My question is: Why are we reacting to a rare, and poorly understood problem? I’m going to give you my personal experience because I do believe that your choice of implants is a local issue and cost is an important aspect of your individual local issues.
My clinical experience includes a prospective randomized study in which I had metal-on-poly bearings as the control. These were followed out to 2 years. None of these had cobalt levels greater than 1PPB [part per billion] (Engh, CORR, 2009). This is supported from the Rush Group in a cohort that they studied for 10 years (Levine, JBJS, 2013). None of their cobalt levels in their polyethylene bearings were above 1PPB.
I followed chrome cobalton-crosslinked poly out to 16 years (Hopper, CORR, 2018) with no revisions for mechanically assisted crevice corrosion.
I’ve taken 56 postmortem retrievals that had a mean implant time of 11 years and had them analyzed at HSS [Hospital for Special Surgery] (Padgett, 2017 Hip Society Specialty Day). The tapers were pristine with a mean corrosion score based on visual analysis—1.4 out of a possible 96. This is compared to HSS retrievals which were substantially higher.
Looking at my own database, 3,000 primary total hips from 2006-2017, about half of these were titanium stems. Some from me, some from my partners. Two revisions. That ends up being a 0.1% of primaries from our center have been revised for this problem.
I also looked at our most recent 350 revisions. We added 1 other that was sent in from outside, so we’re at 1% of our revisions.
In conclusion, cost is an issue. Ceramic balls at my place cost more. They cost $250 more. Corrosion at the taper junction is poorly understood. It’s rare. I take the same point that my opponent’s colleagues have put into publication in Seth’s Supplement to The Bone and Joint Journal and I support the “judicious use of ceramic heads”.
Moderator Berry: First of all I want to see if we can get some agreement about a couple of topics. Would both of you agree that the main reason we’re talking about this is related to taper corrosion? Is that fair to say, Don?
Dr. Garbuz: I would agree with that.
Dr. Engh: I would agree with that.
Moderator Berry: And would you both also agree that the issue of ceramic fracture, at least of the ceramic femoral head in the modern era is no longer really a big talking point or concerning to you? Don, would you agree with that?
Dr. Garbuz: I would agree with that.
Dr. Engh: I would too.
