title: Stability of two angular stable locking plates for open wedge high tibial osteotomy (HTO): TomoFix™ versus LOQTEQ® HTO plate.
abstract: BACKGROUND
  The aim of this study was to test the mechanical stability of LOQTEQ® HTO plate in comparison to the TomoFix™ internal plate fixator.
  
  
  METHODS
  An unstable fracture gap model with two standardized polyoxymethylene (POM) cylinders was used for this study. With this model 5 LOQTEQ® HTO plates and 5 TomoFix™ were cyclically loaded. The start load was 100 N and increased by 50 N after each successful completed cycle. Each load step included 250,000 cycles. All tests were performed in accordance with the American Society for Testing and Materials (ASTM) Standard Specification and Test Method for Metallic Bone Plates F382-99(2003)e1.
  
  
  RESULTS
  The mean fatigue strength of the LOQTEQ® HTO Plate was 155 % of the value gained by the TomoFix™ implant. This difference was statistically significant (t test <0.001). There was also a significant difference in the cycles but both implants survived. The LOQTEQ® HTO Plate system survived 1,520,336.8 (±121,687.7) cycles, whereas the TomoFix™ group passed on average 847,802,600 (±134,660.7) cycles. In both groups, the only failure mode was plate breakage in a shaft hole.
  
  
  CONCLUSIONS
  The results of the present study showed that fatigue strength of the LOQTEQ® HTO plate was significantly higher in comparison to TomoFix™. These results justify the clinical use of the LOQTEQ® HTO plate.
authors.affiliation: Department of Trauma and Orthopaedic Surgery, Martin Luther Hospital, Caspar Theyss Straße 27-31, Grunewald, 14193, Berlin, Germany, w.petersen@mlk-berlin.de.
authors.forename: Wolf
authors.initials: W
authors.lastname: Petersen
authors.forename: Alexander
authors.initials: A
authors.lastname: Wall
authors.forename: Thomas
authors.initials: T
authors.lastname: Paulin
authors.forename: Hi Un
authors.initials: HU
authors.lastname: Park
authors.forename: Lydia
authors.initials: L
authors.lastname: Heymann
mesh_terms: D001860:Bone Plates; D005593:Fracture Fixation, Internal / Q000295:instrumentation* / Q000379:methods; D006801:Humans; D008953:Models, Anatomic; D010027:Osteotomy / Q000295:instrumentation* / Q000379:methods; D013977:Tibia / Q000601:surgery*; D013978:Tibial Fractures / Q000601:surgery*; D016474:Weight-Bearing