Análise biomecânica de um aparelho de fixador externo em um fêmur instrumentado com sensores ópticos

A consolidação de uma fratura tratada cirurgicamente, é influenciada, entre outros fatores, pelas condições mecânicas impostas pelo material de osteossíntese utilizado. Este trabalho tem por objetivo descrever com um estudo preliminar sobre a consolidação de fraturas simples na diáfise do fêmur através do estudo mecânico de fixadores externos. Sensores ópticos baseados em redes de Bragg foram utilizados neste trabalho, para instrumentação de um fêmur sintético com fixador externo circular. Os resultados mostram que a instrumentação com os sensores ópticos foi sensível ao valor da carga transferida (sensibilidade variou entre 0,012 µɛ/N e 0,224 µɛ/N) o que permite análise da rigidez do fixador externo e posterior análise biomecânica da consolidação da fratura. Este estudo mostra que é possível a instrumentação de um fixador externo com sensores ópticos durante o tratamento de uma fratura do fêmur para análise do processo de consolidação óssea

Evaluation of skin temperature, reactive C protein, and hemosedimentation speed variation in uncomplicated primary knee total arthroplasty

OBJECTIVE: To study the variation of skin temperature values (deltaT) on operative site, of reactive C protein (RCP) and of hemosedimentation speed (HSS) in patients submitted to primary knee total arthroplasty (KTA), in an attempt to establish a correlation among its curves over time. MATERIALS AND METHODS: This prospective clinical study evaluated 29 patients followed up during 12 weeks, with measurements of skin temperature in both knees and RCP and HSS serum dosages. RESULTS: After comparing the variables tested (deltaT, RCP and HSS), no statistical correlation was observed for both the Pearson s test (parametric test) and the Spearman s test (non-parametric test) among variables. Skin temperature variation follows a different pattern from that observed both for RCP and for HSS, with no correlation among curves. A standard curve was established for the three variables, and a statistically significant reduction was seen in RCP and HSS values from pre- to post-operative period. CONCLUSION: No correlation was observed between skin temperature and HSS and RCP levels in patients submitted to uncomplicated primary KTA.OBJETIVO: Estudar a variação dos valores da temperatura cutânea (deltaT) do sítio operatório, da proteína C reativa (PCR) e da velocidade de hemossedimentação (VHS) em pacientes submetidos a artroplastia total do joelho (ATJ) primária, tentando estabelecer correlação entre suas curvas ao longo do tempo. MATERIAL E MÉTODOS: Esse estudo clínico prospectivo, avaliou 29 pacientes acompanhados por 12 semanas, sendo aferida a temperatura cutânea em ambos os joelhos e realizada dosagem sérica da PCR e VHS. RESULTADOS: Após a comparação entre as variáveis testadas (deltaT, PCR e VHS), observou-se tanto para o teste de Pearson (avaliação paramétrica), quanto para o de Spearman (avaliação não-paramétrica) que não houve correlação estatística entre elas. A variação da temperatura cutânea segue um padrão diferente do observado tanto para a PCR quanto para a VHS, não existindo correlação entre as curvas. Foi estabelecida a curva padrão das três variáveis, verificando-se redução estatisticamente significativa nos valores da PCR e da VHS entre o pré e o pós-operatório. CONCLUSÃO: Não foi observada correlação entre a temperatura cutânea e os níveis de VHS e PCR em pacientes submetidos a ATJ primária, isenta de complicações.UNIFESPUFMG Faculdade de Medicina Departamento do Aparelho locomotorUFMG Serviço de Ortopedia do HCUNIFESPSciEL

Thermal Variations in Osteoporosis After Aclasta® Administration: Case Study

Osteoporosis is a metabolic disease characterized by an imbalance between bone formation and resorption, that results in an increasing risk of fracture. The aim of the present study was to investigate changes in the thermal pattern of a 50-year-old female patient after intravenous infusion of zaledronic acid Aclasta® in the treatment of osteoporosis. Thermal images were acquired in orthostatic position of the dorsal region between the lumbar and sacral portions using a FLIR® T530 camera with a thermal sensitivity (NETD) < 30 mK and the sensor array size of 320 x 240 pixels, with an accuracy of ±2% of the reading. The image analysis was performed using the Flir Tools® 6.4 software in order to identify the minimum, average and maximum temperature values in the region of interest; and MATLAB® 2017a software to extract histograms from images. The results present a good agreement between the temperature measurements and the painful symptomatology of the sacroiliac region of the vertebral column affected by the disease. Thermography might be a promising method for monitoring bone healing process

Thermal Variations in Osteoporosis After Aclasta® Administration: Case Study

Osteoporosis is a metabolic disease characterized by an imbalance between bone formation and resorption, that results in an increasing risk of fracture. The aim of the present study was to investigate changes in the thermal pattern of a 50-year-old female patient after intravenous infusion of zaledronic acid Aclasta® in the treatment of osteoporosis. Thermal images were acquired in orthostatic position of the dorsal region between the lumbar and sacral portions using a FLIR® T530 camera with a thermal sensitivity (NETD) < 30 mK and the sensor array size of 320 x 240 pixels, with an accuracy of ±2% of the reading. The image analysis was performed using the Flir Tools® 6.4 software in order to identify the minimum, average and maximum temperature values in the region of interest; and MATLAB® 2017a software to extract histograms from images. The results present a good agreement between the temperature measurements and the painful symptomatology of the sacroiliac region of the vertebral column affected by the disease. Thermography might be a promising method for monitoring bone healing process

Application of 3D Printing Technology in the Treatment of Hoffa’s Fracture Nonunion

Abstract Objective To evaluate a proposed three-dimensional (3D) printing process of a biomodel developed with the aid of fused deposition modeling (FDM) technology based on computed tomography (CT) scans of an individual with nonunion of a coronal femoral condyle fracture (Hoffa’s fracture). Materials and Methods Thus, we used CT scans, which enable the evaluation of the 3D volumetric reconstruction of the anatomical model, as well as of the architecture and bone geometry of sites with complex anatomy, such as the joints. In addition, it enables the development of the virtual surgical planning (VSP) in a computer-aided design (CAD) software. This technology makes it possible to print full-scale anatomical models that can be used in surgical simulations for training and in the choice of the best placement of the implant according to the VSP. In the radiographic evaluation of the osteosynthesis of the Hoffa’s fracture nonunion, we assessed the position of the implant in the 3D-printed anatomical model and in the patient’s knee. Results The 3D-printed anatomical model showed geometric and morphological characteristics similar to those of the actual bone. The position of the implants in relation to the nonunion line and anatomical landmarks showed great accuracy in the comparison of the patient’s knee with the 3D-printed anatomical model. Conclusion The use of the virtual anatomical model and the 3D-printed anatomical model with the additive manufacturing (AM) technology proved to be effective and useful in planning and performing the surgical treatment of Hoffa’s fracture nonunion. Thus, it showed great accuracy in the reproducibility of the virtual surgical planning and the 3D-printed anatomical model