There was a time when people over age 40 were expected to become less physically active and adventurous, and more sedentary and cautious. That era has passed. For exercise enthusiasts and amateur athletes, 40 is a meaningless milestone that they blow pass while they’re out jogging, hiking, biking or going to the gym for an interval-training class.

Unfortunately, however, 12 percent of adults in the U.S. develop osteoarthritis of the knee, sidelining them. According to the CDC, 4.2 percent of Americans have undergone knee-replacement procedures, with the largest increase has been among people aged 45 to 64.

Weighing the options: TKR vs. PKR

Jess Lonner, M.D., a board-certified orthopedic surgeon, says, “Knee replacements used to be reserved for old people, but now patients are coming in earlier—at age 55 and younger. These patients are ideal candidates for less invasive knee-replacement procedures that are more conservative with tissue and cartilage removal. They may actually do better long term with partial knee replacements (PKRs).”

“The point of effective robotic surgery is to provide surgeons with a highly sophisticated sculpting device that they can wield, bringing all of their expertise to the process. However, the robot provides boundaries so that we won’t cut too much bone or compromise soft tissue.”

In general, total knee replacements (TKRs)—the majority of knee-replacement procedures—are more invasive and more likely to require revision as the artificial joint wears out. However, many surgeons have chosen not to perform PKRs because of the technical difficulty associated with axial alignment of the compartmental implant into the remaining knee structure. With a high rate of miscalculations regarding how much tissue to take and how much to spare, many surgeons have continued performing TKRs, even when such an invasive procedure is not necessary. 

The evolution of robotic surgery

Dr. Lonner started routinely performing PKRs in early 2008. As an early adopter, he started using computer-assisted surgery, also known as robotic surgery, to reduce the risk of complications and errors. He explains, “PKR is a procedure that is increasingly applicable to our patient population; however the problem is that they have to be done well to optimize results.”

Since the introduction of Robodoc in the 1970s, robotic-surgery technology has evolved. The earliest ‘autonomous’ systems relied on robots working independently of surgeons, who input parameters into a computer. Unfortunately, Robodoc was associated with soft-tissue complications.

By 2006, other robotic systems became available. However, though they were significantly more effective and less risky then Robodoc, as an image-based system, it required that patients receive a pre-operation CAT scan—which is both expensive and a source of radiation exposure. Now, Dr. Lonner is using the Navio system. As a precision freehand sculpting system with a built-in visualization feature, no CAT scan is necessary, and Navio allows surgeons to operate with the necessary precision to optimally orient an implant.

Good for surgeons and patients

According to Dr. Lonner, the major misconception about robotic surgery is that the robot performs the operation while the surgeon looks on or checks out entirely. He says, “The point with Navio is to provide surgeons with a highly sophisticated sculpting device that they can wield, bringing all of their expertise to the process. However, the robot provides boundaries so that we won’t cut too much bone or compromise soft tissue.”

For surgeons, having the right tools allows them to perform well. For patients, it means regaining pain-free function more quickly, in an outpatient setting—so they can get back to the gym as soon as possible.