Listening to surgeons helped startup REX Ortho innovate.

REX Ortho is an exciting new start-up company developing novel expandable screws for orthopaedic applications. It is a platform technology with a beachhead indication in nailing proximal femoral fractures using their proprietary F-REX expandable lag screw. 

Recently they were a part of the Orthopaedic Research Society (ORS) Business Innovation Competition. They were awarded the top prize based on a 10-page business plan and a 10-minute pitch to a panel of judges made up of experienced orthopaedic executives and an audience of surgeons and researchers at the annual ORS conference. 

When asked “what makes a compelling pitch?” Dr Matt Oldakowski, REX Ortho CTO said “A robust and validated set of value propositions”. As a company we listen very carefully to surgeons, payers, patients and potential acquirers to make sure that there is a strong market pull for our devices. Often companies just go through the motions with Voice of Customer research and don’t really listen properly. For example, often engineers going through the mandatory ISO13485 User Needs process don’t take the time to really understand what surgeons are telling them and are then reluctant to take on difficult engineering challenges to meet those requirements that they don’t fully understand. Our team has the opposite approach, spending a lot of time talking to many, many surgeons in the US and around the world, from very senior Key Opinion Leaders down to junior registrars and this feedback has translated into our devices being very attractive to surgeons”

Figure 1 Intan Oldakowska and Matt Oldakowski (CSO and CTO of REX Ortho) discussing device design with Orthopaedic Surgeon Prof Markus Kuster

The four critical requirements that the REX Ortho team identified during their extensive Voice Of Customer development was that the REX screw:

  1. Needs to increase fixation strength in a clinically meaningful way
  2. Has to fit within the existing surgical workflow without significantly increasing surgery time; 
  3. Needs to be easy to remove if necessary; and
  4. Needs to fit within existing manufacturing workflows without significantly increasing cost.

Addressing a real unmet clinical need

Often new orthopaedic fixation devices are designed specifically to maximise performance in a particular simplistic lab test, like pull-out. Then claiming that this performance can be replicated for many different indications around the body. This makes for a great early research paper but if you optimise the design for the test without considering the complex clinical loading and failure criteria for a particular indication, then you end up with a device that doesn’t really address a real unmet clinical need and reduce complications for patients. Surgeons don’t want to use a device like that and payers don’t want to pay unless it saves them money by reducing complications and subsequently revision rates.

REX Ortho developed their F-REX screw specifically for fixating proximal femoral fractures, understanding the loading and the clinical failure modes that need to be optimised to reduce clinically relevant measures like varus collapse and neck rotational failure. Their paper presented at ORS demonstrated a very significant improvement in these failure modes using advanced stereoscopic fragment tracking. 

Minimal disruption to existing surgical workflow

Often new orthopaedic fixation devices add several additional steps to the surgical workflow and change standard steps that surgeons are already used to. This may seem a minor change to a bioengineer, but surgeons know that change means risk for their patients due to the necessary learning curve. In addition, additional operating theatre and surgeon time is cost for payers. 

REX Ortho is developing a device that maintains the current surgical workflow and tools, including fitting over a standard gauge guide wire, using the same screw position, and only adding one extra step; simply turn in the expander bolt into the back of the screw body and in less than a minute you are done.

A reliable and easy removal procedure

A very strong message REX Ortho got from surgeons was that “we don’t want to put anything in the body that we can’t easily remove.” This make sense for surgeons, as they know they could potentially be making a very difficult future revision surgery for themselves or their colleagues, if removal is complicated. In addition, surgeons and orthopaedic companies remember previous removal issues with devices like the Brooker-Wills nail and others.

REX Ortho took this requirement so seriously that they named their company after it; where REX stands for Removable EXpandable screw. Many propriety design features promote ease of removability including no gaps for the bone to grow into the internals of the screw, jamming them and no permanent bending of the screw parts so they can return precisely to their exact pre-expanded position for removal. REX Ortho is the only company ever to do an animal study to validate their technology could be easily removed. They implanted miniaturised REX Screws into the distal femurs of 5 sheep and showed that they could unexpand them to very low torque and remove them without complications after 4 months in the body.

Designed for mass manufacturing

Lastly, the REX Screw must be easy and cost effective to manufacture. The REX Ortho team has achieved this by designing for conventional manufacturing processes and minimising the changes to interfacing sections of the screw. This allows only a marginal increase in total system COGS which will still allow a healthy profit margin with competitive pricing.