Locking Screws

What are orthopedic screws?

Orthopedic screws can be used for the attachment of implants to the bone, bone to bone fixation, or for soft tissue fixation or anchorage. There are many different variations of screws available:

• Design: Conventional, Locking, Headless, Cannulated, Single- or Double-lead threads
• Material: Stainless Steel, Titanium, Bioabsorbable
• Characteristics: Non-self tapping, Self-tapping, Self-drilling and more

Benefits of Locking vs non-locking plate/screw systems:

1. Locking plate and screw systems have advantages over the conventional screw systems. Conventional plate/screw systems require precise adaptation of the plate to the underlying bone. Without this intimate contact, tightening of the screws will draw the bone segments toward the plate, resulting in alterations in the position of the osseous segments and the occlusal relationship. Locking plate/screw systems offer certain advantages over other plates in this regard. The most significant advantage may be that it becomes unnecessary for the plate to intimately contact the underlying bone in all areas. As the screws are tightened, they “lock” to the plate, thus stabilizing the segments without the need to compress the bone to the plate. This makes it impossible for the screw insertion to alter the reduction.
2. Another potential advantage in locking plate/screw systems is that they do not disrupt the underlying cortical bone perfusion as much as conventional plates, which compress the undersurface of the plate to the cortical bone.
3. A third advantage of the use of locking plate/screw systems is that the screws are unlikely to loosen from the plate. This means that even if a screw is inserted into a fracture gap, loosening of the screw will not occur. Similarly, if a bone graft is screwed to the plate, a locking screw will not loosen during the phase of graft incorporation and healing. The possible advantage to this property of a locking plate/screw system is a decreased incidence of inflammatory complications from loosening of the hardware. It is known that loose hardware propagates an inflammatory response and promotes infection. For the hardware or a locking plate/screw system to loosen, loosening of a screw from the plate or loosening of all of the screws from their bony insertions would have to occur.
4. Locking plate/screw systems have been shown to provide more stable fixation than conventional nonlocking plate/screw systems.

Reference: From Nicolas Homsi et al. in Locking Plate Principles, AO Surgery Reference, 2014 available online.

KYON Locking Screws KLS™

• Self-tapping with cutting flutes
• The self-locking pairing of screws and plates  are designed to minimize the risk of cold welding
• Consistent, fretting-free load transfer between bone screws and implants
• Torx-type
• Easy to insert, fast, and safe.
• Easy to take out and a reduced risk of jamming.
• Titanium alloy (TAN) of superior strength and exceptional biocompatibility

How much angulation is possible when using KLS™?

KLS™ with a bead can be inserted with up to 30° longitudinal and 5° transverse swivel.

How to remove a bead from a KLS™?

The easiest way to remove a bead that is tightly sitting on a screw is to use the bead removal instrument.

• Remove the bead with the screw from the implant
• Place the screw with the bead over the respective screw diameter hole on the bead removal instrument
• Give the tip of the screw a little tap with a hammer or other suitable instrument
• The bead becomes loose
• Check both items on structural integrity
• Clean and sterilize the items in order to use them again