Osteoarthritis is one of the most common chronic joint conditions, impacting nearly 27 million Americans, with people over 60 generally having some form of the disease. Of the few surgical solutions with long-term benefits, total knee replacement (TKR) is proven to aid with advanced osteoarthritis. However, 20% of patients report continued pain or stiffness in their knees following TKR – preoperative angular deformity from wear and tear can be difficult to correct, and contributes to post-operative symptoms. Computer navigation during surgery has emerged over the past decade as a solution to correct the knee’s alignment, and the implant’s positioning, during TKR. Whether improved alignment leads to better clinical outcomes after TKR or greater implant longevity, is currently a hot topic of debate.
A new study from the Journal of Bone & Joint Surgery compared computer-assisted navigated vs conventional TKR. 190 patients with inflammatory arthritis or osteoarthritis in their knees were randomly assigned to undergo computer-assisted or conventional TKR. The surgeries were performed by eight experienced surgeons, each with more than 100 conventional TKR operations and 10 computer-assisted TKRs. Computer-assisted Knee replacement requires an additional 1 inch incision in the midpart of the tibia, therefore a similar sham incision was performed on patients who received conventional TKR, to blind both patients and observers to the results. The study assessed responders after two years following their surgery to assess alignment, pain levels, implant position and more. This study is the first randomized, double-blinded responder analysis comparing computer-assisted navigated and conventional TKR. It is one of the largest double-blinded randomized controlled trials of its kind.
In theory, better alignment should lead to an improved clinical outcome and an increased long-term survival of the prosthesis. The study notes how positive functional outcomes and “the longevity of total knee prostheses depends mostly on the correct alignment (frontal, sagittal and axial) of the prosthetic components, soft tissue balancing, and restoring the mechanical axis of the lower limb.”
Researchers found that there is, in fact, a difference between the groups at two years. Overall, the computer-assisted TKR group had significantly better clinical results – they were more pain-free and had better function overall compared to the conventional TKR group. This indicates that computer-assistance navigation should also be predictive of a lower rate of revisions and greater longevity of the prosthesis. This study could not prove a causal relationship between good alignment and a positive clinical outcome. Other explanations for the better functional outcome could be that computer navigation might allow the surgeon to achieve more accurate ligament balancing and proper sizing of implant components. This would result in a less extensive impact on soft tissues, as a possible explanation for lower pain.
With significantly more improvement in the computer-assisted group, we can conclude that for at least 2 years after TKR, computer navigation provides patients with better pain relief and function than conventional surgical techniques. These findings have implications at both the individual patient-level and for the health system at large. This is due to economic expenses involved in diagnosing and treating patients with pain after TKA, not to mention the burden it places on individual patients.
The use of computer-assisted navigation in TKR allows for more predictable, accurate, and reproducible restoration of joint alignment, and improved positioning of implanted prosthetic components. This makes it valuable both for surgical training and better outcomes for patients.
Is arthritis or knee pain impacting your life? Dr. Stickney, a Kirkland orthopedic surgeon can help you determine what surgical or non-surgical options are best for you. He specializes in procedures including total knee replacement, joint replacement, sports medicine, and more. Contact his office today to learn more.