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 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 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 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 Dietary Recommendations in Fracture Healing in Traditional Persian Medicine: A Historical Review of Literature

2017 ◽  
Vol 22 (3) ◽  
pp. 513-517 ◽  
Author(s):  
Seyed Mohammad Hosseini Kasnavieh ◽  
Seyed Mohammad Hasan Sadeghi ◽  
Seyed Mehdi Hosseini Khameneh ◽  
Mahmood Khodadoost ◽  
Azam Bazrafshan ◽  
...  
Keyword(s):  
Fracture Healing ◽  
Nutritive Value ◽  
Current Knowledge ◽  
Callus Formation ◽  
Healing Process ◽  
Fracture Repair ◽  
Dietary Recommendations ◽  
Positive Effects ◽  
Persian Medicine ◽  
Traditional Persian Medicine

Background. Fracture repair is a complex process. An inappropriate diet is a contributing risk factor for fracture nonunion. The aim of this study was to extract dietary recommendations for fracture healing according to traditional Persian medicine (TPM) literature. Method. The contents relevant to diets in fracture healing were selected from main textbooks in TPM like Al Qanon fi Al-teb ( The Canon). Other reference textbooks in traditional medicine were also used for a comprehensive study in this respect. Finally content analysis was used for summarizing and describing the results. Findings. Food stuffs are classified in TPM according to their nutritive value, their assimilability, and the quality of achieved chyme. Some light meals like chicken soup are recommended for the early days of fracture and high-nutrient and dense foods such as goat’s or sheep’s head and nuts are advised in following days for fracture healing acceleration and callus formation. Several recommendations are also provided for pacing the healing process. Conclusion. A comparison of Avicenna and other Persian sage’s recommended regimens with the recent evidence revealed the potential positive effects of their regimen for bone healing acceleration. It can shed light on a part of history of orthopedics and add to current knowledge about bone fracture and its management.

scholarly journals Can Optimizing the Mechanical Environment Deliver a Clinically Significant Reduction in Fracture Healing Time?

Biomedicines ◽  
2021 ◽  
Vol 9 (6) ◽  
pp. 691
Author(s):  
Jan Barcik ◽  
Devakara R. Epari
Keyword(s):  
Fracture Healing ◽  
Bone Healing ◽  
Mechanical Stimulation ◽  
Callus Formation ◽  
Weight Bearing ◽  
Healing Process ◽  
Healing Time ◽  
Mechanical Environment ◽  
Clinically Significant ◽  
The Impact

The impact of the local mechanical environment in the fracture gap on the bone healing process has been extensively investigated. Whilst it is widely accepted that mechanical stimulation is integral to callus formation and secondary bone healing, treatment strategies that aim to harness that potential are rare. In fact, the current clinical practice with an initially partial or non-weight-bearing approach appears to contradict the findings from animal experiments that early mechanical stimulation is critical. Therefore, we posed the question as to whether optimizing the mechanical environment over the course of healing can deliver a clinically significant reduction in fracture healing time. In reviewing the evidence from pre-clinical studies that investigate the influence of mechanics on bone healing, we formulate a hypothesis for the stimulation protocol which has the potential to shorten healing time. The protocol involves confining stimulation predominantly to the proliferative phase of healing and including adequate rest periods between applications of stimulation.

scholarly journals Operational Amplifiers Revisited for Low Field Magnetic Resonance Relaxation Time Measurement Electronics

Proceedings ◽  
2019 ◽  
Vol 42 (1) ◽  
pp. 1
Author(s):  
Najlaa K. Almazrouei ◽  
Michael I. Newton ◽  
Robert H. Morris
Keyword(s):  
Relaxation Time ◽  
Magnetic Resonance ◽  
Field Measurements ◽  
Time Measurement ◽  
Operational Amplifiers ◽  
Frequency Range ◽  
Sensor Applications ◽  
Low Field ◽  
Front End ◽  
Resonance Relaxation

Advances in permanent magnet technology has seen more reports of sensor applications of low field magnetic resonance. Whilst most are either in the 10–20 MHz range or in the earth’s field, measurements at below 1 MHz are beginning to become more widespread. This range is below the need for careful radio frequency electronics design but above the audio domain and represents an interesting cross over. Many commercial spectrometers do not include the pulse power amplifier, duplexer and preamplifier as these depend on the frequency range used. In this work we demonstrate that, with the current specifications of the humble operational amplifier, the most simple form of an inverting design using only two resistors and decoupling, can effectively provide this ‘front end’ electronics. The low powers used mean crossed Ge diodes provide an excellent duplexer and it is suitable for battery powered applications.

Earliest cardiac toxicity induced by iron overload selectively inhibits electrical conduction

2002 ◽  
Vol 93 (2) ◽  
pp. 746-751 ◽  
Author(s):  
Kenneth A. Schwartz ◽  
Zy Li ◽  
Dianne E. Schwartz ◽  
Thomas G. Cooper ◽  
W. Emmett Braselton
Keyword(s):  
Relaxation Time ◽  
Magnetic Resonance ◽  
Left Ventricular Pressure ◽  
Left Ventricular ◽  
Warning Signs ◽  
Cardiac Conduction ◽  
Ventricular Contractility ◽  
Iron Load ◽  
High Incidence ◽  
Resonance Relaxation

Female guinea pigs were injected intraperitoneally with 0.083 g/kg iron dextran (Fe-D) to achieve progressively increasing levels of iron load; controls received dextran. Delayed and blocked cardiac conductivity at the Purkinje fiber-papillary muscle junction was initially observed with Fe-D loads of 0.33 g/kg. Serial magnetic resonance relaxation time measurements obtained from livers of live animals showed a decrease (8.1 ± 0.86 vs. 14.8 ± 1.03 ms in controls, P < 0.001) that was first observed in animals loaded with 0.25 g/kg Fe-D. Iron concentrations in hearts and livers were significantly increased ( P < 0.001). Left ventricular pressure measurements on 1.5 g/kg Fe-D animals failed to demonstrate a defect in contractility, but 27% (9/33) ( P < 0.050) of the animals died without warning signs. We conclude that 1) initial decreases in liver magnetic resonance-relaxation time occur in the same range of iron excess as the threshold of iron load that induces delay or blockade of cardiac conduction and 2) a high incidence of sudden death, presumably from cardiac arrhythmias, was observed with large doses of iron that did not decrease left ventricular contractility.

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