March 26, 2019
Many of us wonder when is the right time to have knee replacement surgery. Dr. Nordt explained recently at the Parham Doctors’ Lecture Series that he spends as much time talking patients out of surgery and focusing first on conservative ways to alleviate knee pain like physical therapy, anti-inflammatory medication, cortisone shots, viscosupplementation, weight loss and exercise: “I spend more time talking people out of knee replacements than into knee replacements, because you really want to get the sense that it’s worth it to you.” Knee replacement surgery is an individual choice. When the pain becomes an obstacle in your life and you are choosing or minimizing your daily activities, then knee replacement surgery might be right for you.
Dr. Nordt performs total knee replacement surgery at Parham Doctors’ Hospital using the latest orthopedic technology, the Mako Robotic Arm. This technology has evolved over the last decade starting with partial knee replacements to now total knee replacements. Many of us believe that a total knee replacement surgery requires the removal of the entire joint. Unlike what most people think, the surgeon removes just the thin surface of the bone. The surgeon removes less than a quarter of an inch or so of the cartilage surface of the bone on one side and less than a quarter inch or so of the cartilage on the other side.
This new technology allows us to get the size of the joint exactly correct. We want the accuracy of the joint replacement to fit your knee perfectly. We also want the balance to be correct. Balance is critical because all joints and in particular the knee have a little looseness in the ligaments and how tight or how loose they are is very critical to the proper functioning of the knee. The balance of the knee is the most important thing because it is how normal it feels to you.
Before the Mako robot , we balanced total knee replacements by feel. As Dr. Nordt related: “ We would do it by feel. High volume surgeons are very good at feeling a knee and balancing it correctly. We can tighten the ligaments on one side and give a little looseness on the other side and make it feel right. Getting just a little bit of laxity is the difference between a knee that feels normal and a knee that doesn’t.” The Mako robot provides a critical advantage to the balance aspect because of its accuracy in both the pre-operative planning and surgical implantation of the prosthetic knee.
The procedure is basically as follows:
A CT scan is performed several weeks prior to surgery. The CT is carefully assessed by a technical team and a “virtual” knee replacement is created. The size and orientation of the proposed knee replacement is determined in such a way to create ideal alignment.
Next, the surgeon confirms this plan prior to surgery.
At the time of surgery, the patient’s actual knee is reconciled with the CT image so that the knee alignment and movement can be assessed in real time on the computer screen. Any adjustments can be made if the surgeon feels that the proposed model should be altered.
Though the alignment and orientation of the prosthesis are critically important, equally important is the “balance” of the components. Our goal as knee specialists is to reproduce an artificial knee joint that feels as close as possible to a perfectly normal knee joint. The knee plan is adjusted to create ideal balance as to provide smooth, stable and fluid knee joint motion.
Next, a robotic cutting arm is moved into position, and guided by the surgeon, the thin cuts to the surfaces of the knee are performed with nearly 1millimeter and 1 degree of accuracy. A trial knee replacement is inserted and the knee movement is assessed for range of motion and balance. Minute adjustments can be performed if necessary. The final components are then implanted. Alignment and balance are confirmed.
To learn more visit: https://patients.stryker.com/knee-replacement/procedures/mako-robotic-arm-assisted-total-knee