But on the other hand, in the generalizable surgeon population, enabling technologies may be necessary. If you look at registry data which is large, generalizable data, the Australian Registry showed a decrease in the rate of failure in younger patients (de Steiger, JBJS-Am 2015).
That’s who you care about because those are the ones that we worry about the most, those are the ones where you are going to see the problems right away. Navigation improved alignment, but what robotics adds is that it can do soft tissue balance which was always the thing that was missing from navigation. You can get sizing, soft tissue balance, and positioning.
Multiple articles have shown that the robotics do improve the early results and the robotic surgery can do lots of things. It can do planning, gap balancing, you can also use it to aid you in the execution of your operative plan.
In conclusion, innovation is good and necessary. Enabling technologies have improved clinical outcome and this is even more important as we go on and do many younger and obese patients and I think many new knee designs require a more individualized approach—as we learn what’s best, we can individualize it.
So, the future I would say is now in robotics and enabling technology.
Dr. MacDonald: My opponent has many accomplishments and accolades for certain. He’s a friend with impeccable fashion sense unquestionably. But since he got into the robotics scene something has changed, and I don’t know what exactly it is.
He’s confused. We need to be very clear about what issue we are debating. It’s not navigation. Instead, it is questionable added benefit of robotically assisted navigation.
We have many enabling technology choices today.
We can use: conventional instrumentation, patient-specific jigs, image-free navigation (where you intra-operatively do the registration with no pre-op imaging), image-guided navigation (where you get a pre-op CT or MRI or intra-operative fluoro), hand-held navigation and then lastly, there is robotic navigation—which is the topic of the debate.
With robotic navigation you generally get a pre-op CT and then guides that take you through intra-operative cuts or milling.
There is lots of hype regarding navigation so here’s a quote, “Long-term cost savings result from shorter hospitalization, decreased morbidity, improved joint stability and decreased rehab time.”
The problem is that’s from a sales brochure from 13 years ago so where have we moved this needle? The first navigated knee was 20 years ago. Yes, technologies evolve—as do techniques. In fact, almost everything changes over 20 years.
After 20 years of navigated total knees there is still no definitive proof. If we can at least agree to aim for a neutral mechanical axis, you’re trying to go down the middle of the runway, plus or minus 3 degrees (which is what we’ve generally aimed for historically) and we want to avoid the outlying. No question, navigation gets you there.
Multiple studies dating back 10 years or more show that you will have a tighter standard deviation and much fewer outliers with navigation.
Meta-analysis shows the same thing. Every paper favors navigation for achieving your alignment goals. Robert Barrack (CORR 2013) did an excellent review and found decreased outliers, improved mechanical alignment, no consistent difference in functional outcomes with navigation.
Also, as Steve mentioned, there are no long-term studies, just short- and medium-term studies. I’m a data-driven guy. The Australian Registry shows if you’re less than 65 years of age and if you navigate versus non-navigate a knee, there’s about a 1% difference at 9 years. About 30% of knees done in Australia right now are navigated compared to North America where we’ve gone from 5% to 3%, and most of our navigation machines look like they’re a glorified closet in our operating room.
