TY - JOUR AU - Dóczi, Martin AU - Sződy, Róbert AU - Zwierczyk, Péter TI - Extended mechanical loads for the analysis of acetabular cages JF - BIOMECHANICS AND MODELING IN MECHANOBIOLOGY J2 - BIOMECH MODEL MECHAN VL - 22 PY - 2023 SP - 1411 EP - 1423 PG - 13 SN - 1617-7959 DO - 10.1007/s10237-023-01728-z UR - https://m2.mtmt.hu/api/publication/33954066 ID - 33954066 N1 - Open access funding provided by Budapest University of Technology and Economics. Project no. TKP-9-8/PALY-2021 has been implemented with the support provided by the Ministry of Culture and Innovation of Hungary from the National Research, Development and Innovation Fund, financed under the TKP2021-EGA funding scheme. AB - To analyse the strength and mechanical behaviour of hip implants, it is essential to employ an appropriate loading model. Generating computational models supplemented with muscle forces is a complicated task, especially in the initial phase of implant development. This research aims to expand the possibilities of the simpler acetabular cage model based on joint loads without significantly increasing the demand for computing resources. A Python script covered and grouped the loads from daily activities. The ten calculated major loads were compared with the maximum of the walking and stair climbing loads through the finite element analyses of a custom-made acetabular cage. Sensitivity analyses were performed for the surrounding bones’ elastic modulus and the pelvis boundary conditions. The major loads can geometrically cover the entire load spectrum of daily activities. The effect of many high-magnitude force vectors is uncertain in the approach that uses the most common maximum loads. Using these resultant major loads, a new stress concentration area could be detected on the acetabular cage, besides the stress concentration areas induced by the loads reported in the literature. The qualitative correctness of the results is also supported by a control computed tomography scan: a fracture occurred in an extensive, high-stress zone. The results are not sensitive to changes in the elastic modulus of the surrounding bone and the boundary conditions of the model. The presented load vectors and the algorithm make more extensive static analyses possible with little computational overhead. The proposed method can be used for checking the static strength of similar implants. LA - English DB - MTMT ER - TY - JOUR AU - Dóczi, Martin AU - Sződy, Róbert AU - Zwierczyk, Péter TI - Equivalent loads from the life-cycle of acetabular cages in relation to bone-graft transformation JF - COMPUTER METHODS AND PROGRAMS IN BIOMEDICINE J2 - COMPUT METH PROG BIO VL - 236 PY - 2023 PG - 10 SN - 0169-2607 DO - 10.1016/j.cmpb.2023.107564 UR - https://m2.mtmt.hu/api/publication/33785140 ID - 33785140 LA - English DB - MTMT ER - TY - JOUR AU - Dóczi, Martin AU - Sződy, Róbert AU - Zwierczyk, Péter TI - Effect of the Design Constraints and the Loading Model on the Geometry of Topology Optimized Acetabular Cages JF - PERIODICA POLYTECHNICA-MECHANICAL ENGINEERING J2 - PERIOD POLYTECH MECH ENG VL - 66 PY - 2022 IS - 3 SP - 253 EP - 259 PG - 7 SN - 0324-6051 DO - 10.3311/PPme.20238 UR - https://m2.mtmt.hu/api/publication/33056354 ID - 33056354 N1 - Correspondence Address: Dóczi, M.O.; Department of Machine and Product Design, 3 Műegyetem rkp., Hungary; email: doczi.martin@gt3.bme.hu AB - The treatment of large acetabular bone defects is a challenging task for the clinical experts. One of the most important part is the selection or the design the most appropriate implant. The aim of the study is to explore the potential of topology optimization for the treatment of extensive pelvic bone defects. Using a finite element method, the authors investigate different design spaces and load cases. Sensitivity tests for the material characteristic of the bone and the constraint of the applied volume-fraction were performed. The results are topology-optimized acetabular cage concepts with similar designs. The conceptual designs are not sensitive to the changing of the elastic modulus of the bone and the volume-fraction constraint. The reason for the similarity between the designs is the close connections, they have a special role in maximizing the stiffness. With the use of our design space, a lot of bone grafts can be put behind the cage and it can give an idea for sheet metal conceptual designs. Due to the close connections, similar conceptual variants are generated under normal walking load, which can be used for faster calculations in similar cases. LA - English DB - MTMT ER - TY - CHAP AU - Dóczi, Martin AU - Zwierczyk, Péter AU - Sződy, Róbert ED - Al-Begain, Khalid ED - Iacono, Mauro ED - Campanile, Lelio ED - Bargiela, Andrzej TI - Implementation of bone graft adaptation's FE model in hypermesh T2 - Proceedings of the 35th ECMS International Conference on Modelling and Simulation ECMS 2021 PB - European Council for Modelling and Simulation (ECMS) CY - Kingston Upon Thames CY - Dudweiler SN - 9783937436739 T3 - Communications of the ECMS, ISSN 2522-2414 ; 35 Issue 1. PY - 2021 SP - 152 EP - 156 PG - 5 DO - 10.7148/2021-0152 UR - https://m2.mtmt.hu/api/publication/32888990 ID - 32888990 N1 - Kuwait College of Science and Technology Department of Machine and Product Design, Budapest University of Technology and Economics, Műegyetem rkp. 3., Budapest, 1111, Hungary Péterfy Hospital, National Institute of Traumatology, Fiumei street 17., Budapest, 1081, Hungary Funding details: Nemzeti Kutatási, Fejlesztési és Innovaciós Alap, NKFIA Funding details: Innovációs és Technológiai Minisztérium Funding text 1: The research reported in this paper and carried out at BME has been supported by the NRDI Fund (TKP2020 NC, Grant No. BME-NCS) based on the charter of bolster issued by the NRDI Office under the auspices of the Ministry for Innovation and Technology. AB - Research significance: In the clinical practice, surgeons sometimes must deal with extended bone defects. Among others, bone grafts are used for filling the large absence. After implantation, the structure of the graft can change, and the graft's load-bearing effect can be significant. This leads to the idea, that during the design of an implant this effect should be taken into account in the finite element simulations. In this paper, the authors show the implementation of the bone graft adaptation. Methodology: This programming task was done by using Python, Tcl and the HyperMesh interface. The bone remodeling algorithm and the related parameters were from the literature research. The results are shown with a finite element model prepared for the Optistruct solver, where the geometry models were based on a patient's CT data. Results: Viewing the bone graft's elemental apparent density, the most loaded areas could be detected. Conclusion: The model can predict qualitatively the bone graft's change, which can provide additional information for the implant design. Further analyses are required to investigate the sensitivity of the results. © ECMS Khalid Al-Begain, Mauro Iacono, Lelio Campanile, Andrzej Bargiela (Editors) LA - English DB - MTMT ER - TY - JOUR AU - Dóczi, Martin AU - Sződy, Róbert AU - Zwierczyk, Péter TI - Csontgraft változásának végeselemes modellezése HyperMesh-Calculix környezetben JF - GÉP J2 - GÉP VL - 71 PY - 2020 IS - 7-8 SP - 15 EP - 18 PG - 4 SN - 0016-8572 UR - https://m2.mtmt.hu/api/publication/31751045 ID - 31751045 LA - Hungarian DB - MTMT ER - TY - CHAP AU - Dóczi, Martin AU - Zwierczyk, Péter AU - Sződy, Róbert ED - Steglich, M ED - Mueller, C ED - Neumann, G ED - Walther, M TI - Failure analysis of a custom-made acetabular cage with finite element method T2 - Proceedings of the 34th International ECMS Conference on Modelling and Simulation, ECMS 2020 PB - European Council for Modelling and Simulation (ECMS) CY - Wilhelmshaven SN - 9783937436692 T3 - Communications of the ECMS, ISSN 2522-2414 ; 34. PY - 2020 SP - 250 EP - 255 PG - 6 DO - 10.7148/2020-0250 UR - https://m2.mtmt.hu/api/publication/31654438 ID - 31654438 N1 - Scopus:hiba:85094948836 2022-10-12 16:32 befoglaló év nem egyezik, befoglaló egyiknél nincsenek szerzők, befoglaló cím nem egyezik LA - English DB - MTMT ER - TY - GEN AU - Dóczi, Martin AU - Simonovics, János AU - Sződy, Róbert TI - Vápakosaras rögzítés vizsgálata végeselemes módszerrel PY - 2019 UR - https://m2.mtmt.hu/api/publication/31654493 ID - 31654493 LA - Hungarian DB - MTMT ER - TY - GEN AU - Dóczi, Martin AU - Simonovics, János AU - Sződy, Róbert TI - Egyedi vápakosár végeselemes vizsgálata PY - 2018 UR - https://m2.mtmt.hu/api/publication/31654498 ID - 31654498 LA - Hungarian DB - MTMT ER - TY - JOUR AU - Dóczi, Martin AU - Simonovics, János TI - Egyedi vápakosaras rögzítés végeselemes modelljének elkészítése JF - GÉP J2 - GÉP VL - 69 PY - 2018 IS - 3 SP - 8 EP - 11 PG - 4 SN - 0016-8572 UR - https://m2.mtmt.hu/api/publication/31654459 ID - 31654459 LA - Hungarian DB - MTMT ER - TY - GEN AU - Dóczi, Martin AU - Simonovics, János AU - Zoltán, Gergely TI - Implantátummal rögzített törött alkar terhelhetőségének végeselemes vizsgálata PY - 2017 UR - https://m2.mtmt.hu/api/publication/31654486 ID - 31654486 LA - Hungarian DB - MTMT ER -