title: Cyclical loading of coracoclavicular ligament reconstructions: a comparative biomechanical study.
abstract: BACKGROUND
  Reconstruction for injuries to the acromioclavicular joint remains controversial.
  
  
  OBJECTIVE
  A coracoclavicular ligament reconstruction with a semitendinosus tendon would have superior performance to the classic coracoacromial ligament transfer with or without augmentation.
  
  
  METHODS
  Controlled laboratory study.
  
  
  METHODS
  Five cadaveric shoulders were used to reconstruct the coracoclavicular ligaments with 3 methods: coracoacromial ligament transfer without augmentation, coracoacromial ligament transfer augmented with No. 5 Ethibond suture, and a semitendinosus tendon. Each reconstruction was cyclically loaded at 40 N to 80 N for 2500 cycles, then from 40 N to 210 N for 2500 cycles, followed by loading to failure. The number of cycles to 50% and 100% loss of acromioclavicular joint reduction were recorded.
  
  
  RESULTS
  During the 40 N to 80 N-loading cycle, the coracoacromial transfer without augmentation failed (15 +/- 16 cycles). The augmented coracoacromial ligament transfer and the semitendinosus reconstruction did not fail (P = .008). During the 40 N to 210 N-loading cycle, the augmented coracoacromial ligament transfer failed (207 +/- 399 cycles). The semitendinosus reconstruction survived through both loading cycles (P < .01).
  
  
  CONCLUSIONS
  Coracoclavicular ligament reconstruction with a semitendinosus graft is a biomechanically superior construct in a cyclically loaded setting to a coracoacromial ligament transfer augmented with a No. 5 Ethibond suture.
  
  
  CONCLUSIONS
  The semitendinosus graft is a strong, biologic option for reconstruction of the coracoclavicular ligaments.
authors.affiliation: Nicholas Institute of Sports Medicine and Athletic Trauma, Lenox Hill Hospital, New York, NY 10075, USA. sjleemd@aol.com
authors.forename: Steven J
authors.initials: SJ
authors.lastname: Lee
authors.forename: Eric P
authors.initials: EP
authors.lastname: Keefer
authors.forename: Malachy P
authors.initials: MP
authors.lastname: McHugh
authors.forename: Ian J
authors.initials: IJ
authors.lastname: Kremenic
authors.forename: Karl F
authors.initials: KF
authors.lastname: Orishimo
authors.forename: Simon
authors.initials: S
authors.lastname: Ben-Avi
authors.forename: Stephen J
authors.initials: SJ
authors.lastname: Nicholas
mesh_terms: D000173:Acromioclavicular Joint / Q000502:physiology / Q000601:surgery*; D000328:Adult; D001696:Biomechanical Phenomena; D002102:Cadaver; D005260:Female; D006801:Humans; D008023:Ligaments, Articular / Q000502:physiology / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D013709:Tendon Transfer; D013710:Tendons / Q000502:physiology / Q000637:transplantation; D016474:Weight-Bearing