My name is Susan Goodman. I am a rheumatologist at the Hospital for Special Surgery (HSS) and my appointments are with Weill Cornell College of Medicine. My research interest is in the perioperative management of patients with rheumatic diseases, [and that is] what we’ve been doing here at HSS — managing both the clinical and biologic features of patients [with RA] as they undergo arthroplasty.
This has led to a collaboration in terms of risk mitigation with a combined project with the American College of Rheumatology (ACR) and the American Academy of Orthopedic Surgeons, so I’d like to go back and tell you a little bit about the research we’re doing. One of the things we’ve learned over the years is that arthritis patients who undergo hip replacement have an increased risk of complications, in particular infection, so we’ve been trying to understand the [associated predisposing] perioperative clinical features so we can try to improve that outcome.
We previously studied the rate characteristics and risk factors for flares after surgery for patients with rheumatoid arthritis and we found that they’re incredibly common; about 60% of patients have a flare after hip or knee replacement surgery. One of the questions is what the long-term impact is – and one of the papers we’re presenting this year is looking at postoperative flare after hip and knee replacement at one year out.
Now we know that flares are frequent. [But] nobody has really studied whether that has an effect on long-term management. In fact, we haven’t completed the studies and are only presenting our preliminary data, but we did find that patients who flared in the postoperative [period] had significantly higher disease activity at baseline and worse baseline function. The are preliminary data, however, showed that there wasn’t a significant difference in function at one year.
If we compare those patients who had a postoperative flare with those patients who didn’t flare, [preliminary data] suggest that physical function is similar in patients whether or not they have a flare in the postoperative period. These results are very encouraging, given the high rate of postoperative flare.
However, we really need to validate them in a much larger sample as we continue to complete the study, as that way we will actually have confidence in these findings, although they are reassuring. So right now we can’t really tell patients what to expect in the postoperative period as we don’t really have the data yet. We will have to wait to tell them what effect that will have on their long-term outcomes.
One of the things we’ve also learned [is that enrolling] patients at the time of surgery is an incredibly rich opportunity to collect both clinical and biologic data. We have been collaborating with some of our bench scientists at [Hospital for Special Surgery]. One of the additional studies our group is presenting this year is being presented by the collaborators Drs Dana Orange and Laura Donlin. The study focused on identifying rheumatoid arthritis subtypes using synovial tissue gene expression profiling, studying the histologic features of the joint and then looking at the gene expression data from that tissue from those cells so we can analyze the relationship between the histology and the gene expression profiles, re-analyzed in the context of their clinical profiles.
There does appear to be distinct clusters that we can identify by gene expression [profiling], so we can hopefully understand more about the disease pathogenesis — because it is really a remarkable opportunity to get both clinical data plus the target organ to study them together.
We are also involved in a year-long project that is a collaboration between the ACR and the American Association of Hip and Knee Surgeons (AAHKS), to come up with a guideline for the perioperative management of disease-modifying antirheumatic therapy for patients with rheumatic diseases undergoing hip and knee replacement. What it’s come down to in our literature review is really contrasting the significance of infection with the significance of flare.
The group that got together from the ACR and AAHKS all felt that the significance of infection far outweighed the consequences of flare. We’ve looked at the literature that is available and what has truly hindered our guideline is that there is a paucity of randomized clinical trial data studying this. Very few people go into a drug trial to either continue or withhold a drug at the time of surgery, so what we ended up doing is taking information from nonsurgical studies and applying the risk of infection from randomized controlled trials to our patients where there wasn’t actually direct evidence. The randomized controlled trials would, as we knew, demonstrate an increase in infection in patients who are taking biologics.
Given that we’re trying to diminish the risk of perioperative infections, we thought that our recommendations would be to hold those medications that were associated with an increase in infection so we could both minimize the risk of flares without compromising an increase in the risk of infection. So our work has been pretty much focused on risk mitigation and the clinical features of perioperative management for patients with rheumatic disease.