New Procedure for Knee Replacement Leads to Better Range of Motion

The problem with many of the total knee replacement surgeries performed today is that they usually involve the cutting of one or both of the ACL (Anterior Cruciate Ligament) or PCL (Posterior Cruciate Ligament)—two of the four ligaments responsible for the way a “natural” knee flexes and rolls when it comes to walking, running, climbing stairs or other such activities. Thanks to a relatively new procedure using the Smith & Nephew JOURNEY II XR total knee arthroplasty, total knee replacement surgery can now be conducted without disturbing either of the cruciate ligaments in the middle of the knee joint.

The result? An innovative treatment option for arthritic patients who have intact and well-functioning cruciate ligaments. The retention of the cruciate ligaments during the replacement surgery may provide patients with a more normal feel and stability throughout all ranges of motion and may lead to a smoother recovery, improved knee function and better overall patient satisfaction.

“From the studies that are out there right now, we’re seeing a 10–15 percent dissatisfaction rate from patients after knee replacement surgery, which means people are not fully satisfied with their new knee,” says Dr. John Aldridge, an orthopaedic surgeon with Hampton Roads Orthopaedics & Sports Medicine in Newport News. “If you look further into those studies at questions like, ‘How natural does your new knee feel when you walk?’ up to 30 percent of respondents said the new knee doesn’t feel like their normal knee. With the new XR knee replacement, you’re saving all of the knee ligaments and you’re creating a joint line and shape of the joint so when the knee moves, it moves much more naturally. It feels much more like their native knee.”

With the new procedure, an “island of bone” is retained that keeps the ACL and PCL attached. Using special instruments, the island is then fitted to a metal cap on the tibia (also known as the shinbone—the larger of the two bones in the leg below the knee that connects the knee to the ankle), and a second cap is placed on the femur (upper leg bone) to complete the procedure.

“The knee is very complex in its range of motions,” says Dr. Anthony Carter, another orthopaedic surgeon with Hampton Roads Orthopaedics & Sports Medicine. “People think of it as a large hinge, but it’s so much more. It flexes, rotates and glides all at the same time. So when you do a knee replacement, typically you alter the mechanics of the knee when you have to sacrifice one or both of the ligaments within the knee. With this new procedure, patients will presumably have better function and the knee will feel more ‘normal’ and natural.”

Both doctors agree that the real proof in how effective the new procedure will be is to measure patient satisfaction in the long run. “The early gains we’ve seen are not the primary goal of this implant,” says Aldridge. “It’s the long-term satisfaction and the long-term kinematics or movement of the knee.”