Three-dimensional virtual bone bank system workflow for structural bone allograft selection: a technical report

Structural bone allograft has been used in bone defect reconstruction during the last fifty years with acceptable results. However, allograft selection methods were based on 2-dimensional templates using X-rays.Thanks to preoperative planning platforms, three dimensional (3D) CT-derived bone models were used to define size and shape comparison between host and donor. The purpose of this study was to describe the workflow of this virtual technique in order to explain how to choose the best allograft using a virtualbone bank system. We measured all bones in a 3D virtual environment determining the best match. The use of a virtual bone banksystem has allowed optimizing the allograft selection in a bone bank, providing more information to the surgeons before surgery.In conclusion, 3D preoperative planning in a virtual environment for allograft selection is an important and helpful tool in order to achieve a good match between host and donor.Fil: Ritacco, Lucas. Hospital Italiano; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Farfalli, Germán Luis. Hospital Italiano; ArgentinaFil: Milano, Federico Edgardo. Hospital Italiano; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Ayerza, Miguel Ángel. Hospital Italiano; ArgentinaFil: Muscolo, Domingo L.. Hospital Italiano; Argentina. Hospital Italiano; ArgentinaFil: Aponte Tinao, Luis. Hospital Italiano; Argentin

Allograft Selection for Transepiphyseal Tumor Resection Around the Knee Using Three-Dimensional Surface Registration

Transepiphyseal tumor resection is a common surgical procedure in patients with malignant bone tumors. The aim of this study is to develop and validate a computer-assisted method for selecting the most appropriate allograft from a cadaver bone bank. Fifty tibiae and femora were 3D reconstructed from computed tomography (CT) images. A transepiphyseal resection was applied to all of them in a virtual environment. A tool was developed and evaluated that compares each metaphyseal piece against all other bones in the data bank. This is done through a template matching process, where the template is extracted from the contralateral healthy bone of the same patient. The method was validated using surface distance metrics and statistical tests comparing it against manual methods. The developed algorithm was able to accurately detect the bone segment that best matches the patient's anatomy. The automatic method showed improvement over the manual counterpart. The proposed method also substantially reduced computation time when compared to state-of-the-art methods as well as the manual selection. Our findings suggest that the accuracy, robustness, and speed of the developed method are suitable for clinical trials and that it can be readily applied for preoperative allograft selectio

Three-Dimensional Printing and Navigation in Bone Tumor Resection

One of the most promising advances raised by the current computer age is performing research “in silico,” which means computer-assisted. The objective of this chapter is firstly to evaluate if a 3D in-silico model of an oncological patient could be used to make a 3D-printed prototype in real scale, discriminating precisely healthy tissues, tumoral tissues and oncological margins. Secondly, the objective is to evaluate if this prototype could be representative enough to allow testing osteotomies under navigated guidance based on images. A tumor resection for a patient with diagnosed metaphyseal osteosarcoma of the proximal tibia was transferred into a rapid prototyping model, fabricated using 3D printing and representing different structures in different colors. The planned osteotomy was executed using Stryker Navigator to guide the cutting saw and the prototype was opened to verify the precision of the performed osteotomy. Both osteotomy planes showed successful correspondence with the safe margin, with a maximum error of 1 mm. The application of these techniques in general orthopedics would help to reduce the incidence of unforeseen intraoperative failures, contributing to obtain predictable surgical procedures. This would implement a new way of performing development, research and training in orthopedics and traumatology by in-silico technology

Postoperative assessment in computer assisted selection of femur osteoarticular allograft

El objetivo de nuestro trabajo fue comparar dos grupos de pacientes tratados con trasplantes osteoarticulares del fémur distal en términos de: 1) el volumen del fémur distal del receptor y del trasplante, 2) la superficie articular de contacto del fémur distal del receptor y del trasplante, 3) el ángulo del valgo anatómico femoral del fémur distal del receptor y del trasplante. Material y métodos: se realizó una búsqueda retrospectiva entre 2002 y 2012 analizando a pacientes tratados con un trasplante osteoarticular de fémur distal. Se incluyó un total de 32 pacientes. Estos fueron divididos en dos grupos de acuerdo con el método de selección del trasplante: Grupo 1, conformado por 16 pacientes con trasplantes seleccionados mediante 2D (tomografía) y Grupo 2, 16 pacientes con trasplantes seleccionados a través de un método 3D. La evaluación fue realizada por un observador independiente y ciego para los dos grupos. Resultados: las diferencias en las pruebas de estimación de volumen y superficie articulares entre el donante y el receptor no fueron estadísticamente significativas (p>0,05). Sin embargo, la diferencia entre los ángulos de valgo del fémur receptor y el fémur donante, seleccionados por el método 2D fue significativa (p0,05). Conclusión: el método de relación de un donante con un banco de huesos virtual luego de resección y reconstrucción con un aloinjerto osteoarticular permite obtener una mejor alineación particular que aquellos seleccionados solo con un método bidimensional.The aim of our study was to compare two groups of patients treated with distal femur osteoarticular allograft in terms of: 1) the volume of the distal femur of the allograft and patient, 2) the articular surface contact, 3) the anatomical femoral valgus angle. Material and methods: a retrospective review was performed between 2002 and 2012 and all patients with an osteo-articular allograft of the distal femur were analysed. A total of 32 patients were included in the study. Patients were divided into two groups according to the selection method of the allograft: Group 1, 16 patients with allograft selected by 2D (CT) and Group 2, 16 patients selected through a 3D method. The evaluation was done by an independent and blind observer. Results: the differences in terms of volume estimation and joint surface contact between the donor allograft and patient distal femur were not statistically significant (p>0.05). However, the difference between the valgus angle showed significant differences between donor and patient femurs selected by the 2D method (p0.05). Conclusion: the 3D method for allograft selection of the distal femur showed better results in limb alignment compared to 2D selection method.Fil: Milano, Federico Edgardo. Instituto Tecnológico de Buenos Aires; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Albergo, José Ignacio. Hospital Italiano; ArgentinaFil: Farfalli, Germán Luis. Hospital Italiano; ArgentinaFil: Aponte Tinao, Luis Alberto. Hospital Italiano; ArgentinaFil: Ayerza, Miguel Angel. Hospital Italiano; ArgentinaFil: Muscolo, Domingo L.. Hospital Italiano; ArgentinaFil: Ritacco, Lucas Eduardo. Hospital Italiano; Argentin

Ewing sarcoma of the bone. Multidisciplinary approach and oncological results in 88 patients

El sarcoma de Ewing óseo es un tumor poco frecuente, agresivo, que afecta principalmente a niñosy adultos jóvenes. Existe ausencia de registros en nuestro país respecto de la prevalencia de estaenfermedad, los esquemas de tratamiento utilizados y sus resultados. El objetivo fue analizar, en un grupode pacientes con sarcoma de Ewing óseo tratados con quimioterapia y cirugía de conservación de miembro,las tasas de supervivencia global, de recurrencia local y los factores de riesgo oncológicos. Se incluyó a 88pacientes. La edad media de la serie fue de 14.5 años y el seguimiento promedio de 8.8 años. La tasa de supervivencia global fue de 79.5% a los 2 años, de 69% a 5 años y de 64% a 10 años. Los factores pronósticosnegativos asociados a menor supervivencia fueron: mala respuesta a la quimioterapia, edad ≥ de 16 años,localización central, y recurrencia local. En el análisis multivariable únicamente la respuesta a la quimioterapiatuvo significancia estadística. La tasa libre de recurrencia local a 2 y 5 años fue del 87%. La mala respuesta ala quimioterapia fue el único factor significativo para la recurrencia local. Consideramos que la cirugía de conservación de miembro asociada a quimioterapia pre y postoperatoria debe ser el tratamiento para el sarcomade Ewing óseo, alcanzando de esta manera una supervivencia global a 5 años del 69%. En nuestra serie, larespuesta a la quimioterapia ha sido el factor pronóstico más relevante para supervivencia y recurrencia local.Ewing sarcoma of the bone is a rare, highly aggressive tumor that typically affects children and young adults. In Argentina, the lack of Ewing’s sarcoma registries reflects in the absence of information regarding prevalence, treatment protocols and patient´s outcome. The purpose of this study was to analyze, in a group of patients diagnosed with Ewing sarcoma of the bone, treated with chemotherapy and limb-conserving surgery, their overall survival rate, local recurrence rate, and oncological risk factors. A retrospective research was conducted between 1990 and 2017. Eighty-eight patients with Ewing sarcoma of the bone matched the inclusion criteria. Median age was 14.5 years and median follow-up was 8.8 years. Overall survival rate was 79.5%, 69% and 64% at 2, 5 and 10 years respectively. Negative prognostic factors, associated with less survival rate after univariate analysis, were: bad response to chemotherapy (tumoral necrosis 0-89%), age > 16 years-old, central tumor localization and local recurrence. Gender and tumor size were not significant prognostic factors. After multivariate analysis, response to chemotherapy remained statistical significant. Local recurrence-free survival rate at 2 and 5 years was 87%. Tumor response to chemotherapy (0-89%) was the only significant factor for local recurrence. We consider that limb-salvage surgery, with neoadjuvant and adjuvant chemotherapy, are the mainstays of treatment for Ewing’s sarcoma, with an overall survival rate, at 5 years, of 69%. In this population, response to chemotherapy is the most relevant prognostic factor, being associated with both local recurrence and overall survival.Fil: Sanchez Saba, Javier E.. Instituto Universidad Escuela de Medicina del Hospital Italiano; ArgentinaFil: Abrego, Mariano O.. Instituto Universidad Escuela de Medicina del Hospital Italiano; ArgentinaFil: Albergo, José I.. Instituto Universidad Escuela de Medicina del Hospital Italiano; ArgentinaFil: Farfalli, Germán Luis. Instituto Universidad Escuela de Medicina del Hospital Italiano; ArgentinaFil: Aponte Tinao, Luis A.. Instituto Universidad Escuela de Medicina del Hospital Italiano; ArgentinaFil: Ayerza, Miguel A.. Instituto Universidad Escuela de Medicina del Hospital Italiano; ArgentinaFil: Cayol, Federico. Instituto Universidad Escuela de Medicina del Hospital Italiano; ArgentinaFil: Streitenberger, Patricia. Instituto Universidad Escuela de Medicina del Hospital Italiano; ArgentinaFil: Risk, Marcelo. Consejo Nacional de Investigaciones Cientificas y Tecnicas. Oficina de Coordinacion Administrativa Houssay. Instituto de Medicina Traslacional E Ingenieria Biomedica. - Hospital Italiano. Instituto de Medicina Traslacional E Ingenieria Biomedica. - Instituto Universitario Hospital Italiano de Buenos Aires. Instituto de Medicina Traslacional E Ingenieria Biomedica.; ArgentinaFil: Roitman, Pablo Daniel. Instituto Universidad Escuela de Medicina del Hospital Italiano; Argentin