Page 17 - BeaufortMemorial

Te personalized knee replacement sys-tem uses 3-D MRI images of the knee to create a custom positioning guide that the surgeon can use to place and align the im-plant more precisely. Beaufort Memorial Hospital’s outpatient imaging center in the Beaufort Medical Plaza provides the special technology required.

About a month before the surgery, an MRI scan is taken of the patient’s leg. Te images are sent to a company that designs and manufactures total joint replace-ment products. Using a special computer program, a plastic template that fts over the patient’s bones is created to show the surgeon exactly where and at what angle to make the cut to best position the implant.

Having the template beforehand allows the doctor to select the implant that will best ft the patient’s bone structure. “So, when I go in to do the surgery, there is no guessing,” Dr. Blocker says. “Te patient’s knee has been mapped out and measured digitally. I have a surgi-cal plan and know what size implant the patient will need even before reaching the operating room.”

In the past, surgeons worked from 2-D x-rays and standard instrumentation or templates.

“I would have about 10 instrumenta-tion trays in the operating room to choose from, depending on what I thought was needed,” Dr. Blocker says. “And we would have an array of joints outside the room to choose from. With this custom technique, I have just one tray and one joint.”

Orthopedic surgeon Kevin Jones, MD, has been using the technology for more than two years. To date, he has performed more than 300 surgeries with the customized surgical instrumentation.

“Te computer determines the opti-mal alignment,” Dr. Jones says. “You get a better range of motion, and the knee will last longer because it’s balanced better, so there’s less wear on the implant.”

Before he began using the customized templates, Dr. Jones often had to modify his surgical plans because the 2-D x-rays didn’t show spurs or other abnormal anatomy.

“It was more art than science,” he says. “Now it’s more scientifc. I make the cuts based on what the computer predicts. I have found it to be routinely accurate. It’s a much more exact procedure.” A computer monitor in the operating room shows the MRI image of the pa-tient’s joint with the implant in place. “I can compare the cut I am making to what I see on the scan,” Dr. Jones says. “What I am looking at on the table should look like what I see on the screen.” Mary Mack, who had her left knee replaced by Dr. Jones last December, has completed her physical therapy and is walking again without a cane—or pain. “I was really amazed at how well the surgery went,” says Mack, a former registered nurse and owner of Red Piano Gallery Too on St. Helena. “Tey had me up on my feet the frst post-op day. Te second day, I took a shower by myself and was walking up steps.”

Not too long ago, people cringed at the thought of having a knee re-placement. It was major surgery involving a lot of pain and months of recovery. But technol-ogy has improved knee surgery to the point that, for many people, it’s a positive step. Tis new method is called the custom technique for knee replacement, and two BMH orthopedic surgeons use it. “Some people think the knee replacement is custom made, but really it’s custom instrumenta-tion,” says BMH ortho-pedic surgeon Edward Blocker, MD.

Patients have an MRI done about a month before the surgery. The company the doctor is working with makes a model of the knee from the MRI and builds up the diseased part of the knee. They use computer modeling to determine the best place to cut and the best angle of the cut, which saves the sur-geon a lot of time. The surgeon uses the model to plan the surgery in advance.

With less guesswork, the surgeon uses the model to rehearse what needs to be done before going into surgery. As a result, the surgery takes less time and the patient has less chance of infec-tion. It’s a win-win for patients and doctors.