Custom Knee Replacement

Dr. Michael Wertz is well known in the community and region for providing patients with the most advanced custom knee replacement using Conformis knee system technology. Conformis does something that no other orthopedic company does. They design and manufacture custom-made implants designed specifically for each individual patient.

Unlike typical off-the-shelf knee replacement surgeries (where the surgeon selects an implant from a limited range of sizes), Conformis utilizes your individual CT scan data to manufacture a knee replacement implant designed just for you. Here are some key differences to better understand why this is important.

Individualized, patient-specific knee implant fit: Conformis implants are designed based on your anatomy. Off-the-shelf knee implants are designed based on a set of pre-determined measurements, and the “closest fit” is selected at the time of surgery.
Maintenance of the natural joint line: did you know you have two joint lines in each knee? One is on the medial side, the other is on the lateral side, and they can be different heights. Conformis is the only technology that maintains both joint lines through the use of individual polyethylene inserts rather than a single piece used in off-the-shelf implants.
Designed for optimal bone preservation: Preserving as much of the patient’s natural knee as possible is important and the unique design of the Conformis implant allows for optimal bone preservation. The implants are patient-specific and have been shown to be thinner than off-the-shelf implants, without sacrificing strength. A thinner implant allows for less bone and healthy tissue removal.

The ConforMIS Advantage

Designed to match your size and shape for optimal patient fit.
Many manufacturers offer a range of “off-the-shelf” sizes, but they do not consider an individualized shape. Your knee is a complex joint. In order to understand it in its entirety, we must think about both size AND shape. Since every knee is distinct in its size and shape, your implant should also be that distinct.

With the ConforMIS customized implants, surgeons do not have to compromise on the fit. Prior to your surgery, your implement is designed based on your CT scan data.

With an off-the-shelf implant, surgeons are forced to make decisions that compromise the fit and feel of the implant, because it was designed to a standardized size, instead of your specific anatomy. These implants require surgeons to make decisions in the OR that may possibly result in the implant being too large or too small for the anatomy (called implant overhang or underhang). These compromises can alter the rotational alignment and joint line of your knee, which have been shown to be the leading causes of residual pain.

ConforMIS customized implants do not require the surgeon to make these compromises, because your implant is designed specifically for your size and shape. Your implant matches your unique anatomy for an optimal fit, and preserves the medial and lateral joint lines. This results in the potential for a more natural feeling knee.

Designed for Optimal Bone Preservation
The average total of all bone resection measurements for iTotal CR was 27% less than the average total for surgeries done using an off-the-shelf implant. In a study by W. Kurtz titled “Patient-Specific Knee Replacement Implants Preserve Bone and Decrease Blood Loss & Swelling” presented at the 2013 BASK Annual Meeting, comparing 66 iTotal patients with 66 patients receiving one off-the-shelf implant brand (Zimmer NexGen), thickness of the femoral (distal and posterior medial/lateral), and tibial (medial/lateral) resections were measured intra-operatively. The average total of all bone resection measurements for iTotal was 27% (14mm) less than for the off-the-shelf total knee. Additionally, the total thickness of the iTotal implants was 25% (15.7mm) thinner on average than the off-the-shelf implants.

Designed to reduce operating time for optimal efficiencies
By using the ConforMIS personalized implant system, we are able to reduce the number of decisions we have to make in the operating room and sterilizing the placement guides. Because the ConforMIS implant is designed specifically for you, we do not have to spend time in the OR selecting the off-the shelf size that would be closest to your size. Instead, there is simply only implant for your surgery, your implant. This implant, your implant, simply would not fit another patient.

Designed for the potential for a more natural feeling knee
Kinematics (or motion) is a word that we like to use that describes the motion of your knee. The motion of your knee and how well it moves is a strong indicator of how natural your knee will feel after surgery. Our goal is to give you the “most natural feeling knee” as we possibly can. We believe that the more an implant mimics the natural shape of your knee, the more likely it is to move more naturally and feel more natural.

Designed to simplify the surgical procedure
You may not spend much time thinking about the steps of a surgical procedure, but we do! Over time, surgeons adopt procedures that are designed to improve the efficiency in the OR. Why should this matter to you, our patient? When we spend less time in the OR, it means you spend less time under anesthesia. The ConforMIS personalized implants and instrumentation offer us a simplified approach to knee replacements. Much of the time saved is due to the pre-sterilization, single-use pre-navigated instruments, designed prior to getting in the operating room. For each surgery we receive a “surgical plan” which works like a map of your knee, showing us what information that typically we can’t see until we are in the operating room.