ABOUT KNEE REPLACEMENT
The knee joint is made up of the ends of the thigh bone (femur) and the shin bone (tibia). These bones normally slide over one another easily because they are covered by soft cartilage. If an injury damages the cartilage or wears it away from arthritis, for example, it can make the joint sore or stiff.
A new knee joint usually improves mobility and decreases pain, although your new knee will not be able to bend as much as a normal knee joint.
Depending on the condition of your knee joint, they will replace part or all of your knee joint. A total knee replacement is more common.
Artificial knee pieces can be made of metal and/or plastic and a knee replacement can last up to 20 years.
WHAT ARE THE ALTERNATIVES?
Surgery is generally recommended only if nonsurgical treatments, such as physical therapy and exercise, taking medications, or using physical support devices such as a cane, no longer help decrease pain or improve mobility.
Alternative surgical procedures include arthroscopy (if the arthritis is not very severe) or osteotomy (in which the leg bones are cut and reattached). You may have already had these procedures before your knee replacement.
The surgeon will explain your options to you.
PREPARATIONS FOR A KNEE REPLACEMENT
The surgeon will explain to you how to prepare for the operation. For example, if you smoke, he or she will ask you to stop smoking, as this increases your risk of chest and wound infection, which can delay your recovery.
You usually need to stay in the hospital for about five days, and the surgery is done under general anesthesia. This means that you will be asleep during the operation. Otherwise, if you prefer, the surgery can be performed with epidural or spinal anesthesia. This type of anesthesia completely numbs you from the waist down, and you will remain awake during the operation.
If you are going to be given general anesthesia, you will be asked to fast. This means that you will not have to eat or drink, usually for about six hours before the general anaesthetic. However, it is important to follow the instructions of your anesthesiologist.
At the hospital, the nurse may check your heart rate and blood pressure and do a urine test.
Your surgeon will explain what will happen before, during, and after the procedure, and any pain you may have. This is your chance to understand what will happen, and you may find it helpful to prepare questions about the risks, benefits, and other alternatives to the procedure. This will help him be informed so that he can give his consent if he is asked to sign a consent form to have the procedure done.
You may be asked to wear compression stockings on your unaffected leg to prevent blood clots from forming in the veins (deep vein thrombosis, DVT). You may need an injection of a blood-thinning medicine called heparin in addition to or instead of wearing compression stockings.
WHAT HAPPENS DURING A KNEE REPLACEMENT?
Generally, a knee replacement takes about two hours.
The surgeon will make a single cut (10 to 30 cm long) in the front of your knee. He will push your kneecap to the side to get to your knee joint. The surgeon will remove worn or damaged surfaces from the end of the femur and the top of the tibia. He will usually remove the anterior cruciate ligament and may remove the posterior cruciate ligament. For support, the surgeon will not remove the collateral ligaments. He will shape the surfaces of the femur and tibia to fit the artificial knee joint and then fit the new joint over both bones.
Sometimes the back of the kneecap is replaced with a piece of plastic. This is known as the patellar overlay.
After placing the new joint, the surgeon will close the wound with stitches or clips and cover it with a bandage. The surgeon will place a tight bandage over your knee to help minimize swelling.
WHAT SHOULD I EXPECT NEXT?
You will need to rest until the anesthesia wears off. After epidural anesthesia, you may not be able to feel or move your legs for several hours.
You may need pain medicine to relieve any discomfort when the effects of anesthesia wear off.
For the first day or so you may have an intermittent compression pump attached to special pads on your lower legs. By inflating the cushions, the pump promotes healthy blood circulation and helps prevent DVT. You may also have a compression stocking on the unaffected leg. This helps maintain circulation.
A physical therapist (a movement and mobility specialist) will visit you daily to guide you through exercises that will help you recover.
She will remain in the hospital until she can walk safely with the help of a cane or crutch. When she is able to return home, she will have to ask someone to give her a ride.
Before you go home, the nurse will give you recommendations for caring for your knee and a date for your follow-up appointment.
The time it takes for the sutures to disappear will depend on the type used in the surgery. However, for this procedure they usually go away in about six weeks. Non-absorbable sutures and clips are removed 10-14 days after surgery.
RECOVERING FROM KNEE REPLACEMENT SURGERY
If necessary, you can take an over-the-counter pain reliever, such as paracetamol or ibuprofen. Follow the instructions in the patient information leaflet that comes with the medicine, and if you have any questions, ask your pharmacist.
Physical therapy exercises are an essential part of your recovery, so it is essential that you continue to do them for at least two months.
You will be able to move around your house and go up and down stairs. For a few weeks, some everyday activities, like shopping, will be difficult for you to do. You may need to use a cane or crutches for about six weeks.
You may be asked to wear compression stockings at home for several weeks.
When you rest, raise your leg and support your knee to help prevent leg and ankle swelling.
Depending on the type of work you do, you may be able to return to work after six to 12 weeks.
Follow your surgeon's recommendations for driving. You should not drive until you are sure that you can break in an emergency without discomfort.
