title: Short Term Evaluation of an Anatomically Shaped Polycarbonate Urethane Total Meniscus Replacement in a Goat Model.
abstract: OBJECTIVE
  Since the treatment options for symptomatic total meniscectomy patients are still limited, an anatomically shaped, polycarbonate urethane (PCU), total meniscus replacement was developed. This study evaluates the in vivo performance of the implant in a goat model, with a specific focus on the implant location in the joint, geometrical integrity of the implant and the effect of the implant on synovial membrane and articular cartilage histopathological condition.
  
  
  METHODS
  The right medial meniscus of seven Saanen goats was replaced by the implant. Sham surgery (transection of the MCL, arthrotomy and MCL suturing) was performed in six animals. The contralateral knee joints of both groups served as control groups. After three months follow-up the following aspects of implant performance were evaluated: implant position, implant deformation and the histopathological condition of the synovium and cartilage.
  
  
  RESULTS
  Implant geometry was well maintained during the three month implantation period. No signs of PCU wear were found and the implant did not induce an inflammatory response in the knee joint. In all animals, implant fixation was compromised due to suture breakage, wear or elongation, likely causing the increase in extrusion observed in the implant group. Both the femoral cartilage and tibial cartilage in direct contact with the implant showed increased damage compared to the sham and sham-control groups.
  
  
  CONCLUSIONS
  This study demonstrates that the novel, anatomically shaped PCU total meniscal replacement is biocompatible and resistant to three months of physiological loading. Failure of the fixation sutures may have increased implant mobility, which probably induced implant extrusion and potentially stimulated cartilage degeneration. Evidently, redesigning the fixation method is necessary. Future animal studies should evaluate the improved fixation method and compare implant performance to current treatment standards, such as allografts.
authors.affiliation: Radboud University Medical Center, Radboud Institute for Health Sciences, Orthopaedic Research Lab, Nijmegen, The Netherlands.
authors.forename: A C T
authors.initials: AC
authors.lastname: Vrancken
authors.affiliation: Radboud University Medical Center, Radboud Institute for Molecular Life Sciences, Orthopaedic Research Lab, Nijmegen, The Netherlands.
authors.forename: W
authors.initials: W
authors.lastname: Madej
authors.affiliation: Radboud University Medical Center, Radboud Institute for Health Sciences, Orthopaedic Research Lab, Nijmegen, The Netherlands.
authors.forename: G
authors.initials: G
authors.lastname: Hannink
authors.affiliation: Radboud University Medical Center, Radboud Institute for Health Sciences, Orthopaedic Research Lab, Nijmegen, The Netherlands; Laboratory for Biomechanical Engineering, University of Twente, Enschede, The Netherlands.
authors.forename: N
authors.initials: N
authors.lastname: Verdonschot
authors.affiliation: Radboud University Medical Center, Radboud Institute for Health Sciences, Orthopaedic Research Lab, Nijmegen, The Netherlands; Department of Orthopaedic Surgery, Via Sana Clinic, Mill, The Netherlands.
authors.forename: T G
authors.initials: TG
authors.lastname: van Tienen
authors.affiliation: Radboud University Medical Center, Radboud Institute for Molecular Life Sciences, Orthopaedic Research Lab, Nijmegen, The Netherlands.
authors.forename: P
authors.initials: P
authors.lastname: Buma
mesh_terms: D000818:Animals; D002358:Cartilage, Articular / Q000473:pathology / Q000601:surgery*; D006041:Goats; D007719:Knee Joint / Q000473:pathology / Q000601:surgery*; D007720:Knee Prosthesis; D008592:Menisci, Tibial / Q000473:pathology / Q000601:surgery*; D023421:Models, Animal; D011076:Polycarboxylate Cement; D011474:Prosthesis Design; D013583:Synovial Membrane / Q000473:pathology; D014520:Urethane
chemical_list: D011076:Polycarboxylate Cement; C005506:polycarbonate; D014520:Urethane