Achieving optimal fit and function in total knee arthroplasty (TKA) requires the right implant and a reproducible process. That’s why Rodney Benner, MD, orthopedic surgeon at the Shelbourne Knee Center uses an evidence-based implant system that consistently optimizes patient outcomes.
“The implant system I use has a wide variety of sizing options to most closely approximate the patient’s knee anatomy, is designed to minimize complications and allows our patients to rehab their knees aggressively after surgery,” says Dr. Benner.
Using the same implant system consistently enables Dr. Benner to deliver dependable reproducible, and optimal results. Since he trained on this implant system, he has extensive experience with the system and knows that the design modifications made over the years are supported by evidence of effectiveness.
A Fit for all Shapes and Sizes
Dr. Benner uses a fixed-bearing implant with cemented fixation. Evidence shows that fixed bearing designs can last at least 15–20 years and cemented fixation is the gold standard. “Cementless fixation has some theoretical advantages, but we have not seen definitive data that this is superior to cemented fixation,” he says.
The components in Dr. Brenner’s preferred implant system are available in a wide variety of shapes and sizes to fit any patient. They 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.
To more accurately predict the size of the implant that a patient will need, Dr. Benner takes pre-surgical measurements using an X-ray templating model. Working closely with the implant manufacturer, Dr. Benner is able to have “every potential implant at the ready for the operation.” This is especially helpful in revision TKA, a more challenging procedure. Advantages of having the right implant in the OR for any TKA include faster procedures and decreased workload for OR and sterile room staff, and, possibly, cost savings.
For patients under age 55, Dr. Benner uses a mobile bearing implant. This design is believed to last longer and feel more normal, allowing patients more rotation to the medial and lateral sides of the knee. While studies of patients up to 16 years post-op don’t show the superiority of mobile bearing implants over fixed bearing implants, they are still generally used in younger patients. Dr. Benner says longer term studies are needed for both fixed bearing and mobile bearing implants.
Fewer Complications
The femoral component of Dr. Brenner’s preferred implant has a shallower box than some implants, which allows the kneecap to glide freely up and down the middle of the implant. This minimizes soft tissue complications such as patellar clunk syndrome. The tibial component closely matches the anatomical shape of the tibial surface.
Easier Rehab
Restoring range of motion (ROM) post-operatively is key to successful outcomes, as shown by Shelbourne Knee Center’s long-term data on ACL reconstruction patients(1).
The practice’s research-based Knee Rehabilitation Program for OA enables patients to regain ROM after surgery, and Dr. Benner’s preferred implant facilitates rehab.
The rehab program includes pre-op rehab to strengthen the knee before surgery and facilitate an easier recovery afterwards. Many patients improve enough that they don’t need TKA. In the practice’s OA Rehab Study, only 24% of patients went on to have a TKA(2).
Thoughtful Innovation
While Dr. Benner and Shelbourne Knee Center value innovations in care, many innovations in TKA implants are not yet proven and possibly unnecessary.
“Often, we come up with a perceived problem and rather than seeing if that problem leads to a difference in patient outcomes, we make a design modification before we know if it will change anything in the outcome,” says Dr. Benner. Studies later show that these design innovations don’t improve patient outcomes.
“I set the bar high for the evidence I want to see from a design modification before I implement it,” says Dr. Benner. “We know that standard implants have generally good outcomes and can give patients a good knee for a long time.”
For more information about TKA, call 888-FIX-KNEE.
References
- Shelbourne DK. Thirty-five Years of ACL Reconstruction, presentation at Andrews University, February 2018.
- Shelbourne DK. Nonoperative Treatment of Knee Osteoarthritis, presentation at the Herodicus Society Meeting, June 2018.