Knee replacement surgery: ConforMIS CEO Philipp Lang on custom joint replacement | Disruptors

January 2, 2013 by Brian Johnson

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In this episode of Disruptors, we talk to ConforMIS founder & CEO Philipp Lang about how the privately-held custom joint implant maker is set to revolutionize knee replacement surgery.

The Bedford, Mass.-based orthopedic maker, which started in 2004, has been on a roll for the past 3 years, having raised $89 million in a Series E funding round in early 2012, bringing its fund-raising collections to about $140 million since 2009.

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MassDevice publisher Brian Johnson sat down with Lang recently to discuss the company's past and its future. Take us back before you founded the company in 2004, what was the genesis of the idea behind Conformis?

Philipp Lang: The genesis was that there are too many compromises today in knee replacement and in fact, in other forms of joint replacement. So if you look at how this was practiced in 2004 and how it is practiced in 2012 it has basically not changed.

So what it means for the surgeon is that every single time [a knee replacement is performed] he or she is confronted with having to find compromises on the shape of the device.

What this translates down to is issues with patient satisfaction. Patients have complaints with pain after surgery, they have difficulty walking downstairs, they have limited range of motion, they can't get back to the same type of physical activity that they have before they have arthritis.

So that's just a summary of some of the issues. If you look at some of the principal thoughts behind all of this was we want to correct any underlying deformities, bow knees, knocked knees so we go back to normal mechanical alignment of the joint. But then we want to recreate the anatomy that the patient had prior to developing arthritis.

No human knee has constant curvatures or constant radii every patient is different. If he can go back and recreate something close to the patient's original anatomy corrected for deformity, you should get a much better clinical result, you should get a much better functional result. What were some of the limitations or questions you faced when you brought this idea before investors and physicians and surgeons?

PL: There were a number of key hurdles that we had to face. The first hurdle that we saw as we started out with earlier commercials looking back at 2008, was that we had historically started out with a partial knee approach. But so literally looking at the market dynamic, our initial implants could only address the 10% of the available market.

That said, the technology per se was so disruptive and the concept was so compelling that for those companies that published their data for the last three years, 12 quarters consecutively in a row, we have been on average the fastest-growing company in the entire space. But we had an intrinsic limitation in accessible market which we addressed now with introduction of iTotal initially in limited release which started in May of 2012 and we've done a couple of thousand surgeries in limited release working with a broad range of surgeons.

Then in September 15 we actually went into full commercial launch with what we call the iTotal G2 and now we can address the largest market segment in knee replacement and in fact in orthopedics in general.

The second major challenge that we had, and full disclosure we didn't foresee when we started out with the company, was the scalability. Traditional manufacturing you would take a block of plastic and you would cap this with the C&C milling machine. The process that we're using today is a process where basically a 3D printing machine lays down a layer of nylon powder, 50 or 100 microns typically and then  laser zips across that layer of nylon melts it, the next layer is being laid down, another layer is being melted. So in additive fashion layer by layer is being added.

What you get out of this is ultimately a disposable instrument that you see here that's generated with an additive manufacturing 3D printing. That was manufactured in this fashion.

The fact that this new technology is available now for manufacturing that was key to our scale-up and that's really what supports and sustains our scale-up so we have really across all manufacturing functions we have basically a cellular manufacturing approach where we look at our quarterly or 6 months forecast we look how we're growing. We know the capacity that we can get out of one existing machine we're just adding machines as we grow.

MassDevice: How is Conformis' customized implant different from the current standard of care with knee replacement surgery?

PL: Well technology is different in that every knee is customized there is no more compromise, there is no over-sizing, there is no under-hang. If you look at this for example, and there is one more and we're looking at it from the back, you can see that this medial condyle the inside of the knee is very wide while the lateral condyle is very narrow. If I had a standard implant, I would likely be two small medially and I would overhand laterally in this area causing soft tissue impingement and pain.

So those compromises are addressed comprehensively they don't happen anymore. I think the other key compromise that we know the surgeon has to do with every single surgery is he is putting in my right hand a standard implant, he is putting a perfectly symmetrical implant into a highly asymmetrical joint. What's the result? The result shows for the surgeon intraoperatively that the surgeon has difficulty to make the ligaments of the patient work and he does, probably has to go through a process called ligament balancing. Which means he has to cut ligaments, he has to cut soft tissue. The joint doesn't give you enough flections or he cuts more soft tissue trying to get more flection. And he will never get the type of motion that the patient had prior to the surgery.

And what is very impressive is that when you look at the primary data at 6 weeks after surgery, close to 70 percent of patients report back that the knee feels natural they can't tell a difference to the un-operated knee. When you look at them one year after surgery 85 percent of patients report they can't tell the difference and that's really unprecedented. We have very similar feedback on the iTotal where again we have less experience because we've just started on the limited release in May of last year. But again we've done a couple of thousand procedures. But we have that type of feedback.

In summary, when we look at knee replacement and today using standard devices, the patient is being fitted to the implant. What we do we take each individual patient and we fit the implant individually to the patient and that's truly unique.