AO innovation resources support development of new spinal screw

A new spinal screw offering better fixation, stability, and—uniquely—removability could be in surgeons’ hands in the next four to five years, thanks to the collaboration of AO’s innovation funding and the Australian company REX Ortho.

The S-REX Screw project, which got underway in late 2023, brings together the AO, REX Ortho, and Switzerland’s 41medical to collaborate to apply novel fixation technology and develop a new spinal screw. The AO—with its global network of over half a million health care professionals—will support the project with input on clinical usability, biomechanical know-how, clinical trials, market access, and funding; 41medical will contribute expertise in regulatory clearance, prototyping, manufacturing, and more.

REX Ortho Executive Chair Ian Brown said the S-REX pedicle screw—the latest innovation in the company’s platform technology—is targeting a design that will provide a clinically meaningful increase in fixation strength by expanding and increasing the contact area and engagement with the bone. At the same time, the screw is un-expandable to facilitate easy removal.

“In fact, REX Ortho presented data at the Orthopaedic Research Society (ORS) in February 2023, demonstrating that the company’s F-REX hip screw could survive more than five times the number of simulated loading cycles compared to competing screws,” said Brown. The F-REX Screw is designed for patients with limited bone quality and should be both easy to use and easy to remove, he added.

Listening to the voice of surgeons

Significantly, as part of the solution’s development, the REX Ortho team decided early on to listen to the voice of surgeons. “What we’ve found is that surgeons want to be able to remove screws if necessary because of infections or other complications,” expressed Brown.

The S-REX Screw project is focused on addressing these concerns, Brown said, adding that significant interest in REX Ortho technology inspires new approaches to unmet needs in implant fixation solutions in orthopedics, dovetailing perfectly with the AO’s mission of promoting excellence in patient care and outcomes in trauma and musculoskeletal disorders.

Recognizing an unmet need

The origins of the S-REX Screw reach back to 2014, when orthopedic surgeons and AO members Phil Hardcastle, Markus Kuster, and Gabriel Lee recognized the need for improved fixation and stability in orthopedic surgery. They reached out to Curtin University (Perth, Western Australia) biomedical engineers Intan Oldakowska and Matt Oldakowski, who took a deeper dive into understanding the problem and the failure modes. The result was a concept that includes removability to the device design. In a first 2022 animal study REX Ortho evaluated the removability of its technology.

With the AO’s innovation funding and expertise, REX Ortho is plowing full steam ahead with the S-REX project to evaluate the innovation’s feasibility, establish proof of concept, verify the design, and prepare for clinical trial.

“It is exciting to have the AO team—including its world-leading surgeons—supporting our REX technology," Brown said. “The S-REX screw promises to deliver what the surgeons have asked for: improved fixation, improved stability, and improved removability all in one fixation screw.”

Brown’s advice for other innovators is simple: “If you believe your innovation has the potential to be best in class and have a real impact on patient outcomes, we recommend you work with the AO as they are best in class in innovation optimization, technology transfer, and commercialization,” he said. “Our collaboration with the AO has already lifted our project to a whole new level. We are super excited about the future.”