-
International Journal of Clinical and... 2015The purpose was to detect the effects of ovariectomy (OVX) on femoral fracture healing through different angiogenesis and HIF-1α expression in mice. Thirty-six young...
The purpose was to detect the effects of ovariectomy (OVX) on femoral fracture healing through different angiogenesis and HIF-1α expression in mice. Thirty-six young female C57 mice were randomized into two groups: OVX and age-matched intact control (CON). The femoral fracture was generated at 3 weeks after OVX or CON. At 2 or 4 weeks after fracture, the femoral fracture area was evaluated healing status by bone mineral density (BMD), callus formation and mineralization and neovascularization in callus, biomechanical analysis, and HIF-1α tests. OVX mice showed lower BMD as compared with CON mice. Callus geometric microstructural parameters of the femora in OVX mice were significantly lower than CON mice. OVX induced significant changes of biomechanical parameters in the femoral fracture healing area. The callus forming, callus neovascularization and HIF-1α tests in OVX mice were significantly lower than in CON mice. HIF-1α results have the positive proportion with osteoporotic fracture healing.
Topics: Animals; Bone Density; Bony Callus; Enzyme-Linked Immunosorbent Assay; Female; Femoral Fractures; Fracture Healing; Humans; Hypoxia-Inducible Factor 1, alpha Subunit; Immunohistochemistry; Mice; Mice, Inbred C57BL; Neovascularization, Physiologic; Osteoporosis, Postmenopausal; Ovariectomy; X-Ray Microtomography
PubMed: 25755698
DOI: No ID Found -
Medicina (Kaunas, Lithuania) 2004Parathyroid hormone naturally secreted by the parathyroid glands is a potent anabolic agent for bone. Parathyroid hormone is primarily thought of as a catabolic protein... (Review)
Review
Parathyroid hormone naturally secreted by the parathyroid glands is a potent anabolic agent for bone. Parathyroid hormone is primarily thought of as a catabolic protein involved in the physiologic release of calcium from bone. Whereas during recent years, a number of animal studies and clinical trials have demonstrated that intermittent parathyroid hormone administration induces anabolic effects on both cancellous and cortical bone, enhances bone mass and increases mechanical strength of the bones. Most of the studies, both animal and human, have addressed the treatment of osteoporosis and parathyroid hormone represents an important new advance in the therapy of osteoporosis. Few studies have investigated the effect of intermittent parathyroid hormone treatment in the field of orthopedics on fracture healing and fixation of orthopedic implants. The results of those studies indicated an enhancement of fracture healing, faster bone repair and better fixation of the implant. Recently there were few animal studies started to investigate the effects of parathyroid hormone treatment on bone formation in regenerated and surrounding bone of distracted callus during limb lengthening. Distraction osteogenesis is a technique for bone lengthening that is widely used clinically and experimentally. Newly forming bone during distraction osteogenesis is expected to be an appropriate pattern for parathyroid hormone anabolic effect. Preclinical studies as well as clinical trials suggest that parathyroid hormone might be useful as a stimulator of bone formation whereas a lot of questions regarding parathyroid hormone therapy remain unanswered and require further experimental studies and investigations.
Topics: Animals; Bone Lengthening; Bony Callus; Controlled Clinical Trials as Topic; Disease Models, Animal; Dogs; Female; Forecasting; Fracture Healing; Haplorhini; Humans; Leg Length Inequality; Orthopedics; Osteogenesis; Osteoporosis; Parathyroid Hormone; Rabbits; Rats; Time Factors
PubMed: 15456969
DOI: No ID Found -
Alcoholism, Clinical and Experimental... Jun 2022During bone fracture repair, mesenchymal stem cells (MSC) differentiate into chondrocytes and osteoblasts to form a fracture callus. Our laboratory previously reported...
BACKGROUND
During bone fracture repair, mesenchymal stem cells (MSC) differentiate into chondrocytes and osteoblasts to form a fracture callus. Our laboratory previously reported that alcohol-exposed rodents with a surgically created tibia fracture display deficient fracture callus formation and diminished signs of endochondral ossification characterized by the absence of chondrocytes and mature hypertrophic chondrocytes, suggesting that alcohol may inhibit MSC differentiation. These findings led to our hypothesis that alcohol exposure inhibits mesenchymal stem cell chondrogenic differentiation within the developing fracture callus.
METHODS
In the present study, we utilized a lineage-tracing approach to determine which stage(s) of chondrogenic differentiation are affected by alcohol exposure. We utilized lineage-specific reporter mice to determine the effects of alcohol on MSC and early and late chondrogenic cell frequencies within the fracture callus. In addition, serially sectioned slides were stained immunofluorescently and immunohistochemically and quantified to determine the effect of alcohol on cell proliferation and apoptosis, respectively, within the fracture callus of alcohol-administered rodents.
RESULTS
Alcohol-administered rodents had a reduced fracture callus area at 4, 6, and 9 days postfracture. Alcohol had no effect on apoptosis in the fracture callus at any of the examined timepoints. Alcohol-administered rodents had significantly fewer proliferative cells in the fracture callus at 9 days postfracture, but no effect on cell proliferation was observed at earlier fracture callus timepoints. Alcohol-administered rodents had reduced Collagen2a1- and Collagen10a1-expressing cells in the developing fracture callus, suggesting that alcohol inhibits both early chondrogenic differentiation and later chondrocyte maturation during fracture callus development.
CONCLUSION
The data suggest that alcohol could affect normal fracture healing through the mitigation of MSC chondrogenic differentiation at the callus site.
Topics: Animals; Bony Callus; Cell Differentiation; Chondrogenesis; Ethanol; Fracture Healing; Fractures, Bone; Mesenchymal Stem Cells; Mice
PubMed: 35403260
DOI: 10.1111/acer.14836 -
Journal of Orthopaedic Surgery and... Jun 2023Therapies using electromagnetic field technology show evidence of enhanced bone regeneration at the fracture site, potentially preventing delayed or nonunions.
BACKGROUND
Therapies using electromagnetic field technology show evidence of enhanced bone regeneration at the fracture site, potentially preventing delayed or nonunions.
METHODS
Combined electric and magnetic field (CEMF) treatment was evaluated in two standardized sheep tibia osteotomy models: a 3-mm non-critical size gap model and a 17-mm critical size defect model augmented with autologous bone grafts, both stabilized with locking compression plates. CEMF treatment was delivered across the fracture gap twice daily for 90 min, starting 4 days postoperatively (post-OP) until sacrifice (9 or 12 weeks post-OP, respectively). Control groups received no CEMF treatment. Bone healing was evaluated radiographically, morphometrically (micro-CT), biomechanically and histologically.
RESULTS
In the 3-mm gap model, the CEMF group (n = 6) exhibited higher callus mineral density compared to the Control group (n = 6), two-fold higher biomechanical torsional rigidity and a histologically more advanced callus maturity (no statistically significant differences). In the 17-mm graft model, differences between the Control (n = 6) and CEMF group (n = 6) were more pronounced. The CEMF group showed a radiologically more advanced callus, a higher callus volume (p = 0.003) and a 2.6 × higher biomechanical torsional rigidity (p = 0.024), combined with a histologically more advanced callus maturity and healing.
CONCLUSIONS
This study showed that CEMF therapy notably enhanced bone healing resulting in better new bone structure, callus morphology and superior biomechanical properties. This technology could transform a standard inert orthopedic implant into an active device stimulating bone tissue for accelerated healing and regeneration.
Topics: Sheep; Animals; Fracture Healing; Tibia; Bony Callus; Tibial Fractures; Magnetic Field Therapy; Osteotomy; Biomechanical Phenomena
PubMed: 37355696
DOI: 10.1186/s13018-023-03910-6 -
Frontiers in Endocrinology 2022To investigate the effects of vibration therapy on fracture healing in diabetic and non-diabetic rats.
OBJECTIVE
To investigate the effects of vibration therapy on fracture healing in diabetic and non-diabetic rats.
METHODS
148 rats underwent fracture surgery and were assigned to four groups: (1) SHAM: weight-matched non-diabetic rats, (2) SHAM+VT: non-diabetic rats treated with vibration therapy (VT), (3) DM: diabetic rats, and (4) DM+VT: diabetic rats treated with VT. Thirty days after diabetes induction with streptozotocin, animals underwent bone fracture, followed by surgical stabilization. Three days after bone fracture, rats began VT. Bone healing was assessed on days 14 and 28 post-fracture by serum bone marker analysis, and femurs collected for dual-energy X-ray absorptiometry, micro-computed tomography, histology, and gene expression.
RESULTS
Our results are based on 88 animals. Diabetes led to a dramatic impairment of bone healing as demonstrated by a 17% reduction in bone mineral density and decreases in formation-related microstructural parameters compared to non-diabetic control rats (81% reduction in bone callus volume, 69% reduction in woven bone fraction, 39% reduction in trabecular thickness, and 45% in trabecular number). These changes were accompanied by a significant decrease in the expression of osteoblast-related genes (), as well as a 92% reduction in serum insulin-like growth factor I (IGF-1) levels. On the other hand, resorption-related parameters were increased in diabetic rats, including a 20% increase in the callus porosity, a 33% increase in trabecular separation, and a 318% increase in serum C terminal telopeptide of type 1 collagen levels. VT augmented osteogenic and chondrogenic cell proliferation at the fracture callus in diabetic rats; increased circulating IGF-1 by 668%, callus volume by 52%, callus bone mineral content by 90%, and callus area by 72%; and was associated with a 19% reduction in circulating receptor activator of nuclear factor kappa beta ligand (RANK-L).
CONCLUSIONS
Diabetes had detrimental effects on bone healing. Vibration therapy was effective at counteracting the significant disruption in bone repair induced by diabetes, but did not improve fracture healing in non-diabetic control rats. The mechanical stimulus not only improved bone callus quality and quantity, but also partially restored the serum levels of IGF-1 and RANK-L, inducing bone formation and mineralization, thus creating conditions for adequate fracture repair in diabetic rats.
Topics: Animals; Bony Callus; Diabetes Mellitus; Fracture Healing; Fractures, Bone; Insulin-Like Growth Factor I; Rats; Vibration; X-Ray Microtomography
PubMed: 36060973
DOI: 10.3389/fendo.2022.909317 -
Journal of Orthopaedic Surgery and... Mar 2022To date, the usefulness of parathyroid hormone [PTH (1-34)] in distraction osteogenesis has been reported in several studies. We aimed to determine the optimal timing of...
BACKGROUND
To date, the usefulness of parathyroid hormone [PTH (1-34)] in distraction osteogenesis has been reported in several studies. We aimed to determine the optimal timing of PTH (1-34) administration in a rabbit distraction osteogenesis model.
METHODS
The lower hind leg of a Japanese white rabbit was externally fixed, and tibial osteotomy was performed. One week after the osteotomy, bone lengthening was carried out at 0.375 mm/12 h for 2 weeks. After 5 weeks, the lower leg bone was collected. Bone mineral density (BMD), peripheral quantitative computed tomography (pQCT), micro-computed tomography (micro-CT), and mechanical tests were performed on the distracted callus. The rabbits were divided into three groups according to the timing of PTH (1-34) administration: 4 weeks during the distraction and consolidation phases (group D + C), 2 weeks of the distraction phase (group D), and the first 2 weeks of the consolidation phase (group C). A control group (group N) was administered saline for 4 weeks during the distraction and consolidation phases. Furthermore, to obtain histological findings, lower leg bones were collected from each rabbit at 2, 3, and 4 weeks after osteotomy, and tissue sections of the distracted callus were examined histologically.
RESULTS
The BMD was highest in group C and was significantly higher than group D. In pQCT, the total cross-sectional area was significantly higher in groups D + C, D, and C than group N, and the cortical bone area was highest in group C and was significantly higher than group D. In micro-CT, group C had the highest bone mass and number of trabeculae. Regarding the mechanical test, group C had the highest callus failure strength, and this value was significantly higher compared to group N. There was no significant difference between groups D and N. The histological findings revealed that the distracted callus mainly consisted of endochondral ossification in the distraction phase. In the consolidation phase, the chondrocytes were almost absent, and intramembranous ossification was the main type of ossification.
CONCLUSION
We found that the optimal timing of PTH (1-34) administration is during the consolidation phase, which is mainly characterized by intramembranous ossification.
Topics: Animals; Bone Density; Bony Callus; Osteogenesis; Osteogenesis, Distraction; Parathyroid Hormone; Rabbits; X-Ray Microtomography
PubMed: 35241115
DOI: 10.1186/s13018-022-03019-2 -
Journal of Orthopaedic Research :... Aug 2017Osteoclasts are abundant within the fracture callus and also localize at the chondro-osseous junction. However, osteoclast functions during fracture healing are not well...
Osteoclasts are abundant within the fracture callus and also localize at the chondro-osseous junction. However, osteoclast functions during fracture healing are not well defined. Inhibition of osteoclast formation or resorptive activity impairs callus remodeling but does not prevent callus formation. Interestingly, though anti-osteoclast therapies differentially affect resolution of callus cartilage into bone. Treatments that inhibit osteoclast formation or viability tend to impair callus cartilage resolution, while treatments that target inhibition of bone resorption generally do not affect callus cartilage resolution. Here, we tested whether depletion of osteoclasts by systemic treatment with clodronate liposomes would similarly impair callus cartilage resolution. ICR mice were treated by intraperitoneal injections of clodronate-laden liposomes or control liposomes and subjected to closed femur fracture. Femurs were resected at multiple times after fracture and analyzed by radiography, histology, and mechanical testing to determine effects on healing. Clodronate liposome treatment did not prevent callus formation. However, radiographic scoring indicated that clodronate liposome treatment impaired healing. Clodronate liposome treatment significantly reduced callus osteoclast populations and delayed resolution of callus cartilage. Consistent with continued presence of callus cartilage, torsional mechanical testing found significant decreases in callus material properties after 28 days of healing. The results support a role for osteoclasts in the resolution of callus cartilage into bone. Whether the cartilage resolution role for osteoclasts is limited to simply resorbing cartilage at the chondro-osseous junction or in promoting bone formation at the chondro-osseous junction through another mechanism, perhaps similar to the reversal process in bone remodeling, will require further experimentation. © 2016 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 35:1699-1706, 2017.
Topics: Animals; Bony Callus; Cartilage; Clodronic Acid; Female; Femoral Fractures; Fracture Healing; Liposomes; Mice, Inbred ICR; Osteoclasts
PubMed: 27653179
DOI: 10.1002/jor.23440 -
Bone Jun 2021Type 1 diabetes (T1DM) impairs bone formation and fracture healing in humans. Akita mice carry a mutation in one allele of the insulin-2 (Ins2) gene, which leads to...
Type 1 diabetes (T1DM) impairs bone formation and fracture healing in humans. Akita mice carry a mutation in one allele of the insulin-2 (Ins2) gene, which leads to pancreatic beta cell dysfunction and hyperglycemia by 5-6 weeks age. We hypothesized that T1DM in Akita mice is associated with decreased bone mass, weaker bones, and impaired fracture healing. Ins2 ± (Akita) and wildtype (WT) males were subjected to femur fracture at 18-weeks age and healing assessed 3-21 days post-fracture. Non-fractured left femurs were assessed for morphology (microCT) and strength (bending or torsion) at 19-21 weeks age. Fractured right femurs were assessed for callus mechanics (torsion), morphology and composition (microCT and histology) and gene expression (qPCR). Both Akita and WT mice gained weight from 3 to 18 weeks age, but Akita mice weighed less starting at 5 weeks (-5.2%, p < 0.05). At 18-20 weeks age Akita mice had reduced serum osteocalcin (-30%), cortical bone area (-16%), and thickness (-17%) compared to WT, as well as reduced cancellous BV/TV (-39%), trabecular thickness (-23%) and vBMD (-31%). Mechanical testing of non-fractured femurs showed decreased structural (stiffness, ultimate load) and material (ultimate stress) properties of Akita bones. At 14 and 21 days post fracture Akita mice had a significantly smaller callus than WT mice (~30%), with less cartilage and bone area. Assessment of torsional strength showed a weaker callus in Akita mice with lower stiffness (-42%), maximum torque (-44%) and work to fracture (-44%). In summary, cortical and cancellous bone mass were reduced in Akita mice, with lower bone mechanical properties. Fracture healing in Akita mice was impaired by T1DM, with a smaller, weaker fracture callus due to decreased cartilage and bone formation. In conclusion, the Akita mouse mimics some of the skeletal features of T1DM in humans, including osteopenia and impaired fracture healing, and may be useful to test interventions.
Topics: Animals; Bony Callus; Diabetes Mellitus, Type 1; Femoral Fractures; Femur; Fracture Healing; Mice
PubMed: 33662611
DOI: 10.1016/j.bone.2021.115906 -
Acta Orthopaedica Apr 2022In fracture healing, ischemia caused by vascular injuries, chronic vascular diseases, and metabolic comorbidities is one of the major risk factors for delayed union and...
BACKGROUND AND PURPOSE
In fracture healing, ischemia caused by vascular injuries, chronic vascular diseases, and metabolic comorbidities is one of the major risk factors for delayed union and non-union formation. To gain novel insights into the molecular and cellular pathology of ischemic fracture healing, appropriate animal models are needed. Murine models are of particular interest, as they allow to study the molecular aspects of fracture healing due to the availability of both a large number of murine antibodies and gene-targeted animals. Thus, we present the development of an ischemic fracture healing model in mice.
MATERIAL AND METHODS
After inducing a mild ischemia by double ligature of the deep femoral artery in CD-1 mice, the ipsilateral femur was fractured by a 3-point bending device and stabilized by screw osteosynthesis. In control animals, the femur was fractured and stabilized without the induction of ischemia. The femora were analyzed at 2 and 5 weeks after fracture healing by means of radiology, biomechanics, histology, and histomorphometry.
RESULTS
The surgically induced ischemia delayed and impaired the process of fracture healing. This was indicated by a lower Goldberg score, decreased bending stiffness, and reduced bone callus formation in the ischemic animals when compared with the controls.
INTERPRETATION
We introduce a novel ischemic femoral fracture healing model in mice, which is characterized by delayed bone healing. In future, the use of this model may allow both the elucidation of the molecular aspects of ischemic fracture healing and the study of novel treatment strategies.
Topics: Animals; Bony Callus; Femoral Fractures; Fracture Fixation, Internal; Fracture Healing; Humans; Ischemia; Mice
PubMed: 35478260
DOI: 10.2340/17453674.2022.2529 -
Basic & Clinical Pharmacology &... Jan 2008Traditional non-steroidal anti-inflammatory drugs (NSAID) and selective cyclooxygenase-2 (COX-2) inhibitors are widely used in the treatment of pain, including bone... (Review)
Review
Traditional non-steroidal anti-inflammatory drugs (NSAID) and selective cyclooxygenase-2 (COX-2) inhibitors are widely used in the treatment of pain, including bone fracture pain and orthopaedic post-operative pain. The gastrointestinal and cardiovascular adverse effects of NSAIDs are acknowledged, but their effects on bone are less widely known. Prostaglandins play an important role in the regulation of osteoblast and osteoclast functions, and inhibition of prostaglandin production retards bone formation. Therefore, NSAIDs could be expected to have significant consequences in divergent clinical situations where bone formation or remodelling is a contributing factor. The present survey reviews current experimental and clinical evidence related to two of those conditions (i.e. on ectopic bone formation and on bone fracture healing). NSAIDs are used clinically to prevent ectopic bone formation (also known as heterotopic ossification) (e.g. after total hip arthroplasty or trauma). The efficacy of NSAIDs in the avoidance of heterotopic ossification has been documented in controlled clinical trials, but the inherent risks (e.g. on healing processes and on loosening of prostheses) need further studies. At the same time, NSAIDs are widely used in the treatment of fracture pain, and their inhibitory effects on the ongoing bone healing process have raised concerns. Results of fracture healing studies in animals treated with NSAIDs or in mice lacking COX-2 gene show that inhibition or deficiency of COX-2 impairs the bone healing process. The limited clinical data also support the assumption that inhibition of COX-2 by non-selective or COX-2-selective NSAIDs delays fracture healing. However, the clinical significance of the effect in various patient groups needs to be carefully assessed and further investigations are needed to characterize the patients at the highest risk for NSAID-induced delayed fracture healing and its complications. In the meantime, use of NSAIDs in fracture patients should be cautious, keeping in mind the benefits of pain relief and inhibition of ectopic bone formation on one hand, and the risks of non-union and retarded union on the other hand.
Topics: Animals; Anti-Inflammatory Agents, Non-Steroidal; Bony Callus; Cyclooxygenase 2; Cyclooxygenase 2 Inhibitors; Disease Models, Animal; Fracture Healing; Gene Silencing; Humans; Mice; Mice, Knockout; Ossification, Heterotopic; Osteogenesis; Pain; Rats
PubMed: 17973900
DOI: 10.1111/j.1742-7843.2007.00149.x