title: [Biomechanical study of four palmar locking plates and one non-locking palmar plate for distal radius fractures: stiffness and load to failure tests in a cadaver model].
abstract: Five different palmar fixation plate designs were compared in a distal radial osteotomy cadaver model with regard to their biomechanical properties. A metaphyseal osteotomy gap of 1 cm was performed and the osteosynthesis was plated according to the manufacturer's instructions. Axial load was applied to the construct by a pneumatic material testing machine. Five implant groups with eight cadavers each were tested concerning stiffness. None of the constructs developed deformity and movement of the fracture gap larger than 2 mm with a load of 100 N. Increasing the load to 250 N revealed significant differences in stiffness and failure load between the different plates. The mean stiffness under axial load (mean+/-standard deviation) was 356.4+/- 138.6 N/mm for the radius correction plate without lateral tongue, 299.7+/-86.3 N/mm for the radius correction plate with lateral tongue, 132.8+/-41.5 N/mm for the distal volar radius plate, 112.5+/-40.2 N/mm for the 3.5 mm titanium locking compression plate and 91.9+/-29.2 N/mm for the standard stainless steel 3.5 mm T-Plate. The non-angular stable implant (STP plate) had the lowest stiffness. Unexpectedly, there were differences over 100% concerning the stiffness between the at first glance nearly similar angular stable implants. Additionally, a review of the literature concerning biomechanical investigations of the distal radial fracture was performed.
authors.affiliation: Klinik für Unfall-, Hand- und Wiederherstellungschirurgie GP Rüsselsheim, Deutschland. rudig@GP-Ruesselsheim.de
authors.forename: Lothar
authors.initials: L
authors.lastname: Rudig
authors.forename: Isabella
authors.initials: I
authors.lastname: Mehling
authors.forename: Daniela
authors.initials: D
authors.lastname: Klitscher
authors.forename: Dorothea
authors.initials: D
authors.lastname: Mehler
authors.forename: Karl-Josef
authors.initials: KJ
authors.lastname: Prommersberger
authors.forename: Pol M
authors.initials: PM
authors.lastname: Rommens
authors.forename: Lars Peter
authors.initials: LP
authors.lastname: Müller
mesh_terms: D000368:Aged; D001696:Biomechanical Phenomena; D001860:Bone Plates; D002102:Cadaver; D019245:Compressive Strength; D004548:Elasticity; D004867:Equipment Design; D019544:Equipment Failure Analysis; D005593:Fracture Fixation, Internal / Q000295:instrumentation*; D006801:Humans; D008297:Male; D011885:Radius Fractures / Q000503:physiopathology* / Q000601:surgery*; D013314:Stress, Mechanical; D013718:Tensile Strength; D016896:Treatment Outcome; D016474:Weight-Bearing; D014954:Wrist Injuries / Q000503:physiopathology* / Q000601:surgery*