Osteotomy Model Is Not Suitable To Provide Insight into Normal Bone Healing (original) (raw)
Related papers
Comparison of Healing Process in Open Osteotomy Model and Closed Fracture Model
Journal of Orthopaedic Trauma, 1999
Murine osteotomy and fracture models have become the standard to study molecular mechanisms of bone healing. Because there is little information whether the healing of osteotomies differs from that of fractures, we herein studied in mice the healing of femur osteotomies compared to femur fractures. Twenty CD-1 mice underwent a standardized open femur osteotomy. Another 20 mice received a standardized open femur fracture. Stabilization was performed by an intramedullary screw. Bone healing was studied by micro-CT, biomechanical, histomorphometric and protein expression analyses. Osteotomies revealed a significantly lower biomechanical stiffness compared to fractures. Micro-CT showed a reduced bone/tissue volume within the callus of the osteotomies. Histomorphometric analyses demonstrated also a significantly lower amount of osseous tissue in the callus of osteotomies (26% and 88% after 2 and 5 weeks) compared to fractures (50% and 100%). This was associated with a delayed remodeling. Western blot analyses demonstrated comparable BMP-2 and BMP-4 expression, but higher levels of collagen-2, CYR61 and VEGF after osteotomy. Therefore, we conclude that open femur osteotomies in mice show a markedly delayed healing when stabilized less rigidly with an intramedullary screw. This should be considered when choosing a model for studying the mechanisms of bone healing in mice.
Clinical Orthopaedics and Related Research®
Background Multiple trauma is frequently associated with hemorrhagic shock and fractures of the extremities. Clinically, the rate of impaired fracture healing (delayed healing and nonunion) seems to be increased in patients with multiple injuries compared with patients with isolated fractures. As the underlying pathogenesis remains poorly understood, we aimed to analyze the biomechanical properties during fracture healing in a murine model. Questions The aim of this study was to determine whether fracture healing after severe hemorrhagic shock results in (1) delayed bridging as determined by macroscopic and radiographic assessment, (2) altered conditions of callus components as determined by lCT, and (3) decreased maximum bending moment measured by a three-pointbending test compared with ordinary fracture healing. Methods Male C57BL/6NCrl mice were randomly assigned to five groups and four different times (five to 10 mice per group and time). Only the right femur from each mouse was used for analysis: the trauma hemorrhage (TH) group received a pressure-controlled hemorrhagic shock via catheter; the osteotomy (Fx) group underwent osteotomy and implantation of an external fixator on the right femur; the combined trauma (THFx) group received hemorrhagic shock and an external fixator with osteotomy; the sham group underwent implantation of a catheter and external fixator but had no blood loss or osteotomy, and the control group underwent no interventions. After 2, 3, 4, or 6 weeks, five to 10 animals of each group were sacrificed. Bones were analyzed macroscopically and via radiographs, lCT, and three-point-bending test. Statistical significance was set at a probability less than 0.05. Comparisons were performed using the Mann-Whitney U or the Kruskal-Wallis test. Results In the Fx group, the osteotomy gap was stable and bridged after 2 weeks in contrast to some bones in the THFx group where stable bridging did not occur. No difference was observed between the groups. lCT analysis showed reduced density of bone including callus (THFx: 1.17 g/ cm 3 ; interquartile range [IQR], 0.04 g/cm 3 ; Fx: 1.22 g/cm 3 ; The institution of one or more of the authors (KB, CM, LMS, SN, CK, and CN) has received, during the study period, funding from Deutsche Forschungsgemeinschaft (grant number NE 1932/1-1). All ICMJE Conflict of Interest Forms for authors and Clinical Orthopaedics and Related Research 1 editors and board members are on file with the publication and can be viewed on request. Clinical Orthopaedics and Related Research 1 neither advocates nor endorses the use of any treatment, drug, or device. Readers are encouraged to always seek additional information, including FDAapproval status, of any drug or device prior to clinical use. Each author certifies that his or her institution approved the animal protocol for this investigation and that all investigations were conducted in conformity with ethical principles of research.
Applied Sciences
Osteotomy is a common step in oncological, reconstructive, and trauma surgery. Drilling and elevated temperature during osteotomy produce thermal osteonecrosis. Heat and associated mechanical damage during osteotomy can impair bone healing, with consequent failure of fracture fixation or dental implants. Several ex vivo studies on animal bone were recently focused on heating production during osteotomy with conventional drill and piezoelectric devices, particularly in endosseous dental implant sites. The current literature on bone drilling and osteotomic surface analysis is here reviewed and the dynamics of bone healing after osteotomy with traditional and piezoelectric devices are discussed. Moreover, the methodologies involved in the experimental osteotomy and clinical studies are compared, focusing on ex vivo and in vivo findings.
The Journal of Indonesian Orthopaedic, 2012
Introduction. Fracture treatment and bone healing is a complicated process and interesting topic. There are a lot of researches in this matter until now. Fracture fixation with additional autogenous bone marrow is well known to have good fracture healing. Bone marrow contains progenitor cells that can be used to facilitate bone healing. Fracture treatment with intramedullary nailing combine with bone marrow from iliac crest or femoral head has shown to have better healing. The purpose of this study was to evaluate bone healing on the fracture site by giving the bone marrow from medulla. Materials and methods. In the present study, we explored bone healing in femoral fracture of Sprague dawley rat with intramedullary wire fixation and the application of medullary bone marrow as much as 0.5 to 1 cc from femur. The effect of given bone marrow in fracture healing was evaluated from callus formation (callus diameter, callus volume) and alkaline phosphatase level. Subjects were divided into 2 group, namely study group and control group. Each group consists of 20 white rats. The control group was treated with intramedullary wire while the study group was treated with medullary bone marrow in addition to intramedullary wire. Observation was followed until 30 days. During that time, both groups were given same environment including cage, wound treatment, food intake, water intake and temperature). Callus diameter and volume was evaluated with radiological and alkaline phosphatase level was measured from blood serum. Results. Callus diameter in study group was 34.1% larger than control group (p < 0.01). Callus volume in study group was 2.02 times larger than control group (123.77 mm 3 compared to 41.23 mm 3 ; p < 0.01). Alkaline phosphatase in study group was 23.63% larger than control group (30.56 IU/L compared to 24.72 IU/L; p < 0.01). Conclusions. We conclude that bone marrow derived from femoral reaming could increase callus formation and alkaline phosphatase level significantly. It has positive effect in femoral fracture healing to increase osteoblast activity.
The development of a novel model of direct fracture healing in the rat
Bone & joint research, 2012
Small animal models of fracture repair primarily investigate indirect fracture healing via external callus formation. We present the first described rat model of direct fracture healing. A rat tibial osteotomy was created and fixed with compression plating similar to that used in patients. The procedure was evaluated in 15 cadaver rats and then in vivo in ten Sprague-Dawley rats. Controls had osteotomies stabilised with a uniaxial external fixator that used the same surgical approach and relied on the same number and diameter of screw holes in bone. Fracture healing occurred without evidence of external callus on plain radiographs. At six weeks after fracture fixation, the mean stress at failure in a four-point bending test was 24.65 N/mm(2) (sd 6.15). Histology revealed 'cutting-cones' traversing the fracture site. In controls where a uniaxial external fixator was used, bone healing occurred via external callus formation. A simple, reproducible model of direct fracture heal...
Development and Characterization of a Standard Closed Tibial Fracture Model in the Rat
European Journal of Trauma, 2004
The aim of this study was to develop a clinically relevant standardized closed tibial fracture model in the rat and to characterize the healing process at different time points using radiologic, biomechanical, and histological methods. Material and Methods: The tibia and fibula were fractured in a closed manner using a guillotine-like device under standardized conditions. After closed reduction, the tibia was stabilized with an intramedullary titanium Kirschner wire. To evaluate the soft tissue trauma, the compartment pressure was measured postoperatively. To follow the healing process, X-ray examinations were performed and bridging of the calluses was scored throughout the experimental period. At 28, 42, and 84 days after fracture, animals were killed and the tibiae prepared for biomechanical torsional testing or histological and histomorphological analyses. Results: Only four of the 69 animals subjected to this procedure showed a complex fracture configuration. The remaining animals showed a transverse midshaft fracture (AO A2-A3) with minimal soft tissue trauma. The healing process could be detected in the radiologic investigations and showed comparable scoring parameters in all animals. The biomechanical strength increased with the healing time and showed the highest values after 84 days. The callus was composed of soft tissue, cartilage and newly formed trabecular bone after 4 weeks. At the later time points, a remodeling process was detectable with a decrease in cartilage and an increase in mineralized tissue. Conclusion: Since this model does not require prepinning of the bone prior to fracture, it mimics a clinical trauma setting. Using this model, the basic cellular events of fracture healing can be investigated and the effects of local or systemic factors or conditions assessed.
Determination of callus quantity in 4- week-old fractures of the rat tibia
Journal of Orthopaedic Research, 1985
In clinical practice the quantity of fracture callus is usually estimated on the basis of radiographs. In experimental studies on fracture healing, more exact chemical measurements (total protein, DNA, and mineral contents) have been used to quantitate the amount of callus. It is not known, however, how these two parameters correlate with each other. In this study we used different (radiographic, histomorphometric, and chemical) methods to evaluate the quantity of fracture callus in 4-week-old tibial fractures of rats stabilized by intramedullary nailing. The wet and dry weights and the nitrogen, collagen, calcium, phosphorus, and DNA contents of the calluses showed no correlation with the radiographic size of the calluses. There was a strong correlation (p < 0.001), however, between radiographic and histomorphometric callus sizes.
Analysis of fracture healing in osteopenic bone caused by disuse: experimental study
Brazilian journal of medical and biological research = Revista brasileira de pesquisas médicas e biológicas / Sociedade Brasileira de Biofísica ... [et al.], 2016
Osteoporosis has become a serious global public health issue. Hence, osteoporotic fracture healing has been investigated in several previous studies because there is still controversy over the effect osteoporosis has on the healing process. The current study aimed to analyze two different periods of bone healing in normal and osteopenic rats. Sixty, 7-week-old female Wistar rats were randomly divided into four groups: unrestricted and immobilized for 2 weeks after osteotomy (OU2), suspended and immobilized for 2 weeks after osteotomy (OS2), unrestricted and immobilized for 6 weeks after osteotomy (OU6), and suspended and immobilized for 6 weeks after osteotomy (OS6). Osteotomy was performed in the middle third of the right tibia 21 days after tail suspension, when the osteopenic condition was already set. The fractured limb was then immobilized by orthosis. Tibias were collected 2 and 6 weeks after osteotomy, and were analyzed by bone densitometry, mechanical testing, and histomorph...
Physiological and haemato-biochemical changes during repair of femur fracture in dogs
The Pharma Innovation Journal, 2017
The research was conducted in clinical cases of twenty four dogs with femur fracture and they were randomly divided into three groups viz., group I, II and III with eight animals in each group. Group I, II and III animals were treated with Dynamic compression plating, Locking compression plating and Intramedullary interlocking nailing techniques respectively. Healing of fractures was studied on before operation, immediately after operation, 30, 60 and 90 post-operative days in 3 groups based on physiological and haemato-biochemical findings. In the present study bradypnoea, bradycardia and hypothermia were found on post-operative days. Progressive increase of packed cell volume, haemoglobin and total erythrocyte count on different post-operative days was seen. Physiological leucocytopenia, neutropenia and relative lymphocytosis was observed on post-operative days. Monocyte and eosinophil count were within physiological range in three groups of animals. Slight hypercalcimia, slight h...