Patients do not conform to a one-size-fits-all implant model, especially when it comes to knee replacements. Off-the-shelf implants often leave room for improvement in terms of fit and comfort because although many total knee replacement patients experience reduced pain following surgery, about 20 percent are not fully satisfied.
Billerica, Mass.-based ConforMIS is personalizing the TKR experience by offering patients one-of-a-kind implants. ConforMIS leverages iFit Image-to-Implant technology to create its Customized Implants that are individually sized and shaped to a patient's unique anatomy.
In May 2017, Arthroplasty Today published a retrospective study comparing customized implants to standard off-the-shelf implants for adverse events rates and cost of care for total knee arthroplasty. Patients treated with customized implants reported lower adverse event and transfusion rates; were less likely to be discharged to a rehabilitation facility; and had lower average total episode-of-care costs.
Orthopedic surgeons Greg Martin, MD, a hip and knee specialist in Boynton Beach, Fla.; Derek Johnson, MD, of Centura Orthopedics Meridian in Parker, Colo.; and Barry Waldman, MD, of OrthoMaryland in Baltimore, share how ConforMIS Customized Implants have boosted patient satisfaction at their practices.
Note: The following responses were slightly edited for length and clarity.
Question: Why do you use ConforMIS Customized Implants for total knee replacements?
Dr. Greg Martin: I began using ConforMIS implants because I needed to find a better way to help my patients that required knee replacement. We know that using traditional off-the-shelf implants, approximately one in five patients are not satisfied with their outcome. As a surgeon, this is frustrating because you can do a great job with the procedure and end up with an unhappy patient. It made intuitive sense to me that if we make an implant that is sized and shaped like the patient's own knee, they are more likely to be happy with how it feels. I think this is the major benefit of these implants. Unlike any other implant available, the ConforMIS knees are customized to the size and shape of the patient's own knee.
Dr. Derek Johnson: I started using [ConforMIS Customized Implants] in the fall of 2014, because there's 20 to 30 percent of people who don't have significant pain but they aren't happy with their knee replacements. It's a challenge for joint replacement specialists, because you think everything looks great, but the patient is not satisfied. We think this may be because we're not restoring normal anatomy and geometry to the knee. It made sense conceptually if we're recreating a patient's unique anatomy; it's about restoring the normal joint line and normal joint geometry. A knee is very asymmetric; the off-the-shelf implants are pretty symmetric and uniform. Every single implant looks different than the one before with ConforMIS [Customized Implants].
Dr. Barry Waldman: ConforMIS uses a CT scan of a knee which allows them to make a knee that fits almost perfectly [with] the patients' actual anatomy. The system looks at hip and the ankle to get everything aligned correctly. We started using [the customized implants] in a few patients and I found that my patients had much more natural motion and could bend their knees more easily early on.
Q: Were you surprised by the results from the retrospective study published in Arthroplasty Today, comparing adverse events rates and cost of care for total knee arthroplasty patients treated with customized individually made implants versus standard off-the-shelf implants?
DJ: I don't think I was surprised; I think it does make sense. If a patient has a more normal, stable feeling knee, they are going to ambulate sooner, which will potentially allow them to discharge sooner. The lower blood transfusion rates also make sense. With the ConforMIS implants, you're covering the cut surfaces of the bone. Off-the-shelf implants leave 20 to 30 percent of the bone uncovered.
BW: That's the exact experience that we've had. One of the advantages to the hospital is we just have one box with all the parts in it — there is no inventory to deal with. Not only are the implants customized, but the actual cutting guides are made of plastic and we are able to simply dispose of them when the case is over.
GM: I was not markedly surprised by the results of the study. I was getting reasonably good results with my prior off-the-shelf device, but once I began using the customized knees I really saw a dramatic difference in how the patients were recovering. They were swelling and bleeding much less, mobilizing sooner and just really feeling better than I was ever used to seeing in knee replacement patients. So if patients mobilize sooner and feel better and go home, I believe they are less likely to have a complication.
Q: How do you think the evidence that ConforMIS knee implants yield lower adverse event and transfusion rates as well as decrease in the likelihood of discharge to high-cost post-acute care facilities will impact the future of TKR?
GM: Well, these things are all interrelated. We know from prior studies that there is a link between blood transfusions and surgical site infections. We also know that patients admitted to a skilled nursing facility are more likely to return to the hospital with a complication. So if patients bleed less, feel better and go home, then they are less likely to have a complication.
When we look at the costs of the overall episode of care we know that patients that have a short hospital stay and quick return to home cost the least. Hospitals and post-acute care facilities are where the bulk of the dollars are spent, so the less these are needed the better. That is also why I believe we are going to see the transition of a lot of these cases to outpatient settings for healthier patients. ConforMIS is uniquely positioned to succeed in this environment.
DJ: Historically joint replacement was looked at [in terms of] how much the implant and surgery costs. Now [payers] want to see what the entire episode of care costs. If you can see savings in total cost over 90 days, it is going to drive a change in the market.
Q: How do you see customized implants positively impacting patients, surgeons, hospitals and payers?
BW: The knee costs about the same as other knee replacements. There is a cost for the CT scan, but not a very high cost. It's cheaper for payers because there are fewer complications. It's cheaper for hospitals [to avoid] preparing eight big trays of metal, and it's less inventory. Patients are happier and that's the whole point of doing the surgery in the first place.
GM: For patients and surgeons the goals are typically aligned. We want to have an excellent outcome with the procedure with a satisfied patient and avoidance of complications. I believe customized implants can provide this in the overwhelming majority of patients. Under new payment models hospitals and payers are to some degree aligned as well. They now care about the overall cost which would include any readmission or problems associated with the initial procedure.
DJ: We did a large study with more than 800 patients comparing off-the-shelf versus customized implants. Watching patients doing simple daily activities, we found the patients with customized implants walked a little faster. Hospitals and payers [look at] revision rates and readmission rates as well as system and societal cost/benefits. If we have lower rates with ConforMIS, that will be astronomical savings.
Q: Do you think ConforMIS Customized Implants align with the value-based care model of high quality and low costs?
DJ: A total episode of care is less expensive with a customized implant. The implant is less than one-third of the episode of care, so you don't want to only look at that cost. [Using customized implants] makes sense for a total value-based care model, it aligns very well.
BW: We're always trying to do more cases in the outpatient or surgery center. There is less inventory to manage and patients enjoy the experience more. We see less bleeding and swelling early on because we don't have to drill as many holes in the bone and cause less trauma during surgery.
GM: I believe the overall ConforMIS model is ahead of its time. The delivery of single use, individualized surgical instrumentation (facilitating a less invasive surgical technique) along with a customized implant is a powerful combination. This study demonstrated that for similar cost to an off-the-shelf implant, use of a customized implant provided benefits of a shorter length of stay, less need for blood transfusions, fewer adverse events, and better discharge disposition. This is a compelling value proposition at this time which I believe will only improve as economies of scale are achieved and manufacturing costs decrease.
This article is sponsored by ConforMIS.