Currently, stailess steel, titanium and carbon-fiber reinforced polyetheretherketone (CF-PEEK) plates are available for the treatment of distal radius fractures. Since the possibility to create a less rigid fixation may represent an advantage in case of ostheoporotic or poor quality bone, the aim of this study is to compare the biomechanical properties of these three materials in terms of bending stiffness with a single static load and after cyclical loading, simulating physiologic wrist motion. Three volar plating systems with fixed angle were tested: Zimmer stainless steel volar lateral column (Warsaw, IN); Hand Innovations titanium DVR (Miami, FL); Lima Corporate CF-PEEK DiPHOS-RM (San Daniele Del Friuli, Udine, Italy). For each type of plate tested four right synthetic composite bone radii were used. An unstable, extraarticular fracture was simulated by making an 8 mm gap with a saw starting 12 mm proximal to the articular surface of the radius on the distal radio-ulnar joint side. The osteotomies were made perpendicular to the long axis of the bone to allow for a consistent fracture gap on the dorsal and volar sides of the radius. Plates were implanted using all the distal and proximal fixation holes [Fig. 1]. Each synthetic radius model was potted in methylmethacrylate and tested in a bi-axial servo-hydraulic test frame (MTS Minibionix 858, universal testing machine) for load to failure by advancing a cobalt chrome sphere centered over the articular surface at a constant rate of displacement of 5 mm/min. The sphere was advanced until the construct failed or the dorsal edges of the fracture met. The resultant force was defined as bending stiffness pre fatigue. Three constructs for each plate were then dynamically loaded for 6000 cycles of fatigue at a frequency of 10Hz, with a load value corresponding to the 50% of the previously calculated bending strength. Finally, the constructs were loaded to failure, measuring the bending stiffness post fatigue.Background
Materials and Methods
Implants based on the polyetheretherketon (PEEK) polymer have been developed in the last decade as an alternative to conventional metallic devices. PEEK devices may provide several advantages over the use of conventional orthopedic materials, including the lack of metal allergies, radiolucency, low artifacts on magnetic resonance imaging scans and the possibility of tailoring mechanical properties. The purpose of this study was to evaluate the clinical results at mean 24-month follow-up using a new plate made of carbon-fiber-reinforced polyetheretherketon (CFR-PEEK) for the treatment of distal radius fractures. We performed a prospective study including all patients who were treated for unstable distal radius fracture with a CFR-PEEK volar fixed angle plate. We included 70 consecutive fractures of AO types B and C that remained displaced after an initial attempt at reduction. The fractures were classified according to the AO classification: 35 fractures were type C1, 13 were type C2, 6 were type C3, 5 were type B1 and 11 were type B2.Background
Materials and methods
