Introducing the "Bone-Screw-Fastener" for improved screw fixation in orthopedic surgery: a revolutionary paradigm shift?
BACKGROUND
Conventional screws used for fracture fixation in orthopedic surgery continue to rely on the historic buttress thread design. While buttress screws generally provide solid resistance against unidirectional axial loading forces, their design suffers from several limitations, as the buttress thread does not adequately resist multiaxial forces. Furthermore, the buttress screw is prone to stripping at the bone-screw interface and can cause microfracturing of the surrounding bone due to its thread design. Standard buttress screws are therefore at risk of adverse postoperative outcomes secondary to failure of bone fixation. A new patented Bone-Screw-Fastener was recently designed that is based on an interlocking thread technology. This new fastener provides distributive forces from the threads onto the bone and therefore resists loads in multiple directions. The underlying concept is represented by a "female thread" bone cutting technology designed to maximize bone volume, preserve bone architecture, and create a circumferential interlocking interface between the implant and bone that protects the thread from stripping and from failing to multiaxial forces.


OBJECTIVE
We hypothesize that the new Bone-Screw-Fastener overcomes the classic shortcomings of conventional orthopedic screws with buttress threads by ease of insertion, improved bone preservation, increased resistance to off-axis multidirectional loading forces and to stripping of the threads. These advanced biomechanical and biological properties can potentially mitigate the classic limitations of conventional buttress screws by providing better resistance to implant failure under physiological loads, preserving bone biology, and thus potentially improving patient outcomes in the future.


METHODS
The presumed superiority of the new fastener will require testing and validation in well-designed prospective multicenter randomized controlled trials (RCTs), using the conventional buttress screw as control.


CONCLUSIONS
Once validated in multicenter RCTs, the new Bone-Screw-Fastener may drive a change in paradigm with regard to its innovative biomechanical principles and biologic bone preservation for surgical applications requiring screw fixation.
Department of Orthopaedic Surgery, Denver Health Medical Center, Denver, CO 80204 USA.|Department of Orthopaedic Surgery, University of Colorado School of Medicine, Aurora, CO 80045 USA.
Philip F
PF
Stahel
Department of Orthopaedic Surgery, University of Colorado School of Medicine, Aurora, CO 80045 USA.
Nicholas A
NA
Alfonso
Department of Orthopaedic Surgery, Denver Health Medical Center, Denver, CO 80204 USA.
Corey
C
Henderson
Department of Orthopaedic Surgery, University of Colorado School of Medicine, Aurora, CO 80045 USA.
Todd
T
Baldini