Evolox Gen 2® plates
2nd Generation Evolox® is our latest advancement in poly-axial locking technology. It is unlike any previous medical thread form seen in the market place.
The usual method to achieve poly-axial locking is to either:
- Create interrupts (breaks) in the thread form, thus allowing the mating thread to pass through the gap to the next thread.
- Self-cut the screw thread into the plate.
The method in system 1 incurs far less complications with removal of the screw and implant, as system 2 requires the plate to be of a softer material than the screw which then cold fuses the screw to the plate. This is what makes the screw difficult to remove. Also the softer plate is inherently weaker than if using harder material. This method is usually reserved for Titanium products, using pure Titanium on the plate and alloyed Titanium on the screws.
System 1 can have limitations, as the interrupts in thread form reduce the thread strength and can result in thread stripping if subjected to excessive load after placement or excessive torque during placement. Thread stripping although uncommon will weaken the overall construct. To avoid this occurrence where excessive load after placement is anticipated, it is usual to advise an increase in the plate size to the next range, ie 2.7mm to 3.5mm or 3.5mm to 3.5mm broad etc.
This is not always ideal for many reasons, including wound closure and poor bone stock. For this reason, N2 UK Ltd have strived to overcome this problem and increased the scope of its useability through innovative design and complex machining strategies. We are pleased to say that after several designs and prototypes we have achieved our goal. Our 2nd generation Evolox® hole system (patent pending) uses a unique twin start tapered triangular thread form that naturally generates the space required to allow the threads to skip to the next level, thus maintaining a continuous thread form and drastically improving the rigidity of the locking interface.
This has allowed N2 UK Ltd to expand its range of poly-axial plates extensively into the 2.7mm and 2.4mm categories.