title: Effect of three remplissage techniques on tendon coverage and shoulder kinematics: a navigated robotic biomechanical study.
abstract: BACKGROUND
  In addition to Bankart repair engaging Hill-Sachs defects in glenohumeral instability have been treated successfully with remplissage procedure. The purpose of this study was to compare three remplissage techniques regarding (I) ability of preventing Hill-Sachs defect from engaging, (II) influence on glenohumeral rotational torque, and (III) resulting tendon coverage over the Hill-Sachs defect.
  
  
  METHODS
  Standardized engaging Hill-Sachs defects and Bankart lesions were created in n = 7 fresh frozen human shoulder specimens. Besides Bankart repair three remplissage techniques (T) with double anchor position in the valley of the defect zone were studied: T1, knots tied over anchors; T2, knots tied between anchors (double-pulley); T3, knotless anchors with a suture tape. A parallel position-orientation and force-moment controlled navigated roboticsystem was used to compare prevention of Hill-Sachs defect engagement and torque [Nm]. Pressure sensitive film was used to study area of infraspinatus tendon coverage over Hill-Sachs defect [%].
  
  
  RESULTS
  All remplissage techniques prevented engagement of the Hill-Sachs defect without showing any construct failures. Regarding humeral torque there were significant impairments observed between intact conditions and the three investigated repair techniques in 60° abduction and ≥30° external rotation (p < .04). There was no significant difference in torque between intervention groups (n.s.). With a mean coverage of 26.8 % over the defect zone the knotless suture tape technique (T3) significantly improved area of soft tissue coverage compared to the other techniques (p = .03).
  
  
  CONCLUSIONS
  All remplissage techniques prevented engagement of the Hill Sachs defect. With high abduction and external rotation ≥30° all techniques showed significant higher humeral torque compared to the intact specimens, while there was not one technique superior over the others. The suture tape technique conferred the largest and most effective area of tendon coverage over the Hill-Sachs defect zone. Long-term success of the remplissage procedure can possibly be enhanced by increasing the interface area of tendon coverage over the Hill-Sachs defect. Clinical studies will be necessary to proof potential benefits for clinical outcome.
authors.affiliation: Department for Orthopedic Sports Medicine, Technische Universität München, Munich, Germany. sokajames@gmail.com.
authors.forename: Chung Hui James
authors.initials: CH
authors.lastname: Tan
authors.affiliation: Department for Orthopedic Sports Medicine, Technische Universität München, Munich, Germany. tim.saier@lrz.tum.de.|Berufsgenossenschaftliche Unfallklinik Murnau, Murnau, Germany. tim.saier@lrz.tum.de.
authors.forename: Tim
authors.initials: T
authors.lastname: Saier
authors.affiliation: Department of Orthopaedics -Biomechanics Laboratory, Technische Universität München, Ismaninger Straße 22, Munich, 81675, Germany. c.deimling@tum.de.
authors.forename: Constantin
authors.initials: C
authors.lastname: von Deimling
authors.affiliation: Department for Orthopedic Sports Medicine, Technische Universität München, Munich, Germany. frank.martetschlaeger@lrz.tu-muenchen.de.
authors.forename: Frank
authors.initials: F
authors.lastname: Martetschläger
authors.affiliation: Department for Orthopedic Sports Medicine, Technische Universität München, Munich, Germany. philippminzlaff@me.com.|Chirurgische Klinik Dr. Rinecker, Munich, Germany. philippminzlaff@me.com.
authors.forename: Philipp
authors.initials: P
authors.lastname: Minzlaff
authors.affiliation: Department for Orthopedic Sports Medicine, Technische Universität München, Munich, Germany. matthias.j.feucht@googlemail.com.|Department of Orthopedic Surgery and Traumatology, Freiburg University Hospital, Freiburg, Germany. matthias.j.feucht@googlemail.com.
authors.forename: Matthias J
authors.initials: MJ
authors.lastname: Feucht
authors.affiliation: Department of Orthopaedics -Biomechanics Laboratory, Technische Universität München, Ismaninger Straße 22, Munich, 81675, Germany. martinez@tum.de.
authors.forename: Horazio
authors.initials: H
authors.lastname: Martinez
authors.affiliation: Department for Orthopedic Sports Medicine, Technische Universität München, Munich, Germany. sepp.braun@lrz.tum.de.
authors.forename: Sepp
authors.initials: S
authors.lastname: Braun
authors.affiliation: Department for Orthopedic Sports Medicine, Technische Universität München, Munich, Germany. imhoff@tum.de.
authors.forename: Andreas B
authors.initials: AB
authors.lastname: Imhoff
authors.affiliation: Department of Orthopaedics -Biomechanics Laboratory, Technische Universität München, Ismaninger Straße 22, Munich, 81675, Germany. burgkart@tum.de.
authors.forename: Rainer
authors.initials: R
authors.lastname: Burgkart
mesh_terms: D001696:Biomechanical Phenomena / Q000502:physiology; D006801:Humans; D008297:Male; D008875:Middle Aged; D065287:Robotic Surgical Procedures / Q000295:instrumentation / Q000379:methods*; D012783:Shoulder Dislocation / Q000473:pathology / Q000601:surgery; D012785:Shoulder Joint / Q000473:pathology / Q000502:physiology* / Q000601:surgery*; D013710:Tendons / Q000473:pathology / Q000502:physiology* / Q000601:surgery*