Unique elastic interference technology solves set screw loosening and eliminates rod bending
August 23, 2022
SALT LAKE CITY–(BUSINESS WIRE)–Nexus Spine, a developer of biomechanically-advanced solutions for spinal pathologies, today announced the full commercial launch of its PressON™ posterior lumbar fixation system. PressON™ features rods that press onto pedicle screws rather than attach using set screws. This novel design is approximately one quarter the size of traditional systems, is faster to implant,1 is biomechanically stronger,2 eliminates the possibility of set screw loosening, and allows for intraoperative construction of patient-specific rods. This full market release adds to the company’s growing compliant mechanism-based portfolio, including its line of flexible Tranquil™ titanium interbody fusion devices, and follows a lengthy validation phase of refinements and system enhancements. 
Nexus’s use of compliant mechanism technology allows for the creation of novel designs that behave in fundamentally new ways to solve unmet clinical needs. Compliant mechanisms function by bending rather than sliding. As an example, PressON™ incorporates flexible bores that are stretched over pedicle screw heads during implantation. The resulting elastic interference fit between screw and rod does not use traditional set screws, which have been shown to loosen during implantation and postoperatively.3,4
Thomas Sweeney, II, MD, PhD, the surgeon designer of the system, commented, “There hasn’t been meaningful innovation in non-deformity posterior fixation technologies in a very long time. PressON™ is unlike anything else on the market in the way that the components are connected. Not only does it result in a construct that is smaller, stronger, and faster to implant, but it is also unique in its ability to create patient-specific multilevel rods intraoperatively. As a result, it eliminates the need for rod bending and the pain associated with improperly bent rods and rod creep. PressON™ is uniquely poised to disrupt the posterior lumbar fixation market that has long been mired by a lack of differentiation.”
“Our expertise in compliant mechanism engineering allows us to do some really unique things,” commented David Hawkes, President of Nexus Spine. “The ability to secure PressON™ rods through elastic interference rather than using set screws is certainly a paradigm shift. We are in the process of shining a light on the incidence and harmful effects4 of set screw loosening through clinical and benchtop research. We look forward to sharing the results of these studies soon.”
About Compliant Mechanisms
Compliant mechanisms mimic nature by providing motion and force transmission through bending rather than from traditional sliding joints. This breakthrough enables bio-friendly materials such as titanium to function more like human tissues, at the macro and microscopic levels. This approach utilizes modern mathematical modeling, 3D finite elemental analysis, and 3D printing to drastically improve the way that spinal implants perform. Nexus compliant mechanism-based devices have been implanted in patients since 2015 with the goal of achieving faster healing with less pain and at a lower cost.
About PressON™ Spinal Fixation System
PressON™ is a unique pedicle screw-based spinal fixation system that features rods that are elastically pressed on to screw heads instead of tightened using traditional set screws, which are prone to loosening and subsequent construct instability.4 PressON™ employs compliant mechanism technology to match the patient’s specific anatomical needs, eliminating spinal rod-bending and other painful persuasion techniques currently used in spinal surgeries. Additionally, PressON™ is substantially faster1 and easier to implant and is roughly one quarter the volume of competitive devices, thus decreasing incision length and soft tissue irritation.
About Tranquil™ Interbody Fusion Technology
Tranquil™ is a flexible interbody fusion device made of titanium that is shaped and engineered using compliant mechanism principals to behave like spinal trabecular bone by mimicking its stiffness, resulting in a device that is 1/10th the stiffness of traditional competitive interbody fusion implants. Tranquil™ is available in cervical, ALIF, PLIF, TLIF, steerable TLIF, and DLIF configurations.
About Nexus Spine
Nexus Spine develops industry-leading spinal implants by leveraging our novel compliant mechanism engineering expertise. Our innovative and evidence-based approach continues to advance the standard of surgical technologies through a rigorous focus on improving clinical outcomes while being easier to implant. Our streamlined spinal fusion systems minimize implant bulk, surgery time, and hospital handling, which make them especially well-suited for the ambulatory surgery center setting. We are wholly owned by Crocker Ventures, an independent, privately-held life science, healthcare and technology investment firm. For more information on Nexus Spine, Tranquil™ and PressON™, please visit www.nexusspine.com.
1 Data on file. Nx22-112.
2 Data on file. ASTM 1717.
4 Serhan, H., Hammerberg, K., O’Neil, M., Sturm, P., Mardjetko, S., & Crawford, A. (2010). Intraoperative Techniques to Reduce the Potential of Set-screw Loosening in Long Spinal Constructs. Journal of Spinal Disorders & Techniques, 23(7), e31–e36. https://doi.org/10.1097/BSD.0b013e3181c982a1
Contacts
Andrew Shepherd
andrew.shepherd@nexusspine.com
