This week’s Orthopaedic Crossfire® debate was part of the 34th Annual Current Concepts in Joint Replacement® (CCJR®), Winter meeting, which took place in Orlando. This week’s topic is “Haas v. MacDonald: Robotic Assisted TKA: The Future Is Now.” For is Steven B. Haas, M.D., Hospital or Special Surgery, New York, New York. Opposing is Steven J. MacDonald, M.D., F.R.C.S.(C), University of Western Ontario -London, Ontario, Canada. Moderating is Thomas S. Thornhill, M.D., Harvard Medical School, Boston, Massachusetts.
Dr. Haas: I’m debating Dr. MacDonald and he’s going to be saying “Bah humbug.”
Dr. MacDonald is someone who embraces technology. For example, he brought his car from Canada down here. He took some people out to lunch in his 1975 Pacer. Yes, Dr. MacDonald embraces new technology.
The rationale for robotics in total knee arthroplasty—and you can look at unicompartmental as an example which is associated with lots of failures related to technical error—like undercorrection, overcorrection, varus angulation, abnormal posterior slopes—which can be corrected with the use of computer-assisted technology for navigation and robotics.
With robotics positioning is much better and you can achieve the goals of alignment that you need to do. That was a major cause for failure of unicompartmental knee arthroplasty. Articles from Hospital for Special Surgery by Dr. Pearle actually have shown that survivorship and results are much better with the use of the robotic technology (J Arthroplasty 2018). His 5-year data is showing improved results with the use of robots.
What about the rationale for a total knee? The major causes for failure in the short term are malalignment and instability: 25% and 21%, respectively, as reported by Nam (J Arthroplasty 2014) and Sharkey (CORR 2002).
If you include accelerometer technology (Nam, J Arthroplasty 2014), it improves tibial component positioning dramatically. You can get over 95% alignment within 2-degrees of neutral with it as opposed to the 60% or 70% without it.
Now, let’s look at the patient population. Obesity is a huge epidemic in the United States and we are taking patients to the OR that have a BMI [body mass index] of 40, 50, even 60.
I will guarantee that aligning these knees is much more difficult and there is data to show that the alignment in those cases is much more likely to be varus, and that they have a much higher rate of failure if you place it in varus (Lustig, Knee Society 2016).
About 32% of the cases of total knees done without navigation or any type of aids are malaligned. Whereas less than 10% with enabling technologies of one variety or another are malaligned. Those are just the facts.
There are a bunch of enabling technologies. There’s computer navigation, gyroscopes, OrthAlign, patient specific robotic surgery with MAKO, NAVIO. Lots of different choices for enabling technologies that are available.
So, I’m sure Dr. MacDonald is going to tell us that navigation has never been shown to improve outcome, but most of these papers are short-term, most of them are underpowered, they’re all from major centers where there are very highly-skilled surgeons.
