title: Biomechanical and viscoelastic properties of different posterior meniscal root fixation techniques.
abstract: OBJECTIVE
  The purpose of the present study was to biomechanically compare three different posterior meniscal root repair techniques. Transtibial fixation of a posterior meniscus root tear (PMRT) combined with an anterior cruciate ligament (ACL) reconstruction via one tunnel only shows similar properties in terms of cyclic loading and load to failure compared with direct anchor fixation.
  
  
  METHODS
  Twenty-eight porcine knees were randomly assigned to 4 groups (n = 7 each): (1) native posterior meniscal root, (2) suture anchor repair, (3) refixation via a tibial ACL tunnel in combination with an interference screw fixation of the ACL graft, and (4) refixation via a tibial ACL tunnel in combination with an interference screw fixation of the ACL graft with an additional extracortical button fixation. The four groups underwent cyclic loading followed by a load-to-failure testing. Construct elongation during 1000 cycles, dynamic stiffness, attenuation, maximum force during load-to-failure testing, and failure mode were recorded.
  
  
  RESULTS
  All reconstructions showed a significant lower maximum load (p < 0.0001) compared with the native meniscal root. The elongation for the transtibial fixation via the ACL tunnel without an additional extracortical backup fixation was significantly higher compared with the suture anchor technique (p < 0.0001). The additional use of a backup fixation led to similar results compared with the anchor repair technique.
  
  
  CONCLUSIONS
  The transtibial refixation of the meniscal root can be combined with an ACL reconstruction using the same tibial bone tunnel. However, an additional extracortical backup fixation is necessary. This might avoid a slippage of suture material and a failure of meniscus root fixation.
authors.affiliation: Department of Orthopaedic Sports Medicine, Technische Universität München (TUM), Ismaninger Str. 22, 81675, Munich, Germany.
authors.forename: Philipp
authors.initials: P
authors.lastname: Forkel
authors.affiliation: Department of Orthopaedics, Technische Universität München (TUM), Ismaninger Str. 22, 81675, Munich, Germany.
authors.forename: Peter
authors.initials: P
authors.lastname: Foehr
authors.affiliation: Department of Orthopaedic Sports Medicine, Technische Universität München (TUM), Ismaninger Str. 22, 81675, Munich, Germany.
authors.forename: Johannes C
authors.initials: JC
authors.lastname: Meyer
authors.affiliation: Department of Orthopaedic Sports Medicine, Technische Universität München (TUM), Ismaninger Str. 22, 81675, Munich, Germany.
authors.forename: Elmar
authors.initials: E
authors.lastname: Herbst
authors.affiliation: Clinic of Orthopaedic and Trauma Surgery, Martin Luther Hospital, Caspar-Theyß-Straße 27-31, 14193, Berlin, Germany.
authors.forename: Wolf
authors.initials: W
authors.lastname: Petersen
authors.affiliation: Department of Orthopaedic Sports Medicine, Technische Universität München (TUM), Ismaninger Str. 22, 81675, Munich, Germany.
authors.forename: Peter U
authors.initials: PU
authors.lastname: Brucker
authors.affiliation: Department of Orthopaedics, Technische Universität München (TUM), Ismaninger Str. 22, 81675, Munich, Germany.
authors.forename: Rainer
authors.initials: R
authors.lastname: Burgkart
authors.affiliation: Department of Orthopaedic Sports Medicine, Technische Universität München (TUM), Ismaninger Str. 22, 81675, Munich, Germany. a.imhoff@lrz.tum.de.
authors.forename: Andreas B
authors.initials: AB
authors.lastname: Imhoff
mesh_terms: D000818:Animals; D016118:Anterior Cruciate Ligament / Q000503:physiopathology / Q000601:surgery*; D000070598:Anterior Cruciate Ligament Injuries / Q000503:physiopathology / Q000601:surgery*; D059549:Anterior Cruciate Ligament Reconstruction / Q000379:methods; D001696:Biomechanical Phenomena; D001863:Bone Screws; D007718:Knee Injuries / Q000601:surgery; D008592:Menisci, Tibial / Q000503:physiopathology / Q000601:surgery*; D019651:Plastic Surgery Procedures / Q000379:methods; D053441:Suture Anchors; D013536:Suture Techniques; D013537:Sutures; D013552:Swine; D013710:Tendons / Q000637:transplantation; D013977:Tibia / Q000601:surgery; D000070600:Tibial Meniscus Injuries / Q000503:physiopathology / Q000601:surgery*; D019737:Transplants / Q000601:surgery
keywords: ACL; Meniscus root fixation; Root tear; Transtibial