title: Displaced olecranon fractures in children: a biomechanical analysis of fixation methods.
abstract: BACKGROUND
  Wire and suture methods have been used to stabilize pediatric olecranon fractures. This study (1) compared differences in simulated intraoperative compression during fracture reduction, (2) evaluated articular surface compression during cyclic loading of the tension band, and (3) compared fracture stabilization after cyclic physiologic loading at low/high levels.
  
  
  METHODS
  Identical olecranon fractures were created in 10 synthetic ulnae and randomized to suture or wire fixation. Compression after fixation and compression during cyclic loading between 10 and 50 N was measured with a load cell at the articular surface and compared with a 1-way analysis of variance (p < 0.05). Twenty-four fractured synthetic ulna were randomly assigned to wire or suture tension band constructs and low- or high-loading groups. The low-load group (12 ulnae) cycled loading from 3 to 10 N for 100 cycles followed by a failure test. The high-load group (12 ulnae) experienced 10 to 100 N before failure testing. Fracture separation (mm) and failure load (N) were compared using a 2-way analysis of variance (p < 0.05). Ten synthetic ulnae were randomized to wire/suture groups and cyclically loaded between 10 to 50 N while measuring loads across the fracture using a load cell. Correlation data were statistically compared with a Fisher transformation and z test (p < 0.05).
  
  
  RESULTS
  Residual compression was statistically greater for wire compared with suture. There was no difference in fracture displacement between groups during low loads. Suture had significantly greater displacement compared with wire at high loads. Failure loads were significantly greater for wire at both load settings. Wires transmitted forces across the joint surface more readily than sutures.
  
  
  CONCLUSIONS
  Suture tension bands had lower ultimate failure loads and less compression at the fracture site. However, if low loads are expected or if the fracture is reduced easily, the suture tension band may be an appropriate alternative to wire fixation.
  
  
  CONCLUSIONS
  Perhaps, in small children or when using casts in bigger children, a bioabsorbable suture may be used for fracture stabilization avoiding the need for extensive surgery to remove the fixation material.
authors.affiliation: Hospital St Justine, Montreal, Quebec, Canada.
authors.forename: Stefan
authors.initials: S
authors.lastname: Parent
authors.forename: Michelle
authors.initials: M
authors.lastname: Wedemeyer
authors.forename: Andrew T
authors.initials: AT
authors.lastname: Mahar
authors.forename: Megan
authors.initials: M
authors.lastname: Anderson
authors.forename: Frances
authors.initials: F
authors.lastname: Faro
authors.forename: Suzanne
authors.initials: S
authors.lastname: Steinman
authors.forename: François
authors.initials: F
authors.lastname: Lalonde
authors.forename: Peter
authors.initials: P
authors.lastname: Newton
mesh_terms: D001672:Biocompatible Materials; D001696:Biomechanical Phenomena; D001864:Bone Wires; D002648:Child; D004551:Elbow Joint / Q000601:surgery*; D005593:Fracture Fixation, Internal / Q000379:methods*; D006801:Humans; D013536:Suture Techniques; D013537:Sutures; D014458:Ulna Fractures / Q000601:surgery*; D000092464:Elbow Injuries
chemical_list: D001672:Biocompatible Materials