Minimally Invasive Total Knee Replacement
What is total knee replacement?
Total knee replacement is a type of surgery to replace a damaged knee joint. A minimally invasive surgery uses a smaller cut (incision) than a traditional total knee replacement. This type of surgery typically requires special tools so that the surgeon can see and do the procedure through the smaller incision.
The knee has several parts: the lower end of the thighbone (femur), the upper end of the shinbone (tibia), and the kneecap (patella). A smooth substance called cartilage caps the ends of these bones and keeps the bones from grinding together. When there is damage to the knee joint, these bones may scrape together abnormally and cause pain.
During minimally invasive total knee replacement, your surgeon makes an incision to access your shinbone and thighbone. Next, he or she removes a portion of the bones that make up the knee joint. Your surgeon replaces these bone parts with metal components that recreate the joint surface. A layer of plastic is placed between the metal components for smooth gliding.
Minimally invasive total knee replacement often takes place under general or spinal anesthesia.
Why might I need total knee replacement?
You might need a total knee replacement if you have significant damage to your knee joint. Different types of medical conditions can damage this joint, such as:
- Osteoarthritis (most common)
- Rheumatoid arthritis
- Injury or fracture of the knee joint
- Bone tumor in the knee joint
This damage might be very painful and limit your normal activities. The procedure may help decrease your pain, improve your joint mobility, and quality of life. Usually, healthcare providers only recommend total knee replacement when you still have significant problems after trying more conservative treatments, like pain medicines and corticosteroid shots (injections).
Talk with your doctor about the benefits and risks of having minimally invasive total knee replacement instead of traditional total knee replacement. Minimally invasive total knee replacement uses a smaller incision than a traditional knee replacement, so it may lead to less pain and decreased recovery time. It's not yet clear whether the procedure leads to increased risk of certain complications, though.
In some cases, you may have other surgical options, like shortening the bone or a partial knee replacement. Talk with your doctor about the risks and benefits of all your options.
How do I get ready for total knee replacement?
Ask your provider how you should plan to get ready for your surgery.
Tell your provider about any medicines you are taking, including:
- All prescription medicines
- Over-the-counter medicines such as aspirin or ibuprofen
- Illegal drugs
- Herbs, vitamins, and other supplements
Ask if there are any medicines you should stop taking ahead of time, like blood thinners.
If you smoke, try to quit before your surgery.
If you are overweight, your provider may advise you to try to lose weight before your surgery.
Don’t eat or drink after midnight the night before your procedure.
You may want to make some changes to your house, to make your recovery smoother. This includes things like adding a handrail in your shower.
In some cases, your provider might want additional tests before you have your surgery. These might include:
- X-rays, to get information about your hip
- MRI, to get more detailed information about your hip
- Electrocardiogram (ECG), to make sure your heart rhythm is normal
Follow any other instructions from your healthcare provider.
What happens during total knee replacement?
Your provider can help explain the details of your particular surgery. An orthopedic surgeon will perform the surgery aided by a team of specialized healthcare professionals. The whole procedure may take a couple of hours. In general, you can expect the following:
- Most likely, you will be given spinal or general anesthesia so that you’ll sleep through the surgery and won’t feel any pain or discomfort during the procedure. Or you may get local anesthesia and a medicine to keep you relaxed but awake.
- A healthcare professional will carefully watch your vital signs, like your heart rate and blood pressure, during the surgery.
- You may get antibiotics, during and after the procedure, to help prevent infection.
- Your surgeon will make an incision over the middle of your knee, cutting through your skin and underlying tissue.
- He or she will remove the damaged portions of your thighbone and shinbone, removing a little of the bone beneath as well.
- Next, metal implants are placed into the joint space, usually cementing them into the remaining bone.
- In most cases, your surgeon will also remove part of the underside of the kneecap.
- A plastic spacer is inserted into the space between the metal implants, for ease of movement.
- The layers of your skin and muscle will be surgically closed.