Locking screw-plate interface stability in carbon-fibre reinforced polyetheretherketone proximal humerus plates

Abstract

The mechanical stability of locking screws in CFR-PEEK plates is comparable or superior to locking screws in SS plates.

Functional results and unfavorable events after treatment of proximal humerus fractures using a new locking plate system

“…According to biomechanical studies, fixation of unstable proximal humerus fractures with a CFR-PEEK plate allows an increased motion at the bone-implant interface compared with a titanium locking plate, which might be an advantage [23,33]. Another biomechanical study showed an equal or higher stability of locking screws in CFR-PEEK plates compared to locking screws in stainless steel plates [15]. There are several clinical studies in the literature that analyzed both the functional results and unfavorable events after angular stable plate fixation of the proximal humerus.…”

“…The CFR-PEEK plates have a modulus of elasticity that is very similar to that of cortical bone [ 33 ]. Biomechanical studies showed several advantages like an increased motion at the bone-implant interface and a higher stability of locking screws in the CFR-PEEK plates [ 15 , 22 , 34 ]. Locking titanium plates have a rigid link between plate and screw, which can lead to failure at the bone-screw interface, especially in osteoporotic bone [ 26 ].…”

Research Progress in Surgical Treatment of Proximal Humeral Fractures in Elderly Osteoporotic Humerus

“…This technique can yield positive results, especially in fracture types with large and strong nodular fracture fragments. After the introduction of locking steel plates, the indications for such treatment increased [22]. Traditionally, at the metaphysis with poor proximal humerus, screw fixation carries the risk of screw detachment.…”

Plate osteosynthesis of proximal humerus fractures: treatment options and technical advancements

“…CF-PEEK plates demonstrated similar mechanical properties to that of titanium plates, except for bending strength, inferior by 20% to that of a metal proximal humerus plate, and yet adequate for proximal humerus fixation, with the advantage of decreased debris particles formation 84,85 . Its increased flexibility may exert a positive effect on fracture healing 87 ; its elastic modulus should unload the screw-tip/bone interface and therefore lower the rate of secondary screw perforation and loss of reduction 88 . The radiolucency grants an easier intraoperative fluoroscopic evaluation of fracture reduction and greater tuberosity position and a clearer post-operative radiographic assessment of reduction loss and fracture healing (Fig.…”

“…Due to the difference in material composition, cold welding between plate and screws is avoided, allowing easier and safer hardware removal 83 . Locking screws of CF-PEEK plates can cut-through plate material, tapping their thread, or can lock to pre-machined threads in the plate holes 87 . No changes in biomechanical properties of the plate was detected depending on plate/screw interface 86 .…”