title: A Biomechanical Analysis of Different Clavicular Tunnel Diameters in Anatomic Acromioclavicular Ligament Reconstruction.
abstract: To evaluate the biomechanical stability of a tendon-to-clavicle bone interface fixation of a graft in revision acromioclavicular reconstruction.
  
  
  
  Fifteen fresh-frozen cadaveric shoulders were used. All specimens underwent bone density evaluation. For the primary reconstruction, a 5-mm semitendinosus allograft was inserted into a 5-mm bone tunnel at 25 and 45 mm from the lateral end of the clavicle using a 5.5 × 8-mm PEEK (polyether ether ketone) tenodesis screw. Each single graft was fixed in a cryo-clamp and cyclically loaded from 5 to 70 N for 3,000 cycles, followed by load-to-failure testing at a rate of 120 mm/min to simulate the revision case. To simulate tunnel widening, the tunnels of the revision series were over-drilled with an 8-mm drill, and a 5-mm semitendinosus graft with an 8 × 12-mm PEEK tenodesis screw was inserted. Biomechanical testing was then repeated.
  
  
  
  The bone mineral density analysis showed a significantly higher density at the 45-mm hole compared with the 25-mm hole (P = .001). The ultimate load to failure increased from the 5.5-mm screw to the 8-mm screw at the 45-mm hole position (P = .001). There was no statistically significant difference at the 25-mm hole position (P = .934). No statistical significance for graft elongation comparing the 5.5-mm screw and the 8-mm screw at the 25-mm (P = .156) and 45-mm (P = .334) positions could be found.
  
  
  
  Comparable biomechanical stability for the tendon-to-bone interface fixation in different clavicular tunnel diameters simulating primary and revision reconstruction was achieved.
  
  
  
  There is a lack of literature regarding revision acromioclavicular joint reconstruction, but our biomechanical results show comparable stability to primary reconstruction. These data provide support for the use of anatomic acromioclavicular ligament reconstruction in revision cases.
authors.affiliation: Department of Orthopaedic Surgery, University of Connecticut, Farmington, Connecticut, U.S.A.. Electronic address: a.voss@tum.de.
authors.forename: Andreas
authors.initials: A
authors.lastname: Voss
authors.affiliation: Department of Orthopaedic Sportsmedicine, Technical University, Munich, Germany.
authors.forename: Knut
authors.initials: K
authors.lastname: Beitzel
authors.affiliation: Department of Orthopaedic Surgery, University of Connecticut, Farmington, Connecticut, U.S.A.
authors.forename: Farhang
authors.initials: F
authors.lastname: Alaee
authors.affiliation: Department of Orthopaedic Surgery, University of Connecticut, Farmington, Connecticut, U.S.A.
authors.forename: Alex
authors.initials: A
authors.lastname: Dukas
authors.affiliation: Department of Orthopaedic Sportsmedicine, Technical University, Munich, Germany.
authors.forename: Elmar
authors.initials: E
authors.lastname: Herbst
authors.affiliation: Department of Orthopaedic Surgery, University of Connecticut, Farmington, Connecticut, U.S.A.
authors.forename: Elifho
authors.initials: E
authors.lastname: Obopilwe
authors.affiliation: Department of Orthopaedic Surgery, University of Connecticut, Farmington, Connecticut, U.S.A.
authors.forename: John
authors.initials: J
authors.lastname: Apostolakos
authors.affiliation: Department of Orthopaedic Surgery, University of Connecticut, Farmington, Connecticut, U.S.A.
authors.forename: Jessica
authors.initials: J
authors.lastname: DiVenere
authors.affiliation: Department of Orthopaedic Surgery, University of Connecticut, Farmington, Connecticut, U.S.A.
authors.forename: Hardeep
authors.initials: H
authors.lastname: Singh
authors.affiliation: Department of Orthopaedic Surgery, University of Connecticut, Farmington, Connecticut, U.S.A.
authors.forename: Mark P
authors.initials: MP
authors.lastname: Cote
authors.affiliation: Department of Orthopaedic Surgery, University of Connecticut, Farmington, Connecticut, U.S.A.
authors.forename: Augustus D
authors.initials: AD
authors.lastname: Mazzocca
mesh_terms: D015502:Absorptiometry, Photon; D000173:Acromioclavicular Joint / Q000000981:diagnostic imaging / Q000601:surgery*; D000368:Aged; D001178:Arthroplasty / Q000379:methods*; D001696:Biomechanical Phenomena; D015519:Bone Density; D001863:Bone Screws; D002102:Cadaver; D002968:Clavicle / Q000000981:diagnostic imaging / Q000601:surgery*; D000070632:Hamstring Tendons / Q000637:transplantation*; D006801:Humans; D008023:Ligaments, Articular / Q000601:surgery*; D008875:Middle Aged; D018482:Muscle, Skeletal / Q000601:surgery; D019651:Plastic Surgery Procedures / Q000379:methods; D053656:Tenodesis / Q000379:methods*; D014184:Transplantation, Homologous