Epidemiology of musculoskeletal tumors in a reference unit. / Epidemiología de los tumores musculoesqueléticos en una unidad de referencia.

OBJECTIVE: The objective of this study was to perform an epidemiological analysis of patients presented to the Musculoskeletal Tumors Committee of a reference hospital. MATERIAL AND METHOD: A retrospective analysis of patients with sarcomas treated in a reference Sarcoma Unit between 2009 and 2022 was carried out. RESULTS: A total of 1978 patients were analyzed, of which 1477 (74.67%) were diagnosed as sarcomas. They were divided into 446 (30.20%) bone tumors and 1.031 (69.80%) soft tissue tumors. The most common benign bone tumor was enchondroma (27.23%), giant cell tumor (59.21%) was the most common tumor of intermediate malignancy and the malignant one was osteosarcoma (24.78%). The most frequently observed benign soft tissue tumor was lipoma (50.74%), the atypical lipomatous tumor (53.25%) was the most frequent tumor of intermediate malignancy and the malignant one was sarcoma of uncertain differentiation (38.10%). CONCLUSION: Our study represents the first work on the epidemiology of sarcomas and other musculoskeletal tumors in our country, being very useful to adapt the resources destined for their diagnosis and treatment.

[Translated article] Mechanical resistance of polylactic acid bone matrices developed by 3D printing for the reconstruction of bone defects.

INTRODUCTION: Bone defects are one of the main limitations in orthopaedic surgery and traumatology. For this reason, multiple bone replacement systems have been developed, either by prosthetic implant or by substitution with osteoforming substances, whose limitations are their survival and lack of structurality, respectively. The objective of this work is the generation of a new material for the creation of biologically active structures that have sufficient tensile strength to maintain the structure during remodelling. MATERIAL AND METHODS: A new filament based on the fusion of natural polylactide acid (PLA) powder was designed for the generation of pieces by means of fused deposition modelling (FDM) on which to carry out tensile mechanical tests of osteosynthesis material. A total of 13 groups with different cortical thickness, filling and layer height were carried out, with 10 tensile tests in each group, defining the tensile breaking limit for each group. The regression lines for each group and their mechanical resistance to traction on the filament used were determined. RESULTS: The filament ratio per contact surface unit with the osteosynthesis used was the main determinant of the mechanical resistance to traction, either at the expense of the increase in cortical thickness or by the increase in the percentage of cancellous bone filling. Layer height had a minor effect on tensile strength. The regression value was high for cortical thickness and cancellous filling, being elements with a predictable biomechanical behaviour. CONCLUSIONS: The new methodology allows the creation of personalised neutral and implantable PLA bone matrices for the reconstruction of large bone defects by means of 3D printing by FDM with a mechanical resistance to traction greater than that of current biological support structures.