title: A new approach to scaffold fixation by magnetic forces: Application to large osteochondral defects.
abstract: Scaffold fixation represents one of the most serious challenges in osteochondral defect surgery. Indeed, the fixation should firmly hold the scaffold in the implanted position as well as it should guaranty stable bone/scaffold interface for efficient tissue regeneration. Nonetheless successful results have been achieved for small defect repair, the fixation remains really problematic for large defects, i.e. defects with areas exceeding 2cm(2). This paper advances an innovative magnetic fixation approach based on application of magnetic scaffolds. Finite element modeling was exploited to investigate the fixation efficiency. We considered three magnetic configurations: (1) external permanent magnet ring placed around the leg near the joint; (2) four small permanent magnet pins implanted in the bone underlying the scaffold; (3) four similarly implanted stainless steel pins which magnetization was induced by the external magnet. It was found that for most appropriate magnetic materials and optimized magnet-scaffold positioning all the considered configurations provide a sufficient scaffold fixation. In addition to fixation, we analyzed the pressure induced by magnetic forces at the bone/scaffold interface. Such pressure is known to influence significantly the bone regeneration and could be used for magneto-mechanical stimulation.
authors.affiliation: Laboratorio di NanoBiotecnologie, Via di Barbiano, 1/10, 40136 Bologna, Italy.
authors.forename: Alessandro
authors.initials: A
authors.lastname: Russo
authors.forename: Tatiana
authors.initials: T
authors.lastname: Shelyakova
authors.forename: Daniela
authors.initials: D
authors.lastname: Casino
authors.forename: Nicola
authors.initials: N
authors.lastname: Lopomo
authors.forename: Alessandro
authors.initials: A
authors.lastname: Strazzari
authors.forename: Alessandro
authors.initials: A
authors.lastname: Ortolani
authors.forename: Andrea
authors.initials: A
authors.lastname: Visani
authors.forename: Valentin
authors.initials: V
authors.lastname: Dediu
authors.forename: Maurilio
authors.initials: M
authors.lastname: Marcacci
mesh_terms: D001842:Bone and Bones / Q000002:abnormalities* / Q000601:surgery*; D002358:Cartilage, Articular / Q000002:abnormalities* / Q000601:surgery*; D020342:Finite Element Analysis; D060328:Magnetic Phenomena; D019736:Prostheses and Implants; D023822:Tissue Engineering; D054457:Tissue Scaffolds