title: Biomechanical performance of different cable and wire cerclage configurations.
abstract: OBJECTIVE
  Cerclage technology is regaining interest due to the increasing number of periprosthetic fractures. Different wiring techniques have been formerly proposed and have hibernated over years. Hereby, they are compared to current cerclage technology.
  
  
  METHODS
  Seven groups (n = 6) of different cable cerclage (Ø1.7 mm, crimp closure) configurations (one single cerclage looped once around the shells, one single cerclage looped twice, two cerclages each looped once) and solid wire cerclages (Ø1.5 mm, twist closure) (same configurations as cable cerclages, and two braided wires, twisted around each other looped once) fixed two cortical half shells of human femoral shaft mounted on a testing jig. Sinusoidal cyclic loading with constantly increasing force (0.1 N/cycle) was applied starting at 50 N peak load. Cerclage pretension (P), load leading to onset of plastic deformation (D) and load at total failure (T) were identified. Statistical differences between the groups were detected by univariate ANOVA.
  
  
  RESULTS
  Double looped cables (P442N ± 129; D1334N ± 319; T2734N ± 330) performed significantly better (p < 0.05) than single looped cables (P292N ± 56; D646N ± 108; T1622N ± 171) and were comparable to two single cables (P392N ± 154; D1191N ± 334; T2675N ± 361). Double looped wires (P335N ± 49; D752N ± 119; T1359N ± 80) were significantly better (p < 0.05) than single looped wires (P181N ± 16; D343N ± 33; T606N ± 109) and performed similarly to single looped cables. Braided wires (P119N ± 26; D225N ± 55; T919N ± 197) exhibited early loss of pretension and plastic deformation.
  
  
  CONCLUSIONS
  Double looped cerclages provided a better fixation stability compared to a single looped cerclage. Double looped wires were comparable to a single looped cable. The use of braided wires could not be recommended mechanically.
authors.affiliation: AO Research Institute Davos, Davos-Platz, Switzerland. mark.lenz@aofoundation.org
authors.forename: Mark
authors.initials: M
authors.lastname: Lenz
authors.forename: Stephan Marcel
authors.initials: SM
authors.lastname: Perren
authors.forename: Robert Geoff
authors.initials: RG
authors.lastname: Richards
authors.forename: Thomas
authors.initials: T
authors.lastname: Mückley
authors.forename: Gunther Olaf
authors.initials: GO
authors.lastname: Hofmann
authors.forename: Boyko
authors.initials: B
authors.lastname: Gueorguiev
authors.forename: Markus
authors.initials: M
authors.lastname: Windolf
mesh_terms: D000704:Analysis of Variance; D001696:Biomechanical Phenomena; D001864:Bone Wires; D002102:Cadaver; D005269:Femur / Q000601:surgery*; D005593:Fracture Fixation, Internal / Q000295:instrumentation*; D006801:Humans; D057068:Periprosthetic Fractures / Q000601:surgery*; D011474:Prosthesis Design; D011475:Prosthesis Failure; D013314:Stress, Mechanical