Customized Knee Replacements Take Functionality to a New Level
Knees that don't hurt? For active people, that's just not enough.
You just learned that you need knee replacement therapy, and you are worried about whether the new knee will feel natural, or if you will have to give up some activities.
But what if the knee replacement exactly replicated your own knee’s alignment and orientation?
Those who suffer from chronic knee pain have a new option that can improve recovery and functionality: Computer-assisted, custom knee replacements. Northwestern Lake Forest Hospital is one of just a few hospitals in the area to offer this new, state-of-the-art orthopedic technology.
“Drawing on elements of computer-assisted surgery, we can create an exact duplicate of the patient’s knee for the replacement, instead of relying just on conventional measurements,” says Tomas Nemickas, MD, a board-certified orthopedic surgeon at Northwestern Lake Forest Hospital who specializes in hip and knee replacements. “It enables a direct measurement of size and orientation to achieve a new level of precision.”
Custom Versus Traditional
In a traditional knee replacement procedure, the surgeon makes as close a match as possible between your original knee’s size and alignment and the replacement knee model using measuring devices based on standard anatomical sizes and selecting from available replacement joints. The surgeon then makes adjustments for fit during the operation, while the patient is under anesthesia.
With custom knee replacement, a magnetic resonance imaging (MRI) or computed tomography (CT) scan and computer algorithm are used to create a three-dimension model that matches the orientation, size and dimensions of the patient’s own knee. This plan is uploaded to the surgeon’s computer, and he or she reviews and adjusts it as needed, before surgery. A custom, surgical-grade nylon knee form is then created with pinholes and blocks that the surgeon uses during the procedure to insert the knee.
“Using these programs and models allows us to maximize the pre-operative planning, ideally decreasing time spent in surgery," says Dr. Nemickas. “The actual surgery can then be performed more efficiently, validating that plan.” Research is ongoing, but some published studies show a decrease of up to 15 minutes in surgical time; patient safety may also be improved.
Benefits for the Athlete or Active Patient
Custom knee replacements are precise to within several tenths of a millimeter, whereas the traditional approach has up to five millimeters of variability in the fit—and those few degrees difference in motion can matter. Peter Thadani, MD, a Northwestern Lake Forest Hospital board-certified orthopedic surgeon who performs both types of procedures, explains:
“Traditional knee replacements are quite successful. But there is a small percentage of cases where the alignment or the sizing of the prosthesis [the replacement knee] could have been improved. More replacements are being performed on younger and more active people, so inserting a prosthesis with more precision means potentially greater longevity and improved function. I’m impressed by how quickly these patients recover and return to their previous activities.”
Talk to a Surgeon About What's Best for You
Patients should keep in mind that the custom joint replacement option can be more costly. There is also a longer wait, since it takes up to four weeks to create the custom model. In comparison, a traditional knee replacement procedure can be scheduled fairly quickly.
“If you are considering knee replacement surgery, ask your orthopedic surgeon about this new technology. A custom fit knee may benefit you, but traditional knee replacement works well too. Either way, a center with advanced technology and board-certified, highly skilled orthopedic surgeons can provide the best care.”