Over time, the cartilage cushion in the knee can wear away, most commonly from osteoarthritis. You may experience sharp pain while walking or climbing stairs, and you may even have knee pain while sitting or lying down. A partial or total knee replacement uses a metal and plastic prosthesis to replace the painful joint and restore a fuller range of motion and function.
A loss of cushioning leads to pain
The knee is a hinge-like joint at the junction of the thighbone, shinbone, and kneecap. It is supported by muscles, tendons, and ligaments, and is lined with cartilage that absorbs stress and allows the bones to glide freely over each other.
As cartilage cracks or wears away—due to usage, certain types of arthritis, inflammation or knee injury—it no longer allows the joint to glide freely. Exposed bones then rub together when the knee bends, causing sharp pain and stiffness.
Get back to pain-free movement
If nonsurgical treatments aren’t working, or you’ve received a referral, see a UCHealth orthopedic specialist to talk about knee replacement surgery. It’s is a safe and effective procedure to relieve your pain, correct any leg deformity and help you get back to doing the activities you love.
Your knee replacement procedure
Your orthopedic surgeon will first assess your knee’s range of motion, stability and strength to determine if a knee replacement is right for your case, and will consider your age, weight, activity level and overall health. Your doctor will then choose the right type of knee replacement prosthesis and surgical technique.
Depending on the specific technique, a procedure takes approximately 1 to 2 hours and is major surgery. A knee replacement is basically a resurfacing of the knee joint because only the surface of the bones are actually replaced.
A knee replacement procedure typically involves four basic steps:
- Preparing the bone. Your surgeon removes the damaged cartilage surfaces at the ends of the femur and tibia, plus a small amount of underlying bone.
- Positioning the metal implants. Your surgeon replaces the removed cartilage and bone with metal components that recreate the surface of the joint.
- Resurfacing the patella (kneecap). Your surgeon cuts and resurfaces the undersurface of the patella with a plastic button. We may not resurface the patella, depending upon the case.
- Inserting a spacer. Your surgeon inserts a medical-grade plastic spacer between the metal components to create a smooth gliding surface.
The new smooth surfaces will allow your bones to glide freely without pain. A knee prosthesis does have limits, but it can let you move with greater comfort.
Your orthopedic team will work with you on a customized treatment plan to help your recovery. You can expect to resume most daily activities three to six weeks after surgery. You might also be able to drive if you can bend your knee far enough to sit in a car, you have enough muscle control to operate the brakes and accelerator, and if you’re not taking narcotic pain medications.
In addition, your treatment plan will include physical therapy to help you return to low-impact activities such as swimming, golfing or biking, as soon as your provider approves.
Your plan will also outline the risk of surgery, and identify certain activities to avoid.
Living with an artificial knee
Most of our knee replacement patients experience significant pain relief, improved mobility, and a better quality of life. You can expect your knee replacement to last more than 15 years.
Orthoinfo: American Academy of Orthopaedic Surgeons. Total Knee Replacement (https://orthoinfo.aaos.org/en/treatment/total-knee-replacement/)
MedlinePlus Magazine: National Library of Medicine. Knee joint replacement (https://medlineplus.gov/ency/article/002974.htm)