It was shown that the spatial insertion angle of screws plays a key role in the performance of joints, not only because it relates to the shank to grain angle, but also because it affects the amount of wood involved in the bearing mechanism.
The prolific Jean Warin, one of the great engravers, finally established the use of the fly press, a variation on the screw press in which the helix angle of the screw was much increased.
As the popularity of volar locked plate fixation for distal radius fractures has increased, so have the number and variety of implants, including variations in plate design, the size and angle of the screws, the locking screw mechanism, and the material of the plates.
Variations in plate design include adaptations to the shape and contour of the plate, the size and angle of the screws, the locking screw mechanism, and the type of plate material.
With the regulation of polyaxial bushing in the plate hole by an angular regulation sleeve, the locking angle of the screw can be regulated as much as 30° which allows the surgeon to insert the locking screw more desirably.
The power law index influences the choice of optimum channel depth and helix angle of the screw extruder.
To evaluate the potential risk of these complications, the length and trajectory angle of each screw were measured on the CT images and compared between the groups with and without the complications.
The C-shaped defect of the polyaxial bushing and the three concaves on its obverse surface fit precisely with the four dental processes on the tip of the polyaxial regulating sleeve which drives the rotation of polyaxial bushing in the polyaxial hole to regulate the locking angle of the screw.
The influence of the number and angle of insertion of screws, screws characteristics, friction and loading on the joint performance was explored.
