RESUMO
PURPOSE: To evaluate the effects of food restriction on fracture healing in growing rats. METHODS: Sixty-eight male Wistar rats were assigned to two groups: (1) Control and (2) Dietary restriction. After weaning the dietary restricted animals were fed ad libitum for 42 days with 50% of the standard chow ingested by the control group. Subsequently, the animals underwent bone fracture at the diaphysis of the right femur, followed by surgical stabilization of bone fragments. On days 14 and 28 post-fracture, the rats were euthanized, and the fractured femurs were dissected, the callus was analyzed by dual-energy X-ray absorptiometry, micro-computed tomography, histomorphometry, mechanical tests, and gene expression. RESULTS: Dietary restriction decreased body mass gain and resulted in several phenotypic changes at the bone callus (a delay in cell proliferation and differentiation, lower rate of newly formed bone and collagen deposition, reductions in bone callus density and size, decrease in tridimensional callus volume, deterioration in microstructure, and reduction in bone callus strength), together with the downregulated expression of osteoblast-related genes. CONCLUSION: Dietary restriction had detrimental effects on osseous healing, with a healing delay and a lower quality of bone callus formation.
Assuntos
Densidade Óssea/fisiologia , Calo Ósseo/fisiologia , Fraturas do Fêmur/fisiopatologia , Consolidação da Fratura/fisiologia , Fraturas Fechadas/fisiopatologia , Desnutrição , Animais , Fraturas do Fêmur/diagnóstico por imagem , Fixação Intramedular de Fraturas , Fraturas Fechadas/diagnóstico por imagem , Masculino , Osteoporose/prevenção & controle , Ratos , Ratos WistarRESUMO
Abstract Purpose: To evaluate the effects of food restriction on fracture healing in growing rats. Methods: Sixty-eight male Wistar rats were assigned to two groups: (1) Control and (2) Dietary restriction. After weaning the dietary restricted animals were fed ad libitum for 42 days with 50% of the standard chow ingested by the control group. Subsequently, the animals underwent bone fracture at the diaphysis of the right femur, followed by surgical stabilization of bone fragments. On days 14 and 28 post-fracture, the rats were euthanized, and the fractured femurs were dissected, the callus was analyzed by dual-energy X-ray absorptiometry, micro-computed tomography, histomorphometry, mechanical tests, and gene expression. Results: Dietary restriction decreased body mass gain and resulted in several phenotypic changes at the bone callus (a delay in cell proliferation and differentiation, lower rate of newly formed bone and collagen deposition, reductions in bone callus density and size, decrease in tridimensional callus volume, deterioration in microstructure, and reduction in bone callus strength), together with the downregulated expression of osteoblast-related genes. Conclusion: Dietary restriction had detrimental effects on osseous healing, with a healing delay and a lower quality of bone callus formation.
Assuntos
Animais , Masculino , Ratos , Calo Ósseo/fisiologia , Densidade Óssea/fisiologia , Consolidação da Fratura/fisiologia , Desnutrição , Fraturas do Fêmur/fisiopatologia , Fraturas Fechadas/fisiopatologia , Osteoporose/prevenção & controle , Ratos Wistar , Fraturas do Fêmur/diagnóstico por imagem , Fixação Intramedular de Fraturas , Fraturas Fechadas/diagnóstico por imagemRESUMO
Las fracturas de los cóndilos femorales en el plano coronal (Hoffa), son lesiones que afectan directamente la biomecánica de la rodilla. Están expuestas a un factor intrínseco de inestabilidad causado por el compromiso de los ligamentos y tendones insertados al fragmento condilar fracturado y a un factor extrínseco de inestabilidad dependiente del estrés mecánico en varo/valgo durante la fase de apoyo de la marcha y movimientos de flexo-extensión. El tratamiento quirúrgico con tornillos canulados sólo permite la compresión interfragmentaria y cierto grado de estabilidad rotacional, sin embargo, ese tipo de fijación podría no ser suficiente para soportar o neutralizar las cargas. Distintos autores han publicado otros métodos de osteosíntesis con el uso de placas en el plano lateral o posterior más la colocación de tornillos en sentido postero-anterior, pero siguen siendo opciones controversiales debido al tipo de morbilidad inherente a cada constructo. El objetivo de este artículo es realizar una revisión de la literatura para analizar la validez de los principios quirúrgicos y biomecánicos en el tratamiento de fracturas tipo hoffa.
Coronal plane fractures of the femoral condyles are commonly known as Hoffa fractures. These are intraarticular fractures that directly affect the biomechanics of the knee and have intrinsic and extrinsic instability patterns. The tendons and ligaments that remain attached to the condylar fragment produce the intrinsic instability. The extrinsic instability is due to the varus/valgus stress applied during the stance phase in the gait cycle as well as the flexion-extension movements. Surgical treatment with cannulated screws only achieves interfragmentary compression and certain amount of rotational stability that is not enough to support or neutralize the loads. Some authors have published different methods of osteosynthesis with lateral or posterior plates in conjunction with screws implanted in the posterior-anterior direction, still these techniques remain controversial due to the morbidity inherent to each construct. The purpose of this article is to review the current concepts of Hoffa fractures including biomechanics and surgical principles with the intention of analyzing their treatment efficacy.
Assuntos
Humanos , Fraturas do Fêmur/cirurgia , Fixação Interna de Fraturas/métodos , Fenômenos Biomecânicos , Parafusos Ósseos , Fraturas do Fêmur/classificação , Fraturas do Fêmur/fisiopatologiaRESUMO
BACKGROUND: Nonsmokers may be affected by environmental tobacco smoke (secondhand smoke), but the effects of such exposure on fracture healing have not been well studied. QUESTIONS/PURPOSES: To explore the possible effects of passive inhalation of tobacco smoke on the healing of a diaphyseal fracture in femurs of rats. We hypothesized that secondhand exposure to tobacco smoke adversely affects fracture healing. METHODS: A mid-diaphyseal fracture was created in the femur of 41 female Wistar rats and fixed with an intramedullary metallic pin; 14 rats were excluded (nine for inadequate fractures and five for K wire extrusion). Tobacco exposure was provided by a smoking machine on a daily basis of four cigarettes a day. Each cigarette yielded 10 mg tar and 0.8 mg nicotine, and was puffed by alternating injections of fresh air for 30 seconds and smoke air for 15 seconds. The smoke exposure was previously adjusted to provide serum levels of cotinine similar to human secondhand tobacco exposure. Cotinine is a predominant catabolite of nicotine that is used as a biological biomarker for exposure to tobacco smoke. In one group (n = 11), the animals were intermittently exposed to tobacco smoke before sustaining the fracture but not afterward. In another group (n = 7), the exposure occurred before and after the fracture. The control group (n = 9) was sham-exposed before and after the fracture. We evaluated the specimens 28 days after bone fracture. The callus quality was measured by dual-energy x-ray absorptiometry (bone mineral density [BMD], bone mineral content [BMC], and callus area), µCT (callus volume and woven bone fraction), and mechanical bending (maximum force and stiffness). RESULTS: Tobacco exposure resulted in delayed bone callus formation, which is represented by decreased BMD (Control: 0.302 ± 0.008 g/cm2 vs Preexposed: 0.199 ± 0.008 g/cm2 and Pre- and Postexposed: 0.146 ± 0.009 g/cm2; mean difference = 0.103 g/cm2, 95% CI, 0.094-0.112 g/cm2and mean difference = 0.156 g/cm2, 95% CI, 0.147-0.167 g/cm2; p < 0.01), BMC (Control: 0.133 ± 0.005 g vs Preexposed: 0.085 ± 0.0034 g and Pre- and Postexposed: 0.048 ± 0.003 g; mean difference = 0.048 g, 95% CI, 0.045-0.052 g and mean difference = 0.085 g, 95% CI, 0.088-0.090 g; p < 0.01), callus volume (Control: 7.656 ± 1.963 mm3 vs Preexposed: 17.952 ± 1.600 mm3 and Pre- and Postexposed: 40.410 ± 3.340 mm3; mean difference = -10.30 mm3, 95% CI, -14.12 to 6.471 mm3 and mean difference, -32.75 mm3, 95% CI, -36.58 to 28.93 mm3; p < 0.01), woven bone fraction (Control: 42.076 ± 3.877% vs Preexposed: 16.655 ± 3.021% and Pre- and Postexposed: 8.015 ± 1.565%, mean difference = 0.103%, 95% CI, 0.094-0.112% and mean difference = 0.156%, 95% CI, 0.147-0.166%; p < 0.01), maximum force (Control: 427.122 ± 63.952 N.mm vs Preexposed: 149.230 ± 67.189 N.mm and Pre- and Postexposed: 123.130 ± 38.206 N.mm, mean difference = 277.9 N.mm, 95% CI, 201.1-354.7 N.mm and mean difference = 304 N.mm, 95% CI, 213.2-394.8 N.mm; p < 0.01) and stiffness (Control: 491.397 ± 96.444 N.mm/mm vs Preexposed: 73.157 ± 36.511 N.mm/mm and Pre- and Postexposed: 154.049 ± 134.939 N.mm/mm, mean difference = 418.2 N.mm/mm, 95% CI, 306.3-530.1 N.mm/mm and mean difference = 337.3 N.mm/mm, 95% CI, 188.8-485.9 N.mm/mm; p < 0. 01). CONCLUSIONS: Rats exposed to tobacco smoke showed delayed fracture healing and callus that was characterized by decreased maturity, density, and mechanical resistance, which was confirmed by all assessment methods of this study. Such effects were more evident when animals were exposed to tobacco smoke before and after the fracture. Future studies should be done in human passive smokers to confirm or refute our findings on fracture callus formation. CLINICAL RELEVANCE: The potential hazardous effects of secondhand smoke on fracture healing in rodents should stimulate future clinical studies in human passive smokers.
Assuntos
Fraturas do Fêmur/cirurgia , Fêmur/cirurgia , Consolidação da Fratura , Poluição por Fumaça de Tabaco/efeitos adversos , Absorciometria de Fóton , Animais , Fenômenos Biomecânicos , Densidade Óssea , Pinos Ortopédicos , Calo Ósseo/diagnóstico por imagem , Calo Ósseo/fisiopatologia , Modelos Animais de Doenças , Feminino , Fraturas do Fêmur/diagnóstico por imagem , Fraturas do Fêmur/fisiopatologia , Fêmur/diagnóstico por imagem , Fêmur/fisiopatologia , Fixação Intramedular de Fraturas/instrumentação , Exposição por Inalação/efeitos adversos , Ratos Wistar , Fatores de Tempo , Microtomografia por Raio-XRESUMO
BACKGROUND: Cortical impingement is a common complication after cephalomedullary nailing, but the evidence about its consequences is very limited. The aim of this study was to assess the clinical implications of cortical impingement on patients treated with cephalomedullary nails. METHODS: A cohort study was carried out at a Level I academic Institution with consecutive patients treated with cephalomedullary nails during 2010 and 2013. Demographic and nail variables were recorded as well as cortical impingement was determined on the radiographs. Clinical outcomes such as pain, femoral fractures, and delayed or nonunion of the fracture were detected during the follow-up. The follow-up was divided into short- (6-12 months), medium- (12.1-36 months), and long-term follow-up (≥36.1months). Descriptive statistics were used, and Chi-square or Fisher's exact tests measured the association between categorical variables. The Mann-Whitney U test was performed to evaluate differences between cortical impingement in terms of pain, and pain and the follow-up categories. RESULTS: A total of 119 patients were analyzed with a mean age of 74.8 years±17.1, and a mean follow-up of 23.5 months±12.1. Overall the pain was present in 61 (51.2%) cases, and it was observed in 28/59 (47.4%) and 33/60 (55%) of the patients with presence or absence of cortical impingement respectively. There was not a statistically significant association between cortical impingement and pain (p=0.20), neither differences were detected between pain and the follow-up groups (p=0.48). Out of 59 cases with cortical impingement, femoral fractures were observed in two patients (3.3%), and delayed union of the fractures was seen in two patients who did not present impingement. Since patients with delayed union received treatment as soon as it was diagnosed, no cases of nonunion of fractures were identified. CONCLUSIONS: Cortical impingement of the anterior cortex of the femur was not associated with the presence of pain, so that other causes should be assessed to explain the pain after 6 months of being treated with a cephalomedullary nail. Femoral fractures, and delayed union or nonunion of the fracture may occur theoretically in patients with cortical impingement.
Assuntos
Impacto Femoroacetabular/etiologia , Fraturas do Fêmur/cirurgia , Fixação Intramedular de Fraturas/métodos , Dor/etiologia , Complicações Pós-Operatórias/etiologia , Idoso , Pinos Ortopédicos , Feminino , Impacto Femoroacetabular/diagnóstico por imagem , Impacto Femoroacetabular/fisiopatologia , Fraturas do Fêmur/diagnóstico por imagem , Fraturas do Fêmur/fisiopatologia , Fixação Intramedular de Fraturas/efeitos adversos , Humanos , Masculino , Dor/fisiopatologia , Complicações Pós-Operatórias/diagnóstico por imagem , Complicações Pós-Operatórias/prevenção & controle , Radiografia , Estudos RetrospectivosRESUMO
PURPOSE: To investigate the effect of vibration therapy on the bone callus of fractured femurs and the bone quality of intact femurs in ovariectomized rats. METHODS: Fifty-six rats aged seven weeks were divided into four groups: control with femoral fracture (CON, n=14), ovariectomized with femoral fracture (OVX, n=14), control with femoral fracture plus vibration therapy (CON+VT, n=14), and ovariectomized with femoral fracture plus vibration therapy (OVX+VT, n=14). Three months after ovariectomy or sham surgery, a complete fracture was produced at the femoral mid-diaphysis and stabilized with a 1-mm-diameter intramedullary Kirschner wire. X-rays confirmed the fracture alignment and fixation. Three days later, the VT groups underwent vibration therapy (1 mm, 60 Hz for 20 minutes, three times per week for 14 or 28 days). The bone and callus quality were assessed by densitometry, three-dimensional microstructure, and mechanical test. RESULTS: Ovariectomized rats exhibited a substantial loss of bone mass and severe impairment in bone microarchitecture, both in the non-fractured femur and the bone callus. Whole-body vibration therapy exerted an important role in ameliorating the bone and fracture callus parameters in the osteoporotic bone. CONCLUSION: Vibration therapy improved bone quality and the quality of the fracture bone callus in ovariectomized rats.
Assuntos
Calo Ósseo/fisiologia , Fraturas do Fêmur/terapia , Consolidação da Fratura/fisiologia , Osteoporose/fisiopatologia , Ovariectomia/efeitos adversos , Vibração/uso terapêutico , Absorciometria de Fóton , Animais , Densidade Óssea/fisiologia , Feminino , Fraturas do Fêmur/etiologia , Fraturas do Fêmur/fisiopatologia , Fraturas por Osteoporose/etiologia , Fraturas por Osteoporose/fisiopatologia , Fraturas por Osteoporose/terapia , Distribuição Aleatória , Ratos Wistar , Reprodutibilidade dos Testes , Fatores de Tempo , Resultado do TratamentoRESUMO
PURPOSE: To investigate the effect of vibration therapy on the bone callus of fractured femurs and the bone quality of intact femurs in ovariectomized rats. METHODS: Fifty-six rats aged seven weeks were divided into four groups: control with femoral fracture (CON, n=14), ovariectomized with femoral fracture (OVX, n=14), control with femoral fracture plus vibration therapy (CON+VT, n=14), and ovariectomized with femoral fracture plus vibration therapy (OVX+VT, n=14). Three months after ovariectomy or sham surgery, a complete fracture was produced at the femoral mid-diaphysis and stabilized with a 1-mm-diameter intramedullary Kirschner wire. X-rays confirmed the fracture alignment and fixation. Three days later, the VT groups underwent vibration therapy (1 mm, 60 Hz for 20 minutes, three times per week for 14 or 28 days). The bone and callus quality were assessed by densitometry, three-dimensional microstructure, and mechanical test. RESULTS : Ovariectomized rats exhibited a substantial loss of bone mass and severe impairment in bone microarchitecture, both in the non-fractured femur and the bone callus. Whole-body vibration therapy exerted an important role in ameliorating the bone and fracture callus parameters in the osteoporotic bone. CONCLUSION: Vibration therapy improved bone quality and the quality of the fracture bone callus in ovariectomized rats.
Assuntos
Animais , Feminino , Calo Ósseo/fisiologia , Fraturas do Fêmur/terapia , Consolidação da Fratura/fisiologia , Osteoporose/fisiopatologia , Ovariectomia/efeitos adversos , Vibração/uso terapêutico , Absorciometria de Fóton , Densidade Óssea/fisiologia , Fraturas do Fêmur/etiologia , Fraturas do Fêmur/fisiopatologia , Fraturas por Osteoporose/etiologia , Fraturas por Osteoporose/fisiopatologia , Fraturas por Osteoporose/terapia , Distribuição Aleatória , Ratos Wistar , Reprodutibilidade dos Testes , Fatores de Tempo , Resultado do TratamentoRESUMO
OBJECTIVES: The biomechanical difficulty in fixation of a Vancouver B1 periprosthetic fracture is purchase of the proximal femoral segment in the presence of the hip stem. Several newer technologies provide the ability to place bicortical locking screws tangential to the hip stem with much longer lengths of screw purchase compared with unicortical screws. This biomechanical study compares the stability of 2 of these newer constructs to previous methods. METHODS: Thirty composite synthetic femurs were prepared with cemented hip stems. The distal femur segment was osteotomized, and plates were fixed proximally with either (1) cerclage cables, (2) locked unicortical screws, (3) a composite of locked screws and cables, or tangentially directed bicortical locking screws using either (4) a stainless steel locking compression plate system with a Locking Attachment Plate (Synthes) or (5) a titanium alloy Non-Contact Bridging system (Zimmer). Specimens were tested to failure in either axial or torsional quasistatic loading modes (n = 3) after 20 moderate load preconditioning cycles. Stiffness, maximum force, and failure mechanism were determined. RESULTS: Bicortical constructs resisted higher (by an average of at least 27%) maximum forces than the other 3 constructs in torsional loading (P < 0.05). Cables constructs exhibited lower maximum force than all other constructs, in both axial and torsional loading. The bicortical titanium construct was stiffer than the bicortical stainless steel construct in axial loading. CONCLUSIONS: Proximal fixation stability is likely improved with the use of bicortical locking screws as compared with traditional unicortical screws and cable techniques. In this study with a limited sample size, we found the addition of cerclage cables to unicortical screws may not offer much improvement in biomechanical stability of unstable B1 fractures.
Assuntos
Placas Ósseas , Parafusos Ósseos , Fraturas do Fêmur/fisiopatologia , Fraturas do Fêmur/cirurgia , Fixação Interna de Fraturas/instrumentação , Prótese de Quadril/efeitos adversos , Análise de Falha de Equipamento , Fraturas do Fêmur/etiologia , Humanos , Desenho de Prótese , Estresse Mecânico , Resistência à Tração , Resultado do TratamentoRESUMO
The effects of kinin B1 receptor (B1 R) deletion were examined on femur bone regeneration in streptozotocin (STZ)-type 1 diabetes. Diabetes induction in wild-type C57/BL6 (WTC57BL6) mice led to decrease in body weight and hyperglycemia, compared to the non-diabetic group of the same strain. The lack of B1 R did not affect STZ-elicited body weight loss, but partially prevented hyperglycemia. Diabetic mice had a clear delay in bone regeneration, and displayed large areas of loose connective tissue within the defects, with a reduced expression of the mineralization-related protein osteonectin, when compared to the non-diabetic WTC57/BL6. The non-diabetic and diabetic B1 R knockout (B1 RKO) mice had bone regeneration levels and osteonectin expression comparable to that seen in control WTC57/BL6 mice. WTC57/BL6 STZ-diabetic mice also showed a marked reduction of collagen contents, with increased immunolabeling for the apoptosis marker caspase-3, whereas diabetic B1 RKO had collagen levels and caspase-3 activity comparable to those observed in non-diabetic WTC57/BL6 or B1 RKO mice. No significant difference was detected in the number of tartrate-resistant acid phosphatase (TRAP)-stained cells, or in RANK/RANKL/OPG system immunolabeling throughout the experimental groups. Data bring novel evidence on the relevance of kinin B1 R under type 1 diabetes with regards to its role in bone regeneration.
Assuntos
Regeneração Óssea , Diabetes Mellitus Experimental/metabolismo , Diabetes Mellitus Tipo 1/metabolismo , Fraturas do Fêmur/metabolismo , Fêmur/metabolismo , Consolidação da Fratura , Receptor B1 da Bradicinina/deficiência , Animais , Apoptose , Caspase 3/metabolismo , Colágeno/metabolismo , Diabetes Mellitus Experimental/genética , Diabetes Mellitus Experimental/patologia , Diabetes Mellitus Experimental/fisiopatologia , Diabetes Mellitus Tipo 1/genética , Diabetes Mellitus Tipo 1/patologia , Diabetes Mellitus Tipo 1/fisiopatologia , Fraturas do Fêmur/genética , Fraturas do Fêmur/patologia , Fraturas do Fêmur/fisiopatologia , Fêmur/patologia , Fêmur/fisiopatologia , Masculino , Camundongos Endogâmicos C57BL , Camundongos Knockout , Osteonectina/metabolismo , Receptor B1 da Bradicinina/genética , Transdução de Sinais , Fatores de TempoRESUMO
UNLABELLED: The pathophysiology of atypical fractures is unknown. We compared characteristics of patients with atypical femoral fractures and hip fractures in typical locations of the femur. Patients with atypical fracture reported a longer duration of use of bisphosphonates, had higher body mass index, and higher total hip bone mineral density. Further studies are needed. INTRODUCTION: This study aims to describe the characteristics of patients with typical and atypical fractures of the femur assessed in a tertiary care osteoporosis center. METHODS: We abstracted clinical, laboratory, and radiographic data on subjects with a history of a low-impact fracture at the femur and/or hip (confirmed by review of radiograph and/or radiology report) from January 2008 to October 2011. Available radiographs were reviewed and fracture categorized as typical or atypical by a radiologist blinded to the original diagnosis. RESULTS: Radiology reports were available for 72 subjects: 40 hip fractures in typical locations (typical fracture), 16 atypical femoral fracture (atypical fracture), and 16 were excluded. While both those with typical and atypical fractures reported taking bisphosphonates at the time of fracture, duration of use was longer with atypical fractures (104.2±42.0 months) compared with typical (71.1±62.8 months) (p=0.04). Body mass index (BMI) was higher in patients with atypical fractures (26.2±3.2 kg/m2) than in those with typical (23.1±4.3 kg/m2) (p=0.006). Total bone mineral density (BMD) was higher in patients with atypical fracture (0.795±0.102) versus typical (0.686±0.130) (p=0.003) Previous history of cancer was reported by 7 of 16 patients with atypical and 7 of 40 patients with typical fracture (p=0.04). CONCLUSIONS: Compared to those with typical fractures, patients with atypical fracture report a longer duration of use of bisphosphonates, higher BMI, and higher total hip BMD. Future studies should examine if these differences contribute to the pathophysiology of atypical fractures.