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6 Points on Patient-Specific Knee Replacement Using Stryker’s ShapeMatch Technology

Written by  Laura Miller| August 24, 2011 Source: Beckers Orthopedic and Spine

The Stryker ShapeMatch Cutting Guides for use with the Triathlon Total Knee System was released in the United States about three months ago and has been used around the world for many years to provide surgeons with a preoperative planning capabilities and more precise implant placement. It is one of multiple devices that provide surgeons with the ability to perform anatomically-specific knee replacement procedures.

Elton Strauss, MD, an orthopedic surgeon at Mount Sinai Medical Center in New York City, uses this technology during knee replacements and predicts it will become an integral tool for orthopedic surgeons in the future. He describes six things to know about this emerging technology.

1. Enhanced preoperative planning.
During traditional knee replacements, surgeons only have a few implant options and they must make the decision about which size to use intraoperatively. In some cases, there are unforeseen factors that could mean the implant size chosen in the OR is too big or too small for the patient. “With this technology, we will know ahead of time what implant size patient needs and we are able to use special instrumentation to prepare a custom-fit knee,” says Dr. Strauss. “During traditional procedures, we take what we think is the best choice and we put it in the patient. With this technology, we will get the specific size, positioning and alignment right for every patient.”

2. Less instrumentation is involved. When surgeons know the implant size and exact instrumentation ahead of time, they are able to streamline the process and potentially use less instrumentation, which makes the case move along more quickly. Since the surgery is already specifically planned out, there are less instrument trays for the OR staff to open preoperatively and fewer pieces to discard or sterilize postoperatively.

“When you have the process streamlined, the turnover time is quicker and more procedures can be done in that OR,” says Dr. Strauss. “Most of us spend a lot of time waiting in the OR for one case to stop or start, and for our instruments to be prepared. This technology allows us to become faster and more efficient, so it saves the hospital money. It also allows us to perform a more precise surgery with less chance of infection.”

3. Precise implant placement. During the preplanning phase of the procedure, the technology is able to give surgeons a more precise cutting guide tailored to each patient’s individual anatomy. This allows surgeons to make smaller incisions, place the implant more accurately and close the incision quicker than in traditional surgeries. The surgeon is also able to see whether patients have more or less rotation of the femur and note the contact size of the patella with the femur and tibia with the femur before making an incision. The precise nature of the procedure also means the patient is able to begin moving around sooner postoperatively, which often promotes better outcomes.

Orthopedic surgeons are always looking for the best implant and we are trying to achieve the best outcome,” says Dr. Strauss. “Most of us went into science to make patients better. We are arriving at the stage now where we can realize that casting a mold of the patient’s knee and having the proper implant size will give us the best result because it will maximize motion and return patients back to their normal lives quicker.”

4. Reduced the need for cement. During traditional surgeries, if surgeons choose an implant that is too small, they use bone cement to fill the gap. Most surgeons prefer not to use bone cement because it acts more like a grout instead of actual cement. “The bone cement is usually a weak link in the system,” says Dr. Strauss. “If we can get an anatomic prosthesis, we will be able to go without cement, which is ideal.”

5. Easy to incorporate into a practice. While the technology doesn’t take much extra training on the part of the surgeon, the other specialists involved may need some convincing. Radiologists must take the MRI in a certain way to achieve the images necessary for the preoperative planning and the OR staff must become comfortable with setting up the instrument trays in a different way.

“The instruments are similar to what we are using already and the implant is the same as we are using already — it’s just going to be more of a standardized fit,” says Dr. Strauss. “I think this technology is going to revolutionize knee replacements. It will be slow in the beginning, but the public will demand it.”

6. Patients are asking for it. Patients are a big driving force behind technology and procedure adoption for some orthopedic surgeons because patients are more educated than ever before about what is available for them. The patient-specific knee technology may fall into this trend of patient-driven procedures because patients will be asking their physicians to use the technology, and if the physicians aren’t able to use it the patients will go elsewhere.

“The current generation of patients is much smarter than previous generations and they are reading about procedures ahead of time,” says Dr. Strauss. “Patients are investigating different treatment options on the Internet and asking surgeons about them. They are also asking more prosthesis-related questions, especially when it comes to metal-on-metal technology. Heading into the future, I think we are going to see more cementless implants developed and a trend toward procedures that require smaller incisions and nanotechnology.”

Learn more about Dr. Elton Strauss.

Related Articles on Orthopedic Implant Technology:

Stryker’s ShapeMatch Cutting Guides Receive FDA 510(k) Clearance

Zimmer Introduces Line of Patient Specific Instruments

10 Points on Personalized Knee Replacements