title: Addition of a suture anchor for coracoclavicular fixation to a superior locking plate improves stability of type IIB distal clavicle fractures.
abstract: OBJECTIVE
  The purpose of this study was to determine the effect of coracoclavicular (CC) fixation on biomechanical stability in type IIB distal clavicle fractures fixed with plate and screws.
  
  
  METHODS
  Twelve fresh-frozen matched cadaveric specimens were used to create type IIB distal clavicle fractures. Dual-energy x-ray absorptiometry (DEXA) scans ensured similar bone quality. Group 1 (6 specimens) was stabilized with a superior precontoured distal clavicle locking plate and supplemental suture anchor CC fixation. Group 2 (6 specimens) followed the same construct without CC fixation. Each specimen was cyclically loaded in the coronal plane at 40 to 80 N for 17,500 cycles. Load-to-failure testing was performed on the specimens that did not fail cyclic loading. Outcome measures included mode of failure and the number of cycles or load required to create 10 mm of displacement in the construct.
  
  
  RESULTS
  All specimens (12 of 12) completed cyclic testing without failure and underwent load-to-failure testing. Group 1 specimens failed at a mean of 808.5 N (range, 635.4 to 952.3 N), whereas group 2 specimens failed at a mean of 401.3 N (range, 283.6 to 656.0 N) (P = .005). Group 1 specimens failed by anchor pullout without coracoid fracture (4 of 6) and distal clavicle fracture fragment fragmentation (1 of 6); one specimen did not fail at the maximal load the materials testing machine was capable of exerting (1,000 N). Group 2 specimens failed by distal clavicle fracture fragment fragmentation (3 of 6) and acromioclavicular (AC) joint displacement (1 of 6); 2 specimens did not fail at the maximal load of the materials testing machine.
  
  
  CONCLUSIONS
  During cyclic loading, type IIB distal clavicle fractures with and without CC fixation remain stable. CC fixation adds stability to type IIB distal clavicle fractures fixed with plate and screws when loaded to failure.
  
  
  CONCLUSIONS
  CC fixation for distal clavicle fractures is a useful adjunct to plate-and-screw fixation to augment stability of the fracture.
authors.affiliation: Department of Orthopaedics, University of Rochester Medical Center, Rochester, NY 14625, USA.
authors.forename: Wes
authors.initials: W
authors.lastname: Madsen
authors.forename: Zaneb
authors.initials: Z
authors.lastname: Yaseen
authors.forename: Russell
authors.initials: R
authors.lastname: LaFrance
authors.forename: Tony
authors.initials: T
authors.lastname: Chen
authors.forename: Hani
authors.initials: H
authors.lastname: Awad
authors.forename: Michael
authors.initials: M
authors.lastname: Maloney
authors.forename: Ilya
authors.initials: I
authors.lastname: Voloshin
mesh_terms: D015502:Absorptiometry, Photon; D001696:Biomechanical Phenomena / Q000502:physiology; D001860:Bone Plates; D001863:Bone Screws; D002102:Cadaver; D002968:Clavicle / Q000293:injuries* / Q000601:surgery; D005260:Female; D005592:Fracture Fixation / Q000295:instrumentation / Q000379:methods*; D005593:Fracture Fixation, Internal; D050723:Fractures, Bone / Q000503:physiopathology / Q000601:surgery*; D006801:Humans; D008297:Male; D053441:Suture Anchors; D013718:Tensile Strength / Q000502:physiology