Let’s move on to stability. Does this approach help? Well, let’s look at the status of the trochanter. If it does not unite, you have up to an 18% rate of instability. Even in those scenarios where it unites, the reported rate of stability with the use of this approach is 2.8%. I would argue that in 2016, that rate is probably higher, given our lack of expertise with routinely utilizing this approach. In addition, multiple studies have looked at contemporary dislocation rates with the posterolateral or several anteriorly based approaches and found them to be approximately 1%.
Finally, and maybe most importantly, when completing a primary total hip arthroplasty, it must be safely reproducible. The transtrochanteric approach is performed by very few. It’s technically demanding. And there is a host of variability with regards to techniques for the osteotomy and techniques for fixation. In my mind, that makes it not reproducible, not reliable, and not durable, and as such, not a good approach for primary total hip arthroplasty.
In the short list there are multiple different ways to complete the osteotomy, including Chevron trochanteric osteotomy; trochanteric slide; and partial trochanteric osteotomies. In addition, there’s significant variation of fixation including wires, cables and claw-type plates; and several of these have issues for patients requiring removal.
There are uses for this approach in the revision setting. In that setting, the reported rate of bony non-union is 16%, lurch in 1-in-3 and dislocation approximately 5%. But as Dr. Gross pointed out, these are traditionally in patients with very difficult situations such as revision procedures or complex primaries.
In summary, I would argue the transtrochanteric approach to primary hip arthroplasty has a very limited role. There are certainly increased rates of pain and limp that are unacceptable to most contemporary patients. In addition, it’s prohibitively high trochanteric non-union and instability rates are certainly no better than other contemporary approaches.
Moderator Trousdale: So let’s try to get a little bit of consensus over the next five minutes. Allan and Matt, I think you’ll agree, because I just heard you say, that a classic trochanteric osteotomy is rarely needed in a primary total hip.
Dr. Gross: Yes, I agree.
Dr. Abdel: I agree with that.
Moderator Trousdale: And would everyone agree that in some revisions, some type of osteotomy can be beneficial, but not necessarily all revisions?
Dr. Gross: In the panel earlier this morning a lot of the cases that were presented by various speakers showed that they had done a trochanteric osteotomy, only for the complex acetabular revision.
Moderator Trousdale: Okay, so let’s talk about the primary first then we’ll talk about the revision because they’re really two different animals. Matt, is there any complex primary…you mentioned a few, I think fusion takedown, where you wouldn’t do an osteotomy on that, but you could, HO and a big deformity, are those the major reasons where you may entertain a classic osteotomy for primary total hip?
Dr. Abdel: I think in addition to those, the other thing you could think about is those patients who have a primary antalgic process; they need the trochanter and abductor mechanism moved out of the way to get at the lesion. So in my practice that’s the primary use of that approach in a primary setting. Complex tumor resection.
Moderator Trousdale: Allan, in a primary setting, when would you do a classical osteotomy?
Dr. Gross: There are some CDH cases where we like to take out the greater trochanter and then we get better exposure, especially if we have to do a graft, and then we can advance it because some of them have a very high riding greater trochanter. We like to cut the neck short to neutralize version, instead of doing a sub-trochanteric osteotomy. In those cases, if we leave the trochanter attached, it ends up to be very high riding. We like to take it off and advance it and it also improves stability.
