title: Functional biomechanical performance of a novel anatomically shaped polycarbonate urethane total meniscus replacement.
abstract: OBJECTIVE
  To evaluate the functional biomechanical performance of a novel anatomically shaped, polycarbonate urethane total meniscus implant.
  
  
  METHODS
  Five human cadaveric knees were flexed between 0° and 90° under compressive loads mimicking a squat movement. Anteroposterior (AP) laxity tests were performed in 30° and 90° flexion. Meniscal kinematics and knee laxity were quantified using roentgen stereophotogrammetric analysis. Tibial cartilage contact mechanics were determined in 90° flexion. Measurements were repeated for the native medial meniscus, the implant, after total medial meniscectomy and allograft transplantation.
  
  
  RESULTS
  The implant and allograft displayed increased posterior and medial displacements compared to the native meniscus, yet no differences were found between the implant and allograft. Meniscal condition did not affect rotational laxity. Compared to the native joint, AP laxity for the implant was increased in 30° flexion, but not in 90°. The implant reduced the mean contact pressure compared to meniscectomy but could not restore contact pressures to native meniscus levels. Compared to the native meniscus, the implant significantly increased the peak pressure, while the contact area was reduced. Contact mechanics of the implant and allograft were never statistically different.
  
  
  CONCLUSIONS
  Biomechanical performance was similar for the implant and allograft. However, both meniscal replacements could not restore outcomes to native meniscus levels or sufficiently improve outcomes after meniscectomy. This was presumably caused by the mobility allowed by the suture-only horn fixation. The similarity of implant and allograft performance suggests that the novel implant has the biomechanical potential to serve as an alternative to meniscal allograft transplantation.
authors.affiliation: Orthopaedic Research Lab, Radboud Institute for Health Sciences, Radboud University Medical Center, Huispost 547, PO Box 9101, 6500 HB, Nijmegen, The Netherlands. Anne.Vrancken@radboudumc.nl.
authors.forename: A C T
authors.initials: AC
authors.lastname: Vrancken
authors.affiliation: Orthopaedic Research Lab, Radboud Institute for Health Sciences, Radboud University Medical Center, Huispost 547, PO Box 9101, 6500 HB, Nijmegen, The Netherlands.
authors.forename: F
authors.initials: F
authors.lastname: Eggermont
authors.affiliation: Orthopaedic Research Lab, Radboud Institute for Health Sciences, Radboud University Medical Center, Huispost 547, PO Box 9101, 6500 HB, Nijmegen, The Netherlands.
authors.forename: T G
authors.initials: TG
authors.lastname: van Tienen
authors.affiliation: Orthopaedic Research Lab, Radboud Institute for Health Sciences, Radboud University Medical Center, Huispost 547, PO Box 9101, 6500 HB, Nijmegen, The Netherlands.
authors.forename: G
authors.initials: G
authors.lastname: Hannink
authors.affiliation: Orthopaedic Research Lab, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, The Netherlands.
authors.forename: P
authors.initials: P
authors.lastname: Buma
authors.affiliation: Orthopaedic Research Lab, Radboud Institute for Health Sciences, Radboud University Medical Center, Huispost 547, PO Box 9101, 6500 HB, Nijmegen, The Netherlands.
authors.forename: D
authors.initials: D
authors.lastname: Janssen
authors.affiliation: Orthopaedic Research Lab, Radboud Institute for Health Sciences, Radboud University Medical Center, Huispost 547, PO Box 9101, 6500 HB, Nijmegen, The Netherlands.|Laboratory for Biomechanical Engineering, University of Twente, Enschede, The Netherlands.
authors.forename: N
authors.initials: N
authors.lastname: Verdonschot
mesh_terms: D064591:Allografts; D001672:Biocompatible Materials; D001696:Biomechanical Phenomena; D002102:Cadaver; D002358:Cartilage, Articular / Q000000981:diagnostic imaging / Q000503:physiopathology; D019245:Compressive Strength; D006801:Humans; D007593:Joint Instability / Q000000981:diagnostic imaging / Q000503:physiopathology*; D007719:Knee Joint / Q000503:physiopathology* / Q000601:surgery; D008592:Menisci, Tibial / Q000503:physiopathology* / Q000601:surgery; D008875:Middle Aged; D011076:Polycarboxylate Cement; D011187:Posture / Q000502:physiology; D019736:Prostheses and Implants; D011474:Prosthesis Design; D019919:Prosthesis Implantation; D059869:Radiostereometric Analysis; D016059:Range of Motion, Articular; D013977:Tibia / Q000000981:diagnostic imaging / Q000503:physiopathology; D014184:Transplantation, Homologous; D014520:Urethane
chemical_list: D001672:Biocompatible Materials; D011076:Polycarboxylate Cement; C005506:polycarbonate; D014520:Urethane
keywords: Contact pressure; Implant; Kinematics; Knee laxity; Meniscal replacement