Why Navigation for TKA didn’t work back in 2009, and why Robot assistance for TKA works today.
Why Navigation was doomed to fail in 2009? And why Robotics rock the house in 2019! (Philip Winnock de Grave, MD – LinkedIn)
Some people argue robotics are industry’s next commercial move after the navigation hype 10 years ago. Indeed, the scene looks quite comparable… but actually the setting changed considerably.
We have to understand the time period navigation made it’s launch. In the 2000’s, many myths and dogma’s were out there. At conferences, the “how to balance the TKA discussion was leading the dance. Are you a ligament balancer or a bony referencer? Do you release or not? And, one those things that was never questioned was… the targeted alignment. The number one, out-of-discussion dogma: the perpendicular tibial cut: “you shall always cut your tibia straight” (=mechanical alignment). Performed a 90.0° tibial cut? Bull’s eye, that knee must perform perfect. Another dogma. Whatever the patient’s native HKA alignment was: “you shall end up with a straight leg”. The straighter the better. Unfortunately… a misleading target for the -poor- navigation guys.
Another feature about navigation, it’s time-consuming. Putting on the trackers, registration of the articular surfaces… it takes time. And there’s more delay. Cuts are performed with a handheld saw and classic jigs, but if you want accuracy… you need to double-check the accuracy of the cuts with navigation, and when inaccurate (eg. flexible sawblade, unstable jig, sclerotic bone, human error) adjust the cuts with new manual cuts. So nowhere time gains, only delays.
So navigation was time-consuming, and notwithstanding being more accurate not leading to better clinical results. So, despite having potential, indeed a premature end of the navigation fairy tale.
Now ten years later, robotic TKA surgery is the new big hit. And nothing seems to stop the success. Clinical outcomes are promising, surgical adherence is growing. Augmenting navigation with robotical execution offers a lot of benefits: accuracy, time-efficiency, soft-tissue friendly (haptic feedback). These benefits are very important but not solely responsable for the success of the current robotic sensation. What else is different from 2009? What else happened between 2009 and 2019? Among TKA surgeons, a degree of ‘enlightenment’ did arise.
Enlightenment: "a European intellectual movement of the late 17th and 18th centuries emphasizing reason and individualism rather than tradition." (Google)
‘Reason and individualism‘ within TKA the surgeon community in 2019 meaning: ‘each individual knee is unique and should be treated in an individualized or personalized way’.
End of the mechanical alignment dogma or the straight-cut-fits-all superstition. Indeed, one of the biggest assets of the robot is the capability to analyze the patient’s unique bony anatomy and it’s unique soft-tissue envelope… helping the surgeon to define the optimal individualized and -oblique- bony cuts. Subsequently, the robot executes the planned cuts single-shot. No releases. Personalized TKA-surgery is making the difference in 2019.
In 2019, we are able to figure out -finally-with the aid of the robot a personalized alignment plan for each individual knee
So… in 2009, navigation was still a time-consuming process with the necessity of accuracy checks, and -most important- chasing a suboptimal target. In 2019, we are able to figure out finally with the aid of the robot a personalized alignment plan for each individual knee… and perform this plan efficiently in a most accurate way.
Read more about the Inverse Kinematic Alignment here – https://www.linkedin.com/pulse/inverse-kinematic-new-individualized-alignment-tka-philip/