So, I’ll freely concede that if you navigate every knee, you’ll have fewer outliers and a tighter distribution of alignment. But what does a robot add to this whole thing?
First of all, it adds an unbelievable cost. It’s hard to get the prices exactly but a typical robot assist unit costs between $1.5-2 million dollars. Annual service agreement of about $150,000; disposables per case, about $1,000. For that cost there must be a large body of evidence for the robot. Right?
If you PubMed search “robotic-assisted total knee,” you get the sum total of 30 papers so it doesn’t take you long to review it and a lot of these are review articles.
What is it show? It doesn’t ever show them comparing navigation to robotics, it’s always conventional to robotic. In one particular article (Bargar et al, CORR 2013), yes you have less outliers with robotics, but this is basically a navigation system. The robot took 25 minutes longer with no difference in PROMS [Patient Reported Outcome Measures].
Another series looked at 30 patients’ bilateral knees conventional vs. robotic (Song et al, Knee Surg Sports Traumatol Arthrosc 2011), the same thing as navigation, less outliers. The robot, again, took 25 minutes longer to do.
Another series retrospectively looked at it (Hansen et al, J Arthroplasty 2014), no difference in clinical or radiographic outcomes. The robot case took 20 minutes longer and the conclusion is further surgical, clinical, and economic study of this technology is necessary.
A review article (Jacofsky et al, J Arthroplasty 2016) [said], “further studies are needed to confirm the cost effectiveness of this” and a third article all published in the last year or two (Banerjee et al, Expert Rev Med Devices 2015) [said], “studies evaluating the projected cost-benefit analyses of this new technology are needed before widespread adoption.”
I could find one paper that supported the use of robotics over conventional with a cost basis (Moschetti et al, J Arthroplasty 2016). The assumptions in the paper were the following; the non-robotic UKA had to have triple the failure rate, unproven, you must do 100 UKAs per year, and then if you actually read the discussion it said, “robot assisted UKAs were more costly than traditional surgery but offered a slightly better outcome.” Again, unproven.
So, in conclusion, the robotic TKA, it’s got no evidence for superiority over navigation, none whatsoever. It does not appear to have any measurable clinical outcome benefits over navigation, but it does come with a substantial increased cost and OR time and I would say there’s really no valid indication for robotic total knee.
