Making the Choice: Osseus Reattachment of the Greater Trochanter Vs Soft Tissue–Only Abductor Repair in Bone Cancers

Author(s):

Reattaching the greater trochanter to the proximal femur endoprosthesis did not show an improvement in Trendelburg gait or reliance on an assistive ambulatory device vs a soft tissue–only abductor repair in patients with bone cancers.

R. Lor Randall, MD

In the study, investigators conducted a retrospective review of 59 patients who received a proximal femur replacement with metallic endoprosthesis post-resection for their bone tumor. Researchers divided the patients into 2 groups: those who received an abductor repair with a trochanteric osteotomy and osseous fixation of the greater trochanter/abductor mechanism to the endoprosthesis (n = 29), and those who did not have a trochanteric osteotomy but had an abductor repair that was only a soft tissue reattachment to the endoprosthesis (n = 24).

The groups were assessed for diagnosis, surgical outcomes with complication rates and failure, demographic characteristics, functional outcomes, and radiographic evidence of trochanteric failure. No differences were noted between the 2 groups.

Ten percent of patients in the trochanter osteotomy group vs 38% in the soft tissue–only group resumed a normal, non-Trendelenburg gait at their final postoperative visit (P = .024). Data showed that radiographic evidence of trochanteric dissociation from the endoprosthesis was observed in 45% of the osteotomy cases. Additionally, the requirement for an assistive ambulatory device was observed in 83% and 67% of patients in the osteotomy and soft-tissue–only groups, respectively (P = .21).

In an interview with OncLive, R. Lor Randall, MD, the David Linn Endowed Chair for Orthopedic Surgery, as well as professor and chair of the Department of Orthopedic Surgery at University of California Davis Comprehensive Cancer Center, discussed these findings in greater detail and how they can lead to a change in surgical practice for bone cancer management.

OncLive: What was the rationale to evaluate this topic in a clinical trial?

Randall: To repair or not to repair? That is the question. In bone sarcomas, around the proximal femur, the whole upper femur will often be resected, and we'll reconstruct it with a big endoprosthesis—an artificial joint. When you get a normal hip replacement, you go between the muscles, and you cut out the ball in the socket, and you replace the ball and socket, but everything around it is left intact.

When you take out a bone sarcoma, you, by definition, are taking out the muscles and the attachments to the bone because the bone is coming out. Then we say, "All right, we need to [re-]attach these muscles." Sometimes, we don't know if all of these muscles being attached really makes a difference in how a patient walks or functions afterwards. But we spend a bunch of time doing it anyway, because it seems like the right thing to do, right?

However, the argument not to do it is, if it doesn't increase the function, then you can get the patient out of the operating room quicker, and can decrease their infection rate and complication rate, because you're not spending all that time doing all those repairs.

Could you discuss the design of your retrospective analysis?

We looked back at our experience with this and we found that, for some of the patients, we could take an x-ray and see that the bolt and bone were still in place. In others, because there's so much force as you walk over time, this piece of bone [was just pulled] off. The x-ray tells us then that the muscle is no longer attached. Then, we looked at how these patients walked. Whether or not this [muscle] was still attached, we found there was no difference [in how they walked]. Whether or not you put the bone in that muscle back or not, there was still the same number of people who had a limp or walked normally.

It's a retrospective analysis, so it has some inherent biases to it. However, it is the first piece of evidence out there to show that maybe not replacing the muscles is just as good as replacing them. The issue sometimes becomes, because the tumor is so extensive, you don't have the bone to attach, and it's just the soft tissues that you sew in. Therefore, we don't know which of those patients have failed or not, because you can't pick it up on MRI or anything, because there's so much metal artifact—you can't get that kind of detail. That is why it's not a conclusive study, but it suggests that perhaps we don't need to spend all the time reattaching the muscles. Maybe what will come of this is a prospective study, looking at whether or not we should do it.

What is the extensiveness of reattaching the muscles? How much time does it add in the operating room?

Just to repair it is probably 30 to 60 minutes, but this after it's already been a 3- or 4-hour operation. You could imagine a wound that has been open for 3 or 4 hours; we're in a sterile environment, but it doesn't take much for something to get into that wound and cause an infection. The shorter you can do the operation, the less likely the risk of an infection or complication [will be].

This is something that we argue about all the time in our own clubs and societies: What is the importance of reattaching? It's amazing how much people are excited about this question. This is a very limited study, at a retrospective level for data. However, it's amazing how much buzz this topic gets.

A prospective trial could be a great approach to answer this question, as patients will likely be interested in enrolling to potentially get less time in the operating room. Right?

It's like with any surgical trial, or any trial, in general. However, with surgical trials, it's the tone that makes the music, so to speak, because, by definition, if we have a well thought out, prospective, randomized, controlled trial, we don't know the right thing to do. There are upsides and downsides of both pathways. The surgeons have to very careful, when we enroll patients in these, to not introduce our own personal biases about what we think is the right thing to do.

For example, we could say, "Oh, it's going to take us less time to do it, but you're more likely to walk with a limp now if we don't do it,” because my bias is to [attach] it versus me saying, "Oh, you'll definitely have a lower chance of infection [without reattaching] because we'll be done quicker."

What could be the practice-changing implications of this research?

It does influence the industry in terms of manufacturers of proximal femoral replacements, and whether or not they want to put the investment into all of these soft tissue reattachments or not. They may or may not make a difference, we don't really know [yet]. But this sort of thing could influence the direction of industry.

Reference

Groundland J, Brown J, Jones K, Randall RL. Is osseous reattachment of the greater trochanter necessary compared to soft‐tissue‐only abductor repair in proximal femoral megaprosthesis reconstruction? J Surg Oncol. Published online March 25, 2021. doi:10.1002/jso.26477