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1.
Sci Rep ; 10(1): 16238, 2020 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-33004928

RESUMO

Over the last years, murine in vivo magnetic resonance imaging (MRI) contributed to a new understanding of tissue composition, regeneration and diseases. Due to artefacts generated by the currently used metal implants, MRI is limited in fracture healing research so far. In this study, we investigated a novel MRI-compatible, ceramic intramedullary fracture implant during bone regeneration in mice. Three-point-bending revealed a higher stiffness of the ceramic material compared to the metal implants. Electron microscopy displayed a rough surface of the ceramic implant that was comparable to standard metal devices and allowed cell attachment and growth of osteoblastic cells. MicroCT-imaging illustrated the development of the callus around the fracture site indicating a regular progressing healing process when using the novel implant. In MRI, different callus tissues and the implant could clearly be distinguished from each other without any artefacts. Monitoring fracture healing using MRI-compatible implants will improve our knowledge of callus tissue regeneration by 3D insights longitudinal in the same living organism, which might also help to reduce the consumption of animals for future fracture healing studies, significantly. Finally, this study may be translated into clinical application to improve our knowledge about human bone regeneration.


Assuntos
Consolidação da Fratura , Fraturas Ósseas/fisiopatologia , Animais , Parafusos Ósseos , Interface Osso-Implante , Cerâmica , Modelos Animais de Doenças , Fraturas do Fêmur/diagnóstico por imagem , Fraturas do Fêmur/metabolismo , Fraturas do Fêmur/fisiopatologia , Fixação Intramedular de Fraturas , Fraturas Ósseas/diagnóstico por imagem , Fraturas Ósseas/metabolismo , Imageamento Tridimensional , Imagem por Ressonância Magnética , Camundongos , Microscopia Eletrônica de Varredura , Zircônio
2.
PLoS One ; 15(5): e0231823, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32369494

RESUMO

Intramedullary nailing of diaphyseal femoral fractures is a commonly used treatment method in dogs because of its biological and biomechanical advantages compared to bone plating. To achieve adequate resistance of the intramedullary nail against torsional and axial compressive forces, additional application of transcortical screws is needed. As these interlocking screws represent a frequent cause of post-operative complications, a new expandable intramedullary nail (EXPN) was developed, which was designed to provide adequate fracture stabilisation without the need for transcortical fixation. The evaluation of the biomechanical properties of the new EXPN with regard to torsional, compressive and bending stability as well as direct comparison to the biomechanical properties of conventional Steinmann (STMN)- and interlocking (ILN) nails was carried out with different biomechanical test arrangements. No significant statistical differences regarding the torsional and bending resistance between the EXPN and ILN group were seen, which indicates that rotatory as well as bending stability of the innovative EXPN is similar to the conventional ILN. Nevertheless, the percentage deviation between the attempted and successfully reached physiological compressive forces was significantly higher (p = 0.045) in the EXPN group compared to the ILN group, which indicates that the compressive stability of the innovative EXPN might be weaker compared to the ILN. In summary, the new EXPN represents an interesting alternative to conventional intramedullary nails. However, in direct comparison to conventional interlocking nails, the EXPN has shown weaknesses in the neutralization of axial compressive forces, which indicates that at least biomechanically the interlocking nail seems advantageous. Further in-vitro and in-vivo investigations are required before clinical use can be recommended.


Assuntos
Fraturas do Fêmur/fisiopatologia , Fraturas do Fêmur/cirurgia , Fixação Intramedular de Fraturas/instrumentação , Animais , Fenômenos Biomecânicos , Parafusos Ósseos , Cães , Fixação Intramedular de Fraturas/veterinária
3.
Gait Posture ; 77: 207-213, 2020 03.
Artigo em Inglês | MEDLINE | ID: mdl-32058285

RESUMO

BACKGROUND: Besides adequate healing of bone and soft tissues, mobility represents a significant factor in functional outcome after lower extremity fractures. Although gait analysis is gaining clinical interest and importance in the rehabilitation of patients with fractures, it is rarely used in experimental fracture healing research. The aim of this study is to establish an accurate gait analysis method for fracture healing research in small animal models and to evaluate the influence of a lower extremity fracture on gait pattern and muscle atrophy in rats. RESEARCH QUESTION: How does an intramedullary stabilized femur fracture influence the gait pattern and muscle atrophy during fracture healing in rats? METHODS: An isolated femur fracture with intramedullary stabilization was induced in 26 Sprague Dawley rats. Different gait parameters (e.g. intensity, print area, stand duration, duty cycle, and swing speed) were evaluated with the CatWalk gait analysis system during the fracture healing process. Furthermore, muscle weight analysis was performed at different time points. RESULTS: The gait analyses with the CatWalk system showed a high correlation with the osteogenesis of fracture healing in this model. Muscle atrophy increased during the early fracture healing stages and then decreased in the later stages. SIGNIFICANCE: We are the first to show that the CatWalk system is a useful tool to perform gait analyses after lower extremity fractures in a murine model. These results could form a basis for future gait analyses research in fracture healing studies to improve knowledge about bone regeneration and rehabilitation after lower extremity fractures.


Assuntos
Fraturas do Fêmur/fisiopatologia , Fixação Intramedular de Fraturas , Consolidação da Fratura/fisiologia , Análise da Marcha/métodos , Atrofia Muscular/etiologia , Complicações Pós-Operatórias/fisiopatologia , Animais , Feminino , Fraturas do Fêmur/cirurgia , Marcha/fisiologia , Extremidade Inferior/fisiopatologia , Atrofia Muscular/fisiopatologia , Distribuição Aleatória , Ratos , Ratos Sprague-Dawley , Resultado do Tratamento
4.
Int Orthop ; 44(2): 391-398, 2020 02.
Artigo em Inglês | MEDLINE | ID: mdl-31796993

RESUMO

INTRODUCTION: The Masquelet procedure proved its efficiency in treating infected nonunion filling bony gaps up to 25 cm. Yet the use of local antibiotics is still questionable in the daily practice with lack of evidence regarding its usefulness in controlling infection. An experimental rat model is put in place to study the antibacterial properties of the induced membrane produced during the first stage of Masquelet. METHOD: Twenty-three-month-old wistar male rats are inoculated with a 0.5 mL solution of 10^8 CFU/mL MRSA over a critical fracture done on the right femur. Six weeks later, remaining 11 rats exhibiting signs of a chronic infection with a sinus tract and oozing pus along with radiological nonunion are used for a first stage Masquelet procedure. They are randomly divided into two groups with six rats having no local antibiotic in the cement mixture and five rats having 3 g of vancomycin mixed with gentamycin loaded cement. Six weeks later (twelve weeks from baseline), all eleven rats are euthanized and blood samples for C-reactive protein are withdrawn. The induced membrane is identified and resected along with bone fragments and sent for cultures and pathology. RESULTS: MRSA is isolated in the cultures of all six rats in the first group where no local antibiotic was added. Altered polymorphonuclears with abscess and pus are noted on four of six pathology samples. However in the second group where local antibiotics were added, three out of five rats exhibited eradication of MRSA (p = 0.034) and all samples did not exhibit clear infection signs on pathology. A pyo-epithelioid over a foreign body reaction is seen predominantly in this group demonstrating a regenerative process. DISCUSSION: The induced membrane does not have antimicrobial properties capable of overcoming an infected nonunion on its own. When local antibiotics were added during the first stage of the Masquelet procedure, new bone formation occurred indicating the need to control an infection in order for bone union to occur. CONCLUSION: Local antibiotics use in adjunction to extensive debridement is advisable during the first stage of a Masquelet procedure for an infected nonunion.


Assuntos
Antibacterianos/administração & dosagem , Cimentos para Ossos/uso terapêutico , Fraturas do Fêmur/terapia , Fraturas não Consolidadas/terapia , Staphylococcus aureus Resistente à Meticilina , Infecções Estafilocócicas/terapia , Administração Tópica , Animais , Transplante Ósseo , Doença Crônica , Desbridamento , Modelos Animais de Doenças , Fraturas do Fêmur/microbiologia , Fraturas do Fêmur/fisiopatologia , Fêmur/microbiologia , Fêmur/fisiopatologia , Fêmur/cirurgia , Consolidação da Fratura/fisiologia , Fraturas não Consolidadas/microbiologia , Fraturas não Consolidadas/fisiopatologia , Gentamicinas/administração & dosagem , Masculino , Membranas/microbiologia , Membranas/fisiopatologia , Polimetil Metacrilato/administração & dosagem , Ratos , Ratos Wistar , Infecções Estafilocócicas/microbiologia , Infecções Estafilocócicas/fisiopatologia , Vancomicina/administração & dosagem
5.
Injury ; 51(2): 436-442, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31703962

RESUMO

OBJECTIVE: To evaluate functional and radiological outcomes in distal femoral fracture patients (distal femoral shaft fractures or metaphyseal fractures) receiving indirect reduction and internal fixation with the minimally invasive percutaneous plate osteosynthesis (MIPPO) assisted by 3D printing navigation templates. METHODS: This retrospective study included all adult (≥18 years) patients who underwent MIPPO for distal femoral fracture (AO32/33) at PLA 960 Hospital, Jinan, China between January 1, 2013 and December 31, 2016. 3D printed navigation templates were used to assist surgery. Functional assessment was performed using the Knee Society Score (KSS) and the Functional Knee Society Score (FKSS). Postoperative deformity was assessed with 3D-CT reconstruction using contralateral (non-fracture) side as the reference. RESULTS: A total of 54 patients underwent MIPPO for distal femoral fracture during the review period (34 and 20 for conventional and template-guided MIPPO, respectively). At 10-14 months, the KSS score was 160.6 ±â€¯18.1 and 167.5 ±â€¯17.2 in the conventional and template-guided MIPPO groups, respectively (p = 0.18). The FKSS was 77.6 ±â€¯9.4 in the conventional MIPPO group vs. 81.0 ±â€¯8.5 in the template-guided MIPPO group (p = 0.15). Femoral length difference was smaller in template-guided MIPPO group (3.31 ±â€¯1.53 vs. 9.50 ±â€¯4.49 mm in the control; p < 0.01). Template-guided MIPPO group also had smaller anatomic lateral distal femoral angle (aLDFA) difference (1.57° ± 0.72° vs. 3.89° ± 1.72° in the control; p < 0.01), anatomic posterior distal femoral angle (aPDFA) difference (1.95° ± 0.78° vs. 5.04° ± 1.78°; p < 0.01), and anteversion angle difference (2.52° ± 1.00° vs. 8.23° ± 4.07°; p < 0.01). The rate of length discrepancy (>20 mm), coronal angulation deformity (aLDFA difference >5°), sagittal angulation deformity (aPDFA difference >10°), and rotational malalignment (anteversion angle >10°) was 5.9%, 20.5%, 2.9%, and 32.4% in the control group. No patients in the template-guided MIPPO group had deformity of any type. CONCLUSIONS: MIPPO assisted by 3D printing navigation templates could practically improve surgical accuracy and eliminate postoperative rotational deformity in patients with distal femoral fractures.


Assuntos
Fraturas do Fêmur/cirurgia , Fixação Interna de Fraturas/métodos , Procedimentos Cirúrgicos Minimamente Invasivos/métodos , Impressão Tridimensional , Adulto , Mau Alinhamento Ósseo/diagnóstico por imagem , Mau Alinhamento Ósseo/etiologia , Placas Ósseas , Parafusos Ósseos , China , Feminino , Fraturas do Fêmur/diagnóstico por imagem , Fraturas do Fêmur/fisiopatologia , Fixação Interna de Fraturas/efeitos adversos , Consolidação da Fratura , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Tomografia Computadorizada por Raios X , Resultado do Tratamento
6.
Rev. osteoporos. metab. miner. (Internet) ; 11(4): 105-110, nov.-dic. 2019. tab, graf
Artigo em Espanhol | IBECS | ID: ibc-187302

RESUMO

OBJETIVO: Las propiedades de los materiales que constituyen el tejido óseo son determinantes en su resistencia mecánica pero los factores que influyen sobre ella son parcialmente desconocidos en la actualidad. MATERIAL Y MÉTODOS: En esta investigación medimos la dureza ósea mediante ensayos de ultra-microindentación con punta tipo Berkovich y una carga de 150 mN en fémures de ratas Sprague-Dawley sometidas a una fractura transversal o a una osteotomía de sustracción, y comparamos los resultados en diferentes localizaciones óseas y grupos experimentales. El estudio comprende los siguientes cuatro grupos experimentales, cada uno de ellos constituido por cuatro ratas: a) fractura diafisiana estándar; b) fractura más osteotomía de 2 mm; c) osteotomía tratada con hormona paratiroidea humana, PTH (1-84); d) osteotomía tratada con ranelato de estroncio. RESULTADOS: Encontramos que la dureza del material era consistentemente mayor en el hueso cortical que en el hueso trabecular. También fue consistentemente más alto en las epífisis femorales superiores que en las epífisis inferiores (diferencia de 1,2 desviaciones estándar). La cirugía redujo la dureza en el fémur operado (diferencia de 0,3 desviaciones estándar, p = 5,5 x 10-2). El tratamiento con PTH indujo un aumento leve pero consistente de la dureza en todos los sitios (p = 1,8 × 10-5) mientras que el efecto del ranelato de estroncio fue inconsistente. CONCLUSIONES: Estos datos muestran que la microdureza tisular está influida por una variedad de factores, incluyendo la anatomía, el tipo de tejido óseo, la lesión esquelética y la terapia farmacológica. Por lo tanto, los estudios futuros sobre la calidad del tejido deberían diseñarse cuidadosamente teniendo en cuenta estos factores


OBJETIVE: The properties of the materials that constitute the bone tissue are decisive in its mechanical strength but the factors that influence it are partially unknown at present. Material and method: In this paper, we gauge bone hardness by means of ultra-microindentation tests with a Berkovich tip and a 150 mN load in femurs of Sprague-Dawley rats subjected to a transverse fracture or a subtraction osteotomy. The results are compared in different bone locations and experimental groups. The study includes the following four experimental groups, each consisting of four rats: a) standard diaphyseal fracture; b) fracture plus osteotomy of 2 mm; c) osteotomy treated with human parathyroid hormone, PTH (1-84); d) osteotomy treated with strontium ranelate. RESULTS: We found the hardness of the material was consistently greater in cortical bone than in trabecular bone. It was also consistently higher in the upper femoral epiphyses than in the lower epiphyses (difference of 1.2 standard deviations). The surgery reduced hardness in the operated femur (difference of 0.3 standard deviations, p = 5.5 x 10-2). PTH treatment induced a slight but consistent increase in hardness at all sites (p = 1.8 x 10-5) while the effect of strontium ranelate was inconsistent. CONCLUSIONS: These data show that tissue micro-hardness is influenced by a variety of factors, including anatomy, type of bone tissue, skeletal injury and drug therapy. Therefore, future studies on tissue quality should be carefully designed with these factors in mind


Assuntos
Animais , Ratos , Resistência à Tração , Resistência à Flexão , Fraturas do Fêmur/fisiopatologia , Hormônio Paratireóideo/uso terapêutico , Fraturas do Fêmur/tratamento farmacológico , Fatores de Risco , Modelos Animais de Doenças , Ratos Sprague-Dawley , Osteotomia
7.
Eklem Hastalik Cerrahisi ; 30(3): 267-74, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31650924

RESUMO

OBJECTIVES: This study aims to investigate whether the motor cortex (MC) or the somatosensory cortex (SC) is more active during the course of bone healing after traumatic brain injury (TBI). MATERIALS AND METHODS: Thirty-three male Wistar albino rats (age, 8 to 10 months; weighing, 250 to 300 g) were randomized into three groups as the control group, MC damage group and SC damage group. Two rats from each brain damage group were sacrificed to verify the locations of the cortical injuries. Callus formation, callus/diaphysis ratios, and serum alkaline phosphatase (ALP) levels were measured at one, three and six weeks. RESULTS: The increases in callus masses in the control, MC, and SC groups were statistically significantly different between one and three weeks (p<0.05). Although this increase in the MC and SC groups was significant compared to the control group at the end of one week, no statistically significant difference was found between the MC and SC groups (p>0.05). There was a statistically significant difference in callus/diaphysis ratio between control, MC and SC groups in favor of MC group only at one week (p<0.05). The increase in serum ALP levels at three weeks was statistically significantly different in the MC and SC groups compared to the control group and significantly higher in the MC group compared to the SC group (p<0.05). CONCLUSION: There is a possible relationship between enhanced fracture healing after TBI and damage in the MC. Motor cortex plays a more active role on fracture healing in TBI.


Assuntos
Lesões Encefálicas Traumáticas/fisiopatologia , Fraturas do Fêmur/fisiopatologia , Animais , Calo Ósseo/fisiopatologia , Lesões Encefálicas Traumáticas/complicações , Diáfises/fisiopatologia , Fraturas do Fêmur/complicações , Fraturas do Fêmur/diagnóstico por imagem , Consolidação da Fratura , Masculino , Modelos Animais , Traumatismo Múltiplo/fisiopatologia , Osteogênese , Distribuição Aleatória , Ratos , Ratos Wistar
8.
J Bone Joint Surg Am ; 101(19): 1761-1767, 2019 Oct 02.
Artigo em Inglês | MEDLINE | ID: mdl-31577681

RESUMO

BACKGROUND: Isolated femoral and tibial fractures are 2 of the top 5 causes of pediatric orthopaedic hospital admission, yet their simultaneous ipsilateral presentation, the "floating knee" injury, remains rare. Historically, treatment consisted of traction and cast immobilization, which resulted in prolonged periods of immobilization, lengthy hospitalizations, and high rates of malunion. As such, previous authors have recommended fixation of at least 1 bone in the setting of a floating knee injury. This strategy, however, has never been evaluated and the outcomes of modern treatment are unknown. METHODS: We performed a multicenter retrospective review of the records of pediatric patients with ipsilateral femoral and tibial fractures that had been treated at 11 tertiary care level-I pediatric trauma centers from 2004 to 2014. Outcomes and treatment strategies were assessed with standardized means. RESULTS: Over the study period, 130 floating knees in 129 patients met the inclusion criteria for evaluation. The average patient age was 10.2 years, and 63.1% were male. One-third of the patients presented with open injuries, and 83.8% of injuries were related to vehicular trauma. Simple diaphyseal fractures (OTA/AO 32-A and B femoral fractures and OTA/AO 42-A and B tibial fractures) were most common. Intramedullary fixation (rigid or flexible) was the most common treatment strategy for femoral fractures (69.2%). Tibial fractures were treated most commonly with casting (27.7%), followed by flexible intramedullary nailing (24.6%). The mean duration of hospitalization was 9.7 days. Outcomes were excellent in 66.6% of cases and good in 26.4% of cases. CONCLUSIONS: Previous literature on pediatric floating knee injuries consisted of small case series that were published prior to the introduction of flexible intramedullary nailing to North America. This multicenter study of a large cohort demonstrates a change in practice pattern from a largely nonoperative treatment strategy to operative fixation of at least the femoral fracture. In the present study, this approach led to good or excellent results in 93.1% of cases and was associated with a short duration of hospitalization. LEVEL OF EVIDENCE: Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.


Assuntos
Moldes Cirúrgicos , Fraturas do Fêmur/cirurgia , Fixação Intramedular de Fraturas/métodos , Traumatismos do Joelho/cirurgia , Fraturas da Tíbia/cirurgia , Acidentes de Trânsito , Criança , Feminino , Fraturas do Fêmur/fisiopatologia , Consolidação da Fratura/fisiologia , Humanos , Traumatismos do Joelho/fisiopatologia , Masculino , Complicações Pós-Operatórias/etiologia , Estudos Retrospectivos , Fraturas da Tíbia/fisiopatologia , Resultado do Tratamento
9.
BMC Musculoskelet Disord ; 20(1): 413, 2019 Sep 05.
Artigo em Inglês | MEDLINE | ID: mdl-31488121

RESUMO

BACKGROUND: This study aimed to determine the influence of ageing on the incidence and site of femoral fractures in trauma patients, by taking the sex, body weight, and trauma mechanisms into account. METHODS: This retrospective study reviewed data from adult trauma patients aged ≥20 years who were admitted into a Level I trauma center, between January 1, 2009 and December 31, 2016. According to the femoral fracture locations, 3859 adult patients with 4011 fracture sites were grouped into five subgroups: proximal type A (n = 1359), proximal type B (n = 1487), proximal type C (n = 59), femoral shaft (n = 640), and distal femur (n = 466) groups. A multivariate logistic regression analysis was applied to identify independent effects of the univariate predictive variables on the occurrence of fracture at a specific site. A two-dimensional plot was presented visually with age and the propensity score accounts for the risk of a fracture at a specific femoral site. RESULTS: This analysis revealed that older age was an independent variable that could positively predict the occurrence of proximal type A (OR [95%CI]: 1.03 [1.03-1.04], p < 0.001) and B fractures (1.02 [1.01-1.02], p < 0.001), and negatively predict the occurrence of proximal type C (0.96 [0.94-0.98], p < 0.001), shaft (0.95 [0.95-0.96], p < 0.001), and distal fractures (0.98 [0.98-0.99], p < 0.001). DISCUSSION: Using the propensity scores which account for the risk of a fracture in a specific femoral site, this study revealed that the older patients were at a higher risk of developing proximal type A and type B fractures, while a lower risk of developing fractures in the shaft and distal femur. This incidence of fracture site can largely be explained by age-related factors, including a decrease in bone strength and falling being the most common mechanism of trauma in older patients. CONCLUSIONS: This study revealed a difference in the involvement of age in the incidence of femoral fracture sites in the trauma patients.


Assuntos
Acidentes por Quedas/estatística & dados numéricos , Envelhecimento/fisiologia , Fraturas do Fêmur/epidemiologia , Cabeça do Fêmur/lesões , Colo do Fêmur/lesões , Adulto , Fatores Etários , Idoso , Idoso de 80 Anos ou mais , Estudos Transversais , Feminino , Fraturas do Fêmur/etiologia , Fraturas do Fêmur/fisiopatologia , Cabeça do Fêmur/fisiopatologia , Colo do Fêmur/fisiopatologia , Humanos , Incidência , Masculino , Pessoa de Meia-Idade , Pontuação de Propensão , Estudos Retrospectivos , Fatores de Risco , Centros de Traumatologia/estatística & dados numéricos
10.
Lakartidningen ; 1162019 Sep 16.
Artigo em Sueco | MEDLINE | ID: mdl-31529420

RESUMO

Atypical fracture of the femur is a well-documented adverse reaction to antiresorptive treatment with bisphosphonates. Although there has been significant gain of knowledge during the past decade, the pathogenesis of this type of fracture is still poorly understood. We present an update on the evidence in regard to epidemiology, pathophysiology, and management of atypical fractures.


Assuntos
Conservadores da Densidade Óssea/efeitos adversos , Difosfonatos/efeitos adversos , Fraturas do Fêmur/induzido quimicamente , Idoso , Difosfonatos/uso terapêutico , Medicina Baseada em Evidências , Feminino , Fraturas do Fêmur/diagnóstico por imagem , Fraturas do Fêmur/fisiopatologia , Fraturas do Fêmur/prevenção & controle , Humanos , Masculino , Radiografia , Fatores de Risco
11.
Arch Orthop Trauma Surg ; 139(12): 1743-1753, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31399754

RESUMO

INTRODUCTION: Delayed union and nonunion development remain a major clinical problematic complication during fracture healing, with partially unclear pathophysiology. Incidences range from 5 to 40% in high-risk patients, such as patients with periosteal damage. The periosteum is essential in adequate fracture healing, especially during soft callus formation. In this study, we hypothesize that inducing periosteal damage in a murine bone healing model will result in a novel delayed union model. MATERIALS AND METHODS: A mid-shaft femoral non-critically sized osteotomy was created in skeletally mature C57BL/6 mice and stabilized with a bridging plate. In half of the mice, a thin band of periosteum adjacent to the osteotomy was cauterized. Over 42 days of healing, radiographic, biomechanical, micro-computed tomography and histological analysis was performed to assess the degree of fracture healing. RESULTS: Analysis showed complete secondary fracture healing in the control group without periosteal injury. Whereas the periosteal injury group demonstrated less than half as much maximum callus volume (p < 0.05) and bridging, recovery of stiffness and temporal expression of callus growth and remodelling was delayed by 7-15 days. CONCLUSION: This paper introduces a novel mouse model of delayed union without a critically sized defect and with standardized biomechanical conditions, which enables further investigation into the molecular biological, biomechanical, and biochemical processes involved in (delayed) fracture healing and nonunion development. This model provides a continuum between normal fracture healing and the development of nonunions.


Assuntos
Fraturas do Fêmur/cirurgia , Consolidação da Fratura/fisiologia , Periósteo/lesões , Animais , Calo Ósseo/fisiopatologia , Cauterização , Modelos Animais de Doenças , Fraturas do Fêmur/patologia , Fraturas do Fêmur/fisiopatologia , Camundongos , Camundongos Endogâmicos C57BL , Microtomografia por Raio-X
12.
Anticancer Res ; 39(8): 4191-4197, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31366505

RESUMO

BACKGROUND/AIM: Biopsy hole for bone tumour biopsy may cause pathological fractures. This study aimed to identify the optimal shape of bone tumour biopsy hole using the rabbit femoral head compression test to avoid pathological fracture. MATERIALS AND METHODS: A compression test with no defect was performed to identify bone fracture location. Three shapes of biopsy holes (same size) were made artificially. Sixty rabbit femurs were randomly divided (n=15 each) into control (no defect), Shape 1 (round), Shape 2 (square), and Shape 3 (rectangular) groups. RESULTS: Twelve out of fifteen femurs were fractured on the femoral shaft; the femoral shaft was targeted for the compression test. Compressive maximum load and fracture energy were significantly higher for Shape 3 than for the other Shapes. CONCLUSION: A rectangular biopsy hole helps minimise reduction in bone strength. The defect width may be related to fragility of the affected bone.


Assuntos
Biópsia/efeitos adversos , Neoplasias Ósseas/fisiopatologia , Fraturas do Fêmur/fisiopatologia , Fêmur/fisiopatologia , Animais , Fenômenos Biomecânicos , Neoplasias Ósseas/complicações , Neoplasias Ósseas/diagnóstico , Modelos Animais de Doenças , Fraturas do Fêmur/diagnóstico , Humanos , Coelhos
13.
Acta Orthop ; 90(5): 445-449, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31282247

RESUMO

Background and purpose - To date, there is not a single clinical or mechanical study directly comparing a cemented and a cementless version of the same stem. We investigated the load-to-failure force of a cementless and a cemented version of a double tapered stem. Material and methods - 10 femurs from 5 human cadaveric specimens, mean age 74 years (68-79) were extracted. Bone mineral density (BMD) was measured using peripheral quantitative computed tomography. None of the specimens had a compromised quality (average T value 0.0, -1.0 to 1.4). Each specimen from a pair randomly received a cemented or a cementless version of the same stem. A material testing machine was used for lateral load-to-failure test of up to a maximal load of 5.0 kN. Results - Average load-to-failure of the cemented stem was 2.8 kN (2.3-3.2) and 2.2 kN (1.8-2.8) for the cementless stem (p = 0.002). The cemented version of the stem sustained a higher load than its cementless counterpart in all cases. Failure force was not statistically significantly correlated to BMD (p = 0.07). Interpretation - Implanting a cemented version of the stem increases the load-to-failure force by 25%.


Assuntos
Artroplastia de Quadril/métodos , Cimentação , Fraturas do Fêmur/etiologia , Prótese de Quadril , Fraturas Periprotéticas/etiologia , Falha de Prótese/etiologia , Idoso , Artroplastia de Quadril/efeitos adversos , Cimentos para Ossos , Densidade Óssea/fisiologia , Cadáver , Feminino , Fraturas do Fêmur/diagnóstico por imagem , Fraturas do Fêmur/fisiopatologia , Fêmur/fisiopatologia , Humanos , Masculino , Teste de Materiais/métodos , Fraturas Periprotéticas/diagnóstico por imagem , Fraturas Periprotéticas/fisiopatologia , Desenho de Prótese , Estresse Mecânico , Tomografia Computadorizada por Raios X , Suporte de Carga/fisiologia
14.
Acta Orthop Belg ; 85(2): 218-223, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-31315013

RESUMO

Instability increases after fracture site resorption. This study aimed to compare the fracture site stabilities of different femoral nails after fracture site resorption. Thirty composite femurs were divided into three groups of 10 interlocking nails. Using axial compression-distraction machines and a custom-made torsion device, the fracture site rotational and axial stabilities after 1 mm fracture site resorption were determined. Between 6 Nm external and 6 Nm internal rotation torques, the means of the maximum fracture site rotation arc of motion were 5.94 mm for compression nails, 5.9 mm for interlocking nails and 3.5 mm for CAROT nails. Between 2300 N compression and 150 N distraction forces, the means of the fracture site axial motion were 3.15 mm for interlocking nails, 1.26 mm for compression nails and 1.26 mm for CAROT nails. CAROT nails are superior to compression and interlocking nails in fracture site rotational and axial stabilities after 1 mm fracture site resorption.


Assuntos
Pinos Ortopédicos , Reabsorção Óssea/fisiopatologia , Fraturas do Fêmur/fisiopatologia , Fêmur/fisiopatologia , Consolidação da Fratura/fisiologia , Fenômenos Biomecânicos/fisiologia , Fraturas do Fêmur/cirurgia , Fêmur/cirurgia , Fixação Intramedular de Fraturas , Humanos
15.
Chin J Traumatol ; 22(4): 246-248, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31230844

RESUMO

Epiphyseal injuries of distal femur are rare with an incidence of 1%-6% among all physeal injuries. Prompt diagnosis and appropriate surgical treatment is crucial to achieve satisfactory functional outcomes. A conjoint bicondylar coronal split (Hoffa) fracture with complete transaction of ipsilateral patellar tendon has been reported in a 12 year old child. The injury was managed by open reduction and internal fixation and bone to tendon repair. This case emphasizes the need of accurate intraepiphyseal fixation for the management of these fractures in skeletally immature patients.


Assuntos
Fraturas do Fêmur/cirurgia , Fêmur/lesões , Fêmur/cirurgia , Fixação Interna de Fraturas/métodos , Traumatismos do Joelho/cirurgia , Articulação do Joelho/cirurgia , Joelho/cirurgia , Ligamento Patelar/lesões , Ligamento Patelar/cirurgia , Criança , Fraturas do Fêmur/fisiopatologia , Humanos , Masculino , Redução Aberta/métodos , Amplitude de Movimento Articular , Resultado do Tratamento
16.
Injury ; 50(7): 1329-1332, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31178148

RESUMO

Proximal femur fractures account for increased healthcare costs whenever patients are unable to return to their previous state of residence. Studies suggest that patients benefit from early weight-bearing, yet compliance to weight-bearing regimes is poorly investigated. Aim of the study was thus to show the clinical feasibility of a new measurement tool able to determine continuous weight-bearing behavior after intramedullary nail osteosynthesis of intertrochanteric femur fractures, assess the influence of weight-bearing on clinical outcome and determine rehabilitation demand based on early postoperative gait performance. In an observational study, gait data of 22 patients with intertrochanteric femur fractures were evaluated. During the inpatient stay patients were continuously monitored with a gait analysis insole. Primary outcome was the amount of weight-bearing reached. Short-term functional outcome, as well as return to the previous state of living were evaluated in relation to weight-bearing and activity during the inpatient stay. With the presented technique continuous gait data of all patients during postoperative mobilization could be obtained. Only 13 patients reached full weight-bearing. The technique was feasible to determine correlations between weight-bearing and outcome, as well as between gait activity and outcome. Significant gait differences between patients able to return to their previous state of living and those who could not were seen. Dynamic insole measurements are feasible to continuously determine the postoperative gait performance. Their postoperative use showed, that the continuous compliance to permissive weight-bearing after intertrochanteric fractures is low. The presented measurement technique has the potential to identify patients at risk for reduced outcome and impending loss of previous residence status. Further studies will have to investigate the effects of technology assisted "patient at risk" identification and adapted therapy on clinical outcome.


Assuntos
Fraturas do Fêmur/fisiopatologia , Fixação Intramedular de Fraturas , Marcha/fisiologia , Avaliação Geriátrica , Suporte de Carga , Idoso , Estudos de Viabilidade , Feminino , Fraturas do Fêmur/reabilitação , Fraturas do Fêmur/cirurgia , Análise da Marcha , Humanos , Masculino , Período Pós-Operatório , Amplitude de Movimento Articular , Características de Residência , Resultado do Tratamento , Suporte de Carga/fisiologia
17.
J Am Acad Orthop Surg ; 27(12): e585-e588, 2019 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-31170099

RESUMO

Carbon fiber reinforced implants have emerged as an alternative to traditional stainless steel and titanium implants because of the improved visibility on advanced imaging and excellent biomechanical strength. This can be advantageous in patients with concern about fracture healing, tumor recurrence, or additional imaging requirements. However, limited long-term data are available to present complications from the use of these implants. We present the case of a failure of a carbon fiber reinforced intramedullary femoral nail used in a closed distal femur fracture.


Assuntos
Pinos Ortopédicos/efeitos adversos , Fibra de Carbono/efeitos adversos , Fraturas do Fêmur/cirurgia , Fêmur/cirurgia , Fixação Intramedular de Fraturas/efeitos adversos , Fixação Intramedular de Fraturas/métodos , Falha de Prótese , Idoso , Aloenxertos , Fenômenos Biomecânicos , Transplante Ósseo , Remoção de Dispositivo , Fraturas do Fêmur/fisiopatologia , Consolidação da Fratura , Humanos , Masculino , Resultado do Tratamento
18.
Med Eng Phys ; 69: 58-71, 2019 07.
Artigo em Inglês | MEDLINE | ID: mdl-31171487

RESUMO

Patient-specific finite element (FE) models are constructed in a way that boundary conditions, material and geometric FE models respect the unique characteristics of the patients, offering a more reliable and realistic structural analysis. This study presents an image-based construction process of a patient-specific FE model applied to a femur with a subtrochanteric fracture. Available procedures are systematized and described in greater depth aiming to investigate the difficulties and possibilities in the development of this type of model. A set of image processing techniques (segmentation, labeling, morphological operations and registering) were performed for volumetric reconstruction and registration of femoral fragments by assessing computed tomography (CT) images in a semi supervised procedure. The CT numbers feed the FE mesh with a non-homogeneous distribution of elasticity modulus. A FE analysis and a bone remodeling simulation with pharmacological stimulus based on the dynamics of bone cells populations were also developed for this study. The FE analysis revealed that the principal stresses provided results close to those obtained using a generic homogeneous model, with a difference of about 2%. In contrast, principal strains presented significant differences, up to 12 and 21 % for the maximum tensile and compressive principal strain values, respectively. The critical values of tensile principal strains were located in the superior part of the femoral neck, a typical region of femoral fractures, and maximum principal strains 2 and 3 (compressive) were concentrated in the diaphyseal region, rather close to the actual fracture. These results corroborate previous works indicating that the strain-based failure criterion is more successful in capturing the bone fracture sites when compared to stress-based criteria. The attempt to reconstruct the material state before the failure as implemented here constitutes an innovative way to analyze and reconstruct bone fractures. In the bone remodeling simulation, the inclusion of an antiresorptive agent stimulus produced cortical bone thickening, an increase in the BMD biomarker, and an overall increase in the bone ash density, just as expected in an osteoporosis therapeutic treatment. In conclusion, this study highlights the advantages of subject-specific FE models compared to generic ones in the study of abnormal clinical cases, evaluation of fracture risk, and optimization of surgical intervention. On the other hand, the high level of human intervention and expertise involved in patient-specific FE analyses hinders the incorporation of this technique into clinical practice.


Assuntos
Remodelação Óssea , Fraturas do Fêmur/diagnóstico por imagem , Fraturas do Fêmur/fisiopatologia , Análise de Elementos Finitos , Processamento de Imagem Assistida por Computador , Modelagem Computacional Específica para o Paciente , Tomografia Computadorizada por Raios X , Fraturas do Fêmur/patologia , Humanos , Razão Sinal-Ruído
19.
Biomed Res Int ; 2019: 5958631, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31183369

RESUMO

Aim: This study aimed at comparing the mechanical properties of conventional and locking dual plates in adjacent and orthogonal orientations for the surgical fixation of transverse femoral shaft fractures. It also assessed the failure mechanics after dual adjacent and orthogonal locking plate removal. Methods: Thirty-two composite femurs were transversally osteotomized and randomly assigned for fixation with either dual locking or compression plates in an adjacent or orthogonal configuration. Sixteen specimens were preloaded axially to 20 N and single-leg stance loads were simulated. The remaining sixteen constructs were subjected to torsional loads of 10 Nm at a rate of 10 Nm/s in external and internal rotation of the femoral head in relation to the knee. Overall combined rotational stiffness was calculated. Eight different specimens with no osteotomy underwent the same experiments after dual locked plate removal and were tested to failure in combined eccentric axial and torsional modes. Data were statistically processed using a two-tailed t-test and one-way analysis of variance for the comparison of means between two or more groups, respectively. Results: Orthogonal constructs were statistically stiffer in axial loading compared to their adjacent counterparts in both conventional and locking configurations (p<0.001). Dual locking plates provided higher torsional stiffness than conventional ones within each plate orientation (p<0.01). Neither axial/torsional strength nor failure loads differed between constructs that had adjacent or orthogonal dual locking plates instrumented and then removed (p>0.05). Conclusions: In both orthogonal and adjacent orientations, double locking plates provide higher stability than their dual conventional counterparts. Orthogonal dual plate configuration is more stable and biomechanically superior to dual adjacent plating for constructs fixed with either standard compression or locking plates.


Assuntos
Placas Ósseas , Fraturas do Fêmur/terapia , Fixação Interna de Fraturas/métodos , Suporte de Carga/fisiologia , Fenômenos Biomecânicos , Desenho de Equipamento , Fraturas do Fêmur/fisiopatologia , Humanos
20.
Orthop Surg ; 11(2): 311-317, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30989797

RESUMO

OBJECTIVE: To compare the biomechanical stabilities of less invasive stabilization system (LISS) plate and retrograde intramedullary nail (IMN) for the comminuted femoral supracondylar fracture fractures in the elderly. METHODS: Sixteen pairs of embalmed cadaver femurs were obtained to simulate a comminuted supracondylar femur fracture (AO/OTA33-A3) gap model. All left-side specimens were fixed with LISS plate, and retrograde IMN were applied to the right-side specimens. All specimens were tested in torsional, axial and cyclic load mode on an Instron testing machine. RESULTS: The mean torsional stiffness for LISS plate group was 34.1% greater than retrograde IMN group (2.90 vs. 1.91 Nm/degree, P = 0.002), but the mean axial stiffness was greater for the retrograde IMN (199.16 vs. 303.93 N/mm, P < 0.001). The total deformation of LISS plate caused by cyclic axial loading was greater than retrograde IMN (4.17 vs. 3.57 mm, P = 0.014). Significantly less mean irreversible deformation was detected in LISS plate than in retrograde IMN (1.64 vs. 1.69 mm, P = 0.699). Failure loads of the constructs were significantly different between the two groups (LISS plate: 2941±128 N; retrograde IMN: 4022±176 N, P < 0.001). CONCLUSION: For comminuted femoral supracondylar fractures in the elderly, the tested instruments can both maintain sufficient biomechanical stabilities, but retrograde IMN is superior to LISS plate in deformation of fracture site.


Assuntos
Placas Ósseas , Fraturas do Fêmur/cirurgia , Fixação Interna de Fraturas/métodos , Fixação Intramedular de Fraturas/métodos , Absorciometria de Fóton , Idoso , Idoso de 80 Anos ou mais , Fenômenos Biomecânicos , Pinos Ortopédicos , Feminino , Fraturas do Fêmur/fisiopatologia , Fêmur/fisiopatologia , Fêmur/cirurgia , Fixação Interna de Fraturas/instrumentação , Fixação Intramedular de Fraturas/instrumentação , Humanos , Masculino , Torção Mecânica , Suporte de Carga
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