Sophie E C M van de Vijfeijken1, Tijmen J A G Münker2, Niek de Jager2, William P Vandertop3, Alfred G Becking4, Cornelis J Kleverlaan2. 1. Department of Oral and Maxillofacial Surgery, Amsterdam University Medical Centers, Academic Medical Center, Amsterdam, The Netherlands. Electronic address: s.e.vandevijfeijken@amc.uva.nl. 2. Department of Dental Material Sciences, Academic Centre for Dentistry Amsterdam, Amsterdam, The Netherlands. 3. Amsterdam University Medical Centers, Neurosurgical Center Amsterdam, Academic Medical Center, Amsterdam, The Netherlands; Amsterdam University Medical Centers, Neurosurgical Center Amsterdam, VU University Medical Center, Amsterdam University Medical Centers, Neurosurgical Center Amsterdam, Amsterdam, The Netherlands. 4. Department of Oral and Maxillofacial Surgery, Amsterdam University Medical Centers, Academic Medical Center, Amsterdam, The Netherlands.
Abstract
BACKGROUND: In 2001, a 27-year-old man was diagnosed with a meningioma with skull bone involvement. A craniectomy was performed and a CMW-3 poly(methyl methacrylate) cranioplasty was manually manufactured to reconstruct the remaining cranial defect. In 2016, he complained about progressive neurologic impairment. A computed tomography scan revealed that the cranioplasty had fractured into 4 dislocated pieces. Removal was indicated, and during the same operation a polyetheretherketone patient-specific implant was inserted. METHODS: The fractured cranioplasty was compared with freshly prepared CMW-3 specimens to determine whether the material properties had changed during 15 years in vivo. Gel permeation chromatography, microcomputed tomography, and flexural strength tests were performed. The fracture itself was analyzed using finite element analysis. RESULTS: The polydispersity index and molecular weight were not significantly different for the fractured cranioplasty and CMW-3. The fractured cranioplasty contained a total porosity of 10.7%, fresh CMW-3 cured at atmospheric pressure contained 4.1%, and 0.06% when cured at 2.2 bar. The flexural strength of the CMW-3 cured at 2.2 bar was significantly higher than both the fractured cranioplasty and CMW-3 cured at atmospheric pressure. Finite element analysis showed stress of 12.2 MPa under a load of 100 N on a weak spot. CONCLUSIONS: This ex vivo study shows that CMW-3 after 15 years in vivo was not influenced in molecular weight or flexural strength. However, the design of the implant and the handling of the poly(methyl methacrylate) seem to be important factors to improve mechanical properties of cranial reconstructions.
BACKGROUND: In 2001, a 27-year-old man was diagnosed with a meningioma with skull bone involvement. A craniectomy was performed and a CMW-3 poly(methyl methacrylate) cranioplasty was manually manufactured to reconstruct the remaining cranial defect. In 2016, he complained about progressive neurologic impairment. A computed tomography scan revealed that the cranioplasty had fractured into 4 dislocated pieces. Removal was indicated, and during the same operation a polyetheretherketonepatient-specific implant was inserted. METHODS: The fractured cranioplasty was compared with freshly prepared CMW-3 specimens to determine whether the material properties had changed during 15 years in vivo. Gel permeation chromatography, microcomputed tomography, and flexural strength tests were performed. The fracture itself was analyzed using finite element analysis. RESULTS: The polydispersity index and molecular weight were not significantly different for the fractured cranioplasty and CMW-3. The fractured cranioplasty contained a total porosity of 10.7%, fresh CMW-3 cured at atmospheric pressure contained 4.1%, and 0.06% when cured at 2.2 bar. The flexural strength of the CMW-3 cured at 2.2 bar was significantly higher than both the fractured cranioplasty and CMW-3 cured at atmospheric pressure. Finite element analysis showed stress of 12.2 MPa under a load of 100 N on a weak spot. CONCLUSIONS: This ex vivo study shows that CMW-3 after 15 years in vivo was not influenced in molecular weight or flexural strength. However, the design of the implant and the handling of the poly(methyl methacrylate) seem to be important factors to improve mechanical properties of cranial reconstructions.
Authors: Kacper Kroczek; Paweł Turek; Damian Mazur; Jacek Szczygielski; Damian Filip; Robert Brodowski; Krzysztof Balawender; Łukasz Przeszłowski; Bogumił Lewandowski; Stanisław Orkisz; Artur Mazur; Grzegorz Budzik; Józef Cebulski; Mariusz Oleksy Journal: Polymers (Basel) Date: 2022-04-09 Impact factor: 4.967
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