanho, Gilberto Luis

2011-01-01

Increasing bone mineralization abnormalities observed among people living with HIV (PLWHIV) result from various factors relating to the host, the virus, and the antiretrovirals used. Today, HIV infection is considered to be a risk factor for bone mineralization disorders. The test most recommended for diagnosing osteoporosis is measurement of bone mineral density by means of dual energy X-ray absorptiometry at two sites. Osteoporosis treatment has the aims of bone mass improvement and fracture control. A combination of calcium and vitamin D supplementation may reduce the risk of fractures. Antiresorptive drugs act by blocking osteoclastic activity and reducing bone remodeling. On the other hand, bone-forming drugs stimulate osteoblastogenesis, thereby stimulating the formation of bone matrix. Mixed-action medications are those that are capable of both stimulating bone formation and inhibiting reabsorption. Antiresorptive drugs form the group of medications with the greatest quantity of scientific evidence confirming their efficacy in osteoporosis treatment. Physical activity is a health promotion strategy for the general population, but only preliminary data on its real value and benefit among PLWHIV are available, especially in relation to osteoporosis.

Inhibition of substance P signaling aggravates the bone loss in ovariectomy-induced osteoporosis.

PubMed

Zheng, Xin-Feng; Zhao, En-Dian; He, Ji-Ye; Zhang, Yue-Hui; Jiang, Sheng-Dan; Jiang, Lei-Sheng

2016-11-01

Substance P signaling regulates the functions of both osteoblast and osteoclast. Available reports on the effects of substance P on bone mass are contradictory. The objective of this study was to determine the change of substance P expression in the osteoporotic bone of OVX mice. The effects of substance P signaling blockade by using its specific receptor antagonist L-703606 on bone remodeling in sham-operated mice and OVX mice were also investigated. Forty-eight nine-week-old female C57BL/6J mice were evenly distributed into three groups with sham surgery, OVX or OVX with estrogen replacement. Substance P expression in the bones of each group of mice was evaluated by immunohistochemistry and enzyme immunoassay. Another thirty-two nine-week-old female C57BL/6J mice were divided into a SHAM group (sham surgery followed by vehicle treatment with DMSO), a SHAM + L group (sham surgery followed by 15 mg/kg/d L-703606 repeated intraperitoneal injections), an OVX group (ovariectomy with the same vehicle treatment) and an OVX + L group (ovariectomy with the same L-703606 injections), with 8 mice in each group. Treatment started 3 weeks after surgery and last for 3 weeks. A 2 × 2 factorial experimental design was used to detect the effects of substance P signaling blockade on bone remodeling in sham-operated mice and OVX mice. Techniques including micro-computed tomography, biomechanical testing, histomorphometric analysis, enzyme immunoassay, and real-time PCR were employed. Immunohistochemistry and enzyme immunoassay revealed that substance P expression significantly decreased in the bones of OVX mice both at 3 weeks and 6 weeks after surgery. Micro-CT tomography demonstrated that application of L-703606 led to bone loss in sham-operated mice, and aggravated the micro-structural deterioration of bones in OVX mice. This was shown by reduced BV/TV (Mean bone volume fraction), Tb.N (Mean trabecular number) and Tb.Th (Mean trabecular thickness), and increased Tb.Sp (Mean trabecular separation). Biomechanical analysis demonstrated that blockade of substance P signaling reduced the maximum stress and maximum load of L3 vertebrae and tibiae. Inhibited recruitment of bone mesenchymal stem cells (BMSCs) to bone remodeling sites, which was evidenced by increased number of osteoclasts, decreased number of osteoblasts and increased osteoid volume in the secondary spongiosa, was observed in the mice treated with L-703606. A significant decrease of OPG/RANKL ratio was also found in the bones of mice treated with L-703606. Body weight, uterine weight and serum estradiol level were not significantly different between the mice treated with L-703606 and those treated with vehicle. The results demonstrated that blocking substance P signaling led to bone loss in sham-operated mice, and exacerbated the bone loss in OVX mice. Substance P signaling had an important role in the maintenance of bone mass. Copyright © 2016 Elsevier Ltd. All rights reserved.

Single-staged vs. two-staged implant placement using bone ring technique in vertically deficient alveolar ridges - Part 1: histomorphometric and micro-CT analysis.

PubMed

Nakahara, Ken; Haga-Tsujimura, Maiko; Sawada, Kosaku; Kobayashi, Eizaburo; Mottini, Matthias; Schaller, Benoit; Saulacic, Nikola

2016-11-01

Simultaneous implant placement with bone grafting shortens the overall treatment period, but might lead to the peri-implant bone loss or even implant failure. The aim of this study was to compare the single-staged to two-staged implant placement using the bone ring technique. Four standardized alveolar bone defects were made in the mandibles of nine dogs. Dental implants (Straumann BL ® , Basel, Switzerland) were inserted simultaneously with bone ring technique in test group and after 6 months of healing period in control group. Animals of both groups were euthanized at 3 and 6 months of osseointegration period. The harvested samples were analyzed by means of histology and micro-CT. The amount of residual bone decreased while the amount of new bone increased up to 9 months of healing period. All morphometric parameters remained stable between 3 and 6 months of osseointegration period within groups. Per a given time point, median area of residual bone graft was higher in test group and area of new bone in control group. The volume of bone ring was greater in test than in control group, reaching the significance at 6 months of osseointegration period (P = 0.002). In the present type of bone defect, single-staged implant placement may be potentially useful to shorten an overall treatment period. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Fabrication of Carbonate Apatite Block through a Dissolution-Precipitation Reaction Using Calcium Hydrogen Phosphate Dihydrate Block as a Precursor.

PubMed

Tsuru, Kanji; Yoshimoto, Ayami; Kanazawa, Masayuki; Sugiura, Yuki; Nakashima, Yasuharu; Ishikawa, Kunio

2017-03-31

Carbonate apatite (CO₃Ap) block, which is a bone replacement used to repair defects, was fabricated through a dissolution-precipitation reaction using a calcium hydrogen phosphate dihydrate (DCPD) block as a precursor. When the DCPD block was immersed in NaHCO₃ or Na₂CO₃ solution at 80 °C, DCPD converted to CO₃Ap within 3 days. β-Tricalcium phosphate was formed as an intermediate phase, and it was completely converted to CO₃Ap within 2 weeks when the DCPD block was immersed in Na₂CO₃ solution. Although the crystal structures of the DCPD and CO₃Ap blocks were different, the macroscopic structure was maintained during the compositional transformation through the dissolution-precipitation reaction. CO₃Ap block fabricated in NaHCO₃ or Na₂CO₃ solution contained 12.9 and 15.8 wt % carbonate, respectively. The diametral tensile strength of the CO₃Ap block was 2 MPa, and the porosity was approximately 57% regardless of the carbonate solution. DCPD is a useful precursor for the fabrication of CO₃Ap block.

Truncal blocks for perioperative pain management: a review of the literature and evolving techniques.

PubMed

Go, Ramon; Huang, Yolanda Y; Weyker, Paul D; Webb, Christopher Aj

2016-10-01

As the American healthcare system continues to evolve and reimbursement becomes tied to value-based incentive programs, perioperative pain management will become increasingly important. Regional anesthetic techniques are only one component of a successful multimodal pain regimen. In recent years, the use of peripheral and paraneuraxial blocks to provide chest wall and abdominal analgesia has gained popularity. When used within a multimodal regimen, truncal blocks may provide similar analgesia when compared with other regional anesthetic techniques. While there are other reviews that cover this topic, our review will also highlight the emerging role for serratus plane blocks, pectoral nerve blocks and quadratus lumborum blocks in providing thoracic and abdominal analgesia.

Autotransplantation of Mandibular Third Molar with Buccal Cortical Plate to Replace Vertically Fractured Mandibular Second Molar: A Novel Technique.

PubMed

Zufía, Juan; Abella, Francesc; Trebol, Ivan; Gómez-Meda, Ramón

2017-09-01

Tooth replacement often leads to inadequate vertical volume in the recipient site bone when a tooth has been extracted because of a vertical root fracture (VRF). This case report presents the autotransplantation of a mandibular third molar (tooth #32) with the attached buccal cortical plate to replace a mandibular second molar (tooth #31) diagnosed with a VRF. After extraction of tooth #31, the recipient socket was prepared based on the size measured in advance with cone-beam computed tomographic imaging. The precise and calculated osteotomy of the cortical bone of tooth #32 allowed for the exact placement of the donor tooth in the position of tooth #31. The total extraoral time was only 25 minutes. The block was fixed to the recipient socket with an osteosynthesis screw and splinted with a double resin wire for 8 weeks. At the 6-month follow-up, the screw was removed, and the stability of the tooth and the regeneration obtained throughout the vestibular area were confirmed. At the 2-year follow-up, the transplanted tooth was asymptomatic and maintained a normal bone level. Advantages of autotransplantation over dental implants include maintenance of proprioception, possible orthodontic movements, and a relatively low cost. This case report demonstrates that an autotransplantation of a third molar attached to its buccal cortical plate is a viable option to replace teeth with a VRF. Copyright © 2017 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

Allograft for maxillary sinus floor augmentation: a retrospective study of 90 cases.

PubMed

Guerrero, Jaime S; Al-Jandan, Badr A

2012-04-01

The aim of this study is to demonstrate the clinical applicability and efficacy of an allograft for maxillary sinus augmentations in patients requiring placement of dental implants. Sixty consecutive patients underwent a total of 90 sinus augmentations. Twenty-nine were women and 31 men, with a mean age of 54 years. Twenty-six patients received a bilateral procedure and 34 unilateral. All cases were treated with the lateral wall technique. Allograft consisted of demineralized freeze-dried blocks in 6 cases, particulate in 82 cases, and a combination of both in 2 cases. In 30 patients, it was combined with platelet-rich plasma. A total of 84 implants were inserted. Bone samples of grafted areas were obtained in two patients for histological examination. Seventy-three implants were clinically successful at the reentry time. Eleven implants in seven patients were removed between 15 days and 6 months after their placement. Seven of these implants were replaced and received prostheses as well, for an overall postloading success rate of 95.2%. Follow-up for all patients after final restoration was between 12 and 96 months. Specimen's histological evaluation revealed bone formation and evidence of inflammatory infiltrate. Based on the findings of this study, it can be suggested that the use of the demineralized freeze-dried bone allograft from the Banco de Huesos y Tejidos Fundación Cosme y Damian for sinus augmentation is effective and constitutes a feasible therapeutic alternative for implant placement.

Whiplash and Whiplash Associated Disorder (WAS)

MedlinePlus

... Patient Education Committee The spine is a long chain of bones, discs, muscles and ligaments that extends ... is to perform an injection called "medial branch block (MBB)," which is discussed below. Disc injury can ...

Alveolar Ridge Split Technique Using Piezosurgery with Specially Designed Tips

PubMed Central

Moro, Alessandro; Foresta, Enrico; Falchi, Marco; De Angelis, Paolo; D'Amato, Giuseppe; Pelo, Sandro

2017-01-01

The treatment of patients with atrophic ridge who need prosthetic rehabilitation is a common problem in oral and maxillofacial surgery. Among the various techniques introduced for the expansion of alveolar ridges with a horizontal bone deficit is the alveolar ridge split technique. The aim of this article is to give a description of some new tips that have been specifically designed for the treatment of atrophic ridges with transversal bone deficit. A two-step piezosurgical split technique is also described, based on specific osteotomies of the vestibular cortex and the use of a mandibular ramus graft as interpositional graft. A total of 15 patients were treated with the proposed new tips by our department. All the expanded areas were successful in providing an adequate width and height to insert implants according to the prosthetic plan and the proposed tips allowed obtaining the most from the alveolar ridge split technique and piezosurgery. These tips have made alveolar ridge split technique simple, safe, and effective for the treatment of horizontal and vertical bone defects. Furthermore the proposed piezosurgical split technique allows obtaining horizontal and vertical bone augmentation. PMID:28246596

Alveolar Ridge Split Technique Using Piezosurgery with Specially Designed Tips.

PubMed

Moro, Alessandro; Gasparini, Giulio; Foresta, Enrico; Saponaro, Gianmarco; Falchi, Marco; Cardarelli, Lorenzo; De Angelis, Paolo; Forcione, Mario; Garagiola, Umberto; D'Amato, Giuseppe; Pelo, Sandro

2017-01-01

The treatment of patients with atrophic ridge who need prosthetic rehabilitation is a common problem in oral and maxillofacial surgery. Among the various techniques introduced for the expansion of alveolar ridges with a horizontal bone deficit is the alveolar ridge split technique. The aim of this article is to give a description of some new tips that have been specifically designed for the treatment of atrophic ridges with transversal bone deficit. A two-step piezosurgical split technique is also described, based on specific osteotomies of the vestibular cortex and the use of a mandibular ramus graft as interpositional graft. A total of 15 patients were treated with the proposed new tips by our department. All the expanded areas were successful in providing an adequate width and height to insert implants according to the prosthetic plan and the proposed tips allowed obtaining the most from the alveolar ridge split technique and piezosurgery. These tips have made alveolar ridge split technique simple, safe, and effective for the treatment of horizontal and vertical bone defects. Furthermore the proposed piezosurgical split technique allows obtaining horizontal and vertical bone augmentation.

"Black Bone" MRI: a novel imaging technique for 3D printing.

PubMed

Eley, Karen A; Watt-Smith, Stephen R; Golding, Stephen J

2017-03-01

Three-dimensionally printed anatomical models are rapidly becoming an integral part of pre-operative planning of complex surgical cases. We have previously reported the "Black Bone" MRI technique as a non-ionizing alternative to CT. Segmentation of bone becomes possible by minimizing soft tissue contrast to enhance the bone-soft tissue boundary. The objectives of this study were to ascertain the potential of utilizing this technique to produce three-dimensional (3D) printed models. "Black Bone" MRI acquired from adult volunteers and infants with craniosynostosis were 3D rendered and 3D printed. A custom phantom provided a surrogate marker of accuracy permitting comparison between direct measurements and 3D printed models created by segmenting both CT and "Black Bone" MRI data sets using two different software packages. "Black Bone" MRI was successfully utilized to produce 3D models of the craniofacial skeleton in both adults and an infant. Measurements of the cube phantom and 3D printed models demonstrated submillimetre discrepancy. In this novel preliminary study exploring the potential of 3D printing from "Black Bone" MRI data, the feasibility of producing anatomical 3D models has been demonstrated, thus offering a potential non-ionizing alterative to CT for the craniofacial skeleton.

Thermal processing of bone: in vitro response of mesenchymal cells to bone-conditioned medium.

PubMed

Sawada, K; Caballé-Serrano, J; Schuldt Filho, G; Bosshardt, D D; Schaller, B; Buser, D; Gruber, R

2015-08-01

The autoclaving, pasteurization, and freezing of bone grafts to remove bacteria and viruses, and for preservation, respectively, is considered to alter biological properties during graft consolidation. Fresh bone grafts release paracrine-like signals that are considered to support tissue regeneration. However, the impact of the autoclaving, pasteurization, and freezing of bone grafts on paracrine signals remains unknown. Therefore, conditioned medium was prepared from porcine cortical bone chips that had undergone thermal processing. The biological properties of the bone-conditioned medium were assessed by examining the changes in expression of target genes in oral fibroblasts. The data showed that conditioned medium obtained from bone chips that had undergone pasteurization and freezing changed the expression of adrenomedullin, pentraxin 3, BTB/POZ domain-containing protein 11, interleukin 11, NADPH oxidase 4, and proteoglycan 4 by at least five-fold in oral fibroblasts. Bone-conditioned medium obtained from autoclaved bone chips, however, failed to change the expression of the respective genes. Also, when bone-conditioned medium was prepared from fresh bone chips, autoclaving blocked the capacity of bone-conditioned medium to modulate gene expression. These in vitro results suggest that pasteurization and freezing of bone grafts preserve the release of biologically active paracrine signals, but autoclaving does not. Copyright © 2015 International Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.

Biophotonics and Bone Biology

NASA Technical Reports Server (NTRS)

Zimmerli, Gregory; Fischer, David; Asipauskas, Marius; Chauhan, Chirag; Compitello, Nicole; Burke, Jamie; Tate, Melissa Knothe

2004-01-01

One of the more serious side effects of extended space flight is an accelerated bone loss. Rates of bone loss are highest in the weight-bearing bones of the hip and spine regions, and the average rate of bone loss as measured by bone mineral density measurements is around 1.2% per month for persons in a microgravity environment. It is well known that bone remodeling responds to mechanical forces. We are developing two-photon microscopy techniques to study bone tissue and bone cell cultures to better understand the fundamental response mechanism in bone remodeling. Osteoblast and osteoclast cell cultures are being studied, and the goal is to use molecular biology techniques in conjunction with Fluorescence Lifetime Imaging Microscopy (FLIM) to study the physiology of in-vitro cell cultures in response to various stimuli, such as fluid flow induced shear stress and mechanical stress. We have constructed a two-photon fluorescence microscope for these studies, and are currently incorporating FLIM detection. Current progress will be reviewed. This work is supported by the NASA John Glenn Biomedical Engineering Consortium.

Non-invasive assessment of bone quantity and quality in human trabeculae using scanning ultrasound imaging

NASA Astrophysics Data System (ADS)

Xia, Yi

Fractures and associated bone fragility induced by osteoporosis and osteopenia are widespread health threat to current society. Early detection of fracture risk associated with bone quantity and quality is important for both the prevention and treatment of osteoporosis and consequent complications. Quantitative ultrasound (QUS) is an engineering technology for monitoring bone quantity and quality of humans on earth and astronauts subjected to long duration microgravity. Factors currently limiting the acceptance of QUS technology involve precision, accuracy, single index and standardization. The objective of this study was to improve the accuracy and precision of an image-based QUS technique for non-invasive evaluation of trabecular bone quantity and quality by developing new techniques and understanding ultrasound/tissue interaction. Several new techniques have been developed in this dissertation study, including the automatic identification of irregular region of interest (iROI) in bone, surface topology mapping (STM) and mean scattering spacing (MSS) estimation for evaluating trabecular bone structure. In vitro results have shown that (1) the inter- and intra-observer errors in QUS measurement were reduced two to five fold by iROI compared to previous results; (2) the accuracy of QUS parameter, e.g., ultrasound velocity (UV) through bone, was improved 16% by STM; and (3) the averaged trabecular spacing can be estimated by MSS technique (r2=0.72, p<0.01). The measurement errors of BUA and UV introduced by the soft tissue and cortical shells in vivo can be quantified by developed foot model and simplified cortical-trabecular-cortical sandwich model, which were verified by the experimental results. The mechanisms of the errors induced by the cortical and soft tissues were revealed by the model. With developed new techniques and understanding of sound-tissue interaction, in vivo clinical trail and bed rest study were preformed to evaluate the performance of QUS in clinical applications. It has been demonstrated that the QUS has similar performance for in vivo bone density measurement compared to current gold-standard method, i.e., DXA, while additional information are obtained by the QUS for predicting fracture risk by monitoring of bone's quality. The developed QUS imaging technique can be used to assess bone's quantity and quality with improved accuracy and precision.

21 CFR 888.5 - Resurfacing technique.

Code of Federal Regulations, 2014 CFR

2014-04-01

... techniques, certain joint prostheses require far less bone resection than other devices intended to repair or replace the same joint. The amount of bone resection may or may not affect the safety and effectiveness of...

21 CFR 888.5 - Resurfacing technique.

Code of Federal Regulations, 2011 CFR

2011-04-01

... techniques, certain joint prostheses require far less bone resection than other devices intended to repair or replace the same joint. The amount of bone resection may or may not affect the safety and effectiveness of...

21 CFR 888.5 - Resurfacing technique.

Code of Federal Regulations, 2013 CFR

2013-04-01

... techniques, certain joint prostheses require far less bone resection than other devices intended to repair or replace the same joint. The amount of bone resection may or may not affect the safety and effectiveness of...

21 CFR 888.5 - Resurfacing technique.

Code of Federal Regulations, 2010 CFR

2010-04-01

... techniques, certain joint prostheses require far less bone resection than other devices intended to repair or replace the same joint. The amount of bone resection may or may not affect the safety and effectiveness of...

21 CFR 888.5 - Resurfacing technique.

Code of Federal Regulations, 2012 CFR

2012-04-01

... techniques, certain joint prostheses require far less bone resection than other devices intended to repair or replace the same joint. The amount of bone resection may or may not affect the safety and effectiveness of...

Quality of Bone Healing: Perspectives and Assessment Techniques

DTIC Science & Technology

2014-01-01

connective tissue specialized for load bearing . Embryologically, the formation of bone occurs via two routes: intramembranous and endochondral ossification.1...primarily suited to load bearing with two distinct configurations: an inner, porous, cancellous architecture and an outer, denser, cortical bone...delineate the multiple functions served by the human skeleton and then evaluate techniques for clinical assessment. Mechanical load bearing and transduction

Transplantation of bone: prerequisites for immunologic and inflammatory conditions - an overview.

PubMed

Knobe, M; Gradl, G

2013-01-01

In this review we have summarized the conditions under which bone grafts have a suitable environment for ingrowth into surrounding bone. Among the topics discussed are the immunological properties of bone and differences between bone grafting and organ transplants. Local osteogenic immune changes following fracture and bone graft transplants are outlined. Moreover, techniques of bone graft harvesting are summarized.

Techniques for deriving tissue structure from multiple projection dual-energy x-ray absorptiometry

NASA Technical Reports Server (NTRS)

Feldmesser, Howard S. (Inventor); Charles, Jr., Harry K. (Inventor); Beck, Thomas J. (Inventor); Magee, Thomas C. (Inventor)

2004-01-01

Techniques for deriving bone properties from images generated by a dual-energy x-ray absorptiometry apparatus include receiving first image data having pixels indicating bone mineral density projected at a first angle of a plurality of projection angles. Second image data and third image data are also received. The second image data indicates bone mineral density projected at a different second angle. The third image data indicates bone mineral density projected at a third angle. The third angle is different from the first angle and the second angle. Principal moments of inertia for a bone in the subject are computed based on the first image data, the second image data and the third image data. The techniques allow high-precision, high-resolution dual-energy x-ray attenuation images to be used for computing principal moments of inertia and strength moduli of individual bones, plus risk of injury and changes in risk of injury to a patient.

Radionuclide imaging of bone marrow disorders

PubMed Central

Agool, Ali; Glaudemans, Andor W. J. M.; Boersma, Hendrikus H.; Dierckx, Rudi A. J. O.; Vellenga, Edo

2010-01-01

Noninvasive imaging techniques have been used in the past for visualization the functional activity of the bone marrow compartment. Imaging with radiolabelled compounds may allow different bone marrow disorders to be distinguished. These imaging techniques, almost all of which use radionuclide-labelled tracers, such as 99mTc-nanocolloid, 99mTc-sulphur colloid, 111In-chloride, and radiolabelled white blood cells, have been used in nuclear medicine for several decades. With these techniques three separate compartments can be recognized including the reticuloendothelial system, the erythroid compartment and the myeloid compartment. Recent developments in research and the clinical use of PET tracers have made possible the analysis of additional properties such as cellular metabolism and proliferative activity, using 18F-FDG and 18F-FLT. These tracers may lead to better quantification and targeting of different cell systems in the bone marrow. In this review the imaging of different bone marrow targets with radionuclides including PET tracers in various bone marrow diseases are discussed. PMID:20625724

New options for vascularized bone reconstruction in the upper extremity.

PubMed

Houdek, Matthew T; Wagner, Eric R; Wyles, Cody C; Nanos, George P; Moran, Steven L

2015-02-01

Originally described in the 1970s, vascularized bone grafting has become a critical component in the treatment of bony defects and non-unions. Although well established in the lower extremity, recent years have seen many novel techniques described to treat a variety of challenging upper extremity pathologies. Here the authors review the use of different techniques of vascularized bone grafts for the upper extremity bone pathologies. The vascularized fibula remains the gold standard for the treatment of large bone defects of the humerus and forearm, while also playing a role in carpal reconstruction; however, two other important options for larger defects include the vascularized scapula graft and the Capanna technique. Smaller upper extremity bone defects and non-unions can be treated with the medial femoral condyle (MFC) free flap or a vascularized rib transfer. In carpal non-unions, both pedicled distal radius flaps and free MFC flaps are viable options. Finally, in skeletally immature patients, vascularized fibular head epiphyseal transfer can provide growth potential in addition to skeletal reconstruction.

[Tumor-like bone lesions of the forearm after karate training].

PubMed

Steckel, H; Oldenburg, M; Klinger, H M; Schultz, W

2005-03-01

Differentiation between malignant bone tumors and tumor-like lesions after repetitive microtrauma following sport activities can be difficult just using radiographic methods. We present the case of a fifteen year old karate fighter, who was examined by imaging diagnostics because of a progressive swelling and pain in the distal right forearm. A tumor-like appearance with bone mass formation in the x-ray, an enhancement in the surrounding tissue shown in the MRI and an increased activity in the bone scintigraphy made the diagnosis of an osteosarcoma very likely. Blood tests were not helpful. Only the evaluation of a bone biopsy could demonstrate hypertrophic reparative bone formation after multiple osseous microtrauma. Cast immobilisation reduced the osseous alteration. With the start of the training the swelling reappeared again but then finally vanished after modifying the training technique. The case demonstrates that even modern imaging techniques cannot always distinguish between tumor and tumor-like lesions caused by sports. It also stresses the importance of a correct technique in sports like karate.

[Fabrication and in vivo implantation of ligament-bone composite scaffolds based on three-dimensional printing technique].

PubMed

Zhang, Wenyou; He, Jiankang; Li, Xiang; Liu, Yaxiong; Bian, Weiguo; Li, Dichen; Jin, Zhongmin

2014-03-01

To solve the fixation problem between ligament grafts and host bones in ligament reconstruction surgery by using ligament-bone composite scaffolds to repair the ligaments, to explore the fabrication method for ligament-bone composite scaffolds based on three-dimensional (3-D) printing technique, and to investigate their mechanical and biological properties in animal experiments. The model of bone scaffolds was designed using CAD software, and the corresponding negative mould was created by boolean operation. 3-D printing techinique was employed to fabricate resin mold. Ceramic bone scaffolds were obtained by casting the ceramic slurry in the resin mould and sintering the dried ceramics-resin composites. Ligament scaffolds were obtained by weaving degummed silk fibers, and then assembled with bone scaffolds and bone anchors. The resultant ligament-bone composite scaffolds were implanted into 10 porcine left anterior cruciate ligament rupture models at the age of 4 months. Mechanical testing and histological examination were performed at 3 months postoperatively, and natural anterior cruciate ligaments of the right sides served as control. Biomechanical testing showed that the natural anterior cruciate ligament of control group can withstand maximum tensile force of (1 384 +/- 181) N and dynamic creep of (0.74 +/- 0.21) mm, while the regenerated ligament-bone scaffolds of experimental group can withstand maximum tensile force of (370 +/- 103) N and dynamic creep of (1.48 +/- 0.49) mm, showing significant differences (t = 11.617, P = 0.000; t = 2.991, P = 0.020). In experimental group, histological examination showed that new bone formed in bone scaffolds. A hierarchical transition structure regenerated between ligament-bone scaffolds and the host bones, which was similar to the structural organizations of natural ligament-bone interface. Ligament-bone composite scaffolds based on 3-D printing technique facilitates the regeneration of biomimetic ligament-bone interface. It is expected to achieve physical fixation between ligament grafts and host bone.

[Computed tomography of the temporal bone in diagnosis of chronic exudative otitis media].

PubMed

Zelikovich, E I

2005-01-01

Computed tomography (CT) of the temporal bone was made in 37 patients aged 2 to 55 years with chronic exudative otitis media (CEOM). In 21 of them the pathology was bilateral. The analysis of 58 CT images has identified CT signs of chronic exudative otitis media. They include partial (17 temporary bones) or complete (38 temporal bones) block of the bone opening of the auditory tube, pneumatic defects of the tympanic cavity (58 temporal bones), pneumatic defects of the mastoid process and antrum (47 temporal bones), pathologic retraction of the tympanic membrane. The examination of the temporal bone detected both CT-signs of CEOM and other causes of hearing disorders in 14 patients (26 temporal bones) with CEOM symptoms and inadequately high hypoacusis. Among these causes were malformation of the auditory ossicula (n=5), malformation of the labynthine window (n=2), malformation of the middle and internal ear (n=4), a wide aqueduct of the vestibule, labyrinthine anomaly of Mondini's type (n=1), cochlear hypoplasia (n=4), stenosis of the internal acoustic meatuses (n=2). Sclerotic fibrous dysplasia was suggested in 2 temporal bones (by CT data). CT was repeated after surgical treatment of 10 patients (14 temporal bones) and visual assessment of tympanostomy results was made.

Role of TGF-β in breast cancer bone metastases

PubMed Central

Chiechi, Antonella; Waning, David L.; Stayrook, Keith R.; Buijs, Jeroen T.; Guise, Theresa A.; Mohammad, Khalid S.

2014-01-01

Breast cancer is the most prevalent cancer among females worldwide leading to approximately 350,000 deaths each year. It has long been known that cancers preferentially metastasize to particular organs, and bone metastases occur in ~70% of patients with advanced breast cancer. Breast cancer bone metastases are predominantly osteolytic and accompanied by increased fracture risk, pain, nerve compression and hypercalcemia, causing severe morbidity. In the bone matrix, transforming growth factor-β (TGF-β) is one of the most abundant growth factors, which is released in active form upon tumor-induced osteoclastic bone resorption. TGF-β, in turn, stimulates bone metastatic tumor cells to secrete factors that further drive osteolytic bone destruction adjacent to the tumor. Thus, TGF-β is a crucial factor responsible for driving the feed-forward vicious cycle of cancer growth in bone. Moreover, TGF-β activates epithelial-to-mesenchymal transition, increases tumor cell invasiveness and angiogenesis and induces immunosuppression. Blocking the TGF-β signaling pathway to interrupt this vicious cycle between breast cancer and bone offers a promising target for therapeutic intervention to decrease skeletal metastasis. This review will describe the role of TGF-β in breast cancer and bone metastasis, and pre-clinical and clinical data will be evaluated for the potential use of TGF-β inhibitors in clinical practice to treat breast cancer bone metastases. PMID:24558636

Bone growth and turnover in progesterone receptor knockout mice.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rickard, David J.; Iwaniec, Urszula T.; Evans, Glenda

2008-05-01

The role of progesterone receptor (PR) signaling in skeletal metabolism is controversial. To address whether signaling through the PR is necessary for normal bone growth and turnover, we performed histomorphometric and mCT analyses of bone from homozygous female PR knockout (PRKO) mice at 6, 12, and 26 weeks of age. These mice possess a null mutation of the PR locus, which blocks the gene expression of A and B isoforms of PR. Body weight gain, uterine weight gain and tibia longitudinal bone growth was normal in PRKO mice. In contrast, total and cortical bone mass were increased in long bonesmore » of post-pubertal (12 and 26-week-old) PRKO mice, whereas cancellous bone mass was normal in the tibia but increased in the humerus. The striking 57% decrease in cancellous bone from the proximal tibia metaphysis which occurred between 6 and 26 weeks in WT mice was abolished in PRKO mice. The improved bone balance in aging PRKO mice was associated with elevated bone formation and a tendency toward reduced osteoclast perimeter. Taken together, these findings suggest that PR signaling in mice attenuates the accumulation of cortical bone mass during adolescence and is required for early age-related loss of cancellous bone.« less

Dentascan – Is the Investment Worth the Hype ???

PubMed Central

Shah, Monali A; Shah, Sneha S; Dave, Deepak

2013-01-01

Background: Open Bone Measurement (OBM) and Bone Sounding (BS) are most reliable but invasive clinical methods for Alveolar Bone Level (ABL) assessment, causing discomfort to the patient. Routinely, IOPAs & OPGs are the commonest radiographic techniques used, which tend to underestimate bone loss and obscure buccal/lingual defects. Novel technique like dentascan (CBCT) eliminates this limitation by giving images in 3 planes – sagittal, coronal and axial. Aim: To compare & correlate non-invasive 3D radiographic technique of Dentascan with BS & OBM, and IOPA and OPG, in assessing the ABL. Settings and Design: Cross-sectional diagnostic study. Material and Methods: Two hundred and five sites were subjected to clinical and radiographic diagnostic techniques. Relative distance between the alveolar bone crest and reference wire was measured. All the measurements were compared and tested against the OBM. Statistical Analysis: Student’s t-test, ANOVA, Pearson correlation coefficient. Results: There is statistically significant difference between dentascan and OBM, only BS showed agreement with OBM (p < 0.05). Dentascan weakly correlated with OBM & BS lingually.Rest all techniques showed statistically significant difference between them (p= 0.00). Conclusion: Within the limitations of this study, only BS seems to be comparable with OBM with no superior result of Dentascan over the conventional techniques, except for lingual measurements. PMID:24551722

Identification of homogeneous genetic architecture of multiple genetically correlated traits by block clustering of genome-wide associations.

PubMed

Gupta, Mayetri; Cheung, Ching-Lung; Hsu, Yi-Hsiang; Demissie, Serkalem; Cupples, L Adrienne; Kiel, Douglas P; Karasik, David

2011-06-01

Genome-wide association studies (GWAS) using high-density genotyping platforms offer an unbiased strategy to identify new candidate genes for osteoporosis. It is imperative to be able to clearly distinguish signal from noise by focusing on the best phenotype in a genetic study. We performed GWAS of multiple phenotypes associated with fractures [bone mineral density (BMD), bone quantitative ultrasound (QUS), bone geometry, and muscle mass] with approximately 433,000 single-nucleotide polymorphisms (SNPs) and created a database of resulting associations. We performed analysis of GWAS data from 23 phenotypes by a novel modification of a block clustering algorithm followed by gene-set enrichment analysis. A data matrix of standardized regression coefficients was partitioned along both axes--SNPs and phenotypes. Each partition represents a distinct cluster of SNPs that have similar effects over a particular set of phenotypes. Application of this method to our data shows several SNP-phenotype connections. We found a strong cluster of association coefficients of high magnitude for 10 traits (BMD at several skeletal sites, ultrasound measures, cross-sectional bone area, and section modulus of femoral neck and shaft). These clustered traits were highly genetically correlated. Gene-set enrichment analyses indicated the augmentation of genes that cluster with the 10 osteoporosis-related traits in pathways such as aldosterone signaling in epithelial cells, role of osteoblasts, osteoclasts, and chondrocytes in rheumatoid arthritis, and Parkinson signaling. In addition to several known candidate genes, we also identified PRKCH and SCNN1B as potential candidate genes for multiple bone traits. In conclusion, our mining of GWAS results revealed the similarity of association results between bone strength phenotypes that may be attributed to pleiotropic effects of genes. This knowledge may prove helpful in identifying novel genes and pathways that underlie several correlated phenotypes, as well as in deciphering genetic and phenotypic modularity underlying osteoporosis risk. Copyright © 2011 American Society for Bone and Mineral Research.

Impaction grafted bone chip size effect on initial stability in an acetabular model: Mechanical evaluation.

PubMed

Holton, Colin; Bobak, Peter; Wilcox, Ruth; Jin, Zhongmin

2013-01-01

Acetabular bone defect reconstruction is an increasing problem for surgeons with patients undergoing complex primary or revision total hip replacement surgery. Impaction bone grafting is one technique that has favourable long-term clinical outcome results for patients who undergo this reconstruction method for acetabular bone defects. Creating initial mechanical stability of the impaction bone graft in this technique is known to be the key factor in achieving a favourable implant survival rate. Different sizes of bone chips were used in this technique to investigate if the size of bone chips used affected initial mechanical stability of a reconstructed acetabulum. Twenty acetabular models were created in total. Five control models were created with a cemented cup in a normal acetabulum. Then five models in three different groups of bone chip size were constructed. The three groups had an acetabular protrusion defect reconstructed using either; 2-4 mm(3), 10 mm(3) or 20 mm(3) bone chip size for impaction grafting reconstruction. The models underwent compression loading up to 9500 N and displacement within the acetabular model was measured indicating the initial mechanical stability. This study reveals that, although not statistically significant, the largest (20 mm(3)) bone chip size grafted models have an inferior maximum stiffness compared to the medium (10 mm(3)) bone chip size. Our study suggests that 10 mm(3) size of bone chips provide better initial mechanical stability compared to smaller or larger bone chips. We dismissed the previously held opinion that the biggest practically possible graft is best for acetabular bone graft impaction.

Laser-induced plasma spectroscopy (LIPS): use of a geological tool in assessing bone mineral content.

PubMed

Andrássy, László; Gomez, Izabella; Horváth, Ágnes; Gulyás, Katalin; Pethö, Zsófia; Juhász, Balázs; Bhattoa, Harjit Pal; Szekanecz, Zoltan

2018-02-17

Bone may be similar to geological formulations in many ways. Therefore, it may be logical to apply laser-based geological techniques in bone research. The mineral and element oxide composition of bioapatite can be estimated by mathematical models. Laser-induced plasma spectrometry (LIPS) has long been used in geology. This method may provide a possibility to determine the composition and concentration of element oxides forming the inorganic part of bones. In this study, we wished to standardize the LIPS technique and use mathematical calculations and models in order to determine CaO distribution and bone homogeneity using bovine shin bone samples. We used polished slices of five bovine shin bones. A portable LIPS instrument using high-power Nd++YAG laser pulses has been developed (OpLab, Budapest). Analysis of CaO distribution was carried out in a 10 × 10 sampling matrix applying 300-μm sampling intervals. We assessed both cortical and trabecular bone areas. Regions of interest (ROI) were determined under microscope. CaO peaks were identified in the 200-500 nm wavelength range. A mathematical formula was used to calculate the element oxide composition (wt%) of inorganic bone. We also applied two accepted mathematical approaches, the Bartlett's test and frequency distribution curve-based analysis, to determine the homogeneity of CaO distribution in bones. We were able to standardize the LIPS technique for bone research. CaO concentrations in the cortical and trabecular regions of B1-5 bones were 33.11 ± 3.99% (range 24.02-40.43%) and 27.60 ± 7.44% (range 3.58-39.51%), respectively. CaO concentrations highly corresponded to those routinely determined by ICP-OES. We were able to graphically demonstrate CaO distribution in both 2D and 3D. We also determined possible interrelations between laser-induced craters and bone structure units, which may reflect the bone structure and may influence the heterogeneity of CaO distributions. By using two different statistical methods, we could confirm if bone samples were homogeneous or not with respect to CaO concentration distribution. LIPS, a technique previously used in geology, may be included in bone research. Assessment of element oxide concentrations in the inorganic part of bone, as well as mathematical calculations may be useful to determine the content of CaO and other element oxides in bone, further analyze bone structure and homogeneity and possibly apply this research to normal, as well as diseased bones.

Bone Healing Around Dental Implants: Simplified vs Conventional Drilling Protocols at Speed of 400 rpm.

PubMed

Gil, Luiz Fernando; Sarendranath, Alvin; Neiva, Rodrigo; Marão, Heloisa F; Tovar, Nick; Bonfante, Estevam A; Janal, Malvin N; Castellano, Arthur; Coelho, Paulo G

This study evaluated whether simplified drilling protocols would provide comparable histologic and histomorphometric results to conventional drilling protocols at a low rotational speed. A total of 48 alumina-blasted and acid-etched Ti-6Al-4V implants with two diameters (3.75 and 4.2 mm, n = 24 per group) were bilaterally placed in the tibiae of 12 dogs, under a low-speed protocol (400 rpm). Within the same diameter group, half of the implants were inserted after a simplified drilling procedure (pilot drill + final diameter drill), and the other half were placed using the conventional drilling procedure. After 3 and 5 weeks, the animals were euthanized, and the retrieved bone-implant samples were subjected to nondecalcified histologic sectioning. Histomorphology, bone-to-implant contact (BIC), and bone area fraction occupancy (BAFO) analysis were performed. Histology showed that new bone was formed around implants, and inflammation or bone resorption was not evident for both groups. Histomorphometrically, when all independent variables were collapsed over drilling technique, no differences were detected for BIC and BAFO; when drilling technique was analyzed as a function of time, the conventional groups reached statistically higher BIC and BAFO at 3 weeks, but comparable values between techniques were observed at 5 weeks; 4.2-mm implants obtained statistically higher BAFO relative to 3.75-mm implants. Based on the present methodology, the conventional technique improved bone formation at 3 weeks, and narrower implants were associated with less bone formation.

Suture anchor fixation strength with or without augmentation in osteopenic and severely osteoporotic bones in rotator cuff repair: a biomechanical study on polyurethane foam model.

PubMed

Er, Mehmet Serhan; Altinel, Levent; Eroglu, Mehmet; Verim, Ozgur; Demir, Teyfik; Atmaca, Halil

2014-08-22

The purpose of the present study was to compare the results of various types of anchor applications with or without augmentation in both osteopenic and severely osteoporotic bone models. Two different types of suture anchors were tested in severely osteoporotic (SOP) and osteopenic polyurethane (PU) foam blocks using an established protocol. An Instron machine applied static loading parallel to the axis of insertion until failure, and the mean anchor failure strengths were calculated. The mode of failure (anchor pullout, suture tear) was recorded. The anchors tested included the Corkscrew (CS) (Arthrex Inc., Naples, FL, USA) (without augmentation, polymethylmethacrylate (PMMA)-augmented, and bioabsorbable tricalcium phosphate (TCP) cement-augmented) and Corkscrew FT II (CS FT II) 5.5 mm (without augmentation as used routinely). The mean failure loads for both SOP and osteopenic PU foam blocks, respectively, were as follows: CS, 16.2 and 212.4 N; CS with TCP, 75.2 and 396 N; CS with PMMA, 101.2 and 528.8 N; CS FT II, 13.8 and 339.8 N. Augmentation of CS with TCP or PMMA would be essential to SOP bones. In the osteopenic bone model, although anchor fixation augmented with PMMA is the best fixation method, CS augmented with TCP cement or CS FT II without any need for augmentation may also be used as an alternative.

Cell Biology of Thiazide Bone Effects

NASA Astrophysics Data System (ADS)

Gamba, Gerardo; Riccardi, Daniela

2008-09-01

The thiazide-sensitive Na+:Cl- cotransporter (NCC) is the major pathway for salt reabsorption in the mammalian kidney. The activity of NCC is not only related to salt metabolism, but also to calcium and magnesium homeostasis due to the inverse relationship between NCC activity and calcium reabsorption. Hence, the thiazide-type diuretics that specifically block NCC have been used for years, not only for treatment of hypertension and edematous disease, but also for the management of renal stone disease. Epidemiological studies have shown that chronic thiazide treatment is associated with higher bone mineral density and reduced risk of bone fractures, which can only partly be explained in terms of their effects on the kidney. In this regard, we have recently shown that NCC is expressed in bone cells and that inhibition of NCC in bone, either by thiazides or by reduction of NCC protein with specific siRNA, is associated with increased mineralization in vitro. These observations open a field of study to begin to understand the cell biology of the beneficial effects of thiazides in bone.

Influence of residual bone thickness on primary stability of hybrid self-tapping and cylindric non-self-tapping implants in vitro.

PubMed

Divac, Marija; Stawarczyk, Bogna; Sahrmann, Philipp; Attin, Thomas; Schmidlin, Patrick R

2013-01-01

To assess the primary stability of a hybrid self-tapping implant and a cylindric non-self-tapping implant in an in vitro test model using polyurethane foam. Eighty standardized blocks of cellular rigid polyurethane foam, 2 cm long and 1 cm wide, with different thicknesses of 2, 4, 6, and 9 mm (n = 10 per group) were cut. Two implant systems--a hybrid self-tapping (Tapered Effect [TE], Straumann) and a cylindric non-self-tapping (Standard Plus [SP] Wide Neck, Straumann) were placed in the block specimens. Subsequently, resonance frequency analysis (RFA) was performed. The RFA measurements were made in triplicate on four aspects of each implant (mesial, distal, buccal, and oral), and the mean RFA value was calculated. Subsequently, the tensile load of the implants was determined by pull-out tests. The data were analyzed using one-way and two-way analysis of variance followed by a post hoc Scheffe test and a t test (α = .05). Additionally, the simple linear correlation between the RFA and tensile load values was evaluated. No statistically significant differences were found between TE and SP in terms of RFA at different bone thicknesses. Starting from a bone thickness of 4 mm, TE implants showed significantly higher tensile load compared to SP implants (P = .016 to .040). A correlation was found between the RFA measurements and tensile load. Mechanically stable placement is possible with TE and SP implants in a trabecular bone model. RFA and tensile load increased with greater bone thickness.

Three-dimensional modeling and animation of two carpal bones: a technique.

PubMed

Green, Jason K; Werner, Frederick W; Wang, Haoyu; Weiner, Marsha M; Sacks, Jonathan M; Short, Walter H

2004-05-01

The objectives of this study were to (a). create 3D reconstructions of two carpal bones from single CT data sets and animate these bones with experimental in vitro motion data collected during dynamic loading of the wrist joint, (b). develop a technique to calculate the minimum interbone distance between the two carpal bones, and (c). validate the interbone distance calculation process. This method utilized commercial software to create the animations and an in-house program to interface with three-dimensional CAD software to calculate the minimum distance between the irregular geometries of the bones. This interbone minimum distance provides quantitative information regarding the motion of the bones studied and may help to understand and quantify the effects of ligamentous injury.

Variability of morphometric parameters of human trabecular tissue from coxo-arthritis and osteoporotic samples.

PubMed

Marinozzi, Franco; Marinozzi, Andrea; Bini, Fabiano; Zuppante, Francesca; Pecci, Raffaella; Bedini, Rossella

2012-01-01

Morphometric and architectural bone parameters change in diseases such as osteoarthritis and osteoporosis. The mechanical strength of bone is primarily influenced by bone quantity and quality. Bone quality is defined by parameters such as trabecular thickness, trabecular separation, trabecular density and degree of anisotropy that describe the micro-architectural structure of bone. Recently, many studies have validated microtomography as a valuable investigative technique to assess bone morphometry, thanks to micro-CT non-destructive, non-invasive and reliability features, in comparison to traditional techniques such as histology. The aim of this study is the analysis by micro-computed tomography of six specimens, extracted from patients affected by osteoarthritis and osteoporosis, in order to observe the tridimensional structure and calculate several morphometric parameters.

Rapid prototyping technology and its application in bone tissue engineering*

PubMed Central

YUAN, Bo; ZHOU, Sheng-yuan; CHEN, Xiong-sheng

2017-01-01

Bone defects arising from a variety of reasons cannot be treated effectively without bone tissue reconstruction. Autografts and allografts have been used in clinical application for some time, but they have disadvantages. With the inherent drawback in the precision and reproducibility of conventional scaffold fabrication techniques, the results of bone surgery may not be ideal. This is despite the introduction of bone tissue engineering which provides a powerful approach for bone repair. Rapid prototyping technologies have emerged as an alternative and have been widely used in bone tissue engineering, enhancing bone tissue regeneration in terms of mechanical strength, pore geometry, and bioactive factors, and overcoming some of the disadvantages of conventional technologies. This review focuses on the basic principles and characteristics of various fabrication technologies, such as stereolithography, selective laser sintering, and fused deposition modeling, and reviews the application of rapid prototyping techniques to scaffolds for bone tissue engineering. In the near future, the use of scaffolds for bone tissue engineering prepared by rapid prototyping technology might be an effective therapeutic strategy for bone defects. PMID:28378568

Rapid prototyping technology and its application in bone tissue engineering.

PubMed

Yuan, Bo; Zhou, Sheng-Yuan; Chen, Xiong-Sheng

Bone defects arising from a variety of reasons cannot be treated effectively without bone tissue reconstruction. Autografts and allografts have been used in clinical application for some time, but they have disadvantages. With the inherent drawback in the precision and reproducibility of conventional scaffold fabrication techniques, the results of bone surgery may not be ideal. This is despite the introduction of bone tissue engineering which provides a powerful approach for bone repair. Rapid prototyping technologies have emerged as an alternative and have been widely used in bone tissue engineering, enhancing bone tissue regeneration in terms of mechanical strength, pore geometry, and bioactive factors, and overcoming some of the disadvantages of conventional technologies. This review focuses on the basic principles and characteristics of various fabrication technologies, such as stereolithography, selective laser sintering, and fused deposition modeling, and reviews the application of rapid prototyping techniques to scaffolds for bone tissue engineering. In the near future, the use of scaffolds for bone tissue engineering prepared by rapid prototyping technology might be an effective therapeutic strategy for bone defects.

Multiscale imaging of bone microdamage

PubMed Central

Poundarik, Atharva A.; Vashishth, Deepak

2015-01-01

Bone is a structural and hierarchical composite that exhibits remarkable ability to sustain complex mechanical loading and resist fracture. Bone quality encompasses various attributes of bone matrix from the quality of its material components (type-I collagen, mineral and non-collagenous matrix proteins) and cancellous microarchitecture, to the nature and extent of bone microdamage. Microdamage, produced during loading, manifests in multiple forms across the scales of hierarchy in bone and functions to dissipate energy and avert fracture. Microdamage formation is a key determinant of bone quality, and through a range of biological and physical mechanisms, accumulates with age and disease. Accumulated microdamage in bone decreases bone strength and increases bone’s propensity to fracture. Thus, a thorough assessment of microdamage, across the hierarchical levels of bone, is crucial to better understand bone quality and bone fracture. This review article details multiple imaging modalities that have been used to study and characterize microdamage; from bulk staining techniques originally developed by Harold Frost to assess linear microcracks, to atomic force microscopy, a modality that revealed mechanistic insights into the formation diffuse damage at the ultrastructural level in bone. New automated techniques using imaging modalities such as microcomputed tomography are also presented for a comprehensive overview. PMID:25664772

Maintaining space in localized ridge augmentation using guided bone regeneration with tenting screw technology.

PubMed

Chasioti, Evdokia; Chiang, Tat Fai; Drew, Howard J

2013-01-01

Prosthetic guided implant surgery requires adequate ridge dimensions for proper implant placement. Various surgical procedures can be used to augment deficient alveolar ridges. Studies have examined new bone formation on deficient ridges, utilizing numerous surgical techniques and biomaterials. The goal is to develop time efficient techniques, which have low morbidity. A crucial factor for successful bone grafting procedures is space maintenance. The article discusses space maintenance tenting screws, used in conjunction with bone allografts and resorbable barrier membranes, to ensure uneventful guided bone regeneration (GBR) enabling optimal implant positioning. The technique utilized has been described in the literature to treat severely resorbed alveolar ridges and additionally can be considered in restoring the vertical and horizontal component of deficient extraction sites. Three cases are presented to illustrate the utilization and effectiveness of tenting screw technology in the treatment of atrophic extraction sockets and for deficient ridges.

Determination of Corrosion Rate of Artificial Bone Made of Metal at Different pH Conditions using X-Ray Radiography

NASA Astrophysics Data System (ADS)

Sutikno; Handayani, L.; Edi, S. S.; Susilo; Elvira

2018-03-01

The purpose of this research is to observe the mechanism and the rate of corrosion of artificial bone made of metal by using x-ray radiography technique. Artificial bones can be made of metallic materials and composites which are biomaterials. The most commonly used metal for bone graft is stainless steel. The interaction between artificial bone and human tissue will have important medical impacts that need to be observed and examined. This interaction can be a mechanical or chemical interaction. X-ray radiography technique is selected because it uses non-destructive method. This method is done by x-ray radiation exposure on the observed body part. The bone density and bone fracture can be seen on the resulted radiographic film or image on the monitor screen.

Determination of the ruminant origin of bone particles using fluorescence in situ hybridization (FISH)

PubMed Central

Lecrenier, M. C.; Ledoux, Q.; Berben, G.; Fumière, O.; Saegerman, C.; Baeten, V.; Veys, P.

2014-01-01

Molecular biology techniques such as PCR constitute powerful tools for the determination of the taxonomic origin of bones. DNA degradation and contamination by exogenous DNA, however, jeopardise bone identification. Despite the vast array of techniques used to decontaminate bone fragments, the isolation and determination of bone DNA content are still problematic. Within the framework of the eradication of transmissible spongiform encephalopathies (including BSE, commonly known as “mad cow disease”), a fluorescence in situ hybridization (FISH) protocol was developed. Results from the described study showed that this method can be applied directly to bones without a demineralisation step and that it allows the identification of bovine and ruminant bones even after severe processing. The results also showed that the method is independent of exogenous contamination and that it is therefore entirely appropriate for this application. PMID:25034259

Determination of the ruminant origin of bone particles using fluorescence in situ hybridization (FISH).

PubMed

Lecrenier, M C; Ledoux, Q; Berben, G; Fumière, O; Saegerman, C; Baeten, V; Veys, P

2014-07-17

Molecular biology techniques such as PCR constitute powerful tools for the determination of the taxonomic origin of bones. DNA degradation and contamination by exogenous DNA, however, jeopardise bone identification. Despite the vast array of techniques used to decontaminate bone fragments, the isolation and determination of bone DNA content are still problematic. Within the framework of the eradication of transmissible spongiform encephalopathies (including BSE, commonly known as "mad cow disease"), a fluorescence in situ hybridization (FISH) protocol was developed. Results from the described study showed that this method can be applied directly to bones without a demineralisation step and that it allows the identification of bovine and ruminant bones even after severe processing. The results also showed that the method is independent of exogenous contamination and that it is therefore entirely appropriate for this application.

[Interventional radiology in bone metastases].

PubMed

Chiras, Jacques; Cormier, Evelyne; Baragan, Hector; Jean, Betty; Rose, Michèle

2007-02-01

Interventional radiology takes a large place in the treatment of bone metastases by numerous techniques, percutaneous or endovascular. Vertebroplasty appears actually as the most important technique for stabilisation of spine metastases as it induces satisfactory stabilisation of the vertebra and offer clear improvement of the quality of life. Due to the success of this technique cementoplasty of other bones, mainly pelvic girdle, largely develop. The heath due to the polymerisation of the cement induce carcinolytic effect but this effect is not as important as that can be created with radiofrequency destruction. This last technique appears actually as the most important development to destroy definitively some bone metastases and replace progressively alcoholic destruction of such lesions. Angiographic techniques appear more confidential but endovascular embolization is very useful to diminish the risk of surgical treatment of hyper vascular metastases. Chemoembolization is actually developped to associate the relief of pain induced by endovascular embolization and the carcinolytic effect obtained by local endovascular chemotherapy. All these techniques should develop largely during the next years and their efficacy and safety should improve largely by treating earlier the metastasis.

Dosimetric Comparison of Bone Marrow-Sparing Intensity-Modulated Radiotherapy Versus Conventional Techniques for Treatment of Cervical Cancer

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mell, Loren K.; Tiryaki, Hanifi; Ahn, Kang-Hyun

2008-08-01

Purpose: To compare bone marrow-sparing intensity-modulated pelvic radiotherapy (BMS-IMRT) with conventional (four-field box and anteroposterior-posteroanterior [AP-PA]) techniques in the treatment of cervical cancer. Methods and Materials: The data from 7 cervical cancer patients treated with concurrent chemotherapy and IMRT without BMS were analyzed and compared with data using four-field box and AP-PA techniques. All plans were normalized to cover the planning target volume with the 99% isodose line. The clinical target volume consisted of the pelvic and presacral lymph nodes, uterus and cervix, upper vagina, and parametrial tissue. Normal tissues included bowel, bladder, and pelvic bone marrow (PBM), which comprisedmore » the lumbosacral spine and ilium and the ischium, pubis, and proximal femora (lower pelvis bone marrow). Dose-volume histograms for the planning target volume and normal tissues were compared for BMS-IMRT vs. four-field box and AP-PA plans. Results: BMS-IMRT was superior to the four-field box technique in reducing the dose to the PBM, small bowel, rectum, and bladder. Compared with AP-PA plans, BMS-IMRT reduced the PBM volume receiving a dose >16.4 Gy. BMS-IMRT reduced the volume of ilium, lower pelvis bone marrow, and bowel receiving a dose >27.7, >18.7, and >21.1 Gy, respectively, but increased dose below these thresholds compared with the AP-PA plans. BMS-IMRT reduced the volume of lumbosacral spine bone marrow, rectum, small bowel, and bladder at all dose levels in all 7 patients. Conclusion: BMS-IMRT reduced irradiation of PBM compared with the four-field box technique. Compared with the AP-PA technique, BMS-IMRT reduced lumbosacral spine bone marrow irradiation and reduced the volume of PBM irradiated to high doses. Therefore BMS-IMRT might reduce acute hematologic toxicity compared with conventional techniques.« less

[Atraumatic bone expansion: Interest of piezo-surgery, conicals expanders and immediate implantation combination].

PubMed

Iraqui, O; Lakhssassi, N; Berrada, S; Merzouk, N

2016-06-01

The durability of dental implants depends on the presence of a 1mm coating bone sheath all around the fixture. Therefore, bone resorption represents a challenge for the practitioner. Bone expansion is a surgical technique that allows the management of horizontal bone atrophy. Cortical bone splitting allows for an enlargement of the residual crest by displacement of the vestibular bone flap. The immediate placement of implants secures the widening and allows for a 97% survival rate. However, bone expansion is hard to undertake in sites with high bone density. Furthermore, the use of traditional instruments increases patient's stress and the risk for an interruptive fracture during bone displacement. Non-traumatic bone expansion is one solution to this problem. The combination of piezo-surgery and conical expanders allows for a secured displacement of the selected bone flap as well as an immediate implant placement, avoiding the risk of slipping, overheating, or fracture, all within an undeniable operative comfort. Non-traumatic bone expansion is a reliable, reproducible, conservative, and economical in time and cost procedure. We describe our atraumatic bone expension and immediate implant placement technique in high bone density sites and illustrate it by a clinical case. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

Bone formation in vivo induced by Cbfa1-carrying adenoviral vectors released from a biodegradable porous β-tricalcium phosphate (β-TCP) material.

PubMed

Uemura, Toshimasa; Kojima, Hiroko

2011-06-01

Overexpression of Cbfa1 (a transcription factor indispensable for osteoblastic differentiation) is expected to induce the formation of bone directly and indirectly in vivo by accelerating osteoblastic differentiation. Adenoviral vectors carrying the cDNA of Cbfa1/til-1(Adv-Cbf1) were allowed to be adsorbed onto porous blocks of β-tricalcium phosphate (β-TCP), a biodegradable ceramic, which were then implanted subcutaneously and orthotopically into bone defects. The adenoviral vectors were released sustainingly by biodegradation, providing long-term expression of the genes. Results of the subcutaneous implantation of Adv-Cbfa1-adsorbed β-TCP/osteoprogenitor cells suggest that a larger amount of bone formed in the pores of the implant than in the control material. Regarding orthotopic implantation into bone defects, the released Adv-Cbfa1 accelerated regeneration in the cortical bone, whereas it induced bone resorption in the marrow cavity. A safer gene transfer using a smaller amount of the vector was achieved using biodegradable porous β-TCP as a carrier.

Bone formation in vivo induced by Cbfa1-carrying adenoviral vectors released from a biodegradable porous β-tricalcium phosphate (β-TCP) material

NASA Astrophysics Data System (ADS)

Uemura, Toshimasa; Kojima, Hiroko

2011-06-01

Overexpression of Cbfa1 (a transcription factor indispensable for osteoblastic differentiation) is expected to induce the formation of bone directly and indirectly in vivo by accelerating osteoblastic differentiation. Adenoviral vectors carrying the cDNA of Cbfa1/til-1(Adv-Cbf1) were allowed to be adsorbed onto porous blocks of β-tricalcium phosphate (β-TCP), a biodegradable ceramic, which were then implanted subcutaneously and orthotopically into bone defects. The adenoviral vectors were released sustainingly by biodegradation, providing long-term expression of the genes. Results of the subcutaneous implantation of Adv-Cbfa1-adsorbed β-TCP/osteoprogenitor cells suggest that a larger amount of bone formed in the pores of the implant than in the control material. Regarding orthotopic implantation into bone defects, the released Adv-Cbfa1 accelerated regeneration in the cortical bone, whereas it induced bone resorption in the marrow cavity. A safer gene transfer using a smaller amount of the vector was achieved using biodegradable porous β-TCP as a carrier.

3D Porous Architecture of Stacks of β-TCP Granules Compared with That of Trabecular Bone: A microCT, Vector Analysis, and Compression Study.

PubMed

Chappard, Daniel; Terranova, Lisa; Mallet, Romain; Mercier, Philippe

2015-01-01

The 3D arrangement of porous granular biomaterials usable to fill bone defects has received little study. Granular biomaterials occupy 3D space when packed together in a manner that creates a porosity suitable for the invasion of vascular and bone cells. Granules of beta-tricalcium phosphate (β-TCP) were prepared with either 12.5 or 25 g of β-TCP powder in the same volume of slurry. When the granules were placed in a test tube, this produced 3D stacks with a high (HP) or low porosity (LP), respectively. Stacks of granules mimic the filling of a bone defect by a surgeon. The aim of this study was to compare the porosity of stacks of β-TCP granules with that of cores of trabecular bone. Biomechanical compression tests were done on the granules stacks. Bone cylinders were prepared from calf tibia plateau, constituted high-density (HD) blocks. Low-density (LD) blocks were harvested from aged cadaver tibias. Microcomputed tomography was used on the β-TCP granule stacks and the trabecular bone cores to determine porosity and specific surface. A vector-projection algorithm was used to image porosity employing a frontal plane image, which was constructed line by line from all images of a microCT stack. Stacks of HP granules had porosity (75.3 ± 0.4%) and fractal lacunarity (0.043 ± 0.007) intermediate between that of HD (respectively 69.1 ± 6.4%, p < 0.05 and 0.087 ± 0.045, p < 0.05) and LD bones (respectively 88.8 ± 1.57% and 0.037 ± 0.014), but exhibited a higher surface density (5.56 ± 0.11 mm(2)/mm(3) vs. 2.06 ± 0.26 for LD, p < 0.05). LP granular arrangements created large pores coexisting with dense areas of material. Frontal plane analysis evidenced a more regular arrangement of β-TCP granules than bone trabecule. Stacks of HP granules represent a scaffold that resembles trabecular bone in its porous microarchitecture.

The ABC7 regimen: a new approach to metastatic breast cancer using seven common drugs to inhibit epithelial-to-mesenchymal transition and augment capecitabine efficacy

PubMed Central

Kast, Richard E; Skuli, Nicolas; Cos, Samuel; Karpel-Massler, Georg; Shiozawa, Yusuke; Goshen, Ran; Halatsch, Marc-Eric

2017-01-01

Breast cancer metastatic to bone has a poor prognosis despite recent advances in our understanding of the biology of both bone and breast cancer. This article presents a new approach, the ABC7 regimen (Adjuvant for Breast Cancer treatment using seven repurposed drugs), to metastatic breast cancer. ABC7 aims to defeat aspects of epithelial-to-mesenchymal transition (EMT) that lead to dissemination of breast cancer to bone. As add-on to current standard treatment with capecitabine, ABC7 uses ancillary attributes of seven already-marketed noncancer treatment drugs to stop both the natural EMT process inherent to breast cancer and the added EMT occurring as a response to current treatment modalities. Chemotherapy, radiation, and surgery provoke EMT in cancer generally and in breast cancer specifically. ABC7 uses standard doses of capecitabine as used in treating breast cancer today. In addition, ABC7 uses 1) an older psychiatric drug, quetiapine, to block RANK signaling; 2) pirfenidone, an anti-fibrosis drug to block TGF-beta signaling; 3) rifabutin, an antibiotic to block beta-catenin signaling; 4) metformin, a first-line antidiabetic drug to stimulate AMPK and inhibit mammalian target of rapamycin, (mTOR); 5) propranolol, a beta-blocker to block beta-adrenergic signaling; 6) agomelatine, a melatonergic antidepressant to stimulate M1 and M2 melatonergic receptors; and 7) ribavirin, an antiviral drug to prevent eIF4E phosphorylation. All these block the signaling pathways – RANK, TGF-beta, mTOR, beta-adrenergic receptors, and phosphorylated eIF4E – that have been shown to trigger EMT and enhance breast cancer growth and so are worthwhile targets to inhibit. Agonism at MT1 and MT2 melatonergic receptors has been shown to inhibit both breast cancer EMT and growth. This ensemble was designed to be safe and augment capecitabine efficacy. Given the expected outcome of metastatic breast cancer as it stands today, ABC7 warrants a cautious trial. PMID:28744157

Fixation of comminuted midshaft clavicle fractures with bone fragments separated by soft tissue using a novel double ligature technique: A case report.

PubMed

Ju, Wei-Na; Wang, Cheng-Xue; Wang, Tie-Jun; Qi, Bao-Chang

2017-11-01

Clavicle fractures are common, and mostly occur in the midshaft. Methods for operative treatment of midshaft clavicle fractures are evolving, as they improve clinical outcomes compared with traditional conservative management. However, fixation of comminuted midshaft clavicle fractures with bone fragments separated by soft tissue remains a challenge. Here, we present a case of comminuted midshaft clavicle fracture with a bone fragment separated from the main fracture by soft tissue. Left comminuted midshaft clavicle fracture. We treated this patient with a novel double ligature technique using absorbable suturing. In the past 7 years, we have treated >50 patients with this technique. We have achieved good clinical outcomes with no complications. We recommend widespread use of our novel double ligature technique for treating comminuted midshaft clavicle fractures with bone fragments separated by soft tissue.

Fixation of comminuted midshaft clavicle fractures with bone fragments separated by soft tissue using a novel double ligature technique

PubMed Central

Ju, Wei-Na; Wang, Cheng-Xue; Wang, Tie-Jun; Qi, Bao-Chang

2017-01-01

Abstract Rationale: Clavicle fractures are common, and mostly occur in the midshaft. Methods for operative treatment of midshaft clavicle fractures are evolving, as they improve clinical outcomes compared with traditional conservative management. However, fixation of comminuted midshaft clavicle fractures with bone fragments separated by soft tissue remains a challenge. Patient concerns: Here, we present a case of comminuted midshaft clavicle fracture with a bone fragment separated from the main fracture by soft tissue. Diagnosis: Left comminuted midshaft clavicle fracture. Interventions: We treated this patient with a novel double ligature technique using absorbable suturing. Outcomes: In the past 7 years, we have treated >50 patients with this technique. We have achieved good clinical outcomes with no complications. Lessons: We recommend widespread use of our novel double ligature technique for treating comminuted midshaft clavicle fractures with bone fragments separated by soft tissue. PMID:29137088

Different configuration of socket shield technique in peri-implant bone preservation: An experimental study in dog mandible.

PubMed

Calvo-Guirado, José Luis; Troiano, Miguel; López-López, P J; Ramírez-Fernandez, María Piedad; de Val, José Eduardo Maté Sánchez; Marin, Jose Manuel Granero; Gehrke, Sergio Alexandre

2016-11-01

The aim of this study was to evaluate the influence of the residual root and peri implant bone dimensions on the clinical success of the socket shield technique. Thirty-six dental implants were installed in 6 dogs. The clinical crowns of teeth P3, P4 and M1 were beheaded. Afterwards, the roots were worn down 2-3mm in apical direction until they were located at crestal level. Posterior implant beds were prepared in the center of the roots passing by 3mm apically forming 6 groups in accordance to the remaining root thickness. Radiography of the crestal bone level was performed on day 0 and after 12 weeks. Histomorphometric analyses of the specimens were carried out to measure the crestal bone level, the bone to implant contact and the buccal and lingual bone thickness at the implant shoulder portion. Correlations between groups were analyzed through nonparametric Friedman test, statistical significance was set as p<0.05. All 36 implants were osseointegrated, but 3 samples showed a clinical inflammatory reaction and some radicular fragments presented a small resorption process. On the buccal and lingual side, the radicular fragment was attached to the buccal bone plate by a physiologic periodontal ligament. In the areas where there was space between the implant and the fragment, newly formed bone was demonstrated directly on the implant surface. Within the limitations of an animal pilot study, root-T belt technique may be beneficial in preserving and protecting the bundle bone and preservation of soft tissues. If the thickness of the buccal bone is 3mm, and the thickness of the remaining root fragment is 2mm, the socket shield technique is more predictable and the bone contours can be maintained. Copyright © 2016 Elsevier GmbH. All rights reserved.

The effect of carrier type on bone regeneration of demineralized bone matrix in vivo.

PubMed

Tavakol, Shima; Khoshzaban, Ahad; Azami, Mahmoud; Kashani, Iraj Ragerdi; Tavakol, Hani; Yazdanifar, Mahbube; Sorkhabadi, Seyed Mahdi Rezayat

2013-11-01

Demineralized bone matrix (DBM) is a bone substitute biomaterial used as an excellent grafting material. Some factors such as carrier type might affect the healing potential of this material. The background data discuss the present status of the field: Albumin as a main protein in blood and carboxymethyl cellulose (CMC) were applied frequently in the DBM gels. We investigated the bone-repairing properties of 2 DBMs with different carriers. Bone regeneration in 3 groups of rat calvaria treated with DBM from the Iranian Tissue Bank Research and Preparation Center, DBM from Hans Biomed Corporation, and an empty cavity was studied. Albumin and CMC as carriers were used. The results of bone regeneration in the samples after 1, 4, and 8 weeks of implantation were compared. The block of the histologic samples was stained with hematoxylin and eosin, and the percentage area of bone formation was calculated using the histomorphometry method. The results of in vivo tests showed a significantly stronger new regenerated bone occupation in the DBM with albumin carrier compared with the one with CMC 8 weeks after the implantation. The 2 types of DBM had a significant difference in bone regeneration. This difference is attributed to the type of carriers. Albumin could improve mineralization and bioactivity compared with CMC.

Scanning electron microscopy of bone.

PubMed

Boyde, Alan

2012-01-01

This chapter described methods for Scanning Electron Microscopical imaging of bone and bone cells. Backscattered electron (BSE) imaging is by far the most useful in the bone field, followed by secondary electrons (SE) and the energy dispersive X-ray (EDX) analytical modes. This chapter considers preparing and imaging samples of unembedded bone having 3D detail in a 3D surface, topography-free, polished or micromilled, resin-embedded block surfaces, and resin casts of space in bone matrix. The chapter considers methods for fixation, drying, looking at undersides of bone cells, and coating. Maceration with alkaline bacterial pronase, hypochlorite, hydrogen peroxide, and sodium or potassium hydroxide to remove cells and unmineralised matrix is described in detail. Attention is given especially to methods for 3D BSE SEM imaging of bone samples and recommendations for the types of resin embedding of bone for BSE imaging are given. Correlated confocal and SEM imaging of PMMA-embedded bone requires the use of glycerol to coverslip. Cathodoluminescence (CL) mode SEM imaging is an alternative for visualising fluorescent mineralising front labels such as calcein and tetracyclines. Making spatial casts from PMMA or other resin embedded samples is an important use of this material. Correlation with other imaging means, including microradiography and microtomography is important. Shipping wet bone samples between labs is best done in glycerol. Environmental SEM (ESEM, controlled vacuum mode) is valuable in eliminating -"charging" problems which are common with complex, cancellous bone samples.

Naringin protects against bone loss in steroid-treated inflammatory bowel disease in a rat model.

PubMed

Li, Chengli; Zhang, Jun; Lv, Fang; Ge, Xingtao; Li, Gang

2018-07-15

We observed the effects of naringin on bone loss in glucocorticoid-treated inflammatory bowel disease (IBD) in a rat model. The IBD model was established in Sprague-Dawley rats by administering 5.0% dextran sodium sulfate. Dexamethasone (DEX) and naringin were given at the second week. Blood, colon and bone samples were collected for biomarker assay, histological analysis or microCT analysis. Superoxide dismutase, catalase and malonaldehyde were measured in bone. A significant decrease of procollagen type 1 N-terminal propeptide (P1NP) level was observed in DEX-treated IBD groups compared with the control (p < 0.05). P1NP levels were dose-dependently increased in the presence of naringin intervention. Bone loss and decreased bone biomechanical properties were observed in DEX-treated IBD rats compared with control rats (p < 0.01). Naringin intervention protected against bone loss and decreased bone biomechanical properties. Bone formation related gene mRNA expressions were significantly decreased in DEX-treated IBD rats compared with control rats. Naringin administration reversed the down-regulation of the expressions of those genes. Naringin treatment reduced the oxidative stress in bone from DEX-treated IBD rats. Our data indicated that naringin may have great potential for the treatment of bone loss in glucocorticoid-treated IBD patients via blocking oxidative stress and promoting bone formation. Copyright © 2018 Elsevier Inc. All rights reserved.

Rotary ultrasonic drilling on bone: A novel technique to put an end to thermal injury to bone.

PubMed

Gupta, Vishal; Pandey, Pulak M; Gupta, Ravi K; Mridha, Asit R

2017-03-01

Bone drilling is common in orthopedic procedures and the heat produced during conventional experimental drilling often exceeds critical temperature of 47 °C and induces thermal osteonecrosis. The osteonecrosis may be the reason for impaired healing, early loosening and implant failure. This study was undertaken to control the temperature rise by interrupted cutting and reduced friction effects at the interface of drill tool and the bone surface. In this work, rotary ultrasonic drilling technique with diamond abrasive particles coated on the hollow drill tool without any internal or external cooling assistance was used. Experiments were performed at room temperature on the mid-diaphysis sections of fresh pig bones, which were harvested immediately after sacrifice of the animal. Both rotary ultrasonic drilling on bone and conventional surgical drilling on bone were performed in a five set of experiments on each process using identical constant process parameters. The maximum temperature of each trial was recorded by K-type thermocouple device. Ethylenediaminetetraacetic acid decalcification was done for microscopic examination of bone. In this comparative procedure, rotary ultrasonic drilling on bone produced much lower temperature, that is, 40.2 °C ± 0.4 °C and 40.3 °C ± 0.2 °C as compared to that of conventional surgical drilling on bone, that is, 74.9 °C ± 0.8 °C and 74.9 °C ± 0.6 °C with respect to thermocouples fixed at first and second position, respectively. The conventional surgical drilling on bone specimens revealed gross tissue burn, microscopic evidence of thermal osteonecrosis and tissue injury in the form of cracks due to the generated force during drilling. But our novel technique showed no such features. Rotary ultrasonic drilling on bone technique is robust and superior to other methods for drilling as it induces no thermal osteonecrosis and does not damage the bone by generating undue forces during drilling.

Electron Microscopy and Analytical X-ray Characterization of Compositional and Nanoscale Structural Changes in Fossil Bone

NASA Astrophysics Data System (ADS)

Boatman, Elizabeth Marie

The nanoscale structure of compact bone contains several features that are direct indicators of bulk tissue mechanical properties. Fossil bone tissues represent unique opportunities to understand the compact bone structure/property relationships from a deep time perspective, offering a possible array of new insights into bone diseases, biomimicry of composite materials, and basic knowledge of bioapatite composition and nanoscale bone structure. To date, most work with fossil bone has employed microscale techniques and has counter-indicated the survival of bioapatite and other nanoscale structural features. The obvious disconnect between the use of microscale techniques and the discernment of nanoscale structure has prompted this work. The goal of this study was to characterize the nanoscale constituents of fossil compact bone by applying a suite of diffraction, microscopy, and spectrometry techniques, representing the highest levels of spatial and energy resolution available today, and capable of complementary structural and compositional characterization from the micro- to the nanoscale. Fossil dinosaur and crocodile long bone specimens, as well as modern ratite and crocodile femurs, were acquired from the UC Museum of Paleontology. Preserved physiological features of significance were documented with scanning electron microscopy back-scattered imaging. Electron microprobe wavelength-dispersive X-ray spectroscopy (WDS) revealed fossil bone compositions enriched in fluorine with a complementary loss of oxygen. X-ray diffraction analyses demonstrated that all specimens were composed of apatite. Transmission electron microscopy (TEM) imaging revealed preserved nanocrystallinity in the fossil bones and electron diffraction studies further identified these nanocrystallites as apatite. Tomographic analyses of nanoscale elements imaged by TEM and small angle X-ray scattering were performed, with the results of each analysis further indicating that nanoscale structure is highly conserved in these four fossil specimens. Finally, the results of this study indicate that bioapatite can be preserved in even the most ancient vertebrate specimens, further supporting the idea that fossilization is a preservational process. This work also underlines the importance of using appropriately selected characterization and analytical techniques for the study of fossil bone, especially from the perspective of spatial resolution and the scale of the bone structural features in question.

Mussel-inspired nano-building block assemblies for mimicking extracellular matrix microenvironments with multiple functions.

PubMed

Wang, Zhenming; Jia, Zhanrong; Jiang, Yanan; Li, Pengfei; Han, Lu; Lu, Xiong; Ren, Fuzeng; Wang, Kefeng; Yuan, Huiping

2017-08-03

The assembly of nano-building blocks is an effective way to produce artificial extracellular matrix microenvironments with hierarchical micro/nano structures. However, it is hard to assemble different types of nano-building blocks, to form composite coatings with multiple functions, by traditional layer-by-layer (LbL) self-assembly methods. Inspired by the mussel adhesion mechanism, we developed polydopamine (PDA)-decorated bovine serum albumin microspheres (BSA-MS) and nano-hydroxyapatite (nano-HA), and assembled them to form bioactive coatings with micro/nano structures encapsulating bone morphogenetic protein-2 (BMP-2). First, PDA-decorated nano-HA (nano-pHA) was obtained by oxidative polymerization of dopamine on nano-HA. Second, BMP-2-encapsulated BSA microspheres were prepared through desolvation, and then were also decorated by PDA (pBSA-MS). Finally, the nano-pHA and pBSA-MS were assembled using the adhesive properties of PDA. Bone marrow stromal cell cultures and in vivo implantation, showed that the pHA/pBSA (BMP-2) coatings can promote cell adhesion, proliferation, and benefited for osteoinductivity. PDA decoration was also applied to assemble various functional nanoparticles, such as nano-HA, polystyrene, and Fe 3 O 4 nanoparticles. In summary, this study provides a novel strategy for the assembly of biofunctional nano-building blocks, which surpasses traditional LbL self-assembly of polyelectrolytes, and can find broad applications in bioactive agents delivery or multi-functional coatings.

Inferior alveolar nerve block: Alternative technique

PubMed Central

Thangavelu, K.; Kannan, R.; Kumar, N. Senthil

2012-01-01

Background: Inferior alveolar nerve block (IANB) is a technique of dental anesthesia, used to produce anesthesia of the mandibular teeth, gingivae of the mandible and lower lip. The conventional IANB is the most commonly used the nerve block technique for achieving local anesthesia for mandibular surgical procedures. In certain cases, however, this nerve block fails, even when performed by the most experienced clinician. Therefore, it would be advantageous to find an alternative simple technique. Aim and Objective: The objective of this study is to find an alternative inferior alveolar nerve block that has a higher success rate than other routine techniques. To this purpose, a simple painless inferior alveolar nerve block was designed to anesthetize the inferior alveolar nerve. Materials and Methods: This study was conducted in Oral surgery department of Vinayaka Mission's dental college Salem from May 2009 to May 2011. Five hundred patients between the age of 20 years and 65 years who required extraction of teeth in mandible were included in the study. Out of 500 patients 270 were males and 230 were females. The effectiveness of the IANB was evaluated by using a sharp dental explorer in the regions innervated by the inferior alveolar, lingual, and buccal nerves after 3, 5, and 7 min, respectively. Conclusion: This study concludes that inferior alveolar nerve block is an appropriate alternative nerve block to anesthetize inferior alveolar nerve due to its several advantages. PMID:25885503

Inferior alveolar nerve block: Alternative technique.

PubMed

Thangavelu, K; Kannan, R; Kumar, N Senthil

2012-01-01

Inferior alveolar nerve block (IANB) is a technique of dental anesthesia, used to produce anesthesia of the mandibular teeth, gingivae of the mandible and lower lip. The conventional IANB is the most commonly used the nerve block technique for achieving local anesthesia for mandibular surgical procedures. In certain cases, however, this nerve block fails, even when performed by the most experienced clinician. Therefore, it would be advantageous to find an alternative simple technique. The objective of this study is to find an alternative inferior alveolar nerve block that has a higher success rate than other routine techniques. To this purpose, a simple painless inferior alveolar nerve block was designed to anesthetize the inferior alveolar nerve. This study was conducted in Oral surgery department of Vinayaka Mission's dental college Salem from May 2009 to May 2011. Five hundred patients between the age of 20 years and 65 years who required extraction of teeth in mandible were included in the study. Out of 500 patients 270 were males and 230 were females. The effectiveness of the IANB was evaluated by using a sharp dental explorer in the regions innervated by the inferior alveolar, lingual, and buccal nerves after 3, 5, and 7 min, respectively. This study concludes that inferior alveolar nerve block is an appropriate alternative nerve block to anesthetize inferior alveolar nerve due to its several advantages.

Design of a surgical instrument for removing bone to provide screw access to a spinal fusion cage.

PubMed

Jabbary Aslani, F; Hukins, D W L; Shepherd, D E T; Parry, J J; Fennell, A J; Lambell, S

2012-01-01

A surgical instrument to aid implantation of a range of lumbar spinal fusion cages has been developed. Once the cage is in position, the entrance to screw holes is partially blocked by the edge of the vertebral body. In order to insert fixation screws to secure the cage between the vertebrae, some part of the blocking edge has to be removed. Rongeurs are currently being used, but they can be time consuming and have the disadvantage that they may remove more bone than is necessary and may cause damage to the fusion cage if not used with care. In addition, access around some of the screw holes may be difficult. The aim of this instrument was to overcome these shortcomings. This paper describes the design of a surgical instrument for cutting edges from vertebral bodies. The development and evaluation of concept designs are presented and discussed. Potential risks were considered and modifications were performed on the selected concept. Functional prototypes were manufactured and tested on sheep lumbar vertebrae. The results showed that the newly designed cutting instrument functions as required and removes the required amount of bone from the vertebral body edge.

Limited posterolateral surgical approach to the knee for excision of osteoid osteoma.

PubMed

Minkoff, J; Jaffe, L; Menendez, L

1987-10-01

An 18-year-old man suffered four years of undiagnosed knee pain until a CAT scan revealed an epiphyseal osteoid osteoma of the tibia located subchondrally, just medial to the proximal tibiofibular joint. A nidus in this location is not easily accessible, and its proximity to the joint surface raised concerns about damage to the tibial plateau. To facilitate excision of the tumor, cadaveric dissections were performed to develop a limited posterior approach to the proximal, lateral portion of the tibia. The CAT scan was used to calculate the precise dimensions of the tumor and its relation to the posterior tibial cortex and the proximal tibiofibular joint. With the use of the exposure developed in the laboratory and the calculations derived from the CAT scan, the tumor could be excised by removing a single block of bone 15 mm3. Intraoperative radiographs confirmed the presence of the nidus within the excised block of bone. This case report reaffirms the frequent difficulties and tardiness in diagnosing osteoid osteomas and the need to include these tumors in the differential diagnosis of knee pain and epiphyseal lesions. Before CAT scans were used, the working diagnoses were torn meniscus, juvenile rheumatoid arthritis, and bone hemangiomatosis.

Tamoxifen regulation of bone growth and endocrine function in the ovariectomized rat: discrimination of responses involving estrogen receptor α/estrogen receptor β, G protein-coupled estrogen receptor, or estrogen-related receptor γ using fulvestrant (ICI 182780).

PubMed

Fitts, James M; Klein, Robert M; Powers, C Andrew

2011-07-01

Tamoxifen is a selective estrogen receptor (ER) modulator, but it is also a deactivating ligand for estrogen-related receptor-γ (ERRγ) and a full agonist for the G protein-coupled estrogen receptor (GPER). Fulvestrant is a selective ER down-regulator that lacks agonist effects on ERα/ERβ, is inactive on ERRγ, but acts as a full agonist on GPER. Fulvestrant effects on tamoxifen actions on uterine and somatic growth, bone, the growth hormone (GH)-insulin-like growth factor I (IGF-I) axis, and pituitary prolactin were analyzed to pharmacologically discriminate tamoxifen effects that may be mediated by ERα/ERβ versus ERRγ versus GPER. Ovariectomized rats received tamoxifen (0.6 mg/kg/daily) plus fulvestrant at 0, 3, 6, or 12 mg/kg/daily for 5 weeks; controls received vehicle or 6 mg/kg fulvestrant daily. Tamoxifen effects to increase uterine weight, decrease serum IGF-I, increase pituitary prolactin, and increase bone mineral density could be fully blocked by fulvestrant, indicating mediation by ERα/ERβ. Tamoxifen effects to decrease pituitary GH, tibia length, and body weight were only partially blocked by fulvestrant, indicating involvement of mechanisms unrelated to ERα/ERβ. Fulvestrant did not inhibit tamoxifen actions to reduce total pituitary protein, again indicating effects not mediated by ERα/ERβ. Tamoxifen actions to reduce serum GH were mimicked rather than inhibited by fulvestrant, pharmacological features consistent with GPER involvement. However, fulvestrant alone increased IGF-I and also blocked tamoxifen-evoked IGF-I decreases; thus fulvestrant effects on serum GH might reflect increased IGF-I feedback inhibition. Fulvestrant alone had no effect on the other parameters. The findings indicate that mechanisms unrelated to ERα/ERβ contribute to tamoxifen effects on body weight, bone growth, and pituitary function.

The split portal: Description of a new accessory posterior portal for arthroscopic shoulder instability procedures.

PubMed

Mirouse, Guillaume; Nourissat, Geoffroy

2016-02-01

Open approach to the posterior shoulder during bone block for posterior shoulder instability is challenging. Anatomical study was performed to identify landmarks of a portal, avoiding soft tissue damage, between the infraspinatus (IS) and teres minor (TM) muscles and distant from the supra-scapular nerve (SSN) for arthroscopic shoulder bone block. Eight fresh-frozen cadaveric shoulder specimens were used. The arthroscope was introduced through the soft point (SP). A guide wire was placed through the SP, in the rotator interval direction. A posterior open dissection exposed the split between the IS and TM. A new guide wire was placed into the split, parallel to the first wire, to locate the new posterior arthroscopic approach. Ten distances were measured to define the safe position. The mean values were: SP to split IS-TM: 2 ± 0.2 (2-2.8); spinal bone to split IS-TM: 5 ± 0.5 (3-6.2); split IS-TM to posterior glenoid 6 o'clock: 1.3 ± 0.3 (0.6-1.6), 9 o'clock: 1.5 ± 0.3 (1-1.9), and 12 o'clock: 2 ± 0.1 (2.1-2.4); SSN to posterior glenoid 6 o'clock: 2.4 ± 0.2 (2.1-2.6), 9 o'clock: 1.7 ± 0.1 (1.5-1.8), and 12 o'clock: 1.5 ± 0.3 (1.2-2.1); and SSN to split IS-TM: 2 ± 0.3 (1.2-2.1). This preliminary anatomical study described a posterior arthroscopic portal located 2 cm under the SP, parallel to the SP portal direction, and finishing between 7 and 8 o'clock at the posterior rim of the glenoid. For arthroscopic shoulder bone block, this portal can avoid muscle and SSN lesions.

Disruption of Lrp4 function by genetic deletion or pharmacological blockade increases bone mass and serum sclerostin levels

PubMed Central

Chang, Ming-Kang; Kramer, Ina; Huber, Thomas; Kinzel, Bernd; Guth-Gundel, Sabine; Leupin, Olivier; Kneissel, Michaela

2014-01-01

We identified previously in vitro LRP4 (low-density lipoprotein receptor-related protein 4) as a facilitator of the WNT (Wingless-type) antagonist sclerostin and found mutations disrupting this function to be associated with high bone mass in humans similar to patients lacking sclerostin. To further delineate the role of LRP4 in bone in vivo, we generated mice lacking Lrp4 in osteoblasts/osteocytes or osteocytes only. Lrp4 deficiency promoted progressive cancellous and cortical bone gain in both mutants, although more pronouncedly in mice deficient in osteoblast/osteocyte Lrp4, consistent with our observation in human bone that LRP4 is most strongly expressed by osteoblasts and early osteocytes. Bone gain was related primarily to increased bone formation. Interestingly, Lrp4 deficiency in bone dramatically elevated serum sclerostin levels whereas bone expression of Sost encoding for sclerostin was unaltered, indicating that osteoblastic Lrp4 retains sclerostin within bone. Moreover, we generated anti-LRP4 antibodies selectively blocking sclerostin facilitator function while leaving unperturbed LRP4–agrin interaction, which is essential for neuromuscular junction function. These antibodies increased bone formation and thus cancellous and cortical bone mass in skeletally mature rodents. Together, we demonstrate a pivotal role of LRP4 in bone homeostasis by retaining and facilitating sclerostin action locally and provide a novel avenue to bone anabolic therapy by antagonizing LRP4 sclerostin facilitator function. PMID:25404300

[Synthesis and characteristics of porous hydroxyapatite bioceramics].

PubMed

Niu, Jinlong; Zhang, Zhenxi; Jiang, Dazong

2002-06-01

The macroporous structure of human bone allows the ingrowth of the soft tissues and organic cells into the bone matrix, profits the development and metabolism of bone tissue, and adapts the bone to the change of load. There is great requirement for artificial biomimic porous bioactive ceramics with the similar structure of bone tissue that can be used clinically for repairing lost bone. Fine hydroxyapatite (HAp) powder produced by wet chemical reaction was mixed with hydrogen peroxide (H2O2), polyvinyl alcohol, methyl cellulose or other pores-making materials to form green cake. After drying at low temperature (below 100 degrees C) and decarbonizing at about 300 degrees C-400 degrees C, the spongy ceramic block was sintered at high temperature, thus, macroporous HAp bioceramic with interconnected pores and reasonable porosity and pore-diameter was manufactured. This kind of porous HAp bioceramics were intrinsically osteoinductive to a certain degree, but its outstanding property was that they can absorb human bone morphogenetic proteins and other bone growth factors to form composites, so that the macroporous HAp bioactive ceramic has appropriate feasibility for clinical application. From the point of biomedical application, the recent developments in synthesis and characteristics investigation of macroporous HAp are reviewed in this paper.

Telehealth Coaching: Impact on Dietary and Physical Activity Contributions to Bone Health During a Military Deployment.

PubMed

Frank, Laura L; McCarthy, Mary S

2016-05-01

To examine the difference in bone health and body composition via blood biomarkers, bone mineral density, anthropometrics and dietary intake following deployment to Afghanistan among soldiers randomized to receive telehealth coaching promoting nutrition and exercise. This was a prospective, longitudinal, cluster-randomized, controlled trial with repeated measures in 234 soldiers. Measures included heel bone scan for bone mineral density, blood biomarkers for bone formation, resorption, and turnover, body composition via Futrex, resting metabolic rate via MedGem, physical activity using the Baecke Habitual Physical Activity Questionnaire, and dietary intake obtained from the Block Food Frequency Questionnaire. There were significant increases in body fat (p = 0.00035), osteocalcin (0.0152), and sports index (p = 0.0152) for the telehealth group. No other statistically significant differences were observed between groups. Vitamin D intake among soldiers was ≤ 35% of the suggested Dietary Reference Intakes for age. A 9-month deployment to Afghanistan increased body fat, bone turnover, and physical activity among soldiers randomized to receive telehealth strategies to build bone with nutrition and exercise. Reprint & Copyright © 2016 Association of Military Surgeons of the U.S.

Integrin αMβ2 is differently expressed by subsets of human osteoclast precursors and mediates adhesion of classical monocytes to bone

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sprangers, Sara, E-mail: s.l.sprangers@acta.nl; Schoenmaker, Ton, E-mail: t.schoenmaker@acta.nl; Department of Periodontology, Academic Centre for Dentistry Amsterdam

Bone-degrading osteoclasts are formed through fusion of their monocytic precursors. In the population of human peripheral blood monocytes, three distinct subsets have been identified: classical, intermediate and non-classical monocytes. We have previously shown that when the monocyte subsets are cultured on bone, significantly more osteoclasts are formed from classical monocytes than from intermediate or non-classical monocytes. Considering that this difference does not exist when monocyte subsets are cultured on plastic, we hypothesized that classical monocytes adhere better to the bone surface compared to intermediate and non-classical monocytes. To investigate this, the different monocyte subsets were isolated from human peripheral bloodmore » and cultured on slices of human bone in the presence of the cytokine M-CSF. We found that classical monocytes adhere better to bone due to a higher expression of the integrin αMβ2 and that their ability to attach to bone is significantly decreased when the integrin is blocked. This suggests that integrin αMβ2 mediates attachment of osteoclast precursors to bone and thereby enables the formation of osteoclasts.« less

Alveolar bone repair with strontium- containing nanostructured carbonated hydroxyapatite

PubMed Central

do Carmo, André Boziki Xavier; Sartoretto, Suelen Cristina; Alves, Adriana Terezinha Neves Novellino; Granjeiro, José Mauro; Miguel, Fúlvio Borges; Calasans-Maia, Jose; Calasans-Maia, Monica Diuana

2018-01-01

ABSTRACT Objective This study aimed to evaluate bone repair in rat dental sockets after implanting nanostructured carbonated hydroxyapatite/sodium alginate (CHA) and nanostructured carbonated hydroxyapatite/sodium alginate containing 5% strontium microspheres (SrCHA) as bone substitute materials. Methods Twenty male Wistar rats were randomly divided into two experimental groups: CHA and SrCHA (n=5/period/group). After one and 6 weeks of extraction of the right maxillary central incisor and biomaterial implantation, 5 μm bone blocks were obtained for histomorphometric evaluation. The parameters evaluated were remaining biomaterial, loose connective tissue and newly formed bone in a standard area. Statistical analysis was performed by Mann-Withney and and Wilcoxon tests at 95% level of significance. Results The histomorphometric results showed that the microspheres showed similar fragmentation and bio-absorbation (p>0.05). We observed the formation of new bones in both groups during the same experimental periods; however, the new bone formation differed significantly between the weeks 1 and 6 (p=0.0039) in both groups. Conclusion The CHA and SrCHA biomaterials were biocompatible, osteoconductive and bioabsorbable, indicating their great potential for clinical use as bone substitutes. PMID:29364342

A concise review of testosterone and bone health

PubMed Central

Mohamad, Nur-Vaizura; Soelaiman, Ima-Nirwana; Chin, Kok-Yong

2016-01-01

Osteoporosis is a condition causing significant morbidity and mortality in the elderly population worldwide. Age-related testosterone deficiency is the most important factor of bone loss in elderly men. Androgen can influence bone health by binding to androgen receptors directly or to estrogen receptors (ERs) indirectly via aromatization to estrogen. This review summarized the direct and indirect effects of androgens on bone derived from in vitro, in vivo, and human studies. Cellular studies showed that androgen stimulated the proliferation of preosteoblasts and differentiation of osteoblasts. The converted estrogen suppressed osteoclast formation and resorption activity by blocking the receptor activator of nuclear factor k-B ligand pathway. In animal studies, activation of androgen and ERα, but not ERβ, was shown to be important in acquisition and maintenance of bone mass. Human epidemiological studies demonstrated a significant relationship between estrogen and testosterone in bone mineral density and fracture risk, but the relative significance between the two remained debatable. Human experimental studies showed that estrogen was needed in suppressing bone resorption, but both androgen and estrogen were indispensable for bone formation. As a conclusion, maintaining optimal level of androgen is essential in preventing osteoporosis and its complications in elderly men. PMID:27703340

Corticotomy facilitated orthodontics: Review of a technique

PubMed Central

AlGhamdi, Ali Saad Thafeed

2009-01-01

Corticotomy found to be effective in accelerating orthodontic treatment. The most important factors in the success of this technique is proper case selection and careful surgical and orthodontic treatment. Corticotomy facilitated orthodontics advocated for comprehensive fixed orthodontic appliances in conjunction with full thickness flaps and labial and lingual corticotomies around teeth to be moved. Bone graft should be applied directly over the bone cuts and the flap sutured in place. Tooth movement should be initiated two weeks after the surgery, and every two weeks thereafter by activation of the orthodontic appliance. Orthodontic treatment time with this technique will be reduced to one-third the time of conventional orthodontics. Alveolar augmentation of labial and lingual cortical plates were used in an effort to enhance and strengthen the periodontium, reasoning that the addition of bone to alveolar housing of the teeth, using modern bone grafting techniques, ensures root coverage as the dental arch expanded. Corticotomy facilitated orthodontics is promising procedure but only few cases were reported in the literature. Controlled clinical and histological studies are needed to understand the biology of tooth movement with this procedure, the effect on teeth and bone, post-retention stability, measuring the volume of mature bone formation, and determining the status of the periodontium and roots after treatment. PMID:23960473

Role of Nanoparticles in Drug Delivery and Regenerative Therapy for Bone Diseases.

PubMed

Gera, Sonia; Sampathi, Sunitha; Dodoala, Sujatha

2017-01-01

Osteoporosis is a disease characterized by progressive bone loss due to aging and menopause in women leading to bone fragility with increased susceptibility towards fractures. The silent disease weakens the bone by altering its microstructure and mass. Therapy is based on either promoting strength (via osteoblast action) or preventing disease (via osteoclast action). Current therapy with different drugs belonging to antiresorptive, anabolic and hormonal classification suffers from poor pharmacokinetic and pharmacodynamic profile. Nanoparticles provide breakthrough as an alternative therapeutic carrier and biomedical imaging tool in bone diseases. The current review highlights bone physiology and pathology along with potential applications of nanoparticles in osteoporosis through use of organic and inorganic particles for drug delivery, biomedical imaging as well as bone tissue regeneration therapy. Inorganic nanoparticles of gold, cerium, platinum and silica have effects on osteoblastic and osteoclastic lineage. Labelling and tracking of bone cells by quantum dots and gold nanoparticles are advanced and non-invasive techniques. Incorporation of nanoparticles into the scaffolds is a more recent technique for improving mechanical strength as well as regeneration during bone grafting. Promising results by in vitro and in vivo studies depicts effects of nanoparticles on biochemical markers and biomechanical parameters during osteoporosis suggesting the bright future of nanoparticles in bone applications. Any therapy which improves the drug profile and delivery to bone tissue will be promising approach. Superparamagnetic, gold, mesoporous silica nanoparticles and quantum dots provide golden opportunities for biomedical imaging by replacing the traditional invasive radionuclide techniques. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

An oxidized implant surface may improve bone-to-implant contact in pristine bone and bone defects treated with guided bone regeneration: an experimental study in dogs.

PubMed

Gurgel, Bruno César de Vasconcelos; Gonçalves, Patrícia Furtado; Pimentel, Suzana Peres; Nociti, Francisco Humberto; Sallum, Enilson Antonio; Sallum, Antonio Wilson; Casati, Marcio Zaffalon

2008-07-01

The aim of the present study was to histometrically evaluate bone healing in the absence of bone defects and in the presence of surgically created bone defects treated by guided bone regeneration at oxidized and turned implant surfaces. Three months after dental extractions, standardized buccal dehiscence defects (height: 5 mm; width: 4 mm) were surgically created following implant site preparation in the mandible of 10 dogs. Oxidized-surface implants (OSI) and turned-surface implants (TSI) were inserted bilaterally, and the bone defects were treated by guided bone regeneration. After 3 months of healing, the animals were sacrificed, blocks were dissected, and undecalcified sections were obtained and processed for histometric analysis. The percentage of bone-to-implant contact (BIC) and bone density (BD) was evaluated inside the threads on the buccal (regenerated bone) and lingual sides (pristine bone) of the implants. Data were evaluated using two-way analysis of variance (P <0.05). New bone formation could be observed in OSI and TSI in the region of the defect creation. The BIC values observed in OSI for pristine and regenerated bone were 57.03% +/- 21.86% and 40.86% +/- 22.73%, respectively. TSI showed lower values of BIC in pristine bone (37.39% +/- 23.33%) and regenerated bone (3.52% +/- 4.87%). The differences between OSI and TSI were statistically significant. BD evaluation showed no statistically significant differences between OSI and TSI in pristine and regenerated bone. The oxidized implant surface promoted a higher level of BIC than the turned implant surface at pristine and regenerated bone.

Cement line staining in undecalcified thin sections of cortical bone

NASA Technical Reports Server (NTRS)

Bain, S. D.; Impeduglia, T. M.; Rubin, C. T.

1990-01-01

A technique for demonstrating cement lines in thin, undecalcified, transverse sections of cortical bone has been developed. Cortical bone samples are processed and embedded undecalcified in methyl methacrylate plastic. After sectioning at 3-5 microns, cross-sections are transferred to a glass slide and flattened for 10 min. Sections of cortical bone are stained for 20 sec free-floating in a fresh solution of 1% toluidine blue dissolved in 0.1% formic acid. The section is dehydrated in t-butyl alcohol, cleared in xylene, and mounted with Eukitt's medium. Reversal lines appear as thin, scalloped, dark blue lines against a light blue matrix, whereas bone formation arrest lines are thicker with a smooth contour. With this technique cellular detail, osteoid differentiation, and fluorochrome labels are retained. Results demonstrate the applicability of a one-step staining method for cement lines which will facilitate the assessment of bone remodeling activity in thin sections of undecalcified cortical bone.

Osteotomy in direct sinus lift. A comparative study of the rotary technique and ultrasound

PubMed Central

Peñarrocha-Diago, Miguel; Sanchez-Recio, Cristina; Peñarrocha-Oltra, David; Romero-Millán, Javier

2012-01-01

Purpose: The present study investigates sinus membrane rupture in direct maxillary sinus lift with the rotary technique and with ultrasound, examining the survival of implants placed after sinus augmentation, and analyzing the bone gain obtained after the operation and 12 months after placement of the prosthetic restoration. Material and Methods: A retrospective study was made of 45 patients requiring maxillary sinus lift or augmentation for implant-prosthetic rehabilitation. Use was made of the hand piece and ostectomy drills for the rotary technique, and of specific tips for ultrasound. The implant success criteria were based on those developed by Buser. The bone gain obtained as a result of sinus lift was calculated from the postoperative panoramic X-rays. Results: A total of 57 direct elevations of the maxillary sinus were carried out: 32 with the rotary technique and 25 with ultrasound. Perforations of Schneider’s membrane with the rotary technique and ultrasound occurred in 7% and 1.7% of the cases, respectively, with membrane integrity being preserved in 91.2%. Of the 100 implants placed, 5 failed after one year of follow-up in the rotary technique group, while one implant failed in the ultrasound group. The rotary technique in turn afforded a bone gain of 5.9 mm, versus 6.7 mm with ultrasound. Conclusions: Perforations of the membrane sinusal in direct lift were more frequent with the rotary technique (7%) than with ultrasound (1.7%). Implant survival and bone gain were both greater when ultrasound was used. Key words:Bone sectioning, maxillary sinus augmentation, piezosurgery. PMID:22143735

Investigating the Role of Global Histogram Equalization Technique for 99mTechnetium-Methylene diphosphonate Bone Scan Image Enhancement.

PubMed

Pandey, Anil Kumar; Sharma, Param Dev; Dheer, Pankaj; Parida, Girish Kumar; Goyal, Harish; Patel, Chetan; Bal, Chandrashekhar; Kumar, Rakesh

2017-01-01

99m Technetium-methylene diphosphonate ( 99m Tc-MDP) bone scan images have limited number of counts per pixel, and hence, they have inferior image quality compared to X-rays. Theoretically, global histogram equalization (GHE) technique can improve the contrast of a given image though practical benefits of doing so have only limited acceptance. In this study, we have investigated the effect of GHE technique for 99m Tc-MDP-bone scan images. A set of 89 low contrast 99m Tc-MDP whole-body bone scan images were included in this study. These images were acquired with parallel hole collimation on Symbia E gamma camera. The images were then processed with histogram equalization technique. The image quality of input and processed images were reviewed by two nuclear medicine physicians on a 5-point scale where score of 1 is for very poor and 5 is for the best image quality. A statistical test was applied to find the significance of difference between the mean scores assigned to input and processed images. This technique improves the contrast of the images; however, oversaturation was noticed in the processed images. Student's t -test was applied, and a statistically significant difference in the input and processed image quality was found at P < 0.001 (with α = 0.05). However, further improvement in image quality is needed as per requirements of nuclear medicine physicians. GHE techniques can be used on low contrast bone scan images. In some of the cases, a histogram equalization technique in combination with some other postprocessing technique is useful.

[Experimental effect of a shot caused by 4.5 mm cartridges fired from a Norica Dragon air-rifle and a Walther PPK/S air-pistol].

PubMed

Smedra-Kaźmirska, Anna; Barzdo, Maciej; Kedzierski, Maciej; Szram, Stefan; Berent, Jarosław

2010-01-01

In Poland, according to the Weapons and Ammunition Act" an air weapon which has kinetic energy of fired projectiles below 17 J does not require registration and can be bought even on the Internet. Sport and recreational shooting with this weapon does not have to be performed in a special shooting-range, but can be carried on in an open terrain providing "particular caution" is exercised. In this study we presented experimental effects of shooting pneumatic weapons (Norica Dragon air-rifle and Walther PPK/S air-pistol) which had kinetic energy of fired projectiles below 17 J. The aim of this study was to assess the effects of shooting the above weapons at human soft tissues and thin bones of the temple region to empirically evaluate the degree of danger to health and life, which such shots can produce. We used 20% gelatine blocks at 10 degrees C, which were the model of human soft tissues, and fresh calf scapulas, which served as the models of the temporal bone of the human cranium. Before the experiment, we had evaluated the weight of all the projectiles and their initial velocity using a chronograph. By these measures, we calculated the kinetic energy of the fired missiles. After shooting, we estimated if projectiles of different shapes shot from air weapons characterized by different kinetic energy and from different distances penetrated the gelatine blocks and if the said missiles perforated the bones. We also measured the depth of missiles penetration in the gelatine blocks.

Multiple Perforations of the Sinus Floor During Maxillary Sinus Floor Augmentation to Provide Access to the Bone Marrow Space: A Technical Report.

PubMed

Ulm, Christian; Bertl, Kristina; Strbac, Georg D; Esfandeyari, Azadeh; Stavropoulos, Andreas; Zechner, Werner

2017-12-01

Sinus floor augmentation is a routinely used surgical technique for increasing the bone height/volume of the atrophic posterior maxilla. Optimal integration of the implanted augmentation material within the newly formed bone will-at least partly-depend on adequate vascularization to ensure sufficient recruitment of osteoblast and osteoclast precursor cells. The present technical note describes a modification intended to facilitate increased blood inflow into the augmented space. After preparation of the lateral window and elevation of the Schneiderian membrane, the cortical bone of the sinus floor is perforated several times either by using a piezoelectric device or a microsurgical handpiece with the corresponding tip or bur; these perforations should extend into the trabecular bone. The experiences with this modified technique after 12 patients are presented and discussed. It is expected that by means of this relatively simple technique, increased blood and cell inflow into the augmented space is achieved. This may, in turn, enhance new bone formation and improve the integration of the augmentation material.

[Bone quantitative ultrasound].

PubMed

Matsukawa, Mami

2016-01-01

The conventional ultrasonic bone densitometry system can give us information of bone as ultrasonic wave velocity and attenuation. However, the data reflect both structural and material properties of bone. In order to focus only on the bone matrix properties without the effect of bone structure, studies of microscopic Brillouin scattering technique are introduced. The wave velocity in a trabecula was anisotropic and depended on the position and structure of the cancellous bone. The glycation also affected on the wave velocities in bone. As a new bone quality, the piezoelectricity of bone is also discussed.

What do you do when you have a loose screw?

PubMed

Brady, Paul C; Arrigoni, Paolo; Burkhart, Stephen S

2006-09-01

This study seeks to compare the pullout strength of various anchor configurations in an osteoporotic bone model. We have tested and present here a technique designed to augment the pullout resistance of an anchor in poor-quality bone with the use of a second anchor as an interference fit; this report describes our in vivo results with this procedure. Four groups of suture anchor constructs were tested. These included a single 5.0-mm Bio-Corkscrew (Arthrex, Naples, FL) (group I), a single 5.5-mm Bio-Corkscrew FT (fully threaded; Arthrex, Naples, FL) (group II), a single 6.5-mm Bio-Corkscrew (Arthrex, Naples, FL) (group III), and an interference fit of two 5.0-mm Bio-Corkscrew suture anchors (group IV). Anchors were secured in a 10-lb/ft3 polyurethane foam block to simulate osteoporotic bone. Each construct was cycled, then was pulled to failure with an Instron testing device (Instron, Canton, MA); measurements regarding cyclic displacement, yield load, and extension at yield load were recorded. During the in vivo portion of the study, the interference fit technique was performed in 18 shoulder arthroscopy cases in which a loose screw was a matter of concern. After the technique was performed, both anchors were pulled so their security could be assessed; cuff repair then proceeded normally. Biomechanical study: In terms of yield load, every anchor construct was significantly different from every other construct. Specifically, pullout strength increased significantly as follows: group I was the weakest against pullout (176 +/- 13 N), group III (223 +/- 17 N) was significantly stronger than group I, group II (247 +/- 12 N) was significantly stronger than group III, and, finally, group IV (305 +/- 16 N) was significantly stronger than group II. The only statistically significant difference in terms of cyclic displacement was that group IV (1.4 mm +/- 0.2) had significantly less displacement than group III (1.9 mm +/- 0.3). No significant differences in extension at yield load were observed among any of the groups. In vivo study: The interference anchor technique was used in 18 of 24 loose screw situations over a 6-month period. In all 18 of these cases (100%), a stable dual-anchor construct was achieved. All anchors were stable to the tug test, and none failed during knot tying or at any time during the procedure. From the perspective of strength against pullout, the strongest suture construct of those tested in the osteoporotic bone model was the dual-anchor-against-an-anchor interference fit construct. The next strongest anchor tested was the 5.5-mm Bio-Corkscrew FT, followed by the 6.5-mm Bio-Corkscrew, and, finally, the 5.0-mm Bio-Corkscrew. Each group was statistically different from every other group in terms of pullout strength. The interference fit construct was not only the strongest in vitro, but it performed well in the in vivo setting, offering the added benefit of additional sutures to be used for securing a cuff defect. This study gives the arthroscopic surgeon important data for use in planning what to do when a loose screw is encountered. Data from this study may be useful for the arthroscopic surgeon in choosing the proper anchor construct for osteoporotic bone. This study also lends support to the technique of press-fitting an anchor against an anchor in the loose screw situation.

RUN LENGTH SYNCHRONIZATION TECHNIQUES

DTIC Science & Technology

An important aspect of digital communications is the problem of determining efficient methods for acquiring block synchronization . In this paper we...utilizes an N-digit sync sequence as prefix to the data blocks. The results of this study show that this technique is a practical method for acquiring block synchronization .

Chronic skin inflammation leads to bone loss by IL-17-mediated inhibition of Wnt signaling in osteoblasts.

PubMed

Uluçkan, Özge; Jimenez, Maria; Karbach, Susanne; Jeschke, Anke; Graña, Osvaldo; Keller, Johannes; Busse, Björn; Croxford, Andrew L; Finzel, Stephanie; Koenders, Marije; van den Berg, Wim; Schinke, Thorsten; Amling, Michael; Waisman, Ari; Schett, Georg; Wagner, Erwin F

2016-03-16

Inflammation has important roles in tissue regeneration, autoimmunity, and cancer. Different inflammatory stimuli can lead to bone loss by mechanisms that are not well understood. We show that skin inflammation induces bone loss in mice and humans. In psoriasis, one of the prototypic IL-17A-mediated inflammatory human skin diseases, low bone formation and bone loss correlated with increased serum IL-17A levels. Similarly, in two mouse models with chronic IL-17A-mediated skin inflammation,K14-IL17A(ind)andJunB(Δep), strong inhibition of bone formation was observed, different from classical inflammatory bone loss where osteoclast activation leads to bone degradation. We show that under inflammatory conditions, skin-resident cells such as keratinocytes, γδ T cells, and innate lymphoid cells were able to express IL-17A, which acted systemically to inhibit osteoblast and osteocyte function by a mechanism involving Wnt signaling. IL-17A led to decreased Wnt signaling in vitro, and importantly, pharmacological blockade of IL-17A rescued Wnt target gene expression and bone formation in vivo. These data provide a mechanism where IL-17A affects bone formation by regulating Wnt signaling in osteoblasts and osteocytes. This study suggests that using IL-17A blocking agents in psoriasis could be beneficial against bone loss in these patients. Copyright © 2016, American Association for the Advancement of Science.

Bone metabolism in oxalosis: a single-center study using new imaging techniques and biomarkers.

PubMed

Bacchetta, Justine; Fargue, Sonia; Boutroy, Stéphanie; Basmaison, Odile; Vilayphiou, Nicolas; Plotton, Ingrid; Guebre-Egziabher, Fitsum; Dohin, Bruno; Kohler, Rémi; Cochat, Pierre

2010-06-01

The deposition of calcium oxalate crystals in the kidney and bone is a hallmark of primary hyperoxaluria type 1 (PH1). We report here an evaluation of the bone status of 12 PH1 children based on bone biomarkers [parathyroid hormone, vitamin D, fibroblast growth factor 23 (FGF23)] and radiological assessments (skeletal age, three-dimensional high-resolution peripheral quantitative computed tomography, HR-pQCT) carried out within the framework of a cross-sectional single-center study. The controls consisted of healthy and children with chronic kidney disease already enrolled in local bone and mineral metabolism studies. The mean age (+ or - standard deviation) age of the patients was 99 (+ or - 63) months. Six children suffered from fracture. Bone maturation was accelerated in five patients, four of whom were <5 years. The combination of new imaging techniques and biomarkers highlighted new and unexplained features of PH1: advanced skeletal age in young PH1 patients, increased FGF23 levels and decreased total volumetric bone mineral density with bone microarchitecture alteration.

Development of candidate reference materials for the measurement of lead in bone

PubMed Central

Hetter, Katherine M.; Bellis, David J.; Geraghty, Ciaran; Todd, Andrew C.; Parsons, Patrick J.

2010-01-01

The production of modest quantities of candidate bone lead (Pb) reference materials is described, and an optimized production procedure is presented. The reference materials were developed to enable an assessment of the interlaboratory agreement of laboratories measuring Pb in bone; method validation; and for calibration of solid sampling techniques such as laser ablation ICP-MS. Long bones obtained from Pb-dosed and undosed animals were selected to produce four different pools of a candidate powdered bone reference material. The Pb concentrations of these pools reflect both environmental and occupational exposure levels in humans. The animal bones were harvested post mortem, cleaned, defatted, and broken into pieces using the brittle fracture technique at liquid nitrogen temperature. The bone pieces were then ground in a knife mill to produce fragments of 2-mm size. These were further ground in an ultra-centrifugal mill, resulting in finely powdered bone material that was homogenized and then sampled-scooped into vials. Testing for contamination and homogeneity was performed via instrumental methods of analysis. PMID:18421443

Effects of the 3D bone-to-implant contact and bone stiffness on the initial stability of a dental implant: micro-CT and resonance frequency analyses.

PubMed

Hsu, J T; Huang, H L; Tsai, M T; Wu, A Y J; Tu, M G; Fuh, L J

2013-02-01

This study investigated the effects of bone stiffness (elastic modulus) and three-dimensional (3D) bone-to-implant contact ratio (BIC%) on the primary stabilities of dental implants using micro-computed tomography (micro-CT) and resonance frequency analyses. Artificial sawbone models with five values of elastic modulus (137, 123, 47.5, 22, and 12.4 MPa) comprising two types of trabecular structure (solid-rigid and cellular-rigid) were investigated for initial implant stability quotient (ISQ), measured using the wireless Osstell resonance frequency analyzer. Bone specimens were attached to 2 mm fibre-filled epoxy sheets mimicking the cortical shell. ISQ was measured after placing a dental implant into the bone specimen. Each bone specimen with an implant was subjected to micro-CT scanning to calculate the 3D BIC% values. The similarity of the cellular type of artificial bone to the trabecular structure might make it more appropriate for obtaining accurate values of primary implant stability than solid-bone blocks. For the cellular-rigid bone models, the ISQ increased with the elastic modulus of cancellous bone. The regression correlation coefficient was 0.96 for correlations of the ISQ with the elasticity of cancellous bone and with the 3D BIC%. The initial implant stability was moderately positively correlated with the elasticity of cancellous bone and with the 3D BIC%. Copyright © 2012 International Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.

Comparison between infrared and Raman spectroscopic analysis of maturing rabbit cortical bone.

PubMed

Turunen, Mikael J; Saarakkala, Simo; Rieppo, Lassi; Helminen, Heikki J; Jurvelin, Jukka S; Isaksson, Hanna

2011-06-01

The molecular composition of the organic and inorganic matrices of bone undergoes alterations during maturation. The aim of this study was to compare Fourier transform infrared (FT-IR) and near-infrared (NIR) Raman microspectroscopy techniques for characterization of the composition of growing and developing bone from young to skeletally mature rabbits. Moreover, the specificity and differences of the techniques for determining bone composition were clarified. The humeri of female New Zealand White rabbits, with age range from young to skeletally mature animals (four age groups, n = 7 per group), were studied. Spectral peak areas, intensities, and ratios related to organic and inorganic matrices of bone were analyzed and compared between the age groups and between FT-IR and Raman microspectroscopic techniques. Specifically, the degree of mineralization, type-B carbonate substitution, crystallinity of hydroxyapatite (HA), mineral content, and collagen maturity were examined. Significant changes during maturation were observed in various compositional parameters with one or both techniques. Overall, the compositional parameters calculated from the Raman spectra correlated with analogous parameters calculated from the IR spectra. Collagen cross-linking (XLR), as determined through peak fitting and directly from the IR spectra, were highly correlated. The mineral/matrix ratio in the Raman spectra was evaluated with multiple different peaks representing the organic matrix. The results showed high correlation with each other. After comparison with the bone mineral density (BMD) values from micro-computed tomography (micro-CT) imaging measurements and crystal size from XRD measurements, it is suggested that Raman microspectroscopy is more sensitive than FT-IR microspectroscopy for the inorganic matrix of the bone. In the literature, similar spectroscopic parameters obtained with FT-IR and NIR Raman microspectroscopic techniques are often compared. According to the present results, however, caution is required when performing this kind of comparison.

Comparison of Lateral Window and Osteotome Techniques in Sinus Augmentation: Histological and Histomorphometric Evaluation

PubMed Central

Esfahanizadeh, N.; Rokn, A. R.; Paknejad, M.; Motahari, P.; Daneshparvar, H.; Shamshiri, AR.

2012-01-01

Objective: The aim of this study was to compare the lateral window and osteotome techniques for sinus lifting using histological and histomorphometric methods. Materials and Methods: In this clinical trial 10 patients (a total number of 14 sinus areas) who needed implant treatment in the atrophic posterior maxilla were enrolled. In all the cases the residual bone height between the sinus floor and the alveolar crest was less than 5 mm. Sinus augmentation was performed. The treatment modality for a given residual bone height was selected randomly and Bio-Oss was applied in all the cases as the graft material. After a healing period of about 10 months, in all the cases, the implants were placed and biopsies of alveolar crestal bone were obtained at the same time; biopsy specimens were evaluated using histological and histomorphometric methods. Fisher’s exact and Mann-Whitney U tests were used to compare distribution of variables in the two groups. Statistical significance was defined at P<0.05. Results: The new bone was located in direct contact with the biomaterial without any gaps. This viable bone consisted of lacunae containing osteocytes. Infiltration of inflammatory cells did not exhibit any significant differences between the two techniques. Foreign body reaction was not observed in any cases. Histomorphometric evaluations demonstrated that The mean values of the new bone in the lateral window and osteotome techniques were 30±6.0 and 25.2±5.2, respectively, with no significant differences between the two groups.. Moreover, the average quantity of residual biomaterial and connective tissue were similar for the two groups. Conclusion: The nature and the volume of the new bone in lateral window and osteotome techniques were the same. PMID:23119133

High quality tissue miniarray technique using a conventional TV/radio telescopic antenna.

PubMed

Elkablawy, Mohamed A; Albasri, Abdulkader M

2015-01-01

The tissue microarray (TMA) is widely accepted as a fast and cost-effective research tool for in situ tissue analysis in modern pathology. However, the current automated and manual TMA techniques have some drawbacks restricting their productivity. Our study aimed to introduce an improved manual tissue miniarray (TmA) technique that is simple and readily applicable to a broad range of tissue samples. In this study, a conventional TV/radio telescopic antenna was used to punch tissue cores manually from donor paraffin embedded tissue blocks which were pre-incubated at 40oC. The cores were manually transferred, organized and attached to a standard block mould, and filled with liquid paraffin to construct TmA blocks without any use of recipient paraffin blocks. By using a conventional TV/radio antenna, it was possible to construct TmA paraffin blocks with variable formats of array size and number (2-mm x 42, 2.5-mm x 30, 3-mm x 24, 4-mm x 20 and 5-mm x 12 cores). Up to 2-mm x 84 cores could be mounted and stained on a standard microscopic slide by cutting two sections from two different blocks and mounting them beside each other. The technique was simple and caused minimal damage to the donor blocks. H and E and immunostained slides showed well-defined tissue morphology and array configuration. This technique is easy to reproduce, quick, inexpensive and creates uniform blocks with abundant tissues without specialized equipment. It was found to improve the stability of the cores within the paraffin block and facilitated no losses during cutting and immunostaining.

No-cost manual method for preparation of tissue microarrays having high quality comparable to semiautomated methods.

PubMed

Foda, Abd Al-Rahman Mohammad

2013-05-01

Manual tissue microarray (TMA) construction had been introduced to avoid the high cost of automated and semiautomated techniques. The cheapest and simplest technique for constructing manual TMA was that of using mechanical pencil tips. This study was carried out to modify this method, aiming to raise its quality to reach that of expensive ones. Some modifications were introduced to Shebl's technique. Two conventional mechanical pencil tips of different diameters were used to construct the recipient blocks. A source of mild heat was used, and blocks were incubated at 38°C overnight. With our modifications, 3 high-density TMA blocks were constructed. We successfully performed immunostaining without substantial tissue loss. Our modifications increased the number of cores per block and improved the stability of the cores within the paraffin block. This new, modified technique is a good alternative for expensive machines in many laboratories.

Intra-oral soft tissue expansion and volume stability of onlay bone grafts.

PubMed

Abrahamsson, Peter

2011-01-01

Insufficient regeneration of missing bone and soft-tissue may present aesthetic or functional problems in patients indicated for dental implant surgery. Several techniques such as bone grafts, bone substitutes and guided tissue regeneration (GTR) have been described to rebuild a compromised alveolar ridge. Adequate soft-tissue coverage of grafted bone and titanium-mesh is important to avoid exposure which may result in loss of the bone graft. The general aim of this thesis was to evaluate use of an osmotic tissue expander for expanding intra-oral soft tissue--creating a surplus of soft tissue-- in preparation for onlay bone grafting. An experimental rabbit model was used in studies (I), (II) and (III). In (I) an osmotic soft-tissue expander was placed bilaterally on the lateral wall of the mandible via an extra-oral approach. After two weeks of expansion the rabbits were killed and specimens were collected for histology. No inflammatory reaction and no resorbtion of the cortical bone occured. The periosteum was expanded and new bone formation was seen in the edges of the expander. In (II) and (III) the expander was placed under the periosteum in the same way as in (I): bilaterally in 13 rabbits in (II) and unilaterally in 11 rabbits in (III). After two weeks of expansion the expander was identified and removed. In (II) particulated bone was placed at the recipient site protected by a titanium mesh in one site and a bio-resorbable mesh on the other site. In (III), DBBM particles and bone particles collected from the lateral border of the mandible separated by a collagen membrane was placed at the recipient site. The graft was protected by a pre-bent titanium mesh covered by a collagen membrane. After a healing period of 3 months specimens were collected for histological and SEM examination. New bone was growing in direct contact with the titanium mesh and bio resorbable mesh. The newly formed bone had the same calcium content as the mature bone in the base of the mandible. In the clinical study (IV) 20 patients were consecutively recruited and randomised into two groups. The experimental group (ten patients) had an osmotic soft tissue expander implanted. After two weeks of expansion the expander was removed and a particulated bone graft protected by a titanium mesh and a collagen membrane was fixed to the recipient site. Titanium implants were installed after a healing period of 6 months. The patients in the reference group had a bone block grafted from the anterior ramus fixated to the recipient site with one or two titanium mini screws. Implants were installed after a healing period of 6 months. A three dimensional optical measuring device was used to measure alterations in the soft tissue profile before each surgical procedure. The three-dimensional changes were then analysed on a PC. The results from the clinical study in patients confirmed the results from the experimental rabbit studies. The osmotic tissue expander expanded the soft tissue. Expander perforations of the soft tissue occurred in two patients. The optical measurements demonstrated a positive volume gain after soft tissue expansion and bone grafting. The expanded tissue could be used to cover a bone graft. There still was a risk of mesh exposure, even after soft tissue expansion, which occurred in two patients. In both groups, implants could be installed in the grafted bone in positions that would allow the crowns to fit aesthetically into the dental arch.

Clinical outcomes of an osteotome technique and simultaneous placement of Neoss implants in the posterior maxilla.

PubMed

Volpe, Stefano; Lanza, Massimiliano; Verrocchi, Damiano; Sennerby, Lars

2013-02-01

Insufficient bone volume often hamper placement of dental implants in the posterior maxilla. The aim of the present clinical study was to evaluate retrospectively the clinical outcome of implant placement in the resorbed posterior maxilla using an osteotome technique without adding any grafting material. Twenty patients with 5 to 9 mm of residual alveolar bone height in the posterior maxilla received twenty-nine implants (Neoss Ltd., Harrogate, UK) using an osteotomy technique without bone grafts. Intraoral radiographs were taken before and after implant placement, at the time of loading and after 11 to 32 months of loading (mean 16.4 months), to evaluate bone formation below the sinus membrane and marginal bone loss. Implant stability measurements (Osstell(TM) , Gothenburg, Sweden) were performed after implant installation and at abutment connection 5 months later. All implants were installed with the prosthetic platform level with the bone crest. No implant was lost giving a survival rate of 100% after a mean follow-up time of 16.4 months. The average vertical bone height was 7.2 ± 1.5 mm at placement and 10.0 ± 1.0 mm after 11 to 32 months. The average increase of 2.8 ± 1.1 mm was statistically significant. There was a statistically significant improvement in implant stability from 70.7 ± 9.2 implant stability quotient (ISQ) at placement to 76.7 ± 5.7 ISQ at abutment connection, 5 months later. The mean marginal bone loss amounted to 0.7 ± 0.3 mm after 11 to 32 months of loading. It is concluded that the osteotome technique evaluated resulted in predictable intrasinus bone formation, firm implant stability, and good clinical outcomes as no implants were lost and minimal marginal bone loss was observed. © 2011 Wiley Periodicals, Inc.

Vertebroplasty and interventional radiology procedures for bone metastases.

PubMed

Laredo, Jean-Denis; Chiras, Jacques; Kemel, Salim; Taihi, Lokmane; Hamze, Bassam

2018-03-01

Advances in cancer treatments have lengthened the survival of patients with bone metastases. Optimal control of the symptoms and prevention of the complications associated with bone metastases improve quality of life. Achieving these goals increasingly involves interventional radiology procedures. These include bone consolidation and analgesic techniques such as cementoplasty (vertebroplasty at the spine); percutaneous implantation of screws, metallic reinforcement devices, or intraosseous implants; and tumor destruction using thermal methods (radiofrequency and cryotherapy), chemicals (alcohol), and drugs (chemoembolization), which have fewer indications. Here, these techniques and their indications are reviewed. Copyright © 2017. Published by Elsevier SAS.

A comparative study of nerve stimulator versus ultrasound-guided supraclavicular brachial plexus block.

PubMed

Duncan, Mithun; Shetti, Akshaya N; Tripathy, Debendra Kumar; Roshansingh, D; Krishnaveni, N

2013-01-01

With the advent of ultrasound (US) guidance, this technique saw resurgence in the late 1990s. As US guidance provides real-time view of the block needle, the brachial plexus, and its spatial relationship to the surrounding vital structures; it not only increased the success rates, but also brought down the complication rates. Most of the studies show use of US guidance for performing brachial plexus block, results in near 100% success with or without complications. This study has been designed to examine the technique and usefulness of state-of-the-art US technology-guided supraclavicular brachial plexus block and compare it with routine nerve stimulator (NS)-guided technique. To note block execution time, time of onset of sensory and motor block, quality of block and success rates. Randomized controlled trial. A total of 60 patients were enrolled in this prospective randomized study and were randomly divided into two groups: US (Group US) and NS (Group NS). Both groups received 1:1 mixture of 0.5% bupivacaine and 2% lignocaine with 1:200000 adrenaline. The amount of local anaesthetic injected calculated according to the body weight and not crossing the toxic dosage (Inj. bupivacaine 2 mg/kg, Inj. lignocaine with adrenaline 7 mg/kg). The parameters compared between the two groups are block execution time, time of onset of sensory and motor block, quality of sensory and motor block, success rates are noted. The failed blocks are supplemented with general anesthesia. The data were analyzed using the SPSS (version 19) software. The parametric data were analyzed with student "t" test and the nonparametric data were analyzed with Chi-square test A P < 0.05 was considered significant. There was no significant difference between patient groups with regard to demographic data, the time of onset of sensory and motor block. Comparing the two groups, we found that the difference in the block execution time and success rates is not statistically significant. A failure rate of 10% in US and 20% in NS group observed and is statistically insignificant (P = 0.278). No complication observed in either group. US and NS group guidance for performing supraclavicular brachial plexus blocks ensures a high success rate and a decreased incidence of complications that are associated with the blind technique. However, our study did not prove the superiority of one technique over the other. The US-guided technique seemed to have an edge over the NS-guided technique. A larger study may be required to analyze the advantages of using US in performing supraclavicular brachial plexus blocks, which could help justify the cost of purchase of the US machine.

Stromal derived factor-1 regulates bone morphogenetic protein 2-induced osteogenic differentiation of primary mesenchymal stem cells

PubMed Central

Hosogane, Naobumi; Huang, Zhiping; Rawlins, Bernard A.; Liu, Xia; Boachie-Adjei, Oheneba; Boskey, Adele L.; Zhu, Wei

2010-01-01

Stromal derived factor-1 (SDF-1) is a chemokine signaling molecule that binds to its transmembrane receptor CXC chemokine receptor-4 (CXCR4). While we previously detected that SDF-1 was co-required with bone morphogenetic protein 2 (BMP2) for differentiating mesenchymal C2C12 cells into osteoblastic cells, it is unknown whether SDF-1 is similarly involved in the osteogenic differentiation of mesenchymal stem cells (MSCs). Therefore, here we examined the role of SDF-1 signaling during BMP2-induced osteogenic differentiation of primary MSCs that were derived from human and mouse bone marrow. Our data showed that blocking of the SDF-1/CXCR4 signal axis or adding SDF-1 protein to MSCs significantly affected BMP2-induced alkaline phosphatase (ALP) activity and osteocalcin (OCN) synthesis, markers of preosteoblasts and mature osteoblasts, respectively. Moreover, disrupting the SDF-1 signaling impaired bone nodule mineralization during terminal differentiation of MSCs. Furthermore, we detected that blocking of the SDF-1 signaling inhibited the BMP2-induced early expression of Runt-related factor-2 (Runx2) and osterix (Osx), two “master” regulators of osteogenesis, and the SDF-1 effect was mediated via intracellular Smad and Erk activation. In conclusion, our results demonstrated a regulatory role of SDF-1 in BMP2-induced osteogenic differentiation of MSCs, as perturbing the SDF-1 signaling affected the differentiation of MSCs towards osteoblastic cells in response to BMP2 stimulation. These data provide novel insights into molecular mechanisms underlying MSC osteogenesis, and will contribute to the development of MSC therapies for enhancing bone formation and regeneration in broad orthopaedic situations. PMID:20362069

Tanshinones that selectively block the collagenase activity of cathepsin K provide a novel class of ectosteric antiresorptive agents for bone.

PubMed

Panwar, Preety; Law, Simon; Jamroz, Andrew; Azizi, Pouya; Zhang, Dongwei; Ciufolini, Marco; Brömme, Dieter

2018-03-01

Attempts to generate active site-directed cathepsin K (CatK) inhibitors for the treatment of osteoporosis have failed because of side effects. We have previously shown that an ectosteric tanshinone CatK inhibitor isolated from Salvia miltiorrhiza blocked, selectively, the collagenase activity of CatK, without affecting the active site and demonstrated its bone-preserving activity in vivo. Here, we have characterize the antiresorptive potential of other tanshinones, which may provide a scaffold for side effect-free CatK inhibitors. Thirty-one tanshinones were tested for their activity against CatK in enzymic and cell-based assays. The inhibitory potency against triple helical and fibrillar collagen degradation was determined in enzymic assays, by scanning electron microscopy and mechanical strength measurements. Human osteoclast assays were used to determine the effects of the inhibitors on bone resorption, its reversibility and osteoclastogenesis. Binding sites were characterized by molecular docking. Twelve compounds showed highly effective anti-collagenase activity and protected collagen against destruction and mechanical instability without inhibiting the hydrolysis of non-collagenous substrates. Six compounds were highly effective in osteoclast bone resorption assays with IC 50 values of <500 nM. None of these tanshinones had effects on cell viability, reversibility of bone resorption inhibition and osteoclastogenesis. The core pharmacophore of the tanshinones appears to be the three-ring system with either a para- or ortho-quinone entity. Our study identified several potent ectosteric antiresorptive CatK inhibitors from the medicinal plant, S. miltiorrhiza, which may avoid side effects seen with active site-directed inhibitors in clinical trials. © 2017 The British Pharmacological Society.

Osteoclast cytosolic calcium, regulated by voltage-gated calcium channels and extracellular calcium, controls podosome assembly and bone resorption

NASA Technical Reports Server (NTRS)

Miyauchi, A.; Hruska, K. A.; Greenfield, E. M.; Duncan, R.; Alvarez, J.; Barattolo, R.; Colucci, S.; Zambonin-Zallone, A.; Teitelbaum, S. L.; Teti, A.

1990-01-01

The mechanisms of Ca2+ entry and their effects on cell function were investigated in cultured chicken osteoclasts and putative osteoclasts produced by fusion of mononuclear cell precursors. Voltage-gated Ca2+ channels (VGCC) were detected by the effects of membrane depolarization with K+, BAY K 8644, and dihydropyridine antagonists. K+ produced dose-dependent increases of cytosolic calcium ([Ca2+]i) in osteoclasts on glass coverslips. Half-maximal effects were achieved at 70 mM K+. The effects of K+ were completely inhibited by dihydropyridine derivative Ca2+ channel blocking agents. BAY K 8644 (5 X 10(-6) M), a VGCC agonist, stimulated Ca2+ entry which was inhibited by nicardipine. VGCCs were inactivated by the attachment of osteoclasts to bone, indicating a rapid phenotypic change in Ca2+ entry mechanisms associated with adhesion of osteoclasts to their resorption substrate. Increasing extracellular Ca2+ ([Ca2+]e) induced Ca2+ release from intracellular stores and Ca2+ influx. The Ca2+ release was blocked by dantrolene (10(-5) M), and the influx by La3+. The effects of [Ca2+]e on [Ca2+]i suggests the presence of a Ca2+ receptor on the osteoclast cell membrane that could be coupled to mechanisms regulating cell function. Expression of the [Ca2+]e effect on [Ca2+]i was similar in the presence or absence of bone matrix substrate. Each of the mechanisms producing increases in [Ca2+]i, (membrane depolarization, BAY K 8644, and [Ca2+]e) reduced expression of the osteoclast-specific adhesion structure, the podosome. The decrease in podosome expression was mirrored by a 50% decrease in bone resorptive activity. Thus, stimulated increases of osteoclast [Ca2+]i lead to cytoskeletal changes affecting cell adhesion and decreasing bone resorptive activity.

Percutaneous Method of Management of Simple Bone Cyst

PubMed Central

Lakhwani, O. P.

2013-01-01

Introduction. Simple bone cyst or unicameral bone cysts are benign osteolytic lesions seen in metadiaphysis of long bones in growing children. Various treatment modalities with variable outcomes have been described in the literature. The case report illustrates the surgical technique of minimally invasive method of treatment. Case Study. A 14-year-old boy was diagnosed as active simple bone cyst proximal humerus with pathological fracture. The patient was treated by minimally invasive percutaneous curettage with titanium elastic nail (TENS) and allogenic bone grafting mixed with bone marrow under image intensifier guidance. Results. Pathological fracture was healed and allograft filled in the cavity was well taken up. The patient achieved full range of motion with successful outcome. Conclusion. Minimally invasive percutaneous method using elastic intramedullary nail gives benefit of curettage cyst decompression and stabilization of fracture. Allogenic bone graft fills the cavity and healing of lesion by osteointegration. This method may be considered with advantage of minimally invasive technique in treatment of benign cystic lesions of bone, and the level of evidence was therapeutic level V. PMID:23819089

Can we improve fixation and outcomes? Use of bone substitutes.

PubMed

Moroni, Antonio; Larsson, Sune; Hoang Kim, Amy; Gelsomini, Letizia; Giannoudis, Peter V

2009-07-01

Hip fractures secondary to osteoporosis are common in the elderly. Stabilizing these fractures until union is achieved is a challenge due to poor bone stock and insufficient purchase of the implant to the bone. The reported high rate of complications has prompted extensive research in the development of fixation techniques. Furthermore, manipulation of both the local fracture environment in terms of application of growth factors, scaffolds, and mesenchymal cells and the systemic administration of agents promoting bone formation and bone strength has been considered as a treatment option with promising results. There are only a few evidence-based studies reporting on fixation augmentation techniques. This article reports on the efficacy of bone graft substitutes for the fixation of hip fractures, in particular calcium phosphates, which have been used as granules, cements, and implant coatings.

Homing of human B cells to lymphoid organs and B-cell lymphoma engraftment are controlled by cell adhesion molecule JAM-C.

PubMed

Doñate, Carmen; Ody, Christiane; McKee, Thomas; Ruault-Jungblut, Sylvie; Fischer, Nicolas; Ropraz, Patricia; Imhof, Beat A; Matthes, Thomas

2013-01-15

Junctional adhesion molecule C (JAM-C) is expressed by vascular endothelium and human but not mouse B lymphocytes. The level of JAM-C expression defines B-cell differentiation stages and allows the classification of marginal zone-derived (JAM-C-positive) and germinal center-derived (JAM-C-negative) B-cell lymphomas. In the present study, we investigated the role of JAM-C in homing of human B cells, using a xenogeneic nonobese diabetic/severe combined immunodeficient mouse model. Treatment with anti-JAM-C antibodies in short-term experiments reduced migration of normal and malignant JAM-C-expressing B cells to bone marrow, lymph nodes, and spleen. Blocking homing to the spleen is remarkable, as most other antiadhesion antibodies reduce homing of B cells only to bone marrow and lymph nodes. Long-term administration of anti-JAM-C antibodies prevented engraftment of JAM-Cpos lymphoma cells in bone marrow, spleen, and lymph nodes of mice. Plasmon resonance studies identified JAM-B as the major ligand for JAM-C, whereas homotypic JAM-C interactions remained at background levels. Accordingly, anti-JAM-C antibodies blocked adhesion of JAM-C-expressing B cells to their ligand JAM-B, and immunofluorescence analysis showed the expression of JAM-B on murine and human lymphatic endothelial cells. Targeting JAM-C could thus constitute a new therapeutic strategy to prevent lymphoma cells from reaching supportive microenvironments not only in the bone marrow and lymph nodes but also in the spleen.

Suture anchor fixation strength with or without augmentation in osteopenic and severely osteoporotic bones in rotator cuff repair: a biomechanical study on polyurethane foam model

PubMed Central

2014-01-01

Background The purpose of the present study was to compare the results of various types of anchor applications with or without augmentation in both osteopenic and severely osteoporotic bone models. Methods Two different types of suture anchors were tested in severely osteoporotic (SOP) and osteopenic polyurethane (PU) foam blocks using an established protocol. An Instron machine applied static loading parallel to the axis of insertion until failure, and the mean anchor failure strengths were calculated. The mode of failure (anchor pullout, suture tear) was recorded. The anchors tested included the Corkscrew® (CS) (Arthrex Inc., Naples, FL, USA) (without augmentation, polymethylmethacrylate (PMMA)-augmented, and bioabsorbable tricalcium phosphate (TCP) cement-augmented) and Corkscrew® FT II (CS FT II) 5.5 mm (without augmentation as used routinely). Results The mean failure loads for both SOP and osteopenic PU foam blocks, respectively, were as follows: CS, 16.2 and 212.4 N; CS with TCP, 75.2 and 396 N; CS with PMMA, 101.2 and 528.8 N; CS FT II, 13.8 and 339.8 N. Conclusions Augmentation of CS with TCP or PMMA would be essential to SOP bones. In the osteopenic bone model, although anchor fixation augmented with PMMA is the best fixation method, CS augmented with TCP cement or CS FT II without any need for augmentation may also be used as an alternative. PMID:25148925

Mechanical Characterization of Bone: State of the Art in Experimental Approaches-What Types of Experiments Do People Do and How Does One Interpret the Results?

PubMed

Bailey, Stacyann; Vashishth, Deepak

2018-06-18

The mechanical integrity of bone is determined by the direct measurement of bone mechanical properties. This article presents an overview of the current, most common, and new and upcoming experimental approaches for the mechanical characterization of bone. The key outcome variables of mechanical testing, as well as interpretations of the results in the context of bone structure and biology are also discussed. Quasi-static tests are the most commonly used for determining the resistance to structural failure by a single load at the organ (whole bone) level. The resistance to crack initiation or growth by fracture toughness testing and fatigue loading offers additional and more direct characterization of tissue material properties. Non-traditional indentation techniques and in situ testing are being increasingly used to probe the material properties of bone ultrastructure. Destructive ex vivo testing or clinical surrogate measures are considered to be the gold standard for estimating fracture risk. The type of mechanical test used for a particular investigation depends on the length scale of interest, where the outcome variables are influenced by the interrelationship between bone structure and composition. Advancement in the sensitivity of mechanical characterization techniques to detect changes in bone at the levels subjected to modifications by aging, disease, and/or pharmaceutical treatment is required. As such, a number of techniques are now available to aid our understanding of the factors that contribute to fracture risk.

Which is the preferred revision technique for loosened iliac screw? A novel technique of boring cement injection from the outer cortical shell.

PubMed

Yu, Bin-Sheng; Yang, Zhan-Kun; Li, Ze-Min; Zeng, Li-Wen; Wang, Li-Bing; Lu, William Weijia

2011-08-01

An in vitro biomechanical cadaver study. To evaluate the pull-out strength after 5000 cyclic loading among 4 revision techniques for the loosened iliac screw using corticocancellous bone, longer screw, traditional cement augmentation, and boring cement augmentation. Iliac screw loosening is still a clinical problem for lumbo-iliac fusion. Although many revision techniques using corticocancellous bone, larger screw, and polymethylmethacrylate (PMMA) augmentation were applied in repairing pedicle screw loosening, their biomechanical effects on the loosened iliac screw remain undetermined. Eight fresh human cadaver pelvises with the bone mineral density values ranging from 0.83 to 0.97 g/cm were adopted in this study. After testing the primary screw of 7.5 mm diameter and 70 mm length, 4 revision techniques were sequentially established and tested on the same pelvis as follows: corticocancellous bone, longer screw with 100 mm length, traditional PMMA augmentation, and boring PMMA augmentation. The difference of the boring technique from traditional PMMA augmentation is that PMMA was injected into the screw tract through 3 boring holes of outer cortical shell without removing the screw. On an MTS machine, after 5000 cyclic compressive loading of -200∼-500 N to the screw head, axial maximum pull-out strengths of the 5 screws were measured and analyzed. The pull-out strengths of the primary screw and 4 revised screws with corticocancellous bone, longer screw and traditional and boring PMMA augmentation were 1167 N, 361 N, 854 N, 1954 N, and 1820 N, respectively. Although longer screw method obtained significantly higher pull-out strength than corticocancellous bone (P<0.05), the revised screws using these 2 techniques exhibited notably lower pull-out strength than the primary screw and 2 PMMA-augmented screws (P<0.05). Either traditional or boring PMMA screw showed obviously higher pull-out strength than the primary screw (P<0.05); however, no significant difference of pull-out strength was detected between the 2 PMMA screws (P>0.05). Wadding corticocancellous bone and increasing screw length failed to provide sufficient anchoring strength for a loosened iliac screw; however, both traditional and boring PMMA-augmented techniques could effectively increase the fixation strength. On the basis of the viewpoint of minimal invasion, the boring PMMA augmentation may serve as a suitable salvage technique for iliac screw loosening.

Rapid orthodontic treatment after the ridge-splitting technique--a combined surgical-orthodontic approach for implant site development: case report.

PubMed

Amato, Francesco; Mirabella, A Davide; Borlizzi, Diego

2012-08-01

This article presents a clinical case of bilateral partial edentulism in the posterior mandible with severe horizontal and moderate vertical bone atrophy. A new technique using rapid orthodontics after ridge splitting is presented. The split-crest technique was carried out using piezosurgical instruments in the first molar and second premolar areas to widen the bone crest and open a channel for tooth movement. Immediately after, orthodontic appliances were used to move the first premolars distally and the second molars mesially into the surgical site. The rationale was to facilitate and accelerate orthodontic movement of the teeth, which is otherwise difficult in a cortical knife-edged ridge. The bone defect was filled with the alveolar bone of the adjacent teeth that were moved into the surgically opened path. Adequate bone volume for implant placement was generated in the first premolar area. Implants were then inserted, and the patient was rehabilitated.

Comparison of conventional and synchrotron-radiation-based microtomography of bone around dental implants

NASA Astrophysics Data System (ADS)

Cattaneo, Paolo M.; Dalstra, Michel; Beckmann, Felix; Donath, Tilman; Melsen, Birte

2004-10-01

This study explores the application of conventional micro tomography (μCT) and synchrotron radiation (SR) based μCT to evaluate the bone around titanium dental implants. The SR experiment was performed at beamline W2 of HASYLAB at DESY using a monochromatic X-ray beam of 50 keV. The testing material consisted of undecalcified bone segments harvested from the upper jaw of a macaca fascicularis monkey each containing a titanium dental implant. The results from the two different techniques were qualitatively compared with conventional histological sections examined under light microscopy. The SR-based μCT produced images that, especially at the bone-implant interface, are less noisy and sharper than the ones obtained with conventional μCT. For the proper evaluation of the implant-bone interface, only the SR-based μCT technique is able to display the areas of bony contact and visualize the true 3D structure of bone around dental implants correctly. This investigation shows that both conventional and SR-based μCT scanning techniques are non-destructive methods, which provide detailed images of bone. However with SR-based μCT it is possible to obtain an improved image quality of the bone surrounding dental implants, which display a level of detail comparable to histological sections. Therefore, SR-based μCT scanning could represent a valid, unbiased three-dimensional alternative to evaluate osseointegration of dental implants

Skeletal scintigraphy and quantitative tracer studies in metabolic bone disease

NASA Astrophysics Data System (ADS)

Fogelman, Ignac

Bone scan imaging with the current bone seeking radiopharmaceuticals, the technetium-99m labelled diphosphonates, has dramatically improved our ability to evaluate skeletal pathology. In this thesis, chapter 1 presents a review of the history of bone scanning, summarises present concepts as to the mechanism of uptake of bone seeking agents and briefly illustrates the role of bone scanning in clinical practice. In chapter 2 the applications of bone scan imaging and quantitative tracer techniques derived from the bone scan in the detection of metabolic bone disease are discussed. Since skeletal uptake of Tc-99m diphosphonate depends upon skeletal metabolism one might expect that the bone scan would be of considerable value in the assessment of metabolic bone disease. However in these disorders the whole skeleton is often diffusely involved by the metabolic process and simple visual inspection of the scan image may not reveal the uniformly increased uptake of tracer. Certain patterns of bone scan abnormality have, however, been reported in patients with primary hyperparathyroidism and renal osteo-dystrophy; the present studies extend these observations and introduce the concept of "metabolic features" which are often recognisable in conditions with generalised increased bone turnover. As an aid to systematic recognition of these features on a given bone scan image a semi-quantitative scoring system, the metabolic index, was introduced. The metabolic index allowed differentiation between various groups of patients with metabolic disorders and a control population. In addition, in a bone scan study of patients with acromegaly, it was found that the metabolic index correlated well with disease activity as measured by serum growth hormone levels. The metabolic index was, however, found to be a relatively insensitive means of identifying disease in individual patients. Patients with increased bone turnover will have an absolute increase in skeletal uptake of tracer. As a means of quantitating this uptake the use of bone to soft-tissue ratios derived from the bone scan image by computer was critically evaluated. The technique was shown to be observer dependent and again found to be of limited value due to the large overlap of patient results with those from control subjects. In chapter 3 the use of bone scan imaging in metabolic bone disease has been compared with radiology. Despite the difficulties mentioned above the metabolic index was employed, and the bone scan found to be the more sensitive investigation in primary hyperparathyroidism, renal osteodystrophy and osteomalacia. In osteoporosis, however, the bone scan was often unable to identify disease and radiology remains the investigation of choice. In a further study comparing bone scanning and radiology in Paget's disease, the bone scan was found to be clearly the more sensitive investigation. As a result of the work described in chapter 2 it became apparent that a sensitive means of quantitating absolute bone uptake of tracer could be of diagnostic value. In chapter 4 a promising new quantitative technique is described in which the 24-hour whole-body retention of Tc-99m diphosphonate (WBR) is measured using a shadow-shield whole-body monitor. At 24 hours after injection, diphosphonate has reached a stable equilibrium in bone reflecting skeletal metabolic activity, while tracer in the soft-tissues of the body has been largely excreted via the urinary tract. It was found that this technique provided a sensitive means of detecting patients with primary hyperparathyroidism, osteomalacia, renal osteodystrophy and Paget's disease and that in these conditions all the results from individual patients lay outside the control range. In further studies the WBR technique was shown to be highly reproducible and not subject to any significant technical errors.

What Is a Gene? (For Kids)

MedlinePlus

... For example, if both of your parents have green eyes, you might inherit the trait for green eyes from them. Or if your mom has ... PRO-teens) in the cell. Proteins are the building blocks for everything in your body. Bones and ...

CD147 deficiency blocks IL-8 secretion and inhibits lung cancer-induced osteoclastogenesis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wang, Hongkai; Zhuo, Yunyun; Hu, Xu

2015-03-06

Bone is a frequent target of lung cancer metastasis, which is associated with significant morbidity and poor prognosis; however, the molecular basis of this process is still unknown. This study investigated the role of extracellular matrix metalloproteinase inducer (also known as cluster of differentiation (CD)147) in osteoclastogenesis resulting from bone metastasis, based on the enrichment of this glycoprotein on the surface of many malignant bone tumors. RNA interference was used to silence CD147 expression in A549 human lung cancer cells. Compared with conditioned medium (CM) from control cells (A549-CM), CM from CD147-deficient cells (A549-si-CM) suppressed receptor activator of nuclear factormore » κB ligand-stimulated osteoclastogenesis in RAW 264.7 cells and bone marrow-derived macrophages. The mRNA levels of osteoclast-specific genes such as tartrate-resistant acid phosphatase, calcitonin receptor, and cathepsin K were also reduced in the presence of A549-si-CM. CD147 knockdown in A549 cells decreased interleukin (IL)-8mRNA and protein expression. IL-8 is present in large amounts in A549-CM and mimicked its inductive effect on osteoclastogenesis; this was reversed by depletion of IL-8 from the medium. Taken together, these results indicate that CD147 promotes lung cancer-induced osteoclastogenesis by modulating IL-8 secretion, and suggest that CD147 is a potential therapeutic target for cancer-associated bone resorption in lung cancer patients. - Highlights: • Bone loss frequently results from lung cancer metastasis. • Cluster of differentiation (CD)147 was depleted in A549 lung adenocarcinoma cells. • RAW 264.7 cell osteoclastogenesis was blocked by medium from CD147-deficient cells. • Interleukin (IL)-8 level was reduced in the conditioned medium. • Osteoclastogenesis induced by lung tumor cells requires CD147-mediated IL-8 release.« less

Function of Matrix IGF-1 in Coupling Bone Resorption and Formation

PubMed Central

Crane, Janet L.; Cao, Xu

2013-01-01

Balancing bone resorption and formation is the quintessential component for the prevention of osteoporosis. Signals that determine the recruitment, replication, differentiation, function, and apoptosis of osteoblasts and osteoclasts direct bone remodeling and determine whether bone tissue is gained, lost, or balanced. Therefore understanding the signaling pathways involved in the coupling process will help develop further targets for osteoporosis therapy, by blocking bone resorption or enhancing bone formation in a space and time dependent manner. Insulin-like growth factor type 1 (IGF-1) has long been known to play a role in bone strength. It is one of the most abundant substances in the bone matrix, circulates systemically and is secreted locally, and has a direct relationship with bone mineral density. Recent data has helped further our understanding of the direct role of IGF-1 signaling in coupling bone remodeling which will be discussed in this review. The bone marrow microenvironment plays a critical role in the fate of MSCs and HSCs and thus how IGF-1 interacts with other factors in the microenvironment are equally important. While previous clinical trials with IGF-1 administration have been unsuccessful at enhancing bone formation, advances in basic science studies have provided insight into further mechanisms that should be considered for future trials. Additional basic science studies dissecting the regulation and the function of matrix IGF-1 in modeling and remodeling will continue to provide further insight for future directions for anabolic therapies for osteoporosis. PMID:24068256

Function of matrix IGF-1 in coupling bone resorption and formation.

PubMed

Crane, Janet L; Cao, Xu

2014-02-01

Balancing bone resorption and formation is the quintessential component for the prevention of osteoporosis. Signals that determine the recruitment, replication, differentiation, function, and apoptosis of osteoblasts and osteoclasts direct bone remodeling and determine whether bone tissue is gained, lost, or balanced. Therefore, understanding the signaling pathways involved in the coupling process will help develop further targets for osteoporosis therapy, by blocking bone resorption or enhancing bone formation in a space- and time-dependent manner. Insulin-like growth factor type 1 (IGF-1) has long been known to play a role in bone strength. It is one of the most abundant substances in the bone matrix, circulates systemically and is secreted locally, and has a direct relationship with bone mineral density. Recent data has helped further our understanding of the direct role of IGF-1 signaling in coupling bone remodeling which will be discussed in this review. The bone marrow microenvironment plays a critical role in the fate of mesenchymal stem cells and hematopoietic stem cells and thus how IGF-1 interacts with other factors in the microenvironment are equally important. While previous clinical trials with IGF-1 administration have been unsuccessful at enhancing bone formation, advances in basic science studies have provided insight into further mechanisms that should be considered for future trials. Additional basic science studies dissecting the regulation and the function of matrix IGF-1 in modeling and remodeling will continue to provide further insight for future directions for anabolic therapies for osteoporosis.

The three-dimensional reconstruction of the jaw with "bone slat technique" in conjunction with third molar removal.

PubMed

Santagata, Mario; Cecere, Atirge; Prisco, Rosario V E; Tartaro, Gianpaolo; D'Amato, Salvatore

2017-01-01

The purpose of this study was to report the outcome of the management of both horizontal and vertical defects of alveolar crest using the bone slat technique approach in conjunction with third molar removal prior to implant placement in the aesthetic area. We present a 20-year-old female patient who lost a maxillary lateral incisor. The objective of treatment was to replace the lateral incisor with an implant-supported crown restoration without interfering with the integrity and topography of the adjacent gingival tissues. Because the future implant site showed horizontal and vertical bone defect the Authors decided to perform bone regeneration. The need for such bone augmentation in the younger patient often coincides with the timing for third molar removal. By combining third molar extraction with bone harvest and alveolar grafting, the patient undergoes only one surgical approach. The bone height (9.5 mm) and width (5.7 mm) were measured at the point of interest (tooth 12) both before and after implant placement in the reconstructed panoramic and parasagittal views by Cone Beam Computed Tomography (CBCT) scan. The final results demonstrated an increase in length of 5 mm after bone slat technique (from 9.5 mm to 13.5 mm) and an increase in width of 1 mm (from 5.7 mm to 6.7 mm). ISQ measurements were recorded at the time of implant placement (the mean was: 68.5) and immediately after individualized screw-retained provisional crown (the mean was: 77). This technique is reliable and aesthetic and functional results appear to be stable and respect this requisite: simple and fast graft harvesting and low risk of morbidity especially in conjunction with third molar removal.

Photoacoustic FTIR spectroscopic study of undisturbed human cortical bone

NASA Astrophysics Data System (ADS)

Gu, Chunju; Katti, Dinesh R.; Katti, Kalpana S.

2013-02-01

Chemical pretreatment has been the prevailing sample preparation procedure for infrared (IR) spectroscopic studies on bone. However, experiments have indicated that chemical pretreatment can potentially affect the interactions between the components. Typically the IR techniques have involved transmission experiments. Here we report experimental studies using photoacoustic Fourier transform infrared spectroscopy (PA-FTIR). As a nondestructive technique, PA-FTIR can detect absorbance spectrum from a sample at controllable sampling depth and with little or no sample preparation. Additionally, the coupling inert gas, helium, which is utilized in the PA-FTIR system, can inhibit bacteria growth of bone by displacing oxygen. Therefore, we used this technique to study the undisturbed human cortical bone. It is found that photoacoustic mode (linear-scan, LS-PA-FTIR) can obtain basically similar spectra of bone as compared to the traditional transmission mode, but it seems more sensitive to amide III and ν2 carbonate bands. The ν3 phosphate band is indicative of detailed mineral structure and symmetry of native bone. The PA-FTIR depth profiling experiments on human cortical bone also indicate the influence of water on OH band and the cutting effects on amide I and mineral bands. Our results indicate that phosphate ion geometry appears less symmetric in its undisturbed state as detected by the PA-FTIR as compared to higher symmetry observed using transmission techniques on disturbed samples. Moreover, the PA-FTIR spectra indicate a band at 1747 cm-1 possibly resulting from Cdbnd O stretching of lipids, cholesterol esters, and triglycerides from the arteries. Comparison of the spectra in transverse and longitudinal cross-sections demonstrates that, the surface area of the longitudinal section bone appears to have more organic matrix exposed and with higher mineral stoichiometry.

Novel, near-infrared spectroscopic, label-free, techniques to assess bone abnormalities such as Paget's disease, osteoporosis and bone fractures

NASA Astrophysics Data System (ADS)

Sordillo, Diana C.; Sordillo, Laura A.; Shi, Lingyan; Budansky, Yury; Sordillo, Peter P.; Alfano, Robert R.

2015-02-01

Near- infrared (NIR) light with wavelengths from 650 nm to 950 nm (known as the first NIR window) has conventionally been used as a non-invasive technique that can reach deeper penetration depths through media than light at shorter wavelengths. Recently, several novel, NIR, label-free, techniques have been developed to assess Paget's disease of bone, osteoporosis and bone microfractures. We designed a Bone Optical Analyzer (BOA) which utilizes the first window to measure changes of Hb and HbO2. Paget's disease is marked by an increase in vascularization in bones, and this device can enable easy diagnosis and more frequent monitoring of the patient's condition, without exposing him to a high cumulative dose of radiation. We have also used inverse imaging algorithms to reconstruct 2D and 3D maps of the bone's structure. This device could be used to assess diseases such as osteoporosis. Using 800 nm femtosecond excitation with two-photon (2P) microscopy, we acquired 2PM images of the periosteum and spatial frequency spectra (based on emission of collagen) from the periosteal regions. This technique can provide information on the structure of the periosteum and can detect abnormalities which may be an indication of disease. Most recently, we showed that longer NIR wavelengths in the second and third NIR windows (1100 nm-1350 nm, 1600 nm-1870 nm), could be used to image bone microfractures. Use of NIR light could allow for repeated studies in patients with diseases such as Paget's and osteoporosis quickly and non-invasively, and could impact the current management for these diseases.

In vivo analysis of insertional torque during pedicle screwing using cortical bone trajectory technique.

PubMed

Matsukawa, Keitaro; Yato, Yoshiyuki; Kato, Takashi; Imabayashi, Hideaki; Asazuma, Takashi; Nemoto, Koichi

2014-02-15

The insertional torque of pedicle screws using the cortical bone trajectory (CBT) was measured in vivo. To investigate the effectiveness of the CBT technique by measurement of the insertional torque. The CBT follows a mediolateral and caudocephalad directed path, engaging with cortical bone maximally from the pedicle to the vertebral body. Some biomechanical studies have demonstrated favorable characteristics of the CBT technique in cadaveric lumbar spine. However, no in vivo study has been reported on the mechanical behavior of this new trajectory. The insertional torque of pedicle screws using CBT and traditional techniques were measured intraoperatively in 48 consecutive patients. A total of 162 screws using the CBT technique and 36 screws using the traditional technique were compared. In 8 of 48 patients, the side-by-side comparison of 2 different insertional techniques for each vertebra were performed, which formed the H group. In addition, the insertional torque was correlated with bone mineral density. The mean maximum insertional torque of CBT screws and traditional screws were 2.49 ± 0.99 Nm and 1.24 ± 0.54 Nm, respectively. The CBT screws showed 2.01 times higher torque and the difference was significant between the 2 techniques (P < 0.01). In the H group, the insertional torque were 2.71 ± 1.36 Nm in the CBT screws and 1.58 ± 0.44 Nm in the traditional screws. The CBT screws demonstrated 1.71 times higher torque and statistical significance was achieved (P < 0.01). Positive linear correlations between maximum insertional torque and bone mineral density were found in both technique, the correlation coefficient of traditional screws (r = 0.63, P < 0.01) was higher than that of the CBT screws (r = 0.59, P < 0.01). The insertional torque using the CBT technique is about 1.7 times higher than the traditional technique. 2.

Advances in the surface modification techniques of bone-related implants for last 10 years

PubMed Central

Qiu, Zhi-Ye; Chen, Cen; Wang, Xiu-Mei; Lee, In-Seop

2014-01-01

At the time of implanting bone-related implants into human body, a variety of biological responses to the material surface occur with respect to surface chemistry and physical state. The commonly used biomaterials (e.g. titanium and its alloy, Co–Cr alloy, stainless steel, polyetheretherketone, ultra-high molecular weight polyethylene and various calcium phosphates) have many drawbacks such as lack of biocompatibility and improper mechanical properties. As surface modification is very promising technology to overcome such problems, a variety of surface modification techniques have been being investigated. This review paper covers recent advances in surface modification techniques of bone-related materials including physicochemical coating, radiation grafting, plasma surface engineering, ion beam processing and surface patterning techniques. The contents are organized with different types of techniques to applicable materials, and typical examples are also described. PMID:26816626

Phosphorus-31 MRI of bones using quadratic echo line-narrowing

NASA Astrophysics Data System (ADS)

Frey, Merideth; Barrett, Sean; Insogna, Karl; Vanhouten, Joshua

2012-02-01

There is a great need to probe the internal composition of bone on the sub-0.1 mm length scale, both to study normal features and to look for signs of disease. Despite the obvious importance of the mineral fraction to the biomechanical properties of skeletal tissue, few non-destructive techniques are available to evaluate changes in its chemical structure and functional microarchitecture on the interior of bones. MRI would be an excellent candidate, but bone is a particularly challenging tissue to study given the relatively low water density and wider linewidths of its solid components. Recent fundamental research in quantum computing gave rise to a new NMR pulse sequence - the quadratic echo - that can be used to narrow the broad NMR spectrum of solids. This offers a new route to do high spatial resolution, 3D ^31P MRI of bone that complements conventional MRI and x-ray based techniques to study bone physiology and structure. We have used our pulse sequence to do 3D ^31P MRI of ex vivo bones with a spatial resolution of (sub-450 μm)^3, limited only by the specifications of a conventional 4 Tesla liquid-state MRI system. We will describe our plans to push this technique towards the factor of 1000 increase in spatial resolution imposed by fundamental limits.

Reconstruction of the Shallow Acetabulum With a Combination of Autologous Bulk and Impaction Bone Grafting Fixed by Cement.

PubMed

Maruyama, Masaaki; Wakabayashi, Shinji; Ota, Hiroshi; Tensho, Keiji

2017-02-01

Acetabular bone deficiency, especially proximal and lateral deficiency, is a difficult technical problem during primary total hip arthroplasty (THA) in developmental dysplasia of the hip (DDH). We report a new reconstruction method using a medial-reduced cemented socket and additional bulk bone in conjunction with impaction morselized bone grafting (additional bulk bone grafting method). In a population of patients with acetabular dysplasia undergoing THA using a medial-reduced cemented socket and additional bulk bone with impacted morselized bone grafting, we evaluated (1) the radiographic appearance of bone graft; (2) the proportion of cups that developed loosening and subsequent revision; and (3) clinical results (outcome scores and complications). Forty percent of 330 THAs for DDH performed at one center between 1999 and 2009 were defined as shallow dysplastic hips. The additional bulk bone grafting method was performed on 102 THAs with shallow acetabulum (31% for DDH) at one center between 1999 and 2009. We used this approach and technique for shallow acetabuli when a cup protruded from the lateral acetabular edge in preoperative templating. The other 132 dysplastic hips without bone grafting had THA performed at the same periods and served as a control. Acetabuli were defined as shallow when the depth was less than or equal to one-fifth of the pelvic height (cranial-caudal length on radiograph). The additional bulk bone grafting technique was as follows: the resected femoral head was sectioned at 1 to 2 cm thickness, and a suitable size of the bulk bone graft was placed on the lateral iliac cortex and fixed by poly-L-lactate absorbable screws. Autologous impaction morselized bone grafting, with or without hydroxyapatite granules, was performed along with the implantation of a medial-reduced cemented socket. We defined an "incorporated" graft as remodeling and trabeculation including rounding off of the protruding edge of a graft beyond the socket. Radiographic criteria used for determining loosening were migration or a continuous radiolucent zone between the prosthesis/bone cement and host bone. Clinical outcomes were assessed using the Japanese Orthopaedic Association (JOA) and the Merle d'Aubigne and Postel score; complications were tallied from chart review. The followup was 10 ± 3 years (range, 6-15 years). One acetabular component (1%) with severe shallow and steep acetabuli showed definite radiographic evidence of loosening and was revised. Clinically, the mean JOA score for the hips treated with additional bulk bone grafting THA in this study improved from 39 ± 10 points preoperatively to 95 ± 5 points postoperatively (p < 0.05, paired t-test). The mean Merle d'Aubigne and Postel score for the hips improved from 7 ± 2 points to 17 ± 1 points (p < 0.05, paired t-test). Complications included a Trendelenburg sign in one hip, dislocation in one, and transient partial sciatic nerve palsy in one. Within 3 years 6 months postoperatively, 101 of 102 additional bulk bone grafting cases showed successful bone remodeling and bone graft reorientation without collapse on radiographs. Partial resorption of the additional bone graft on the lateral side was observed in two hips (2%) with socket abduction angles of < 35°. Achieving stable acetabular fixation is often challenging in the dysplastic hip, especially shallow acetabulum, and a variety of techniques have been described. Early results of combining bulk graft with impaction of morselized graft are promising. Although each surgical technique was well established, further investigation for clinical results of a combination of these techniques might be necessary to confirm longer term outcomes. Level IV, therapeutic study.

Ammonium tetrathiomolybdate enhances the antitumor effects of cetuximab via the suppression of osteoclastogenesis in head and neck squamous carcinoma.

PubMed

Morisawa, Ayaka; Okui, Tatsuo; Shimo, Tsuyoshi; Ibaragi, Soichiro; Okusha, Yuka; Ono, Mitsuaki; Nguyen, Thi Thu Ha; Hassan, Nur Mohammad Monsur; Sasaki, Akira

2018-03-01

Head and neck squamous cell carcinoma (HNSCC) poses a significant challenge clinically where one of the mechanisms responsible for the invasion into facial bones occurs via the activation of osteoclasts. Copper has been demonstrated to play a key role in skeletal remodeling. However, the role of copper in cancer-associated bone destruction is thus far unknown. Lysyl oxidase (LOX) is a copper-dependent enzyme that promotes osteoclastogenesis. In the present study, we investigated the effects of copper on HNSCC with bone invasion by the copper chelator, ammonium tetrathiomolybdate (TM) in vitro and in vivo. We demonstrate that TM blocks the proliferation of HNSCC cells, inhibits LOX activation and decreases the expression of the receptor activator of nuclear factor-κB ligand (RANKL) in osteoblasts and osteocytes, subsequently suppressing bone destruction. These findings suggest that copper is a potential target for the treatment of HNSCCs associated with bone destruction.

Ablation of the pro-apoptotic protein Bax protects mice from glucocorticoid-induced bone growth impairment.

PubMed

Zaman, Farasat; Chrysis, Dionisios; Huntjens, Kirsten; Fadeel, Bengt; Sävendahl, Lars

2012-01-01

Dexamethasone (Dexa) is a widely used glucocorticoid to treat inflammatory diseases; however, a multitude of undesired effects have been reported to arise from this treatment including osteoporosis, obesity, and in children decreased longitudinal bone growth. We and others have previously shown that glucocorticoids induce apoptosis in growth plate chondrocytes. Here, we hypothesized that Bax, a pro-apoptotic member of the Bcl-2 family, plays a key role in Dexa-induced chondrocyte apoptosis and bone growth impairment. Indeed, experiments in the human HCS-2/8 chondrocytic cell line demonstrated that silencing of Bax expression using small-interfering (si) RNA efficiently blocked Dexa-induced apoptosis. Furthermore, ablation of Bax in female mice protected against Dexa-induced bone growth impairment. Finally, Bax activation by Dexa was confirmed in human growth plate cartilage specimens cultured ex vivo. Our findings could therefore open the door for new therapeutic approaches to prevent glucocorticoid-induced bone growth impairment through specific targeting of Bax.

Bone mineral measurement from Apollo experiment M-078. [derangement of bone mineral metabolism in spacecrews

NASA Technical Reports Server (NTRS)

Vogel, J. M.; Rambaut, P. C.; Smith, M. C., Jr.

1974-01-01

Loss of mineral from bone during periods of immobilization, recumbency, or weightlessness is examined. This report describes the instrumentation, technique, and bone mineral changes observed preflight and postflight for the Apollo 14, 15, and 16 missions. The bone mineral changes documented during the Apollo Program are reviewed, and their relevance to future missions is discussed.

Efficacy of the Greater Occipital Nerve Block for Cervicogenic Headache: Comparing Classical and Subcompartmental Techniques.

PubMed

Lauretti, Gabriela R; Corrêa, Selma W R O; Mattos, Anita L

2015-09-01

The aim of the study was to compare the efficacy of the greater occipital nerve (GON) block using the classical technique and different volumes of injectate with the subcompartmental technique for the treatment of cervicogenic headache (CH). Thirty patients acted as his/her own control. All patients were submitted to the GON block by the classical technique with 10 mg dexamethasone, plus 40 mg lidocaine (5 mL volume). Patients were randomly allocated into 1 of 3 groups (n = 10) when pain VAS was > 3 cm. Each group was submitted to a GON subcompartmental technique (10 mg dexamethasone + 40 mg lidocaine + nonionic iodine contrast + saline) under fluoroscopy using either 5, 10, or 15 mL final volume. Analgesia and quality of life were evaluated. The classical GON technique resulted in 2 weeks of analgesia and less rescue analgesic consumption, compared to 24 weeks after the subcompartmental technique (P < 0.01). Quality of life improved at 2 and 24 weeks after the classical and the suboccipital techniques, respectively (P < 0.05). The data revealed that groups were similar regarding analgesia when compared to volume of injection (P > 0.05). While the classical technique for GON block resulted in only 2 weeks of analgesia, the subcompartmental technique resulted in at least 24 weeks of analgesia, being 5 mL volume sufficient for the performance of the block under fluoroscopy. © 2014 World Institute of Pain.

Sacroplasty procedural extravasation with high viscosity bone cement: comparing the intraoperative long-axis versus short-axis techniques in osteoporotic cadavers.

PubMed

Miller, Jeffrey W; Diani, Art; Docsa, Steve; Ashton, Kristi; Sciamanna, Michele

2017-09-01

Percutaneous sacroplasty involves image-guided injection of bone cement for sacral insufficiency fractures to alleviate pain and facilitate mobility. Correct sacral placement of the cement and the risk of cement extravasation present procedural challenges. This study compares the occurrence, number, location, and surface area of high viscosity radiopaque bone cement extravasation via biplane fluoroscopy with Dyna CT between the fluoroscopically-guided intraoperative long-axis and short-axis sacroplasty techniques in osteoporotic cadavers. Ten osteoporotic cadavers underwent bilateral percutaneous instillation of VertaPlex HV High Viscosity Radiopaque Bone Cement. Long- and short-axis sacroplasty techniques were randomly assigned to zone 1 of the left or right sacral ala of each cadaver. Cement extravasation data were summarized by technique (long-axis vs short-axis) and time period (15-min and 3-hour post-procedure syngo DynaCT scan) in the form of point and CI estimates for the true proportions of cement extravasation. No procedural sacral extravasation differences were observed between the long-axis and short-axis sacroplasty techniques. There were no occurrences of intra-procedural or post-procedural cement extravasation at 15 min or 3 hours in association with either the long-axis sacroplasty technique or the short-axis sacroplasty technique. The long- and short-axis sacroplasty techniques, using high viscosity cement with careful post-procedural positioning, result in no occurrence of cement extravasation in porous osteoporotic cadaver bone. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

Investigating the Role of Global Histogram Equalization Technique for 99mTechnetium-Methylene diphosphonate Bone Scan Image Enhancement

PubMed Central

Pandey, Anil Kumar; Sharma, Param Dev; Dheer, Pankaj; Parida, Girish Kumar; Goyal, Harish; Patel, Chetan; Bal, Chandrashekhar; Kumar, Rakesh

2017-01-01

Purpose of the Study: 99mTechnetium-methylene diphosphonate (99mTc-MDP) bone scan images have limited number of counts per pixel, and hence, they have inferior image quality compared to X-rays. Theoretically, global histogram equalization (GHE) technique can improve the contrast of a given image though practical benefits of doing so have only limited acceptance. In this study, we have investigated the effect of GHE technique for 99mTc-MDP-bone scan images. Materials and Methods: A set of 89 low contrast 99mTc-MDP whole-body bone scan images were included in this study. These images were acquired with parallel hole collimation on Symbia E gamma camera. The images were then processed with histogram equalization technique. The image quality of input and processed images were reviewed by two nuclear medicine physicians on a 5-point scale where score of 1 is for very poor and 5 is for the best image quality. A statistical test was applied to find the significance of difference between the mean scores assigned to input and processed images. Results: This technique improves the contrast of the images; however, oversaturation was noticed in the processed images. Student's t-test was applied, and a statistically significant difference in the input and processed image quality was found at P < 0.001 (with α = 0.05). However, further improvement in image quality is needed as per requirements of nuclear medicine physicians. Conclusion: GHE techniques can be used on low contrast bone scan images. In some of the cases, a histogram equalization technique in combination with some other postprocessing technique is useful. PMID:29142344

Transperitoneal rectus sheath block and transversus abdominis plane block for laparoscopic inguinal hernia repair: A novel approach.

PubMed

Nagata, Jun; Watanabe, Jun; Nagata, Masato; Sawatsubashi, Yusuke; Akiyama, Masaki; Tajima, Takehide; Arase, Koichi; Minagawa, Noritaka; Torigoe, Takayuki; Nakayama, Yoshifumi; Horishita, Reiko; Kida, Kentaro; Hamada, Kotaro; Hirata, Keiji

2017-08-01

A laparoscopic approach for inguinal hernia repair is now considered the gold standard. Laparoscopic surgery is associated with a significant reduction in postoperative pain. Epidural analgesia cannot be used in patients with perioperative anticoagulant therapy because of complications such as epidural hematoma. As such, regional anesthetic techniques, such as ultrasound-guided rectus sheath block and transversus abdominis plane block, have become increasingly popular. However, even these anesthetic techniques have potential complications, such as rectus sheath hematoma, if vessels are damaged. We report the use of a transperitoneal laparoscopic approach for rectus sheath block and transversus abdominis plane block as a novel anesthetic procedure. An 81-year-old woman with direct inguinal hernia underwent laparoscopic transabdominal preperitoneal inguinal repair. Epidural anesthesia was not performed because anticoagulant therapy was administered. A Peti-needle™ was delivered through the port, and levobupivacaine was injected though the peritoneum. Surgery was performed successfully, and the anesthetic technique did not affect completion of the operative procedure. The patient was discharged without any complications. This technique was feasible, and the procedure was performed safely. Our novel analgesia technique has potential use as a standard postoperative regimen in various laparoscopic surgeries. Additional prospective studies to compare it with other techniques are required. © 2017 Japan Society for Endoscopic Surgery, Asia Endosurgery Task Force and John Wiley & Sons Australia, Ltd.

Bone mass density estimation: Archimede’s principle versus automatic X-ray histogram and edge detection technique in ovariectomized rats treated with germinated brown rice bioactives

PubMed Central

Muhammad, Sani Ismaila; Maznah, Ismail; Mahmud, Rozi Binti; Esmaile, Maher Faik; Zuki, Abu Bakar Zakaria

2013-01-01

Background Bone mass density is an important parameter used in the estimation of the severity and depth of lesions in osteoporosis. Estimation of bone density using existing methods in experimental models has its advantages as well as drawbacks. Materials and methods In this study, the X-ray histogram edge detection technique was used to estimate the bone mass density in ovariectomized rats treated orally with germinated brown rice (GBR) bioactives, and the results were compared with estimated results obtained using Archimede’s principle. New bone cell proliferation was assessed by histology and immunohistochemical reaction using polyclonal nuclear antigen. Additionally, serum alkaline phosphatase activity, serum and bone calcium and zinc concentrations were detected using a chemistry analyzer and atomic absorption spectroscopy. Rats were divided into groups of six as follows: sham (nonovariectomized, nontreated); ovariectomized, nontreated; and ovariectomized and treated with estrogen, or Remifemin®, GBR-phenolics, acylated steryl glucosides, gamma oryzanol, and gamma amino-butyric acid extracted from GBR at different doses. Results Our results indicate a significant increase in alkaline phosphatase activity, serum and bone calcium, and zinc and ash content in the treated groups compared with the ovariectomized nontreated group (P < 0.05). Bone density increased significantly (P < 0.05) in groups treated with estrogen, GBR, Remifemin®, and gamma oryzanol compared to the ovariectomized nontreated group. Histological sections revealed more osteoblasts in the treated groups when compared with the untreated groups. A polyclonal nuclear antigen reaction showing proliferating new cells was observed in groups treated with estrogen, Remifemin®, GBR, acylated steryl glucosides, and gamma oryzanol. There was a good correlation between bone mass densities estimated using Archimede’s principle and the edge detection technique between the treated groups (r2 = 0.737, P = 0.004). Conclusion Our study shows that GBR bioactives increase bone density, which might be via the activation of zinc formation and increased calcium content, and that X-ray edge detection technique is effective in the measurement of bone density and can be employed effectively in this respect. PMID:24187491

Bioactive borate glass promotes the repair of radius segmental bone defects by enhancing the osteogenic differentiation of BMSCs.

PubMed

Zhang, Jieyuan; Guan, Junjie; Zhang, Changqing; Wang, Hui; Huang, Wenhai; Guo, Shangchun; Niu, Xin; Xie, Zongping; Wang, Yang

2015-11-20

Bioactive borate glass (BG) has emerged as a promising alternative for bone regeneration due to its high osteoinductivity, osteoconductivity, compressive strength, and biocompatibility. However, the role of BG in large segmental bone repair is unclear and little is known about the underlying mechanism of BG's osteoinductivity. In this study, we demonstrated that BG possessed pro-osteogenic effects in an experimental model of critical-sized radius defects. Transplanting BG to radius defects resulted in better repair of bone defects as compared to widely used β-TCP. Histological and morphological analysis indicated that BG significantly enhanced new bone formation. Furthermore, the degradation rate of the BG was faster than that of β-TCP, which matched the higher bone regeneration rate. In addition, ions from BG enhanced cell viability, ALP activity, and osteogenic-related genes expression. Mechanistically, the critical genes Smad1/5 and Dlx5 in the BMP pathway and p-Smad1/5 proteins were significantly elevated after BG transplantation, and these effects could be blocked by the BMP/Smad specific inhibitor. Taken together, our findings suggest that BG could repair large segmental bone defects through activating the BMP/Smad pathway and osteogenic differentiation in BMSCs.

Oncoplastic round block technique has comparable operative parameters as standard wide local excision: a matched case-control study.

PubMed

Lim, Geok-Hoon; Allen, John Carson; Ng, Ruey Pyng

2017-08-01

Although oncoplastic breast surgery is used to resect larger tumors with lower re-excision rates compared to standard wide local excision (sWLE), criticisms of oncoplastic surgery include a longer-albeit, well concealed-scar, longer operating time and hospital stay, and increased risk of complications. Round block technique has been reported to be very suitable for patients with relatively smaller breasts and minimal ptosis. We aim to determine if round block technique will result in operative parameters comparable with sWLE. Breast cancer patients who underwent a round block procedure from 1st May 2014 to 31st January 2016 were included in the study. These patients were then matched for the type of axillary procedure, on a one to one basis, with breast cancer patients who had undergone sWLE from 1st August 2011 to 31st January 2016. The operative parameters between the 2 groups were compared. 22 patients were included in the study. Patient demographics and histologic parameters were similar in the 2 groups. No complications were reported in either group. The mean operating time was 122 and 114 minutes in the round block and sWLE groups, respectively (P=0.64). Length of stay was similar in the 2 groups (P=0.11). Round block patients had better cosmesis and lower re-excision rates. A higher rate of recurrence was observed in the sWLE group. The round block technique has comparable operative parameters to sWLE with no evidence of increased complications. Lower re-excision rate and better cosmesis were observed in the round block patients suggesting that the round block technique is not only comparable in general, but may have advantages to sWLE in selected cases.

Freeze Casting for Assembling Bioinspired Structural Materials.

PubMed

Cheng, Qunfeng; Huang, Chuanjin; Tomsia, Antoni P

2017-12-01

Nature is very successful in designing strong and tough, lightweight materials. Examples include seashells, bone, teeth, fish scales, wood, bamboo, silk, and many others. A distinctive feature of all these materials is that their properties are far superior to those of their constituent phases. Many of these natural materials are lamellar or layered in nature. With its "brick and mortar" structure, nacre is an example of a layered material that exhibits extraordinary physical properties. Finding inspiration in living organisms to create bioinspired materials is the subject of intensive research. Several processing techniques have been proposed to design materials mimicking natural materials, such as layer-by-layer deposition, self-assembly, electrophoretic deposition, hydrogel casting, doctor blading, and many others. Freeze casting, also known as ice-templating, is a technique that has received considerable attention in recent years to produce bioinspired bulk materials. Here, recent advances in the freeze-casting technique are reviewed for fabricating lamellar scaffolds by assembling different dimensional building blocks, including nanoparticles, polymer chains, nanofibers, and nanosheets. These lamellar scaffolds are often infiltrated by a second phase, typically a soft polymer matrix, a hard ceramic matrix, or a metal matrix. The unique architecture of the resultant bioinspired structural materials displays excellent mechanical properties. The challenges of the current research in using the freeze-casting technique to create materials large enough to be useful are also discussed, and the technique's promise for fabricating high-performance nacre-inspired structural materials in the future is reviewed. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

A simplified technique for delivering total body irradiation (TBI) with improved dose homogeneity

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yao Rui; Bernard, Damian; Turian, Julius

2012-04-15

Purpose: Total body irradiation (TBI) with megavoltage photon beams has been accepted as an important component of management for a number of hematologic malignancies, generally as part of bone marrow conditioning regimens. The purpose of this paper is to present and discuss the authors' TBI technique, which both simplifies the treatment process and improves the treatment quality. Methods: An AP/PA TBI treatment technique to produce uniform dose distributions using sequential collimator reductions during each fraction was implemented, and a sample calculation worksheet is presented. Using this methodology, the dosimetric characteristics of both 6 and 18 MV photon beams, including lungmore » dose under cerrobend blocks was investigated. A method of estimating midplane lung doses based on measured entrance and exit doses was proposed, and the estimated results were compared with measurements. Results: Whole body midplane dose uniformity of {+-}10% was achieved with no more than two collimator-based beam modulations. The proposed model predicted midplane lung doses 5% to 10% higher than the measured doses for 6 and 18 MV beams. The estimated total midplane doses were within {+-}5% of the prescribed midplane dose on average except for the lungs where the doses were 6% to 10% lower than the prescribed dose on average. Conclusions: The proposed TBI technique can achieve dose uniformity within {+-}10%. This technique is easy to implement and does not require complicated dosimetry and/or compensators.« less

Block of the superior cervical ganglion, description of a novel ultrasound-guided technique in human cadavers.

PubMed

Siegenthaler, Andreas; Haug, Matthias; Eichenberger, Urs; Suter, Marc Rene; Moriggl, Bernhard

2013-05-01

Injection of opioids to the superior cervical ganglion (SCG) has been reported to provide pain relief in patients suffering from different kinds of neuropathic facial pain conditions, such as trigeminal neuralgia, postherpetic neuralgia, and atypical facial pain. The classic approach to the SCG is a transoral technique using a so-called "stopper" to prevent accidental carotid artery puncture. The main disadvantage of this technique is that the needle tip is positioned distant from the actual target, possibly impeding successful block of the SCG. A further limitation is that injection of local anesthetics due to potential carotid artery puncture is contraindicated. We hypothesized that the SCG can be identified and blocked using ultrasound imaging, potentially increasing precision of this technique. In this pilot study, 20 US-guided simulated blocks of the SCG were performed in 10 human cadavers in order to determine the accuracy of this novel block technique. After injection of 0.1 mL of dye, the cadavers were dissected to evaluate the needle position and coloring of the SCG. Nineteen of the 20 needle tips were located in or next to the SCG. This corresponded to a simulated block success rate of 95% (95% confidence interval 85-100%). In 17 cases, the SCG was completely colored, and in two cases, the caudal half of the SCG was colored with dye. The anatomical dissections confirmed that our ultrasound-guided approach to the SCG is accurate. Ultrasound could become an attractive alternative to the "blind" transoral technique of SCG blocks. Wiley Periodicals, Inc.

Novel 3D Tissue Engineered Bone Model, Biomimetic Nanomaterials, and Cold Atmospheric Plasma Technique for Biomedical Applications

NASA Astrophysics Data System (ADS)

Wang, Mian

This thesis research is consist of four chapters, including biomimetic three-dimensional tissue engineered nanostructured bone model for breast cancer bone metastasis study (Chapter one), cold atmospheric plasma for selectively ablating metastatic breast cancer (Chapter two), design of biomimetic and bioactive cold plasma modified nanostructured scaffolds for enhanced osteogenic differentiation of bone marrow derived mesenchymal stem cells (Chapter three), and enhanced osteoblast and mesenchymal stem cell functions on titanium with hydrothermally treated nanocrystalline hydroxyapatite/magnetically treated carbon nanotubes for orthopedic applications (Chapter four). All the thesis research is focused on nanomaterials and the use of cold plasma technique for various biomedical applications.

Primary bone tumors of adulthood

PubMed Central

Teo, Harvey E L; Peh, Wilfred C G

2004-01-01

Imaging plays a crucial role in the evaluation of primary bone tumors in adults. Initial radiographic evaluation is indicated in all cases with suspected primary bone tumors. Radiographs are useful for providing the diagnosis, a short list of differential diagnosis or at least indicating the degree of aggressiveness of the lesion. More detailed information about the lesion, such as cortical destruction or local spread, can be obtained using cross-sectional imaging techniques such as computed tomography and magnetic resonance imaging. This article discusses the characteristic features of the more common primary bone tumors of adulthood, and also the pre-treatment evaluation and staging of these lesions using imaging techniques. PMID:18250012

Methods: a comparative analysis of radiography, microcomputed tomography, and histology for bone tissue engineering.

PubMed

Hedberg, Elizabeth L; Kroese-Deutman, Henriette C; Shih, Charles K; Lemoine, Jeremy J; Liebschner, Michael A K; Miller, Michael J; Yasko, Alan W; Crowther, Roger S; Carney, Darrell H; Mikos, Antonios G; Jansen, John A

2005-01-01

This study focused on the assessment of radiography, microcomputed tomography, and histology for the evaluation of bone formation in a 15.0-mm defect in the rabbit radius after the implantation of a tissue-engineered construct. Radiography was found to be useful as a noninvasive method for obtaining images of calcified tissue throughout the time course of the experiment. With this method, however, image quality was low, making it difficult to obtain precise information about the location and quantity of the bone formed. Microcomputed tomography was used to create three-dimensional reconstructions of the bone (25-microm resolution). These reconstructions allowed for greater spatial resolution than the radiography, but did not allow for imaging of the implanted scaffold material or the surrounding, nonmineralized tissue. To visualize all materials within the defect area at the cellular level, histology was used. Histological analysis, however, is a destructive technique that did not allow for any further analysis of the samples. Each technique examined here has its own advantages and limitations, but each yields unique information regarding bone regeneration. It is only through the use of all three techniques that complete characterization of the bone growth and tissue/construct responses after implantation in vivo.

Minimally invasive esthetic ridge preservation with growth-factor enhanced bone matrix.

PubMed

Nevins, Marc L; Said, Sherif

2017-12-28

Extraction socket preservation procedures are critical to successful esthetic implant therapy. Conventional surgical approaches are technique sensitive and often result in alteration of the soft tissue architecture, which then requires additional corrective surgical procedures. This case series report presents the ability of flapless surgical techniques combined with a growth factor-enhanced bone matrix to provide esthetic ridge preservation at the time of extraction for compromised sockets. When considering esthetic dental implant therapy, preservation, or further enhancement of the available tissue support at the time of tooth extraction may provide an improved esthetic outcome with reduced postoperative sequelae and decreased treatment duration. Advances in minimally invasive surgical techniques combined with recombinant growth factor technology offer an alternative for bone reconstruction while maintaining the gingival architecture for enhanced esthetic outcome. The combination of freeze-dried bone allograft (FDBA) and rhPDGF-BB (platelet-derived growth factor-BB) provides a growth-factor enhanced matrix to induce bone and soft tissue healing. The use of a growth-factor enhanced matrix is an option for minimally invasive ridge preservation procedures for sites with advanced bone loss. Further studies including randomized clinical trials are needed to better understand the extent and limits of these procedures. The use of minimally invasive techniques with growth factors for esthetic ridge preservation reduces patient morbidity associated with more invasive approaches and increases the predictability for enhanced patient outcomes. By reducing the need for autogenous bone grafts the use of this technology is favorable for patient acceptance and ease of treatment process for esthetic dental implant therapy. © 2017 Wiley Periodicals, Inc.

Early loss of subchondral bone following microfracture is counteracted by bone marrow aspirate in a translational model of osteochondral repair

PubMed Central

Gao, Liang; Orth, Patrick; Müller-Brandt, Kathrin; Goebel, Lars K. H.; Cucchiarini, Magali; Madry, Henning

2017-01-01

Microfracture of cartilage defects may induce alterations of the subchondral bone in the mid- and long-term, yet very little is known about their onset. Possibly, these changes may be avoided by an enhanced microfracture technique with additional application of bone marrow aspirate. In this study, full-thickness chondral defects in the knee joints of minipigs were either treated with (1) debridement down to the subchondral bone plate alone, (2) debridement with microfracture, or (3) microfracture with additional application of bone marrow aspirate. At 4 weeks after microfracture, the loss of subchondral bone below the defects largely exceeded the original microfracture holes. Of note, a significant increase of osteoclast density was identified in defects treated with microfracture alone compared with debridement only. Both changes were significantly counteracted by the adjunct treatment with bone marrow. Debridement and microfracture without or with bone marrow were equivalent regarding the early cartilage repair. These data suggest that microfracture induced a substantial early resorption of the subchondral bone and also highlight the potential value of bone marrow aspirate as an adjunct to counteract these alterations. Clinical studies are warranted to further elucidate early events of osteochondral repair and the effect of enhanced microfracture techniques. PMID:28345610

Stem cell therapy for reconstruction of alveolar cleft and trauma defects in adults: A randomized controlled, clinical trial.

PubMed

Bajestan, Mona N; Rajan, Archana; Edwards, Sean P; Aronovich, Sharon; Cevidanes, Lucia H S; Polymeri, Angeliki; Travan, Suncica; Kaigler, Darnell

2017-10-01

Stem cell therapy with bone marrow-derived mesenchymal stem cells is a promising tissue engineering strategy to promote regeneration of craniofacial bone. To determine whether cell therapy with ex vivo expanded stem cell populations would be safe and efficacious in the regeneration of large alveolar defects in patients with a history of cleft palate or craniofacial trauma. Eighteen patients (10 patients with traumatic injury and 8 patients with cleft palate) presenting with missing teeth associated with horizontal alveolar bone deficiencies were included in this randomized controlled clinical trial. Patients were randomized to receive either conventional autogenous block grafts or stem cell therapy. After a healing period of 4 months the treated sites were re-entered and the bone width re-assessed prior to implant placement. Implant stability was evaluated through torque testing of the implant upon insertion and at 6 months postloading. The mean gain in bone width was 1.5 ± 1.5 mm in the stem cell therapy group and 3.3 ± 1.4 mm in the control group. Overall, bone gain was higher in trauma patients as compared to patients with cleft palate, for both the control and the stem cell therapy groups. Most postoperative complications were wound dehiscences and incision line openings. Implants were placed successfully in 5 out of 10 patients in the stem cell therapy group and in all 8 patients in the control group. One implant from the control/cleft palate group failed before loading, while the rest of the implants were loaded successfully and remained stable at 6 months. The patients who did not receive implants were re-treated with autogenous block bone graft. The ability of stem cells to treat large alveolar defects is safe, yet, their ability to completely reconstitute large alveolar defects is limited. This approach requires further optimization to meet the outcomes seen using current methods to treat large defects, particularly those resultant of cleft palate. © 2017 Wiley Periodicals, Inc.

Assessment of bone health in children with disabilities.

PubMed

Kecskemethy, Heidi H; Harcke, H Theodore

2014-01-01

Evaluating the bone health of children with disabilities is challenging and requires consideration of many factors in clinical decision-making. Feeding problems and growth deficits, immobility/inability to bear weight, effect of medications, and the nature of his or her disease can all directly affect a child's overall picture of bone health. Familiarity with the tools available to assess bone health is important for practitioners. The most commonly used method to assess bone density, dual energy x-ray absorptiometry, can be performed effectively when one appreciates the techniques that make scanning patients with disabilities possible. There are specific techniques that are especially useful for measuring bone density in children with disabilities; standard body sites are not always obtainable. Consideration of clinical condition and treatment must be considered when interpreting dual energy x-ray absorptiometry scans. Serial measurements have been shown to be effective in monitoring change in bone content and in providing information on which to base decisions regarding medical treatment.

Clinical Imaging of Bone Microarchitecture with HR-pQCT

PubMed Central

Nishiyama, Kyle K.; Shane, Elizabeth

2014-01-01

Osteoporosis, a disease characterized by loss of bone mass and structural deterioration, is currently diagnosed by dual-energy x-ray absorptiometry (DXA). However, DXA does not provide information about bone microstructure, which is a key determinant of bone strength. Recent advances in imaging permit the assessment of bone microstructure in vivo using high-resolution peripheral quantitative computed tomography (HR-pQCT). From these data, novel image processing techniques can be applied to characterize bone quality and strength. To date, most HR-pQCT studies are cross-sectional comparing subjects with and without fracture. These studies have shown that HR-pQCT is capable of discriminating fracture status independent of DXA. Recent longitudinal studies present new challenges in terms of analyzing the same region of interest and multisite calibrations. Careful application of analysis techniques and educated clinical interpretation of HR-pQCT results have improved our understanding of various bone-related diseases and will no doubt continue to do so in the future. PMID:23504496

Transversus abdominis plane block in renal allotransplant recipients: A retrospective chart review.

PubMed

Gopwani, S R; Rosenblatt, M A

2016-01-01

The efficacy of the transversus abdominis plane (TAP) block appears to vary considerably, depending on the surgical procedure and block technique. This study aims to add to the existing literature and provide a more clear understanding of the TAP blocks role as a postoperative analgesic technique, specifically in renal allotransplant recipients. A retrospective chart review was conducted by querying the intraoperative electronic medical record system of a 1200-bed tertiary academic hospital over a 5 months period, and reviewing anesthetic techniques, as well as postoperative morphine equivalent consumption. Fifty renal allotransplant recipients were identified, 13 of whom received TAP blocks while 37 received no regional analgesic technique. All blocks were performed under ultrasound guidance, with 20 mL of 0.25% bupivacaine injected in the transversus abdominis fascial plane under direct visualization. The primary outcome was postoperative morphine equivalent consumption. Morphine consumption was compared with the two-tailed Mann-Whitney U -test. Continuous variables of patient baseline characteristics were analyzed with unpaired t -test and categorical variables with Fischer Exact Test. A P < 0.05 was considered statistically significant. A statistically significant decrease in cumulative morphine consumption was found in the group that received the TAP block at 6 h (2.46 mg vs. 7.27 mg, P = 0.0010), 12 h (3.88 mg vs. 10.20 mg, P = 0.0005), 24 h (6.96 mg vs. 14.75 mg, P = 0.0013), and 48 h (11 mg vs. 20.13 mg, P = 0.0092). The TAP block is a beneficial postoperative analgesic, opiate-sparing technique in renal allotransplant recipients.

Osteoimmunology: Influence of the Immune System on Bone Regeneration and Consumption.

PubMed

Limmer, Andreas; Wirtz, Dieter C

2017-06-01

Background Stimulating bone regeneration is a central aim in orthopaedic and trauma surgery. Although the replacement of bone with artificial materials like cement or apatite helps to keep up bone stability, new bone often cannot be regenerated. Increasing research efforts have led to the clinical application of growth factors stimulating bone growth (e.g. bone morphogenic protein, BMP) and inhibitors preventing bone consumption (e.g. RANKL blocking antibodies). These factors mostly concentrate on stimulating osteoblast or preventing osteoclast activity. Current Situation It is widely accepted that osteoblasts and osteoclasts are central players in bone regeneration. This concept assumes that osteoblasts are responsible for bone growth while osteoclasts cause bone consumption by secreting matrix-degrading enzymes such as cathepsin K and matrix metalloproteinases (MMP). However, according to new research results, bone growth or consumption are not regulated by single cell types. It is rather the interaction of various cell types that regulates bone metabolism. While factors secreted by osteoblasts are essential for osteoclast differentiation and activation, factors secreted by activated osteoclasts are essential for osteoblast activity. In addition, recent research results imply that the influence of the immune system on bone metabolism has long been neglected. Factors secreted by macrophages or T cells strongly influence bone growth or degradation, depending on the bone microenvironment. Infections, sterile inflammation or tumour metastases not only affect bone cells directly, but also influence immune cells such as T cells indirectly. Furthermore, immune cells and bone are mechanistically regulated by similar factors such as cytokines, chemokines and transcription factors, suggesting that the definition of bone and immune cells has to be thought over. Outlook Bone and the immune system are regulated by similar mechanisms. These newly identified similarities between bone and the immune system imply that medication developed for tumour and autoimmune patients could also be applied in bone diseases. Georg Thieme Verlag KG Stuttgart · New York.

Definitions of Health Terms: Vitamins

MedlinePlus

... citrus, red and green peppers, tomatoes, broccoli, and greens. Some juices and cereals have added vitamin C. Source : NIH MedlinePlus Vitamin D Vitamin D helps your body absorb calcium. Calcium is one of the main building blocks of bone. A lack of vitamin D ...

Biological effect of hydrolyzed collagen on bone metabolism.

PubMed

Daneault, Audrey; Prawitt, Janne; Fabien Soulé, Véronique; Coxam, Véronique; Wittrant, Yohann

2017-06-13

Osteoporosis is a chronic and asymptomatic disease characterized by low bone mass and skeletal microarchitectural deterioration, increased risk of fracture, and associated comorbidities most prevalent in the elderly. Due to an increasingly aging population, osteoporosis has become a major health issue requiring innovative disease management. Proteins are important for bone by providing building blocks and by exerting specific regulatory function. This is why adequate protein intake plays a considerable role in both bone development and bone maintenance. More specifically, since an increase in the overall metabolism of collagen can lead to severe dysfunctions and a more fragile bone matrix and because orally administered collagen can be digested in the gut, cross the intestinal barrier, enter the circulation, and become available for metabolic processes in the target tissues, one may speculate that a collagen-enriched diet provides benefits for the skeleton. Collagen-derived products such as gelatin or hydrolyzed collagen (HC) are well acknowledged for their safety from a nutritional point of view; however, what is their impact on bone biology? In this manuscript, we critically review the evidence from literature for an effect of HC on bone tissues in order to determine whether HC may represent a relevant alternative in the design of future nutritional approaches to manage osteoporosis prevention.

Effects of immediate and delayed loading on peri-implant trabecular structures: a cone beam CT evaluation.

PubMed

Huang, Yan; Van Dessel, Jeroen; Liang, Xin; Depypere, Maarten; Zhong, Weijian; Ma, Guowu; Lambrichts, Ivo; Maes, Frederik; Jacobs, Reinhilde

2014-12-01

To develop a method for characterizing trabecular bone microarchitecture using cone beam computed tomography (CBCT) and to evaluate trabecular bone changes after rehabilitation using immediate versus delayed implant protocols. Six mongrel dogs randomly received 27 titanium implants in the maxillary incisor or mandibular premolar areas, following one of four protocols: (1) normal extraction socket healing; (2) immediate implant placement and immediate loading; (3) delayed implant placement and delayed loading; (4) delayed implant placement and immediate loading. The animals were euthanized at 8 weeks, and block biopsies were scanned using high resolution CBCT. Standard bone structural variables were assessed in coronal, middle, and apical levels. Coronal and middle regions had more compact, more platelike, and thicker trabeculae. Protocols (2), (3), and (4) had significantly higher values (p < 0.001) than protocol (1) for bone surface density, bone surface volume ratio, and connectivity density, while significantly lower values (p < 0.001) were found for trabecular separation and fractal dimension. However, protocols (2), (3), and (4) did not show significantly different bone remodeling. Compared with normal extraction healing, the implant protocols have an improved bone structural integration. Results do not suggest a different bone remodeling pattern when a delayed versus an immediate implant protocol is used. © 2013 Wiley Periodicals, Inc.

Biomechanical and histologic basis of osseodensification drilling for endosteal implant placement in low density bone. An experimental study in sheep.

PubMed

Lahens, Bradley; Neiva, Rodrigo; Tovar, Nick; Alifarag, Adham M; Jimbo, Ryo; Bonfante, Estevam A; Bowers, Michelle M; Cuppini, Marla; Freitas, Helora; Witek, Lukasz; Coelho, Paulo G

2016-10-01

A bone drilling concept, namely osseodensification, has been introduced for the placement of endosteal implants to increase primary stability through densification of the osteotomy walls. This study investigated the effect of osseodensification on the initial stability and early osseointegration of conical and parallel walled endosteal implants in low density bone. Five male sheep were used. Three implants were inserted in the ilium, bilaterally, totaling 30 implants (n=15 conical, and n=15 parallel). Each animal received 3 implants of each type, inserted into bone sites prepared as follows: (i) regular-drilling (R: 2mm pilot, 3.2mm, and 3.8mm twist drills), (ii) clockwise osseodensification (CW), and (iii) counterclockwise (CCW) osseodensification drilling with Densah Bur (Versah, Jackson, MI, USA): 2.0mm pilot, 2.8mm, and 3.8mm multi-fluted burs. Insertion torque as a function of implant type and drilling technique, revealed higher values for osseodensification relative to R-drilling, regardless of implant macrogeometry. A significantly higher bone-to-implant contact (BIC) for both osseodensification techniques (p<0.05) was observed compared to R-drilling. There was no statistical difference in BIC as a function of implant type (p=0.58), nor in bone-area-fraction occupancy (BAFO) as a function of drilling technique (p=0.22), but there were higher levels of BAFO for parallel than conic implants (p=0.001). Six weeks after surgery, new bone formation along with remodeling sites was observed for all groups. Bone chips in proximity with the implants were seldom observed in the R-drilling group, but commonly observed in the CW, and more frequently under the CCW osseodensification technique. In low-density bone, endosteal implants present higher insertion torque levels when placed in osseodensification drilling sites, with no osseointegration impairment compared to standard subtractive drilling methods. Copyright © 2016 Elsevier Ltd. All rights reserved.

Arched needle technique for inferior alveolar mandibular nerve block.

PubMed

Chakranarayan, Ashish; Mukherjee, B

2013-03-01

One of the most commonly used local anesthetic techniques in dentistry is the Fischer's technique for the inferior alveolar nerve block. Incidentally this technique also suffers the maximum failure rate of approximately 35-45%. We studied a method of inferior alveolar nerve block by injecting a local anesthetic solution into the pterygomandibular space by arching and changing the approach angle of the conventional technique and estimated its efficacy. The needle after the initial insertion is arched and inserted in a manner that it approaches the medial surface of the ramus at an angle almost perpendicular to it. The technique was applied to 100 patients for mandibular molar extraction and the anesthetic effects were assessed. A success rate of 98% was obtained.

Pharmacological management of osteogenesis

PubMed Central

Nardone, Valeria; D'Asta, Federica; Brandi, Maria Luisa

2014-01-01

Osteogenesis and bone remodeling are complex biological processes that are essential for the formation of new bone tissue and its correct functioning. When the balance between bone resorption and formation is disrupted, bone diseases and disorders such as Paget's disease, fibrous dysplasia, osteoporosis and fragility fractures may result. Recent advances in bone cell biology have revealed new specific targets for the treatment of bone loss that are based on the inhibition of bone resorption by osteoclasts or the stimulation of bone formation by osteoblasts. Bisphosphonates, antiresorptive agents that reduce bone resorption, are usually recommended as first-line therapy in women with postmenopausal osteoporosis. Numerous studies have shown that bisphosphonates are able to significantly reduce the risk of femoral and vertebral fractures. Other antiresorptive agents indicated for the treatment of osteoporosis include selective estrogen receptor modulators, such as raloxifene. Denosumab, a human monoclonal antibody, is another antiresorptive agent that has been approved in Europe and the USA. This agent blocks the RANK/RANKL/OPG system, which is responsible for osteoclastic activation, thus reducing bone resorption. Other approved agents include bone anabolic agents, such as teriparatide, a recombinant parathyroid hormone that improves bone microarchitecture and strength, and strontium ranelate, considered to be a dual-action drug that acts by both osteoclastic inhibition and osteoblastic stimulation. Currently, anti-catabolic drugs that act through the Wnt-β catenin signaling pathway, serving as Dickkopf-related protein 1 inhibitors and sclerostin antagonists, are also in development. This concise review provides an overview of the drugs most commonly used for the control of osteogenesis in bone diseases. PMID:24964310

Bone Tumor Environment as a Potential Therapeutic Target in Ewing Sarcoma

PubMed Central

Redini, Françoise; Heymann, Dominique

2015-01-01

Ewing sarcoma is the second most common pediatric bone tumor, with three cases per million worldwide. In clinical terms, Ewing sarcoma is an aggressive, rapidly fatal malignancy that mainly develops not only in osseous sites (85%) but also in extra-skeletal soft tissue. It spreads naturally to the lungs, bones, and bone marrow with poor prognosis in the two latter cases. Bone lesions from primary or secondary (metastases) tumors are characterized by extensive bone remodeling, more often due to osteolysis. Osteoclast activation and subsequent bone resorption are responsible for the clinical features of bone tumors, including pain, vertebral collapse, and spinal cord compression. Based on the “vicious cycle” concept of tumor cells and bone resorbing cells, drugs, which target osteoclasts, may be promising agents as adjuvant setting for treating bone tumors, including Ewing sarcoma. There is also increasing evidence that cellular and molecular protagonists present in the bone microenvironment play a part in establishing a favorable “niche” for tumor initiation and progression. The purpose of this review is to discuss the potential therapeutic value of drugs targeting the bone tumor microenvironment in Ewing sarcoma. The first part of the review will focus on targeting the bone resorbing function of osteoclasts by means of bisphosphonates or drugs blocking the pro-resorbing cytokine receptor activator of NF-kappa B ligand. Second, the role of this peculiar hypoxic microenvironment will be discussed in the context of resistance to chemotherapy, escape from the immune system, or neo-angiogenesis. Therapeutic interventions based on these specificities could be then proposed in the context of Ewing sarcoma. PMID:26779435

Bone Tumor Environment as a Potential Therapeutic Target in Ewing Sarcoma.

PubMed

Redini, Françoise; Heymann, Dominique

2015-01-01

Ewing sarcoma is the second most common pediatric bone tumor, with three cases per million worldwide. In clinical terms, Ewing sarcoma is an aggressive, rapidly fatal malignancy that mainly develops not only in osseous sites (85%) but also in extra-skeletal soft tissue. It spreads naturally to the lungs, bones, and bone marrow with poor prognosis in the two latter cases. Bone lesions from primary or secondary (metastases) tumors are characterized by extensive bone remodeling, more often due to osteolysis. Osteoclast activation and subsequent bone resorption are responsible for the clinical features of bone tumors, including pain, vertebral collapse, and spinal cord compression. Based on the "vicious cycle" concept of tumor cells and bone resorbing cells, drugs, which target osteoclasts, may be promising agents as adjuvant setting for treating bone tumors, including Ewing sarcoma. There is also increasing evidence that cellular and molecular protagonists present in the bone microenvironment play a part in establishing a favorable "niche" for tumor initiation and progression. The purpose of this review is to discuss the potential therapeutic value of drugs targeting the bone tumor microenvironment in Ewing sarcoma. The first part of the review will focus on targeting the bone resorbing function of osteoclasts by means of bisphosphonates or drugs blocking the pro-resorbing cytokine receptor activator of NF-kappa B ligand. Second, the role of this peculiar hypoxic microenvironment will be discussed in the context of resistance to chemotherapy, escape from the immune system, or neo-angiogenesis. Therapeutic interventions based on these specificities could be then proposed in the context of Ewing sarcoma.

Vascular Spaces in Compact Bone: A Technique to Correct a Common Misinterpretation of Structure

ERIC Educational Resources Information Center

Locke, M.; Dean, Rob L.

2003-01-01

Old bones are often discolored by the grime that infiltrates spaces in the matrix once occupied by blood vessels. This suggested that allowing dry bone to absorb colorants might be a useful way to show the three dimensional complexity of bone vascularization. The authors have developed a simple way to show blood vessels spaces in bone at a glance…

Role and mechanism of action of Sclerostin in bone

PubMed Central

Delgado-Calle, Jesus; Sato, Amy Y.; Bellido, Teresita

2016-01-01

After discovering that lack of Sost/sclerostin expression is the cause of the high bone mass human syndromes Van Buchem disease and sclerosteosis, extensive animal experimentation and clinical studies demonstrated that sclerostin plays a critical role in bone homeostasis and that its deficiency or pharmacological neutralization increases bone formation. Dysregulation of sclerostin expression also underlies the pathophysiology of skeletal disorders characterized by loss of bone mass as well as the damaging effects of some cancers in bone. Thus, sclerostin has quickly become a promising molecular target for the treatment of osteoporosis and other skeletal diseases, and beneficial skeletal outcomes are observed in animal studies and clinical trials using neutralizing antibodies against sclerostin. However, the anabolic effect of blocking sclerostin decreases with time, bone mass accrual is also accompanied by anti-catabolic effects, and there is bone loss over time after therapy discontinuation. Further, the cellular source of sclerostin in the bone/bone marrow microenvironment under physiological and pathological conditions, the pathways that regulate sclerostin expression and the mechanisms by which sclerostin modulates the activity of osteocytes, osteoblasts, and osteoclasts remain unclear. In this review, we highlight the current knowledge on the regulation of Sost/sclerotin expression and its mechanism(s) of action, discuss novel observations regarding its role in signaling pathways activated by hormones and mechanical stimuli in bone, and propose future research needed to understand the full potential of therapeutic interventions that modulate Sost/sclerostin expression. PMID:27742498

Inhibitory effect of auranofin (I) and chloroquine (II) on bone degradation induced by the interleukin 1-like (IL-1-like) factor released from rheumatoid synovial tissue (RAST) in vitro

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hodges, Y.; Maser, M.R.; Britton, M.C.

1986-03-01

RAST, maintained in organ culture, releases two distinct types of bone resorptive factors and one co-resorptive factor. The first is prostaglandin E/sub 2/ (PGE/sub 2/), while the second is a protein with properties of IL-1. The co-resorptive factor collagenase, cannot induce bone resorption by itself, but augments the bone resorptive activity initiated by either PGE/sub 2/ or the IL-l-like factor. Bone resorptive activity was assessed by measuring the release of /sup 45/Ca from prelabelled rat fetal bones. We investigated the effects of five non-steroidal anti-inflammatory drugs (NSAIDs) and two disease-modifying anti-rheumatic drugs (DMARDs), (I) and (II), on bone degradation mediatedmore » by the IL-l-like factor. None of the NSAIDs tested inhibited bone degradation at 5 x 10/sup -5/ M. On the other hand, both (I) and (II) inhibited bone degradation 60 to 100% at 1 x 10/sup -6/ M and 8 x 10/sup -6/ M respectively. They can inhibit the action of IL-l-like factor on bone at therapeutically attainable concentrations. Additionally, both (I) and (II) block the release of collagenase from the organ culture of RAST with IC/sub 50/s of 5 x 10/sup -6/ M. This unique ability to inhibit collagenase release may contribute to their effectiveness is preventing bone loss in this test model.« less

Comparison of Demineralized Dentin and Demineralized Freeze Dried Bone as Carriers for Enamel Matrix Proteins in a Rat Critical Size Defect

DTIC Science & Technology

2005-05-01

matrix derivative or connective tissue . Part 1: comparison of clinical parameters. J Periodontol 2003;74:1110-1125. Minabe M.: A critical review of the... connective tissue , both bone and PDL can serve as sources of progenitor cells for regeneration. Surgical techniques started to evolve with the knowledge...regeneration was Prichard in 1977. This technique involved removal of overlying gingival tissue leaving interdental bone denuded (Prichard 1977). In 1983

Biomechanical Property of a Newly Designed Assembly Locking Compression Plate: Three-Dimensional Finite Element Analysis

PubMed Central

Liu, Da

2017-01-01

In this study, we developed and validated a refined three-dimensional finite element model of middle femoral comminuted fracture to compare the biomechanical stability after two kinds of plate fixation: a newly designed assembly locking compression plate (NALCP) and a locking compression plate (LCP). CT data of a male volunteer was converted to middle femoral comminuted fracture finite element analysis model. The fracture was fixated by NALCP and LCP. Stress distributions were observed. Under slow walking load and torsion load, the stress distribution tendency of the two plates was roughly uniform. The anterolateral femur was the tension stress area, and the bone block shifted toward the anterolateral femur. Maximum stress was found on the lateral border of the number 5 countersink of the plate. Under a slow walking load, the NALCP maximum stress was 2.160e+03 MPa and the LCP was 8.561e+02 MPa. Under torsion load, the NALCP maximum stress was 2.260e+03 MPa and the LCP was 6.813e+02 MPa. Based on those results of finite element analysis, the NALCP can provide adequate mechanical stability for comminuted fractures, which would help fixate the bone block and promote bone healing. PMID:29065654

Effects of titanium surface topography on bone integration: a systematic review.

PubMed

Wennerberg, Ann; Albrektsson, Tomas

2009-09-01

To analyse possible effects of titanium surface topography on bone integration. Our analyses were centred on a PubMed search that identified 1184 publications of assumed relevance; of those, 1064 had to be disregarded because they did not accurately present in vivo data on bone response to surface topography. The remaining 120 papers were read and analysed, after removal of an additional 20 papers that mainly dealt with CaP-coated and Zr implants; 100 papers remained and formed the basis for this paper. The bone response to differently configurated surfaces was mainly evaluated by histomorphometry (bone-to-implant contact), removal torque and pushout/pullout tests. A huge number of the experimental investigations have demonstrated that the bone response was influenced by the implant surface topography; smooth (S(a)<0.5 microm) and minimally rough (S(a) 0.5-1 mum) surfaces showed less strong bone responses than rougher surfaces. Moderately rough (S(a)>1-2 microm) surfaces showed stronger bone responses than rough (S(a)>2 microm) in some studies. One limitation was that it was difficult to compare many studies because of the varying quality of surface evaluations; a surface termed 'rough' in one study was not uncommonly referred to as 'smooth' in another; many investigators falsely assumed that surface preparation per se identified the roughness of the implant; and many other studies used only qualitative techniques such as SEM. Furthermore, filtering techniques differed or only height parameters (S(a), R(a)) were reported. * Surface topography influences bone response at the micrometre level. * Some indications exist that surface topography influences bone response at the nanometre level. * The majority of published papers present an inadequate surface characterization. * Measurement and evaluation techniques need to be standardized. * Not only height descriptive parameters but also spatial and hybrid ones should be used.

Noninvasive evaluation system of fractured bone based on speckle interferometry

NASA Astrophysics Data System (ADS)

Yamanada, Shinya; Murata, Shigeru; Tanaka, Yohsuke

2010-11-01

This paper presents a noninvasive evaluation system of fractured bone based on speckle interferometry using a modified evaluation index for higher performance, and the experiments are carried out to examine the feasibility in evaluating bone fracture healing and the influence of some system parameters on the performance. From experimental results, it is shown that the presence of fractured part of bone and the state of bone fracture healing are successfully estimated by observing fine speckle fringes on the object surface. The proposed evaluation index also can successfully express the difference between the cases with cut and without it. Since most system parameters are found not to affect the performance of the present technique, the present technique is expected to be applied to various patients that have considerable individual variability.

A neural network technique for remeshing of bone microstructure.

PubMed

Fischer, Anath; Holdstein, Yaron

2012-01-01

Today, there is major interest within the biomedical community in developing accurate noninvasive means for the evaluation of bone microstructure and bone quality. Recent improvements in 3D imaging technology, among them development of micro-CT and micro-MRI scanners, allow in-vivo 3D high-resolution scanning and reconstruction of large specimens or even whole bone models. Thus, the tendency today is to evaluate bone features using 3D assessment techniques rather than traditional 2D methods. For this purpose, high-quality meshing methods are required. However, the 3D meshes produced from current commercial systems usually are of low quality with respect to analysis and rapid prototyping. 3D model reconstruction of bone is difficult due to the complexity of bone microstructure. The small bone features lead to a great deal of neighborhood ambiguity near each vertex. The relatively new neural network method for mesh reconstruction has the potential to create or remesh 3D models accurately and quickly. A neural network (NN), which resembles an artificial intelligence (AI) algorithm, is a set of interconnected neurons, where each neuron is capable of making an autonomous arithmetic calculation. Moreover, each neuron is affected by its surrounding neurons through the structure of the network. This paper proposes an extension of the growing neural gas (GNN) neural network technique for remeshing a triangular manifold mesh that represents bone microstructure. This method has the advantage of reconstructing the surface of a genus-n freeform object without a priori knowledge regarding the original object, its topology, or its shape.

Clinical determination of target registration error of an image-guided otologic surgical system using patients with bone-anchored hearing aids

NASA Astrophysics Data System (ADS)

Balachandran, Ramya; Labadie, Robert F.; Fitzpatrick, J. Michael

2007-03-01

Image guidance in otologic surgery has been thwarted by the need for a non-invasive fiducial system with target registration error (TRE) at the inner ear below 1.5mm. We previously presented a fiducial frame for this purpose that attaches to the upper dentition via patient-specific bite blocks and demonstrated a TRE of 0.73mm (+/-0.23mm) on cadaveric skulls. In that study, TRE measurement depended upon placement of bone-implanted, intracranial target fiducials-clearly impossible to repeat clinically. Using cadaveric specimens, we recently presented a validation method based on an auditory implant system (BAHA System® Cochlear Corp., Denver, CO). That system requires a skull-implanted titanium screw behind the ear upon which a bone-anchored hearing aid (BAHA) is mounted. In our validation, we replace the BAHA with a fiducial marker to permit measurement of TRE. That TRE is then used to estimate TRE at an internal point. While the method can be used to determine accuracy at any point within the head, we focus in this study on the inner ear, in particular the cochlea, and we apply the method to patients (N=5). Physical localizations were performed after varying elapsed times since bite-block fabrication, and TRE at the cochlea was estimated. We found TRE to be 0.97mm at the cochlea within one month and 2.5mm after seven months. Thus, while accuracy deteriorates considerably with delays of seven months or more, if this frame is used within one month of the fabrication of the bite-block, it achieves the goal and in fact exhibits submillimetric accuracy.

Alendronate promotes bone formation by inhibiting protein prenylation in osteoblasts in rat tooth replantation model.

PubMed

Komatsu, Koichiro; Shimada, Akemi; Shibata, Tatsuya; Wada, Satoshi; Ideno, Hisashi; Nakashima, Kazuhisa; Amizuka, Norio; Noda, Masaki; Nifuji, Akira

2013-11-01

Bisphosphonates (BPs) are a major class of antiresorptive drug, and their molecular mechanisms of antiresorptive action have been extensively studied. Recent studies have suggested that BPs target bone-forming cells as well as bone-resorbing cells. We previously demonstrated that local application of a nitrogen-containing BP (N-BP), alendronate (ALN), for a short period of time increased bone tissue in a rat tooth replantation model. Here, we investigated cellular mechanisms of bone formation by ALN. Bone histomorphometry confirmed that bone formation was increased by local application of ALN. ALN increased proliferation of bone-forming cells residing on the bone surface, whereas it suppressed the number of tartrate-resistant acid phosphatase (TRAP)-positive osteoclasts in vivo. Moreover, ALN treatment induced more alkaline phosphatase-positive and osteocalcin-positive cells on the bone surface than PBS treatment. In vitro studies revealed that pulse treatment with ALN promoted osteocalcin expression. To track the target cells of N-BPs, we applied fluorescence-labeled ALN (F-ALN) in vivo and in vitro. F-ALN was taken into bone-forming cells both in vivo and in vitro. This intracellular uptake was inhibited by endocytosis inhibitors. Furthermore, the endocytosis inhibitor dansylcadaverine (DC) suppressed ALN-stimulated osteoblastic differentiation in vitro and it suppressed the increase in alkaline phosphatase-positive bone-forming cells and subsequent bone formation in vivo. DC also blocked the inhibition of Rap1A prenylation by ALN in the osteoblastic cells. These data suggest that local application of ALN promotes bone formation by stimulating proliferation and differentiation of bone-forming cells as well as inhibiting osteoclast function. These effects may occur through endocytic incorporation of ALN and subsequent inhibition of protein prenylation.

[Comparative study on graft of autogeneic iliac bone and tissue engineered bone].

PubMed

Shen, Bing; Xie, Fu-lin; Xie, Qing-fang

2002-11-01

To compare the clinical results of repairing bone defect of limbs with tissue engineering technique and with autogeneic iliac bone graft. From July 1999 to September 2001, 52 cases of bone fracture were randomly divided into two groups (group A and B). Open reduction and internal fixation were performed in all cases as routine operation technique. Autogeneic iliac bone was implanted in group A, while tissue engineered bone was implanted in group B. Routine postoperative treatment in orthopedic surgery was taken. The operation time, bleeding volume, wound healing and drainage volume were compared. The bone union was observed by the X-ray 1, 2, 3, and 5 months after operation. The sex, age and disease type had no obvious difference between groups A and B. all the wounds healed with first intention. The swelling degree of wound and drainage volume had no obvious difference. The operation time in group A was longer than that in group B (25 minutes on average) and bleeding volume in group A was larger than that in group B (150 ml on average). Bone union completed within 3 to 7 months in both groups. But there were 2 cases of delayed union in group A and 1 case in group B. Repair of bone defect with tissue engineered bone has as good clinical results as that with autogeneic iliac bone graft. In aspect of operation time and bleeding volume, tissue engineered bone graft is superior to autogeneic iliac bone.

Two injection digital block versus single subcutaneous palmar injection block for finger lacerations.

PubMed

Okur, O M; Şener, A; Kavakli, H Ş; Çelik, G K; Doğan, N Ö; Içme, F; Günaydin, G P

2017-12-01

We aimed to compare two digital nerve block techniques in patients due to traumatic digital lacerations. This was a randomized-controlled study designed prospectively in the emergency department of a university-based training and research hospital. Randomization was achieved by sealed envelopes. Half of the patients were randomised to traditional (two-injection) digital nerve block technique while single-injection digital nerve block technique was applied to the other half. Score of pain due to anesthetic infiltration and suturing, onset time of total anesthesia, need for an additional rescue injection were the parameters evaluated with both groups. Epinephrin added lidocaine hydrochloride preparation was used for the anesthetic application. Visual analog scale was used for the evaluation of pain scores. Outcomes were compared by using Mann-Whitney U test and Student t-test. Fifty emergency department patients ≥18 years requiring digital nerve block were enrolled in the study. Mean age of the patients was 33 (min-max: 19-86) and 39 (78 %) were male. No statistically significant difference was found between the two groups in terms of our main parameters; anesthesia pain score, suturing pain score, onset time of total anesthesia and rescue injection need. Single injection volar digital nerve block technique is a suitable alternative for digital anesthesias in emergency departments.

Bone remodeling and calcium homeostasis in patients with spinal cord injury: a review.

PubMed

Maïmoun, Laurent; Fattal, Charles; Sultan, Charles

2011-12-01

Patients with spinal cord injury exhibit early and acute bone loss with the major functional consequence being a high incidence of pathological fractures. The bone status of these patients is generally investigated by dual-energy x-ray absorptiometry, but this technique does not reveal the pathophysiological mechanism underlying the bone loss. Bone cell activity can be indirectly evaluated by noninvasive techniques, including measurement of specific biochemical markers of bone formation (such as osteocalcin or bone-alkaline phosphatase) and resorption (such as procollagen type I N- or C-terminal propeptide). The bone loss in spinal cord injury is clearly due to an uncoupling of bone remodeling in favor of bone resorption, which starts just after the injury and peaks at about 1 to 4 months. Beyond 6 months, bone resorption activity decreases progressively but remains elevated for many years after injury. Conversely, bone formation is less affected. Antiresorptive treatment induces an early and acute reduction in bone resorption markers. Level of injury and health-related complications do not seem to be implicated in the intensity of bone resorption. During the acute phase, the hypercalcemic status is associated with the suppression of parathyroid hormone and vitamin D metabolites. The high sensitivity of these markers after treatment suggests that they can be used for monitoring treatment efficacy and patient compliance. The concomitant use of bone markers and dual-energy x-ray absorptiometry may improve the physician's ability to detect patients at risk of severe bone loss and subsequent fractures. Copyright © 2011 Elsevier Inc. All rights reserved.

Quantitative MRI and spectroscopy of bone marrow

PubMed Central

Ruschke, Stefan; Dieckmeyer, Michael; Diefenbach, Maximilian; Franz, Daniela; Gersing, Alexandra S.; Krug, Roland; Baum, Thomas

2017-01-01

Bone marrow is one of the largest organs in the human body, enclosing adipocytes, hematopoietic stem cells, which are responsible for blood cell production, and mesenchymal stem cells, which are responsible for the production of adipocytes and bone cells. Magnetic resonance imaging (MRI) is the ideal imaging modality to monitor bone marrow changes in healthy and pathological states, thanks to its inherent rich soft‐tissue contrast. Quantitative bone marrow MRI and magnetic resonance spectroscopy (MRS) techniques have been also developed in order to quantify changes in bone marrow water–fat composition, cellularity and perfusion in different pathologies, and to assist in understanding the role of bone marrow in the pathophysiology of systemic diseases (e.g. osteoporosis). The present review summarizes a large selection of studies published until March 2017 in proton‐based quantitative MRI and MRS of bone marrow. Some basic knowledge about bone marrow anatomy and physiology is first reviewed. The most important technical aspects of quantitative MR methods measuring bone marrow water–fat composition, fatty acid composition, perfusion, and diffusion are then described. Finally, previous MR studies are reviewed on the application of quantitative MR techniques in both healthy aging and diseased bone marrow affected by osteoporosis, fractures, metabolic diseases, multiple myeloma, and bone metastases. Level of Evidence: 3 Technical Efficacy: Stage 2 J. Magn. Reson. Imaging 2018;47:332–353. PMID:28570033

Biomaterial-Stabilized Soft Tissue Healing for Healing of Critical-Sized Bone Defects: the Masquelet Technique.

PubMed

Tarchala, Magdalena; Harvey, Edward J; Barralet, Jake

2016-03-01

Critical-sized bone defects present a significant burden to the medical community due to their challenging treatment. However, a successful limb-salvaging technique, the Masquelet Technique (MT), has significantly improved the prognosis of many segmental bone defects in helping to restore form and function. Although the Masquelet Technique has proven to be clinically effective, the physiology of the healing it induces is not well understood. Multiple modifiable factors have been implicated by various surgical and research teams, but no single factor has been proven to be critical to the success of the Masquelet Technique. In this review the most recent clinical and experimental evidence that supports and helps to decipher the traditional Masquelet, as well as the modifiable factors and their effect on the success of the technique are discussed. In addition, future developments for the integration of the traditional Masquelet Technique with the use of alternative biomaterials to increase the effectiveness and expand the clinical applicability of the Masquelet Technique are reviewed. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Materials and scaffolds in medical 3D printing and bioprinting in the context of bone regeneration.

PubMed

Heller, Martin; Bauer, Heide-Katharina; Goetze, Elisabeth; Gielisch, Matthias; Ozbolat, Ibrahim T; Moncal, Kazim K; Rizk, Elias; Seitz, Hermann; Gelinsky, Michael; Schröder, Heinz C; Wang, Xiaohong H; Müller, Werner E G; Al-Nawas, Bilal

The structural and functional repair of lost bone is still one of the biggest challenges in regenerative medicine. In many cases, autologous bone is used for the reconstruction of bone tissue; however, the availability of autologous material is limited, which always means additional stress to the patient. Due to this, more and more frequently various biocompatible materials are being used instead for bone augmentation. In this context, in order to ensure the structural function of the bone, scaffolds are implanted and fixed into the bone defect, depending on the medical indication. Nevertheless, for the surgeon, every individual clinical condition in which standardized scaffolds have to be aligned is challenging, and in many cases the alignment is not possible without limitations. Therefore, in the last decades, 3D printing (3DP) or additive manufacturing (AM) of scaffolds has become one of the most innovative approaches in surgery to individualize and improve the treatment of patients. Numerous biocompatible materials are available for 3DP, and various printing techniques can be applied, depending on the process conditions of these materials. Besides these conventional printing techniques, another promising approach in the context of medical AM is 3D bioprinting, a technique which makes it possible to print human cells embedded in special carrier substances to generate functional tissues. Even the direct printing into bone defects or lesions becomes possible. 3DP is already improving the treatment of patients, and has the potential to revolutionize regenerative medicine in future.

Applications of the direct photon absorption technique for measuring bone mineral content in vivo. Determination of body composition in vivo

NASA Technical Reports Server (NTRS)

Cameron, J. R.

1972-01-01

The bone mineral content, BMC, determined by monoenergetic photon absorption technique, of 29 different locations on the long bones and vertebral columns of 24 skeletons was measured. Compressive tests were made on bone from these locations in which the maximum load and maximum stress were measured. Also the ultimate strain, modulus of elasticity and energy absorbed to failure were determined for compact bone from the femoral diaphysis and cancellous bone from the eighth through eleventh thoracic vertebrae. Correlations and predictive relationships between these parameters were examined to investigate the applicability of using the BMC at sites normally measured in vivo, i.e. radius and ulna in estimating the BMC and/or strength of the spine or femoral neck. It was found that the BMC at sites on the same bone were highly correlated r = 0.95 or better; the BMC at sites on different bones were also highly interrelated, r = 0.85. The BMC at various sites on the long bones could be estimated to between 10 and 15 per cent from the BMC of sites on the radius or ulna.

Novel Technique: Knee Arthrodesis Using Trabecular Metal Cones with Intramedullary Nailing and Intramedullary Autograft.

PubMed

Peterson, Blake E; Bal, Sonny; Aggarwal, Ajay; Crist, Brett D

2016-08-01

The failed total knee arthroplasty is a challenge to the surgeon and the patient. Infection, bone loss, and instability lead to a chronically painful and dysfunctional limb. Two-stage revision arthroplasty has been successful in clearing a majority of periprosthetic joint infections. However, there are many cases when the multiply revised and infected total knee arthroplasty cannot be salvaged. We report, a review of knee arthrodesis and a novel technique to manage significant bone loss. The use of trabecular metal cones and a long intramedullary nail can be used in concert with an autologous intramedullary bone graft to provide a stable, length restoring construct with sufficient biology to heal very large bone voids. With this technique we have successfully restored function and stability in the failed knee arthroplasty. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

Hydroxyapatite crystals as a bone graft substitute in benign lytic lesions of bone

PubMed Central

Gupta, Anil Kumar; Kumar, Praganesh; Keshav, Kumar; Singh, Anant

2015-01-01

Background: Bone grafts are required to fill a cavity created after curettage of benign lytic lesions of the bone. To avoid the problems associated at donor site with autologous bone graft, we require allograft or bone graft substitutes. We evaluated the healing of lytic lesions after hydroxyapatite (HA) grafting by serial radiographs. Materials and Methods: Forty cases of benign lytic lesions of bone were managed by simple curettage and grafting using HA blocks. Commercially available HA of bovine origin (Surgiwear Ltd., Shahjahanpur, India) was used for this purpose. Mean duration of followup was 34.8 months (range 12–84 months). Mean patient age was 19.05 years (range 3–55 years). Radiological staging of graft incorporation was done as per criteria of Irwin et al. 2001. Results: In our series, two cases were in stage I. A total of 11 cases were in stage II and 27 were in stage III. Graft incorporation was radiologically complete by 15 months. Clinical recovery was observed before radiological healing. The average time taken to return to preoperative function was 3 months. Recurrence was observed in giant cell tumor (n = 3) and chondromyxoid fibroma (n = 1). There was no incidence of graft rejection, collapse, growth plate disturbances or antigenic response. Conclusions: We conclude that calcium HA is biologically acceptable bone graft substitute in the management of benign lytic lesions of bone. PMID:26806973

A pragmatic randomised controlled trial comparing the efficacy of a femoral nerve block and periarticular infiltration for early pain relief following total knee arthroplasty.

PubMed

Wall, P D H; Parsons, N R; Parsons, H; Achten, J; Balasubramanian, S; Thompson, P; Costa, M L

2017-07-01

The aim of this study was to compare the effectiveness of a femoral nerve block and a periarticular infiltration in the management of early post-operative pain after total knee arthroplasty (TKA). A pragmatic, single centre, two arm parallel group, patient blinded, randomised controlled trial was undertaken. All patients due for TKA were eligible. Exclusion criteria included contraindications to the medications involved in the study and patients with a neurological abnormality of the lower limb. Patients received either a femoral nerve block with 75 mg of 0.25% levobupivacaine hydrochloride around the nerve, or periarticular infiltration with 150 mg of 0.25% levobupivacaine hydrochloride, 10 mg morphine sulphate, 30 mg ketorolac trometamol and 0.25 mg of adrenaline all diluted with 0.9% saline to make a volume of 150 ml. A total of 264 patients were recruited and data from 230 (88%) were available for the primary analysis. Intention-to-treat analysis of the primary outcome measure of a visual analogue score for pain on the first post-operative day, prior to physiotherapy, was similar in both groups. The mean difference was -0.7 (95% confidence interval (CI) -5.9 to 4.5; p = 0.834). The periarticular group used less morphine in the first post-operative day compared with the femoral nerve block group (74%, 95% CI 55 to 99). The femoral nerve block group reported 39 adverse events, of which 27 were serious, in 31 patients and the periarticular group reported 51 adverse events, of which 38 were serious, in 42 patients up to six weeks post-operatively. None of the adverse events were directly attributed to either of the interventions under investigation. Periarticular infiltration is a viable and safe alternative to femoral nerve block for the early post-operative relief of pain following TKA. Cite this article: Bone Joint J 2017;99-B:904-11. ©2017 The British Editorial Society of Bone & Joint Surgery.

Caveolin-1 regulates chemokine receptor 5-mediated contribution of bone marrow-derived cells to dermal fibrosis

PubMed Central

Lee, Rebecca; Perry, Beth; Heywood, Jonathan; Reese, Charles; Bonner, Michael; Hatfield, Corey M.; Silver, Richard M.; Visconti, Richard P.; Hoffman, Stanley; Tourkina, Elena

2014-01-01

In fibrotic diseases caveolin-1 underexpression in fibroblasts results in collagen overexpression and in monocytes leads to hypermigration. These profibrotic behaviors are blocked by the caveolin-1 scaffolding domain peptide (CSD) which compensates for caveolin-1 deficiency. Monocytes and fibroblasts are related in that monocytes are the progenitors of fibrocytes (CD45+/Collagen I+ cells) that, in turn, are the progenitors of many fibroblasts in fibrotic tissues. In an additional anti-fibrotic activity, CSD blocks monocyte differentiation into fibrocytes. We studied a mouse fibrosis model (Pump Model) involving systemic bleomycin delivery that closely models scleroderma (SSc) in several ways, the most important of which for this study is that fibrosis is observed in the lungs, skin, and internal organs. We show here that dermal thickness is increased 2-fold in the Pump Model and that this effect is almost completely blocked by CSD (p < 0.001). Concomitantly, the subcutaneous fat layer becomes >80% thinner. This effect is also blocked by CSD (p < 0.001). Even in mice receiving vehicle instead of bleomycin, CSD increases the thickness of the fat layer. To study the mechanisms of action of bleomycin and CSD, we examined the accumulation of the chemokine receptor CCR5 and its ligands MIP1α and MIP1β in fibrotic tissue and their roles in monocyte migration. Fibrocytes and other leukocytes expressing CCR5 and its ligands were present at high levels in the fibrotic dermis of SSc patients and Pump Model mice while CSD blocked their accumulation in mouse dermis. Migration toward CCR5 ligands of SSc monocytes and Pump Model bone marrow cells was 3-fold greater than cells from control subjects. This enhanced migration was almost completely blocked by CSD. These results suggest that low monocyte caveolin-1 promotes fibrosis by enhancing the recruitment of fibrocytes and their progenitors into affected tissue. PMID:24966836

Fabrication of interconnected porous β-tricalcium phosphate (β-TCP) based on a setting reaction of β-TCP granules with HNO3 followed by heat treatment.

PubMed

Ishikawa, Kunio; Putri, Tansza Setiana; Tsuchiya, Akira; Tanaka, Keisuke; Tsuru, Kanji

2018-03-01

β-Tricalcium phosphate [β-TCP] is the typical bone substitute due to its excellent osteoconductivity and bioresorbability. One of the keys to improve its potential as bone substitute is to introduce porous structure and its regulation. In this study, interconnected porous β-TCP blocks were fabricated through a setting reaction of β-TCP granules and subsequent heat treatment. First, β-TCP granules were mixed with HNO 3 . Upon mixing, β-TCP granules were bridged with dicalcium phosphate dihydrate [DCPD: CaHPO 4 ·2H 2 O] containing Ca(NO 3 ) 2 . Then, the DCPD-bridged β-TCP was heated at 1100°C. During the heating process, DCPD containing Ca(NO 3 ) 2 transformed into β-TCP and bonded with β-TCP granules. As a result, an interconnected porous β-TCP block formed. The diametral tensile strength and porosity of the interconnected porous β-TCP block fabricated from 200-300-μm β-TCP granules and 5 N HNO 3 and then heated at 1,100°C were 1.4 ± 0.2 MPa and 57% ± 2%, respectively. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 106A: 797-804, 2018. © 2017 Wiley Periodicals, Inc.

Local dynamic range compensation for scanning electron microscope imaging system by sub-blocking multiple peak HE with convolution.

PubMed

Sim, K S; Teh, V; Tey, Y C; Kho, T K

2016-11-01

This paper introduces new development technique to improve the Scanning Electron Microscope (SEM) image quality and we name it as sub-blocking multiple peak histogram equalization (SUB-B-MPHE) with convolution operator. By using this new proposed technique, it shows that the new modified MPHE performs better than original MPHE. In addition, the sub-blocking method consists of convolution operator which can help to remove the blocking effect for SEM images after applying this new developed technique. Hence, by using the convolution operator, it effectively removes the blocking effect by properly distributing the suitable pixel value for the whole image. Overall, the SUB-B-MPHE with convolution outperforms the rest of methods. SCANNING 38:492-501, 2016. © 2015 Wiley Periodicals, Inc. © Wiley Periodicals, Inc.

Heat generation during implant placement in low-density bone: effect of surgical technique, insertion torque and implant macro design.

PubMed

Marković, Aleksa; Mišić, Tijana; Miličić, Biljana; Calvo-Guirado, Jose Luis; Aleksić, Zoran; Ðinić, Ana

2013-07-01

The study aimed to investigate the effect of surgical technique, implant macrodesign and insertion torque on bone temperature changes during implant placement. In the in vitro study, 144 self-tapping (blueSKY(®) 4 × 10 mm; Bredent) and 144 non-self-tapping (Standard implant(®) 4.1 × 10 mm; Straumann) were placed in osteotomies prepared in pig ribs by lateral bone condensing or bone drilling techniques. The maximum insertion torque values of 30, 35 and 40 Ncm were used. Real-time bone temperature measurement during implant placement was performed by three thermocouples positioned vertically, in tripod configuration around every osteotomy, at a distance of 5 mm from it and at depths of 1, 5 and 10 mm. Data were analysed using Kruskal-Wallis, Mann-Whitney U-tests and Regression analysis. Significant predictor of bone temperature at the osteotomy depth of 1 mm was insertion torque (P = 0.003) and at the depth of 10-mm implant macrodesign (P = 0.029), while no significant predictor at depth of 5 mm was identified (P > 0.05). Higher insertion torque values as well as non-self-tapping implant macrodesign were related to higher temperatures. Implant placement in sites prepared by bone drilling induced significantly higher temperature increase (P = 0.021) compared with bone condensing sites at the depth of 5 mm, while no significant difference was recorded at other depths. Compared with 30 Ncm, insertion torque values of 35 and 40 Ncm produced significantly higher temperature increase (P = 0.005; P = 0.003, respectively) at the depth of 1 mm. There was no significant difference in temperature change induced by 35 and 40 Ncm, neither by implant macrodesign at all investigated depths (P > 0.05). Placement of self-tapping implants with low insertion torque into sites prepared by lateral bone condensing technique might be advantageous in terms of thermal effect on bone. © 2012 John Wiley & Sons A/S.

Piezoelectric osteotomy in hand surgery: first experiences with a new technique

PubMed Central

Hoigne, Dominik J; Stübinger, Stefan; Kaenel, Oliver Von; Shamdasani, Sonia; Hasenboehler, Paula

2006-01-01

Background In hand and spinal surgery nerve lesions are feared complications with the use of standard oscillating saws. Oral surgeons have started using a newly developed ultrasound bone scalpel when performing precise osteotomies. By using a frequency of 25–29 kHz only mineralized tissue is cut, sparing the soft tissue. This reduces the risk of nerve lesions. As there is a lack of experience with this technique in the field of orthopaedic bone surgery, we performed the first ultrasound osteotomy in hand surgery. Method While performing a correctional osteotomy of the 5th metacarpal bone we used the Piezosurgery® Device from Mectron [Italy] instead of the usual oscillating saw. We will report on our experience with one case, with a follow up time of one year. Results The cut was highly precise and there were no vibrations of the bone. The time needed for the operation was slightly longer than the time needed while using the usual saw. Bone healing was good and at no point were there any neurovascular disturbances. Conclusion The Piezosurgery® Device is useful for small long bone osteotomies. Using the fine tip enables curved cutting and provides an opportunity for new osteotomy techniques. As the device selectively cuts bone we feel that this device has great potential in the field of hand- and spinal surgery. PMID:16611362

Quantitative imaging methods in osteoporosis.

PubMed

Oei, Ling; Koromani, Fjorda; Rivadeneira, Fernando; Zillikens, M Carola; Oei, Edwin H G

2016-12-01

Osteoporosis is characterized by a decreased bone mass and quality resulting in an increased fracture risk. Quantitative imaging methods are critical in the diagnosis and follow-up of treatment effects in osteoporosis. Prior radiographic vertebral fractures and bone mineral density (BMD) as a quantitative parameter derived from dual-energy X-ray absorptiometry (DXA) are among the strongest known predictors of future osteoporotic fractures. Therefore, current clinical decision making relies heavily on accurate assessment of these imaging features. Further, novel quantitative techniques are being developed to appraise additional characteristics of osteoporosis including three-dimensional bone architecture with quantitative computed tomography (QCT). Dedicated high-resolution (HR) CT equipment is available to enhance image quality. At the other end of the spectrum, by utilizing post-processing techniques such as the trabecular bone score (TBS) information on three-dimensional architecture can be derived from DXA images. Further developments in magnetic resonance imaging (MRI) seem promising to not only capture bone micro-architecture but also characterize processes at the molecular level. This review provides an overview of various quantitative imaging techniques based on different radiological modalities utilized in clinical osteoporosis care and research.

The Effect of Liquid Nitrogen on Bone Graft Survival.

PubMed

Sirinoglu, Hakan; Çilingir, Özlem Tuğçe; Çelebiler, Ozhan; Ercan, Feriha; Numanoglu, Ayhan

2015-08-01

Liquid nitrogen is used in medicine for cancer treatment and tissue preservation; however, bone viability after its application is controversial. This study aims to evaluate both the tissue viability and the clinical and histopathologic findings following liquid nitrogen application with different thawing techniques in rats. Mandibular bone grafts were taken from 45 Wistar rats and freezed in liquid nitrogen for 20 minutes. In the rapid-thawing technique (Rapid Thawing-1, Rapid Thawing-2), the grafts were held for 20 minutes in room temperature; in the slow-thawing technique (Slow Thawing-1, Slow Thawing-2), 20 minutes in -20°C, 20 minutes in +4°C, and 20 minutes in room temperature, respectively. In Rapid Thawing-2 and Slow Thawing-2 groups, autografts were implanted to their origin for 3 weeks and bone staining with India ink was performed and samples taken for histologic examination. The amount of cells and blood vessels and the density of bone canaliculi were significantly reduced in Rapid Thawing-1 and Slow Thawing-1 groups comparing to the Control group. However, the reduction rate was more significant in the Slow Thawing-1 group. Histomorphometric evaluation of the healing autografts after 3 weeks revealed that the decreased amounts of canaliculi were not changed in Slow Thawing-2 group. The study results demonstrated that bone tissue survives after liquid nitrogen treatment regardless of the performed thawing technique; however, slow thawing causes more tissue damage and metabolism impairment. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.