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

Clinical Study Allograft Reconstruction for the Treatment of Musculoskeletal Tumors of the Upper Extremity

In comparison with the lower extremity, there is relatively paucity literature reporting survival and clinical results of allograft reconstructions after excision of a bone tumor of the upper extremity. We analyze the survival of allograft reconstructions in the upper extremity and analyze the final functional score according to anatomical site and type of reconstruction. A consecutive series of 70 allograft reconstruction in the upper limb with a mean followup of 5 years was analyzed, 38 osteoarticular allografts, 24 allograft-prosthetic composites, and 8 intercalary allografts. Kaplan-Meier survival analysis of the allografts was performed, with implant revision for any cause and amputation used as the end points. The function evaluation was performed using MSTS functional score. Sixteen patients (23%) had revision surgery for 5 factures, 2 infections, 5 allograft resorptions, and 2 local recurrences. Allograft survival at five years was 79% and 69% at ten years. In the group of patients treated with an osteoarticular allograft the articular surface survival was 90% at five years and 54% at ten years. The limb salvage rate was 98% at five and 10 years. We conclude that articular deterioration and fracture were the most frequent mode of failure in proximal humeral osteoarticular reconstructions and allograft resorption in elbow reconstructions. The best functional score was observed in the intercalary humeral allograft

Allograft Reconstruction for the Treatment of Musculoskeletal Tumors of the Upper Extremity

In comparison with the lower extremity, there is relatively paucity literature reporting survival and clinical results of allograft reconstructions after excision of a bone tumor of the upper extremity. We analyze the survival of allograft reconstructions in the upper extremity and analyze the final functional score according to anatomical site and type of reconstruction. A consecutive series of 70 allograft reconstruction in the upper limb with a mean followup of 5 years was analyzed, 38 osteoarticular allografts, 24 allograft-prosthetic composites, and 8 intercalary allografts. Kaplan-Meier survival analysis of the allografts was performed, with implant revision for any cause and amputation used as the end points. The function evaluation was performed using MSTS functional score. Sixteen patients (23%) had revision surgery for 5 factures, 2 infections, 5 allograft resorptions, and 2 local recurrences. Allograft survival at five years was 79% and 69% at ten years. In the group of patients treated with an osteoarticular allograft the articular surface survival was 90% at five years and 54% at ten years. The limb salvage rate was 98% at five and 10 years. We conclude that articular deterioration and fracture were the most frequent mode of failure in proximal humeral osteoarticular reconstructions and allograft resorption in elbow reconstructions. The best functional score was observed in the intercalary humeral allograft

Resultados clínicos y funcionales en reconstrucciones con aloinjertos intercalares de tibia

BackgroundThe purpose of this study was to evaluate the survival, the complications and the functional outcome of intercalary tibial allografts reconstructions following tumor resections.MethodsIntercalary 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).ConclusionsDespite 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.IntroducciónEl objetivo de éste trabajo fue evaluar la sobrevida, complicaciones y resultados funcionales en un grupo de pacientes tratados con un aloinjerto intercalar de tibia luego de la resección tumoral primaria.Material y métodosSe evaluaron  26 tratados con aloinjertos intercalares de tibia luego de un defecto óseo secundario a una resección tumoral primaria. El seguimiento promedio fue de 6 años. La supervivencia del aloinjerto fue determinada por el método de Kaplan –Meier.  La evaluación funcional fue realizada con la escala de la Musculoskeletal Tumor Society (MSTS). También fueron registradas las complicaciones.ResultadosLa sobrevida global de las reconstrucciones fue del 84% (CI 95%: 90%-70%) a los 5 años y 79%  a los 10 años (CI 95%: 95%-63%). El aloinjerto debió ser removido en 5  pacientes, en 3 casos debido a infección y en 2 casos por recurrencia local. Dos pacientes presentaron falta de consolidación diafisaria y 3 pacientes presentaron una fractura incompleta. En ninguno  de estos pacientes el aloinjerto debió ser removido.  El resultado funcional promedio fue  de 27 puntos con un rango de 27 a 30 puntos.  Esto corresponde a un miembro funcional con capacidad funcional aceptable y sin dolor limitante.ConclusionesA pesar de la incidencia de complicaciones, éste análisis demostró una sobrevida aceptable con excelentes resultados funcionales. La reconstrucción con aloinjerto intercalar de tibia permite restaurar la anatomía de la pierna proporcionando buenos resultados clínicos y funcionales

Proximal Femur Allograft-prosthesis with Compression Plates and a Short Stem

Proximal femur allograft-prosthesis composites (APCs) performed with compression plates and a short stem theoretically could minimize the resorption or nonunion that reportedly occurs with long stems bypassing the diaphyseal osteotomy. To confirm this theoretical consideration, we retrospectively reviewed 34 patients with 38 proximal femoral APCs using a short-cemented femoral stem and compression plates for diaphyseal osteotomy fixation. In 26 patients, the plate fixation extended over at least half the femoral stem and in 12, it did not. We reinserted the abductor mechanism with two techniques: in 10 cases the host trochanter was reattached to the APC, and in 28 the host tendons were sutured to the tendinous insertion of the allograft. The overall survival of the entire series was 72% at 5 years and 69% at 10 years. Eleven of the 38 (29%) APCs were removed: three for infection, one for local recurrence of tumor, and seven for fractures. Trendelenburg gait occurred in four of 21 patients with direct tendon-to-tendon suture of the abductor mechanism and in three of six patients with trochanteric osteotomy. The overall APC survival rate was greater in patients in whom the allograft was adequately protected with internal fixation than in patients in whom it was not

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