Quality of life and activity after surgery can be important factors in the decision-making process.
Fred Kozlo, 61, vice president of Nexus Protective Services in Calgary, Alberta, likes his left knee better than his right knee. He’s OK with the standard right partial knee replacement he had done five years ago in Canada. But he’s ecstatic about the left he had less than a month ago in Arizona, which involved computer-assisted surgery with robotic technology. For Kozlo, short-term recovery has been much smoother the second time around.
Partial or Total Knee
The knee joint is made up of three separate areas, or compartments: the medial or inside part of the knee, the lateral or outside part of the knee and the patellofemoral compartment at the front of the knee, beneath the thighbone. If you have damage from arthritis confined to just one compartment of your knee, along with significant pain and disability despite medical treatment, you might be a candidate for partial knee replacement.
Yet orthopedic surgeons say too many people who could get a partial replacement – which spares healthy surrounding bone and tissue – receive a instead.
There are “distinct” advantages to opting for partial knee replacement if you’re a suitable candidate with , says Dr. Andrew Pearle, founder of the Computer-Assisted Surgery Center at the Hospital for Special Surgery in New York City. “It tends to be a more natural-feeling knee,” he says. “It tends to be a more athletic knee – you can play more sports on it.” Partial knee replacement involves a “much quicker return to work and is a lot less expensive to go through,” he adds.
Longevity or Satisfaction
Pearle just published a comparing partial and total-knee procedures in the Journal of Bone and Joint Surgery. For patients 65 and older, partial knee replacements led to lower lifetime costs and higher quality of life. However, because of the need for eventual revisions, partial knee replacement was less cost-effective in patients under 65.
Having the longest-lasting implant isn’t always top priority for patients, Pearle says. “In most studies, about 10 to 20 percent of people who had a total knee replacement are not satisfied,” he says. While implant longevity is important, he says, quality of life and activity after surgery also matter – and people with partial knee replacements tend to have higher satisfaction scores.
Standard or Robotic Surgery
Standard partial knee replacement uses X-ray images and relies on the surgeon’s visual assessment of the knee and direct manual surgery.
The robotic partial knee procedure used for Kozlo, called MAKOplasty, involves CT scanning, which allows the surgeon to build a virtual model of the patient’s knee and make a preoperative plan. With computer assistance, the surgeon guides the programmed robotic arm in resurfacing the damaged part of the knee.
In both methods, the surgeon places metal components on the ends of the thigh bone and tibia (the larger leg bone below the kneecap). These metal pieces are cemented in place. Then, the surgeon places a plastic insert between the metal pieces to allow smooth movement of the knee.
Partial knee replacement is increasingly being performed as an outpatient surgery.
Do Patients Notice?
Dr. Stefan Tarlow, an orthopedic surgeon with Advanced Knee Care in Scottsdale and Mesa, Arizona, performed Kozlo’s recent knee replacement. Tarlow switched entirely over to the robot-assisted method in 2011. With traditional surgery, “there are many factors we can’t control when we use our eyes and skill,” he says. “For a partial knee replacement, the precision in which we can adjust how that implant is placed in the patient’s knee is, I think, critical.”
While surgeons agree that robot-assisted surgery increases the precision of bone cuts to within a single millimeter or less, the issue is whether patients experience an appreciable benefit. For his part, Dr. Sharat Kusuma, director of adult reconstruction at the Grant Medical Center in Columbus, Ohio, isn’t sure.
“The question is – does it make a difference?” Kusuma says. “Is it clinically relevant?” It might be, he says. But without more and longer-term data to back that up, it’s too soon to tell. Kusuma did a , published in the September 2014 Journal of Arthroplasty, comparing results with manual and robotic techniques. He found no significant differences in patients’ outcomes, which were “excellent” for both groups.