About total knee replacement surgery
When your knee is healthy, it can bend and flex easily. The cartilage between the bones absorbs stress and allows the bones to move freely over each other. Your knee, when unhealthy, can cause you pain and stiffness resulting in limitations to your daily activities. An unhealthy knee is due to inflammation, injury, or simply a long lifetime of use, leading to increased friction and stiffness. Often, the damaged cartilage may allow the knee and leg bones to rub against each other, causing significant pain and often times swelling of the knee joint.
The right combination of orthopedic surgeon, implant, and technique can help you get back to the life and activities you love.
Total knee replacement is the removal of damaged cartilage and bone replaced by a new implant. It can be highly effective in relieving pain, restoring function and letting you return to your daily activities. When put in properly, the new implant creates a new, properly functioning joint that prevents painful bone-on-bone contact.
The knee joint
The knee joint is formed by three bones with the support of ligaments and muscles. The large bone in your thigh is called the femur. On the opposing end is the tibia (shin bone). Along with the patella (knee cap), the knee joint is held together by several ligaments. These ligaments interact with the leg muscles to stabilize and control the motion of the knee and protect it from damage. Between the weight-bearing surfaces of the knee, a layer of cartilage helps the bony surfaces of the knee move smoothly against one another.
The medial/lateral collateral ligaments (MCL/LCL) run parallel down the side of the knee, and provide stability side-to-side. The anterior cruciate ligament (ACL) and posterior cruciate ligament (PCL) cross in the center of the knee and provide stability front-to-back as the knee flexes and extends. The patellar tendon connects the patella to the muscles in the thigh and the tibia. The patella moves along the front of the knee joint, providing extra stability and protection. The knee cannot function correctly if all the parts do not move smoothly.
The cartilage interacts with two horse-shoe shaped shock absorbers called menisci. These shock absorbers are cartilaginous structures that cushion the knee from the stress of everyday activities. The combination of the menisci, the articular cartilage, and a small amount of fluid creates a nearly frictionless gliding surface. For the knee joint to function well, a person must also have healthy, flexible muscles, and the cartilage and ligaments must be smooth and strong. Problems occur when any of these parts are damaged or irritated.
Total knee replacement
Total knee replacement implants are designed to replace affected areas with components that re-create healthy knee joint mechanics. The main components of an artificial knee consist of the tibia component (shin bone), the femoral component (thigh bone), and the patellar component (knee cap). The tibia component is a two-piece construct: a metal baseplate that is fit into the tibia, and a polyethylene (plastic) insert that locks onto the baseplate. The insert is shaped to create a smooth articulating surface for the femoral component. With each of these components working together, you should be able to move your knee joint without pain. After examining your knee’s damage, your physician will determine what procedure is necessary to get you back to a normal, active life.
Which surgical approach is best for knee replacement?
Once you have made the decision to have knee replacement surgery, you will discover that there are options not only for the types of implants, but the surgical approach as well. You should discuss this with your surgeon who will determine which implant and surgical approach are right for you based on your specific anatomy and physical condition.
Using this approach, the surgeon makes an eight to twelve inch incision and operates on the knee using standard surgical technique. Generally, the incision is made along the front and toward the middle or along the front and to the side of the knee. This approach typically requires three to five recovery days in the hospital and about twelve weeks of recovery time.
Robotic assisted surgery
Robotic assisted surgical techniques help the surgeon to plan and execute a surgical procedure that is truly specific to your condition and anatomy resulting in improved joint function. OMNIBotics, an innovative computer controlled, robotic assisted total knee replacement procedure designed by OMNI, provides your surgeon with the robotics to plan and execute a surgical procedure that is truly specific to your condition and anatomy. This procedure has been proven to improve the accuracy of the intended leg alignment, which may result in improved joint function*. To learn more about the OMNIBotics procedure, click here.
*Clarke, “Robotic vs Computer assisted Navigation in TKA, Intraoperative Efficiency and Accuracy”, ISRN Orthopedics Colume 2013, Article ID 794827
Minimally invasive surgery
Knee replacement surgery can also be performed using minimally invasive techniques. With a MIS procedure, the incision is typically three to four inches, which can result in reduced trauma to tissue, less pain during recovery, and decreased blood loss, all of which can contribute to a quicker recovery. Because the surgeon cuts less muscle, healing occurs faster and you also may experience better range of motion after recovery.
Q: Is there a maximum age limit for knee replacement surgery?
A: Consult your physician about your general health and your ability to withstand surgery. In general age is not a factor for knee replacement surgery if you are in reasonably good health and you have the desire to continue pursuing an active and productive life.
Q: Will my recovery from surgery be painful?
A: As with most surgeries you should expect considerable amounts of tenderness on the repaired area. Pain medication will be given to you during the hospital stay and the pain should decrease over several weeks.
Q: How much pain relief or increased mobility should I expect?
A: You should experience significant reduction in pain and improved mobility after knee replacement surgery. Many factors, including physical condition, weight, activity level, personal anatomy and willingness to comply with your surgeon’s instructions prior to and after surgery will play an important role in your recovery.
Q: When will I be “me” again?
A: You should be able to stand and walk with assistance soon after surgery. Physical therapy will begin as soon as you feel ready, generally one to two days after surgery.
You should expect six weeks or more of physical therapy before you can completely resume your normal activities. In general, however, you should be able to partake in certain low-impact activities within a few weeks. This will depend on multiple factors, including your health, the type of surgery and your recovery. Typically surgeons discourage patients from any high impact activities such as running and other strenuous sports. Complete recovery usually takes several months.
Q: How long will I be in the hospital?
A: In most cases, knee replacement patients are discharged from two to five days. If you need more time for rehabilitation, other options might be available.
Q: How long does the procedure take?
A: Your doctor will discuss with you all of the details regarding your surgery including how long the procedure is expected to take. Most knee replacement surgeries take approximately two and a half hours. Some of this time is taken by the operating room staff to prepare for surgery.
Q: How do I know if I need a knee replacement?
A: If you have chronic knee pain that restricts regular activities, chronic stiffness of the knee, constant knee instability, or a severe deformity of the knee, then you are likely a good candidate for a total knee replacement. As always, it is best to discuss possible treatments with your physician.