Moderator Thornhill: Do you both agree, Butch, that you want to put the humeral head in an anatomic position compared to the native anatomy?
Dr. Krishnan: We do.
Moderator Thornhill: Evan, you’re saying don’t put one of those in because when you take it out, it’s going to be a lot harder for the revision.
Dr. Lederman: Well potentially. They are different and frankly there haven’t been many revisions. The resurfacings can be easy to revise assuming it’s been done right in the first place. I think these are both good options, the stemless being the newer device with short term follow up. It may be the future, particularly because of access to the glenoid. But resurfacing is a great tried and true operation for anatomic reconstruction.
Moderator Thornhill: I’m going to move down to the hip. For many years we’ve had experience with hip resurfacing arthroplasty. Lot of bone loss around the periphery of the cup—which is what we would see in failure of hip hemiarthroplasty. Does that not concern you at all?
Dr. Lederman: From a long-term clinical outcome standpoint, we are not seeing loosening of the resurfacing implants based upon the published literature. There is enough ingrowth where it is stable and the hip and shoulder are different, we are not walking on it so I don’t think it’s as big of an issue. Fixation isn’t a problem with the resurfacing.
Dr. Krishnan: I hate revising resurfacings. The reason for the resurfacing head revision is completely different from the reason for stem revisions as far as the proximal humerus goes. So, with any kind of a stem there is still bone around that proximal humerus just like you find with resurfacing hips but with resurfacing shoulders, that proximal humerus is destroyed and it takes away a lot of clubs from my bag to be able to revise that. So, I tell my residents and my fellows, “I hate that operation.” I use that line…every day of the week, twice on Sundays I’ll do a stemmed revision versus a resurfacing hip revision.
Moderator Thornhill: If you look at a knee replacement one of the real problems in tibial fixation or tibial alignment in knee replacement is using too short a stem. What the stem does is sort of centralize the implant. What made you go away from using a stem? Did you want to improve your anatomic capability?
Dr. Krishnan: What I actually do is use a short stem because metaphyseal fixation allows you to put the humeral head where it should be. With a resurfacing you have to be exactly perpendicular and perfect to the humerus just like you would with a hip to make it anatomic.
Dr. Lederman: I agree with Butch. The stem is the training wheels for the shoulder arthroplasty surgeon to get the anatomy closer to right than the resurfacing implants. My go-to implant is also a short stem implant.
Moderator Thornhill: Now we have a 50-year-old person, so we assume the bone quality is pretty good. What do you do in people with marginal bone quality or metabolic bone disease and you are doing a shoulder?
Dr. Krishnan: With the current stem designs that we use, it’s relatively easy if you cannot obtain perfect cementless fixation just with the implant. Take some bone from the proximal humerus, impact it as you would in impaction grafting and implant the stem. So, we haven’t used cement in the proximal humerus for any type of shoulder arthroplasty, other than revisions occasionally, in more than three years.
Moderator Thornhill: You ever use cement?
Dr. Lederman: Same answer as Butch, I rarely use cement. The exception would be in a situation of very large cystic cavities in a bad rheumatoid or a very elderly patient.
Moderator Thornhill: Well this is very interesting. I think you both handled this very well, thank you and let’s appreciate them.
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