title: Latarjet Fixation: A Cadaveric Biomechanical Study Evaluating Cortical and Cannulated Screw Fixation.
abstract: BACKGROUND
  Attritional bone loss in patients with recurrent anterior instability has successfully been treated with a bone block procedure such as the Latarjet. It has not been previously demonstrated whether cortical or cancellous screws are superior when used for this procedure.
  
  
  OBJECTIVE
  To assess the strength of stainless steel cortical screws versus stainless steel cannulated cancellous screws in the Latarjet procedure.
  
  
  METHODS
  Controlled laboratory study.
  
  
  METHODS
  Ten fresh-frozen matched-pair shoulder specimens were randomized into 2 separate fixation groups: (1) 3.5-mm stainless steel cortical screws and (2) 4.0-mm stainless steel partially threaded cannulated cancellous screws. Shoulder specimens were dissected free of all soft tissue and a 25% glenoid defect was created. The coracoid process was osteomized, placed at the site of the glenoid defect, and fixed in place with 2 parallel screws.
  
  
  RESULTS
  All 10 specimens failed by screw cutout. Nine of 10 specimens failed by progressive displacement with an increased number of cycles. One specimen in the 4.0-mm screw group failed by catastrophic failure on initiation of the testing protocol. The 3.5-mm screws had a mean of 274 cycles (SD, ±171 cycles; range, 10-443 cycles) to failure. The 4.0-mm screws had a mean of 135 cycles (SD, ±141 cycles; range, 0-284 cycles) to failure. There was no statistically significant difference between the 2 types of screws for cycles required to cause failure (P = .144).
  
  
  CONCLUSIONS
  There was no statistically significant difference in energy or cycles to failure when comparing the stainless steel cortical screws versus partially threaded cannulated cancellous screws.
  
  
  CONCLUSIONS
  Latarjet may be performed using cortical or cancellous screws without a clear advantage of either option.
authors.affiliation: Department of Orthopaedic Surgery, Northwestern University, Chicago, Illinois, USA.
authors.forename: Hasham M
authors.initials: HM
authors.lastname: Alvi
authors.affiliation: Department of Orthopaedic Surgery, Northwestern University, Chicago, Illinois, USA.
authors.forename: Emily J
authors.initials: EJ
authors.lastname: Monroe
authors.affiliation: Musculoskeletal Biomechanics Laboratory, Edward Hines Jr. VA Hospital, Hines, Illinois, USA.
authors.forename: Muturi
authors.initials: M
authors.lastname: Muriuki
authors.affiliation: Feinberg School of Medicine, Northwestern University, Chicago, Illinois, USA.
authors.forename: Rajat N
authors.initials: RN
authors.lastname: Verma
authors.affiliation: Department of Orthopaedic Surgery, Northwestern University, Chicago, Illinois, USA.
authors.forename: Guido
authors.initials: G
authors.lastname: Marra
authors.affiliation: Department of Orthopaedic Surgery, Northwestern University, Chicago, Illinois, USA.
authors.forename: Matthew D
authors.initials: MD
authors.lastname: Saltzman
keywords: Latarjet; biomechanics; general sports trauma; glenoid bone loss; shoulder instability