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

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

Clinical and functional outcomes of tibial intercalary allograft reconstructions

Background The purpose of this study was to evaluate the survival, the complications and the functional outcome of intercalary tibial allografts reconstructions following tumor resections. Methods Intercalary tibia segmental allografts were implanted in 26 consecutive patients after segmental resections. Average follow-up was 6 years. Allograft survival was determined with the Kaplan-Meier method. Function was evaluated with the Musculoskeletal Tumor Society scoring system (MSTS). Results The rate of survival was 84% (CI 95%: 90%- 70%) at 5 years and 79% at 10 years (CI 95%: 95%-63%). Allografts were removed in 5 patients (3 due to infections and 2 due to local recurrences). Two patients showed diaphyseal nonunion and 3 had an incomplete fracture, but it was not necessary to remove the allografts. Average MSTS functional score was 29 points (range 27 to 30). Conclusions Despite the incidence of complications, this analysis showed an acceptable survival with excellent functional scores. The use of intercalary allograft clearly has a place in the reconstruction of a segmental defect created by the resection of a tumor in the diaphyseal and/or metaphyseal portion of the tibia

Transfer accuracy and precision scoring in planar bone cutting validated with ex vivo data

The use of interactive surgical scenarios for virtual preoperative planning of osteotomies has increased in the last 5 years.As it has been reported by several authors, this technology has been used in tumor resection osteotomies, knee osteotomies, and spine surgery with good results. A digital three-dimensional preoperative plan makes possible to quantitatively evaluate the transfer processfrom the virtual plan to the anatomy of the patient. We introduce an exact definition of accuracy and precision of this transfer process for planar bone cutting. We present a method to compute these properties from ex vivo data. We also propose a clinical score to assess the goodness of a cut. A computer simulation is used to characterize the definitions and the data generated by the measurement method. The definitions and method are evaluated in 17 ex vivo planar cuts of tumor resection osteotomies. The results show that the proposed method and definitions are highly correlated with a previous definition of accuracy based in ISO 1101. The score is also evaluated by showing that it distinguishes among different transfer techniques based in its distribution location and shape. The introduced definitions produce acceptable results in cases where the ISO-based definition produce counter intuitive results.Fil: Milano, Federico Edgardo. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Instituto Tecnológico de Buenos Aires; ArgentinaFil: Ritacco, Lucas. Hospital Italiano; ArgentinaFil: Farfalli, Germán Luis. Hospital Italiano; ArgentinaFil: Bahamonde, Luis Alberto. Universidad de Chile; ChileFil: Aponte Tinao, Luis Alberto. Hospital Italiano; ArgentinaFil: Risk, Marcelo. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Instituto Tecnológico de Buenos Aires; Argentin

Is navigation-guided en bloc resection advantageous compared with intralesional curettage for locally aggressive bone tumors?

Background: The treatment of locally aggressive bone tumors is a balance between achieving local tumor control and surgical morbidity.Wide resection decreases the likelihood of local recurrence, although wide resection may result in more complications than would happen after curettage.Navigationassisted surgery may allow more precise resection, perhaps making it possible to expand the procedures indications and decrease the likelihood of recurrence; however, to our knowledge, comparative studies have not been performed. Questions/purposes The purpose of this study was to compare curettage plus phenol as a local adjuvant with navigation-guided en bloc resection in terms of (1) local recurrence; (2) nononcologic complications; and (3) function as measured by revised Musculoskeletal Tumor Society (MSTS) scores. Methods Patients with a metaphyseal and/or epiphyseal locally aggressive primary bone tumor treated by curettage and adjuvant therapy or en bloc resection assisted by navigation between 2010 and 2014were considered for this retrospective study. Patients with a histologic diagnosis of a primary aggressive benign bone tumor or low-grade chondrosarcoma were included. During this time period, we treated 45 patients with curettage of whom 43 (95%)were available for followup at a minimum of 24 months (mean, 37 months; range, 24-61 months), andwe treated 26 patientswith navigation-guided en bloc resection, of whom all (100%) were available for study. During this period, we generally performed curettage with phenol when the lesionwas in contactwith subchondral bone. We treated tumors that were at least 5 mm from the subchondral bone, such that en bloc resection was considered possible with computer-Assisted block resection. There were no differences in terms of age, gender, tumor type, or tumor location between the groups. Outcomes, including allograft healing, nonunion, tumor recurrence, fracture, hardware failure, infection, and revised MSTS score, were recorded. Bone consolidation was defined as complete periosteal and endosteal bridging visible between the allograft-host junctions in at least two different radiographic views and the absence of pain and instability in the union site. All study data were obtained from our longitudinally maintained oncology database. Results In the curettage group, two patients developed a local recurrence, and no local recurrences were recorded in patients treated with en bloc resection. All patients who underwent navigation-guided resection achieved tumorfree margins. Intraoperative navigation was performed successfully in all patients and there were no failures in registration. Postoperative complications did not differ between the groups: in patients undergoing curettage, 7%(three of 43) and in patients undergoing navigation, 4% (one of 26) had a complication. There was no difference in functional scores: mean MSTS score for patients undergoing curettage was 28 points (range, 2730 points) and for patients undergoing navigation, 29 (range, 27-30 points; p = 0.10). Conclusions In this small comparative series, navigationassisted resection techniques allowed conservative en bloc resection of locally aggressive primary bone tumors with no local recurrence. Nevertheless, with the numbers available, we saw no difference between the groups in terms of local recurrence risk, complications, or function. Until or unless studies demonstrate an advantage to navigation-guided en bloc resection, we cannot recommend wide use of this novel technique because it adds surgical time and expense. Level of Evidence Level III, therapeutic study.Fil: Farfalli, Germán Luis. Hospital Italiano; ArgentinaFil: Albergo, Jose I.. Hospital Italiano; ArgentinaFil: Piuzzi, Nicolas Santiago. Hospital Italiano; ArgentinaFil: Ayerza, Miguel A.. Hospital Italiano; ArgentinaFil: Muscolo, D. Luis. Hospital Italiano; ArgentinaFil: Ritacco, Lucas. Hospital Italiano; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Aponte Tinao, Luis A.. Hospital Italiano; Argentin