Mechanical evaluation of fourth-generation composite femur hybrid locking plate constructs

In Vitro Biomechanical Comparison of 3.5 String of Pearl Plate Fixation to 3.5 Locking Compression Plate Fixation in a Canine Fracture Gap Model

“…This was done to reflect the clinical reality that locking screws are more expensive than standard cortical screw and therefore the latter are used in combination with locking screws to decrease cost in clinical settings. Also it has been shown that a locking screw near an osteotomy (fracture) gap and another at the proximal end provide sufficient axial stiffness and torsional rigidity even if the remaining screws are standard cortical screws . This combination of screws can potentially influence the biomechanical properties of the constructs and consequently our results can only be applied to this specific construct.…”

“…Also it has been shown that a locking screw near an osteotomy (fracture) gap and another at the proximal end provide sufficient axial stiffness and torsional rigidity even if the remaining screws are standard cortical screws. 20 This combination of screws can potentially influence the biomechanical properties of the constructs and consequently our results can only be applied to this specific construct.…”

Locked Plating of Comminuted Distal Femur Fractures

“…33 Far cortical locking is one suggested method of maintaining the strength of a locked construct while promoting micromotion and callus formation. 37 In our study, we evaluated 4 locking plate constructs in a cadaveric low bone mineral density model to study the spectrum of stiffness and whether fixation strength can be altered by the position of the unlocked screw. 36 The same group also revealed that the locked screws at opposite ends of the diaphyseal fixation resulted in greater plate deformation and decreased locking screw pull-out torque, suggesting that locked screws at proximal-most and distal-most diaphyseal positions resulted in greater conduction of forces to the plate and plate-screw articulation itself.…”

Failure Analysis of PHILOS Plate Construct Used for Pantalar Arthrodesis Paper II—Screws and FEM Simulations

“…We ignored the effect of screw failure on the adjacent level screws both in terms of construct plate-screw placement angles and load transfer. As there is no viable way to identify the amount of screw micro-motion in this construct, it was assumed that displacement in the cortical screws within the range of 0.05-0.25 mm occurring within the few months after load bearing based on our research on hybrid constructs where the stiffness drop occurs within the first 5000 fatigue cycles [7] resulting in altering the coefficients of friction between the screws and bone; 0.5 with all screws intact to 0.1 when screws began to fail. All the locking screws were assumed to be fixed, while some displacement was allowed for the cortical screws along the x-axis, as shown in Figure 8, simulating human gait to reflect loading and deformation.…”

“…Hybrid fixation uses a combination of both locking and non-locking screws, which improve the stabilization economically. The locking and hybrid construct principles are outlined in Goswami et al [7].…”