When a knee has been damaged from injury or has substantial pain from arthritis, a knee replacement (or knee arthroscopy) is a way to relieve pain and help the affected person return to doing the activities they love. Since the first knee replacement was performed more than 50 years ago, techniques and tools have increasingly improved, making it one of the safest and most effective orthopedic procedures currently available.
Dr. Keith Fehring, a fellowship-trained hip and knee surgeon, and physician assistant Jennifer Suckow have performed many joint replacements including knee replacements. As a medical team at OrthoCarolina’s Hip and Knee Center, they focus only on hips and knees. Here they offer some need-to-know information on knees:
What is a total knee replacement?
Jennifer: A total knee replacement (TKR) is when we take out the damaged parts of the knee and replace them with an artificial joint made up of carefully designed, high-grade metal and plastic. The metal will actually set off metal detectors at the airport! Your damaged cartilage and bone come out, and the plastic acts as your new cartilage and bone. It sits in between two metal pieces.
The tibia (shinbone) has a cut in it that we insert a new piece into during surgery. A special cement holds it in place. A plastic insert sits in between and allows you to bend your knee and acts as a new cushion (pain-free!)
Dr. Fehring: We keep your MCL and LCL, but we do remove the anterior cruciate ligament (ACL). We replace the ACL with a plastic insert. Even if you’ve had an ACL surgery you can still have a knee replacement. There is also a plastic button on the back of the kneecap that helps the kneecap track in its groove and takes away the pain of arthritis under your kneecap.
Jennifer: The cement on your new joint replacement hardens almost immediately, which is why we are able to let you walk right away after surgery. It’s pretty neat to be able to go from walking on a diseased joint to a brand new one in a matter of mere hours.
What is a partial knee replacement?
Dr. Fehring: When patients have arthritis spread throughout the entire knee joint, we usually do a total knee replacement, which is much more common than a partial knee replacement. However, some patients only have arthritis in one area of the knee joint. The rest of the knee joint may be healthy and not have arthritis. When some of the knee is still considered “good” there’s an opportunity to do a partial knee replacement.
Jennifer: Like a TKR, for a partial knee replacement metal pieces go on your thigh bone and shin bone and a plastic piece is inserted in between. A partial knee replacement can often mean faster recovery, a shorter hospital stay and more of an overall natural feeling knee post-op than a TKR. However, it’s important to remember that only a small portion of patients are candidates for a partial knee replacement.
What is a robotic-assisted knee replacement?
Dr. Fehring: Robotics has existed in medicine for many years but has only just started to become feasible in orthopedics. We currently use robotics for partial knee replacements and are looking at a platform for robotic-assisted total knee replacements. One of the most frequent questions we get is whether a robot performs the surgery. The answer is no: our physician/physician assistant performs the surgery. However, we use a robotic-assisted arm to help us be more precise putting the surgical implants where we want them.
Jennifer: Robotic-assisted knee replacement surgery is quickly evolving and changing. It utilizes smaller incisions and can help with reduced risk of injury to nearby tissues. This type of technology is an aid and can give patients a better outcome and a longer lasting partial knee replacement. Your doctor will consult with you to develop the best plan for surgery and the best possible surgical outcome for your specific case.