Overview
Total knee arthroplasty, also known as total knee replacement, remains the gold standard treatment for advanced knee arthritis when appropriate conservative treatment has failed. Unlike arthroscopic surgery, which can remove damaged tissue and smooth irregular areas, total knee arthroplasty replaces the worn-out joint surfaces themselves.
I like to compare the joint surface to a tile floor. With arthroscopy, I can remove loose pieces, smooth rough edges, and transition from healthy areas to damaged areas, but I cannot bring new tile into the room. The damaged surface is still there. Total knee arthroplasty is different. We remove the worn-out surfaces and replace them with new artificial surfaces. The goal is to relieve pain, restore alignment, improve motion and function, and allow patients to return to a more active lifestyle.
When Is Total Knee Arthroplasty Recommended?
Total knee replacement is generally considered after appropriate conservative treatment has failed to provide adequate relief. Many patients can manage knee arthritis for years with activity modification, medications, injections, and other nonoperative treatments. Arthroscopic surgery may also have a role in selected patients. When arthritis progresses to the point that pain, stiffness, loss of motion, sleep disturbance, or loss of function significantly affects quality of life, total knee arthroplasty often becomes the most effective and predictable treatment option.
What Is Replaced?
During total knee arthroplasty, the worn cartilage surfaces of the femur and tibia are replaced with artificial components. I also resurface the patella, or kneecap, replacing the back half of the patella where it articulates with the femur. Depending on the patient's age and bone quality, the implants may be cemented or press-fit. The goal is not simply to treat the symptoms of arthritis, but to replace the damaged joint surfaces that are producing the problem.
MAKO Robotic-Assisted Knee Arthroplasty
I use the MAKO robotic-assisted system, one of the most advanced technologies available for total knee arthroplasty. This state-of-the-art system combines detailed preoperative planning with real-time information during the operation, allowing the replacement to be individualized to each patient's anatomy. Before surgery, a CT scan creates a three-dimensional model of the knee, allowing me to plan implant size, position, and alignment before entering the operating room.
More importantly, during surgery, the MAKO system provides detailed information that allows me to make highly accurate adjustments to the surgical plan based on the patient's actual anatomy and knee mechanics at the time of the operation. This allows the final implant position and alignment to be fine-tuned specifically for that individual patient. The robot does not perform the surgery. I perform the operation, while the robotic system serves as a sophisticated tool that provides information and guidance throughout the procedure.
Surgery and Recovery
Patients begin walking immediately after surgery using a walker or crutches and transition to a cane as soon as they are comfortable. Most patients discontinue all walking aids within approximately 4-6 weeks. Physical therapy typically begins at home, with a physical therapist and home health nurse visiting approximately two to three times each week. The first postoperative visit is approximately three weeks after surgery. At that point, most patients transition from home therapy to outpatient physical therapy.
Knee Extension
The single most important principle following total knee replacement is restoring full knee extension, or the ability to get the knee completely straight. I tell patients that the knee does not have to stay straight all day. It simply has to be able to get completely straight. A simple way to monitor this is to check the knee first thing in the morning. If it gets completely straight, move on and work on the other aspects of recovery. If it does not, spend time throughout the day applying pressure and working on knee extension. Check it again that evening. If the knee gets completely straight, move on to other things. If it still does not, continue focusing on extension. Until the knee can reliably get completely straight, extension needs to remain a daily priority. Failure to regain full extension during the early postoperative period can permanently affect walking mechanics and the overall result.
Blood Clot Prevention
All patients receive anticoagulation following total knee arthroplasty to reduce the risk of developing a deep vein thrombosis (DVT) or pulmonary embolism (PE). Most patients receive one full-strength 325 mg aspirin twice daily for approximately 30 days. Patients with a previous history of DVT or pulmonary embolism are typically treated with a stronger anticoagulant, such as Xarelto. It is important to let me know before surgery if you have ever had a DVT or pulmonary embolism because this places you in a different risk category and may change the postoperative anticoagulation plan.
Potential Complications
Total knee arthroplasty is an extremely successful operation, but potential complications include implant loosening, joint stiffness, blood clot or pulmonary embolism, and infection. Infection is fortunately uncommon but can be the most devastating complication following knee arthroplasty. These infections usually occur months or even years after surgery, when bacteria circulating in the bloodstream attach to the prosthesis. Treatment requires additional surgery and usually involves removal of the prosthesis, placement of a temporary antibiotic spacer, IV antibiotics, and eventual revision knee arthroplasty. Fortunately, the overwhelming majority of patients experience significant improvements in pain, function, and quality of life.