scholarly journals Evaluation of longitudinal time-lapsed in vivo micro-CT for monitoring fracture healing in mouse femur defect models

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Esther Wehrle ◽  
Duncan C. Tourolle né Betts ◽  
Gisela A. Kuhn ◽  
Ariane C. Scheuren ◽  
Sandra Hofmann ◽  
...  
Keyword(s):  
Fracture Healing ◽  
Radiation Effects ◽  
Callus Formation ◽  
Healing Process ◽  
Fracture Repair ◽  
Micro Ct ◽  
Micro Computed Tomography ◽  
Healing Phase ◽  
Longitudinal Imaging

AbstractLongitudinal in vivo micro-computed tomography (micro-CT) is of interest to non-invasively capture the healing process of individual animals in preclinical fracture healing studies. However, it is not known whether longitudinal imaging itself has an impact on callus formation and remodeling. In this study, a scan group received weekly micro-CT measurements (week 0–6), whereas controls were only scanned post-operatively and at week 5 and 6. Registration of consecutive scans using a branching scheme (bridged vs. unbridged defect) combined with a two-threshold approach enabled assessment of localized bone turnover and mineralization kinetics relevant for monitoring callus remodeling. Weekly micro-CT application did not significantly change any of the assessed callus parameters in the defect and periosteal volumes. This was supported by histomorphometry showing only small amounts of cartilage residuals in both groups, indicating progression towards the end of the healing period. Also, immunohistochemical staining of Sclerostin, previously associated with mediating adverse radiation effects on bone, did not reveal differences between groups. The established longitudinal in vivo micro-CT-based approach allows monitoring of healing phases in mouse femur defect models without significant effects of anesthesia, handling and radiation on callus properties. Therefore, this study supports application of longitudinal in vivo micro-CT for healing-phase-specific monitoring of fracture repair in mice.

scholarly journals Evaluation of longitudinal time-lapsedin vivomicro-CT for monitoring fracture healing in mouse femur defect models

2019 ◽  
Author(s):  
Esther Wehrle ◽  
Duncan C Tourolle né Betts ◽  
Gisela A Kuhn ◽  
Ariane C Scheuren ◽  
Sandra Hofmann ◽  
...  
Keyword(s):  
Fracture Healing ◽  
Radiation Effects ◽  
Callus Formation ◽  
Healing Process ◽  
Fracture Repair ◽  
Micro Ct ◽  
Micro Computed Tomography ◽  
Healing Phase ◽  
Longitudinal Imaging

AbstractLongitudinalin vivomicro-computed tomography (micro-CT) is of interest to non-invasively capture the healing process of individual animals in preclinical fracture healing studies. However, it is not known whether longitudinal imaging itself has an impact on callus formation and remodeling. In this study, a scan group received weekly micro-CT measurements (week 0-6), whereas controls were only scanned post-operatively and at week 5 and 6. Registration of consecutive scans using a branching scheme (bridged vs. unbridged defect) combined with a two-threshold approach enabled assessment of localized bone turnover and mineralization kinetics relevant for monitoring callus remodeling. Weekly micro-CT application did not significantly change any of the assessed callus parameters in the defect and periosteal volumes. This was supported by histomorphometry showing only small amounts of cartilage residuals in both groups, indicating progression towards the end of the healing period. Also, immunohistochemical staining of Sclerostin, previously associated with mediating adverse radiation effects on bone, did not reveal differences between groups.The established longitudinalin vivomicro-CT-based approach allows monitoring of healing phases in mouse femur defect models without significant effects of anesthesia, handling and radiation on callus properties. Therefore, this study supports application of longitudinalin vivomicro-CT for healing-phase-specific monitoring of fracture repair in mice.

scholarly journals Endogenous Production of n-3 Polyunsaturated Fatty Acids Promotes Fracture Healing in Mice

2017 ◽  
Vol 2017 ◽  
pp. 1-6 ◽  
Author(s):  
Yuhui Chen ◽  
He Cao ◽  
Dawei Sun ◽  
Changxin Lin ◽  
Liang Wang ◽  
...  
Keyword(s):  
Transgenic Mice ◽  
Fracture Healing ◽  
Histological Analysis ◽  
Callus Formation ◽  
Healing Process ◽  
Proximal Femoral Fracture ◽  
Fracture Repair ◽  
Micro Ct ◽  
Micro Computed Tomography ◽  
X Ray

Bone fracture is a global healthcare issue for high rates of delayed healing and nonunions. Although n-3 polyunsaturated fatty acid (PUFA) is considered as a beneficial factor for bone metabolism, only few studies till date focused on the effects of n-3 PUFAs on fracture healing. In this study, we investigated the effect of endogenous n-3 PUFAs on fracture healing by measuring femur fracture repair in bothfat-1transgenic mice and WT mice. Proximal femoral fracture model was established infat-1transgenic mice and WT mice, respectively, and then the fracture was analyzed by using X-ray, micro-computed tomography (micro-CT), and histological assessment at 7, 14, 21, 28, and 35 days after fixation. The results showed that compared with WT mice,fat-1mice exhibited acceleration in fracture healing through radiographic and histological analysis (18–21 days versus 21–28 days postfracture). Meanwhile, X-ray and micro-CT analysis that showed better remodeling callus formation were in thefat-1group compared to WT group. Furthermore, histological analysis revealed that endogenous n-3 PUFAs promoted local endochondral ossification and accelerated the remodeling of calcified calluses after fracture. In conclusion, the present study indicated that endogenously produced n-3 PUFAs promote fracture healing process and accelerate bone remodeling in mice, and supplementation of n-3 PUFAs was positively associated with fracture healing.

scholarly journals Longitudinal in vivo micro-CT-based approach allows spatio-temporal characterization of fracture healing patterns and assessment of biomaterials in mouse femur defect models

2020 ◽  
Author(s):  
Esther Wehrle ◽  
Duncan C Tourolle né Betts ◽  
Gisela A Kuhn ◽  
Erica Floreani ◽  
Malavika H Nambiar ◽  
...  
Keyword(s):  
Bone Regeneration ◽  
Healing Process ◽  
Micro Ct ◽  
Micro Computed Tomography ◽  
Collagen Scaffolds ◽  
Non Union ◽  
Spatio Temporal ◽  
Large Bone

AbstractThorough preclinical evaluation of novel biomaterials for treatment of large bone defects is essential prior to clinical application. Using in vivo micro-computed tomography (micro-CT) and mouse femoral defect models with different defect sizes, we were able to detect spatio-temporal healing patterns indicative of physiological and impaired healing in three defect sub-volumes and the adjacent cortex. The time-lapsed in vivo micro-CT-based approach was then applied to evaluate the bone regeneration potential of biomaterials using collagen and BMP-2 as test materials. Both collagen and BMP-2 treatment led to distinct changes in bone turnover in the different healing phases. Despite increased periosteal bone formation, 87.5% of the defects treated with collagen scaffolds resulted in non-unions. Additional BMP-2 application significantly accelerated the healing process and increased the union rate to 100%. This study further shows potential of time-lapsed in vivo micro-CT for capturing spatio-temporal deviations preceding non-union formation and how this can be prevented by application of biomaterials.This study therefore supports the application of longitudinal in vivo micro-CT for discrimination of normal and disturbed healing patterns and for the spatio-temporal characterization of the bone regeneration capacity of biomaterials.

scholarly journals Correlating mRUST scoring with fracture healing in the mouse model

2020 ◽  
Vol 3 ◽  
Author(s):  
Anthony McGuire ◽  
Adam Knox ◽  
Caio de Andrade Staut ◽  
Melissa Kacena ◽  
Roman Natoli ◽  
...  
Keyword(s):  
Mouse Model ◽  
Fracture Healing ◽  
Bone Fractures ◽  
Healing Process ◽  
Fracture Repair ◽  
Long Bone ◽  
Post Surgery ◽  
Method Of Assessment ◽  
Non Destructive

Background/Objective: Long bone fractures are an expensive and frequent cause of disability in humans. Research seeking to accelerate and improve the healing process is more essential than ever. Animal models, mice especially, provide an inexpensive and reproducible model of in vivo fracture healing. However, many measures of murine fracture healing outcomes are either expensive or destructive, limiting their ability to be translated to clinical studies. We seek to determine how these measures such as biomechanics, µCT, and histology correlate to the relatively new, inexpensive, and non-destructive method of mRUST scoring in a mouse model.  Methods: One hundred and thirty-five, 12-week old male C57BL6/J mice were divided into nine groups of 15 mice. Mice underwent a surgically created, femoral fracture. At biweekly timepoints, anteroposterior and lateral radiographs were taken, and 15 mice were sacrificed at each time point (7, 10, 14, 17, 21, 24, 28, 35, and 42 days post-surgery) for biomechanical, µCT, and histological analyses. The modified Radiographic Union Scale for Tibial fractures (mRUST scoring) provides a score based on the visualization of a callus and fracture line in four cortices on the radiographs. Data analysis will be performed to determine the degree of correlation between mRUST scoring and other fracture healing outcomes.  Results/Conclusion: Data collection in this experiment is still forthcoming. Upon successful completion of this project, we will have established numerical correlations between mRUST scoring and other fracture healing outcomes, such as biomechanics, µCT microarchitecture, and histology. These correlations will provide a powerful tool in future mouse fracture healing studies, as data on the state and strength of fracture repair could be determined by simple radiograph.  Scientific/Clinical Policy Impact and Implications: This study will both provide future murine fracture studies with an inexpensive and non-destructive method of assessment that is more directly translatable to human fracture studies. 

scholarly journals Spatio-temporal characterization of fracture healing patterns and assessment of biomaterials by time-lapsed in vivo micro-computed tomography

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Esther Wehrle ◽  
Duncan C. Tourolle né Betts ◽  
Gisela A. Kuhn ◽  
Erica Floreani ◽  
Malavika H. Nambiar ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Bone Regeneration ◽  
Healing Process ◽  
Micro Ct ◽  
Micro Computed Tomography ◽  
Collagen Scaffolds ◽  
Non Union ◽  
Spatio Temporal

AbstractThorough preclinical evaluation of functionalized biomaterials for treatment of large bone defects is essential prior to clinical application. Using in vivo micro-computed tomography (micro-CT) and mouse femoral defect models with different defect sizes, we were able to detect spatio-temporal healing patterns indicative of physiological and impaired healing in three defect sub-volumes and the adjacent cortex. The time-lapsed in vivo micro-CT-based approach was then applied to evaluate the bone regeneration potential of functionalized biomaterials using collagen and bone morphogenetic protein (BMP-2). Both collagen and BMP-2 treatment led to distinct changes in bone turnover in the different healing phases. Despite increased periosteal bone formation, 87.5% of the defects treated with collagen scaffolds resulted in non-unions. Additional BMP-2 application significantly accelerated the healing process and increased the union rate to 100%. This study further shows potential of time-lapsed in vivo micro-CT for capturing spatio-temporal deviations preceding non-union formation and how this can be prevented by application of functionalized biomaterials. This study therefore supports the application of longitudinal in vivo micro-CT for discrimination of normal and disturbed healing patterns and for the spatio-temporal characterization of the bone regeneration capacity of functionalized biomaterials.

scholarly journals Short-wave enhances mesenchymal stem cell recruitment in fracture healing by increasing HIF-1 in callus

2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Dongmei Ye ◽  
Chen Chen ◽  
Qiwen Wang ◽  
Qi Zhang ◽  
Sha Li ◽  
...  
Keyword(s):  
Stem Cell ◽  
Mesenchymal Stem Cell ◽  
Fracture Healing ◽  
Callus Formation ◽  
Healing Process ◽  
Short Wave ◽  
Fracture Site ◽  
Related Factors

Abstract Background As a type of high-frequency electrotherapy, a short-wave can promote the fracture healing process; yet, its underlying therapeutic mechanisms remain unclear. Purpose To observe the effect of Short-Wave therapy on mesenchymal stem cell (MSC) homing and relative mechanisms associated with fracture healing. Materials and methods For in vivo study, the effect of Short-Wave therapy to fracture healing was examined in a stabilized femur fracture model of 40 SD rats. Radiography was used to analyze the morphology and microarchitecture of the callus. Additionally, fluorescence assays were used to analyze the GFP-labeled MSC homing after treatment in 20 nude mice with a femoral fracture. For in vitro study, osteoblast from newborn rats simulated fracture site was first irradiated by the Short-Wave; siRNA targeting HIF-1 was used to investigate the role of HIF-1. Osteoblast culture medium was then collected as chemotaxis content of MSC, and the migration of MSC from rats was evaluated using wound healing assay and trans-well chamber test. The expression of HIF-1 and its related factors were quantified by q RT-PCR, ELISA, and Western blot. Results Our in vivo experiment indicated that Short-Wave therapy could promote MSC migration, increase local and serum HIF-1 and SDF-1 levels, induce changes in callus formation, and improve callus microarchitecture and mechanical properties, thus speeding up the healing process of the fracture site. Moreover, the in vitro results further indicated that Short-Wave therapy upregulated HIF-1 and SDF-1 expression in osteoblast and its cultured medium, as well as the expression of CXCR-4, β-catenin, F-actin, and phosphorylation levels of FAK in MSC. On the other hand, the inhibition of HIF-1α was significantly restrained by the inhibition of HIF-1α in osteoblast, and it partially inhibited the migration of MSC. Conclusions These results suggested that Short-Wave therapy could increase HIF-1 in callus, which is one of the crucial mechanisms of chemotaxis MSC homing in fracture healing.

MAGNETIC RESONANCE RELAXATION-TIME STUDIES OF FRACTURE REPAIR IN CHICKS: A POTENTIAL METHOD FOR EVALUATION OF FRACTURE HEALING

2005 ◽  
Vol 09 (02) ◽  
pp. 85-92
Author(s):  
I. Nusem ◽  
S. Edelstein ◽  
I. Otremski
Keyword(s):  
Relaxation Time ◽  
Magnetic Resonance ◽  
Fracture Healing ◽  
Callus Formation ◽  
Healing Process ◽  
Potential Method ◽  
Fracture Repair ◽  
Angular Deformation ◽  
Biomechanical Changes ◽  
Resonance Relaxation

Purpose: To investigate whether magnetic resonance relaxation-time measurements have a role in monitoring fracture healing. Methods: Magnetic resonance relaxation-time measurements were used to assess callus formation in chicks' tibiae and were correlated to the histopathologic and biomechanical changes that occur throughout the process of fracture repair. Results: The effective transverse relaxation time (T2) values recorded during fracture healing process were significantly longer (p = 0.0151) at day 14 (65.5575 ms.), compared with those recorded at days 3 (52.68 ms.) and 7 (55.4313 ms.). The T2 values distributions (a) at day 14 (0.2304) were significantly lower (p = 0.0313) compared with those recorded at days 7 (0.2721) and 10 (0.2742). Using a semiquantitative histologic evaluation, a significant increase in the amount of endosteal new bone (p = 0.048), and periosteal new bone (p = 0.008), associated with a significant decrease in the amount of old bone (p = 0.007) and cartilaginous tissue (p = 0.001) was observed. Analysis of the torque-angle curves demonstrated a low torque and a large angular deformation associated with low stiffness at 3–7 days post-fracture, and a high torque and a small angular deformation associated with high stiffness at 10–14 days post-fracture. Interpretation: Magnetic resonance relaxation-time follows the histopathologic and biomechanical changes occurring during the process of fracture repair and it may have a role as a potential method for objective estimation of fracture repair.

scholarly journals Short-Wave Enhances Mesenchymal Stem Cells Recruitment in Fracture Healing by Increasing HIF-1 in Callus

2020 ◽  
Author(s):  
Dongmei Ye ◽  
Chen Chen ◽  
Qiwen Wang ◽  
Qi Zhang ◽  
Sha Li ◽  
...  
Keyword(s):  
Fracture Healing ◽  
Callus Formation ◽  
Healing Process ◽  
Short Wave ◽  
Fracture Site ◽  
Related Factors ◽  
Femur Fractures ◽  
Osteoblast Culture

Abstract Background: As a type of high-frequency electrotherapy, a Short-Wave can promote the fracture healing process; yet, its underlying therapeutic mechanisms remain unclear.Purpose: To observe the effect of Short-Wave therapy on mesenchymal stem cell (MSC) homing and relative mechanisms associated with fracture healing. Materials and Methods: For in vivo study, the effect of Short-Wave therapy to fracture healing was examined in stabilized femur fractures model of 40 SD rats. Radiography was used to analyze the morphology and microarchitecture of the callus. Additionally, fluorescence assays were used to analyze the GFP-labeled MSC homing after treatment in 20 nude mice with a femoral fracture. For in vitro study, osteoblast from newborn rats simulated fracture site was first irradiated by the Short-Wave; siRNA targeting HIF-1 was used to investigate the role of HIF-1. Osteoblast culture medium was then collected as chemotaxis content of MSC, and the migration of MSC from rats was evaluated using wound healing assay and trans-well chamber test. The expression of HIF-1 and its related factors were quantified by q RT-PCR, ELISA, and Western blot.Results: Our in vivo experiment indicated that Short-Wave therapy could promote MSC migration, increase local and serum HIF-1 and SDF-1 levels, induce changes in callus formation, and improve callus microarchitecture and mechanical properties, thus speeding up the healing process of the fracture site. Moreover, the in vitro results further indicated that Short-Waves therapy upregulated HIF-1 and SDF-1 expression in osteoblast and its cultured medium, as well as the expression of CXCR-4, β-catenin, F-actin and phosphorylation levels of FAK in MSC. On the other hand, the inhibition of HIF-1α was significantly restrained by the inhibition of HIF-1α in osteoblast, and it partially inhibited the migration of MSC.Conclusions: These results suggested that Short-Wave therapy could increase HIF-1 in callus, which is one of the crucial mechanisms of chemotaxis MSC homing in fracture healing.

scholarly journals Short-Wave Enhances MSC Recruitment in Fracture Healing from Increasing HIF-1 in Callus

2020 ◽  
Author(s):  
Dongmei Ye ◽  
Chen Chen ◽  
Qiwen Wang ◽  
Qi Zhang ◽  
Sha Li ◽  
...  
Keyword(s):  
Fracture Healing ◽  
Callus Formation ◽  
Healing Process ◽  
Short Wave ◽  
Fracture Site ◽  
Related Factors ◽  
Femur Fractures ◽  
Osteoblast Culture

Abstract Background: As a type of high-frequency electrotherapy, a Short-Wave can promote the fracture healing process; yet, its underlying therapeutic mechanisms still remain unclear.Purpose: To observe the effect of Short-Wave therapy on mesenchymal stem cell (MSC) homing and relative mechanisms associated with fracture healing. Materials and Methods: For in vivo study, the effect of Short-Wave therapy in relation to fracture healing was examined in stabilized femur fractures model of 40 SD rats. Radiography was used to analyze the morphology and micro-architecture of the callus. Additionally, fluorescence assays were used to analyze the GFP-labeled MSC homing after treatment in 20 nude mice with a femoral fracture. For in vitro study, osteoblast from newborn rats simulated fracture site was first irradiated by the Short-Wave; siRNA targeting HIF-1 was used to investigate the role of HIF-1. Osteoblast culture medium was then collected as chemotaxis content of MSC, and the migration of MSC from rats was evaluated using wound healing assay and trans-well chamber test. The expression of HIF-1 and its related factors were quantified by q RT-PCR, ELISA, and Western blot.Results: Our in vivo experiment indicated that Short-Wave therapy could promote MSC migration, increase local and serum HIF-1 and SDF-1 levels, induce changes in callus formation, and improve callus microarchitecture and mechanical properties, thus speeding up the healing process of the fracture site. Moreover, the in vitro results further indicated that Short-Waves therapy upregulated HIF-1 and SDF-1 expression in osteoblast and in the medium, as well as the expression of CXCR-4, β-catenin, F-actin and phosphorylation levels of FAK in MSC. On the other hand, the inhibition of HIF-1α was significantly restrained by the inhibition of HIF-1α in osteoblast, and it partially inhibited the migration of MSC.Conclusions: These results suggested that Short-Wave therapy could increase HIF-1 in callus, which is one of the crucial mechanisms of chemotaxis MSC homing in fracture healing.

scholarly journals Review of Fracture Healing and Outcomes Assessment

2020 ◽  
Vol 3 ◽  
Author(s):  
Adam Knoximprs ◽  
Anthony McGuire ◽  
Christopher Collier ◽  
Melissa Kacena ◽  
Roman Natoli
Keyword(s):  
Fracture Healing ◽  
Bone Fractures ◽  
Healing Process ◽  
Biomechanical Testing ◽  
Fracture Repair ◽  
Long Bone ◽  
Micro Computed Tomography ◽  
Fracture Callus ◽  
Medical Interventions ◽  
Healing Assessment

Background/Objective: Long bone fractures are of the most common and costly medical traumas humans experience.  Adequate characterization of the fracture healing process and development of potential medical interventions generally involves fracture induction operations on animal models of varying treatment or genetic groups, then analyzing relative repair success via synthesis of diverse assessment methodologies.  This review discusses the procedures, relevant parameters, special considerations, and key correlations of these major methodologies of fracture repair quantification.  Methods: A literature review was conducted for articles discussing the procedures or identifying correlations between each of the major fracture healing assessment methodologies.    Results: These methodologies include biomechanical testing, which provides the most direct quantification of skeletal functionality; micro-computed tomography, which enables high resolution visualization of fracture callus architecture; histology which helps elucidate the intricate processes underlying fracture repair; and x-ray which offers a non-invasive and clinically relevant view of fracture repair progress.  Each of these methodologies measure parameters directly correlating to restored functionality of fractured bone.  Conclusion: When appropriately integrated, synthesis of relevant parameters from each methodology of fracture repair assessment enables a comprehensive understanding of varying fracture healing outcomes and associated causalities.  Scientific/Clinical Policy Impact and Implications: This review may guide the interpretation and planning of fracture healing studies utilizing murine models. 

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