TKA Innovation: Healthy Skepticism Benefits Patients

When it comes to total knee arthroplasty (TKA), the tried and true is usually better than innovations like robotic-assisted surgery, computer navigation, patient-specific cutting blocks and custom implants.  

“All of these innovations are made with the goal of doing the operation better in hopes it will improve the outcome for our patients. That’s a noble goal. But often, once we have long-term data, the new and improved thing turns out not to be an improvement,” says Rodney Benner, MD, an orthopedic surgeon at Shelbourne Knee Center.

While these innovations can make TKA slightly more precise and efficient, this doesn’t lead to better patient outcomes or longer implant survivorship, according to Dr. Benner. Instead, these innovations lead to more time in the operating room and higher costs.

Lack of Evidence Supporting TKA Innovations  

Research already shows that computer navigation does not improve patient outcomes, and that robotic-assisted TKA results in more time in the operating room early in the surgeon’s experience. Dr. Benner expects long-term data on robotic-assisted TKA to show that the increase in operating time is permanent and that this technique doesn’t improve patient outcomes. Also, robotic-assisted surgical systems are expensive to purchase and maintain.

Patient-specific cutting blocks potentially improve accuracy and efficiency, however, research has not shown that the improvements are large enough to make a difference in the outcome or implant survivorship. Custom implants are a good idea in theory, but they aren’t necessary for high-volume joint replacement surgeons like Dr. Benner. He knows how to choose available sizes and components to best match the patient’s knee anatomy.

Decisions Based on Decades of Data  

Healthy skepticism about these and other TKA innovations benefits Dr. Benner’s patients. “I fall back on implants that we have decades of experience and data for,” he says.

Dr. Benner uses an evidence-based implant system that consistently optimizes patient outcomes. This implant system has a wide variety of sizing options to most closely match the patient’s knee anatomy. Its components are designed to match the shape and size of the resected bone, instead of matching the bone to the implant shape and size as many implants do.

Using the same implant system consistently enables Dr. Benner to deliver dependable, reproducible and optimal results. Because he trained on this implant system, he has extensive experience with it and knows that design modifications made over the years are supported by evidence of effectiveness.

New Designs and Techniques Based on Research

Dr. Benner follows the TKA literature closely to determine whether to make changes. For example, after research showed that highly cross-linked and antioxidant-infused polyethylene bearings prevent oxidative degradation of the polyethylene, Dr. Benner began using these bearings.

Also, he is following a new technology that could potentially give patients more normal range of motion, better stability and less pain: a medial-congruent bearing design. While one study examining several types of implants found that patients were happiest with this technology, the study was not a randomized controlled trial and Dr. Benner has concerns about the study methodology. “It’s interesting and in time we’re going to get more data about whether outcomes are any different,” he says.

Results from the Shelbourne Knee Center research program on TKA outcomes also inform Dr. Benner’s treatment. “If we make a change, we follow it with data and make sure it’s better,” he says. The Shelbourne Knee Center research program has 38 years of data on more than 13,000 patients.

Optimal Patient Outcomes Through Rehab

One major factor in optimal patient outcomes lies outside the operating room: Shelbourne Knee Center’s research-backed pre-op and post-op rehab program. “We prepare our patients for surgery from a functional perspective so they do better before the operation and maximize their outcome after surgery,” says Dr. Benner.

“Rehab is a much more significant factor than anything I’m going to do with surgical technique or implant design,” he adds.

Shelbourne Knee Center is the only orthopedic practice in Indiana with physical therapists and athletic trainers who are highly-trained in—and only focus on—the knee. Most patients with knee osteoarthritis (OA) improve enough through pre-op rehab that they no longer need surgery.

For more information about TKA at Shelbourne Knee Center, call 888-FIX-KNEE or email