title: Tendon graft fixation sites at the coracoid process for reconstruction of the coracoclavicular ligaments: a kinematic evaluation of three different surgical techniques.
abstract: OBJECTIVE
  The virtual graft length kinematics of 3 operative techniques were investigated and compared with kinematics of the native coracoclavicular ligaments.
  
  
  METHODS
  Thirteen healthy volunteers underwent magnetic resonance imaging (MRI) of the shoulder in 30° increments of abduction (0° to 120°). A 3-dimensional model of the coracoid process (CP) and the clavicle (CL) was created. Footprints of the conoid and the trapezoid ligament were identified. At the CP the potential fixation sites of 3 techniques for reconstruction of the coracoclavicular ligaments (CCLs) were marked. The techniques investigated were (1) horizontal transcoracoid drilling (TH), (2) transclavicular-transcoracoid drilling (TT), and (3) tendon graft passage underneath (PU) the coracoid process. Distances between the clavicular and coracoidal footprints of the coracoclavicular ligaments and to the virtual footprints on the coracoid process were determined for each abduction increment.
  
  
  RESULTS
  All methods investigated resulted in a significantly longer virtual trapezoidal graft (P = .001). In PU, in addition, the virtual conoidal graft was significantly longer. TT resulted in a virtual conoidal graft and conoid ligament of equal length. TH showed identical length and distance regulation of the virtual conoidal graft and the conoid ligament, but significant shortening of the virtual trapezoidal graft during abduction. PU showed isometry of the virtual trapezoidal and conoidal grafts.
  
  
  CONCLUSIONS
  None of the described procedures for graft fixation restores the kinematics of the native coracoclavicular ligaments. Graft fixation techniques should be chosen with respect to the preoperative type of instability. Persisting isolated vertical instability might benefit from fixation of the conoidal grafts at the native clavicular footprint. For horizontal clavicular instabilities, techniques more preserving of trapezoid ligament kinematics might be favorable.
  
  
  CONCLUSIONS
  The data suggest that the technique of fixation in conoid and trapezoid ligament reconstruction should depend on the underlying type of instability.
authors.affiliation: Department of Orthopaedic and Trauma Surgery, University Hospital Freiburg, Freiburg, Germany. izadpanah@me.com
authors.forename: Kaywan
authors.initials: K
authors.lastname: Izadpanah
authors.forename: Martin
authors.initials: M
authors.lastname: Jaeger
authors.forename: Dirk
authors.initials: D
authors.lastname: Maier
authors.forename: Peter
authors.initials: P
authors.lastname: Ogon
authors.forename: Matthias
authors.initials: M
authors.lastname: Honal
authors.forename: Marco
authors.initials: M
authors.lastname: Vicari
authors.forename: Jürgen
authors.initials: J
authors.lastname: Hennig
authors.forename: Norbert P
authors.initials: NP
authors.lastname: Südkamp
authors.forename: Matthias
authors.initials: M
authors.lastname: Weigel
mesh_terms: D000328:Adult; D001696:Biomechanical Phenomena; D002968:Clavicle / Q000502:physiology; D005260:Female; D006801:Humans; D021621:Imaging, Three-Dimensional; D008022:Ligaments / Q000502:physiology; D008023:Ligaments, Articular / Q000503:physiopathology*; D008279:Magnetic Resonance Imaging; D008297:Male; D012540:Scapula / Q000502:physiology* / Q000601:surgery; D012782:Shoulder / Q000502:physiology* / Q000601:surgery; D013710:Tendons / Q000637:transplantation; D055815:Young Adult