A Guide to Understanding Total Knee Surgery
Why Does My Knee Hurt?
Your knee joint is made up of three bones. Your thigh bone (femur) sits on top of your shin bone (tibia). When you bend or straighten your knee, the rounded end of your thigh bone roll and glides across the relatively flat upper surface of your shin bone. The third bone is often called the kneecap (patella), which is attached to the muscles that allow you to straighten your knee. Your kneecap provides leverage that reduces strain on these muscles.
In a normal, healthy knee, the bone surface that come together at the joint are smooth and hard. A cushioning layer of tissue, called cartilage, prevents direct contact among these bones. This tough layer of tissue allow the three bones to move without creating friction or wear on the bone surfaces.
However, when this cartilage is damaged or worn away, your bones rub together causing friction, pain and, eventually deterioration of the bone surfaces. The most common causes of damage to your cartilage are the various types of arthritis. There is no medication or treatment that will make damaged cartilage grow back.
What is Total Knee Replacement?
In total knee replacement surgery, the parts of the bones that rub together are resurfaced with metal and plastic implants. Using special, precision instruments, your surgeon will typically remove the damaged surfaces of all three bones. The replacement surfaces will then be fixed into place.
The surface of the upper bone is replaced with a rounded metal component that comes very close to matching the curve of your natural bone. The surface of the lower bone is replaced with a flat metal component with a piece of ultra-high-molecular weight polyethylene plastic to serve as the cartilage. The undersurface of the kneecap may also be replaced with a round disc made of the same polythylene plastic.
How Will I Know If I Should Have Knee Replacement?
Our orthopaedic surgeon will perform a very thorough examination of your knee. This will include a test of your range of motion-how far you can bend and extend your knee. Our surgeon will also look for deformities in your legs which may show up as conditions commonly called bowlegged or knock-kneed. You will be asked to walk, sit, and perhaps go up and down a few steps.
Our surgeon will also ask you many important questions to determine our medical history. Answering these questions thoroughly helps the surgeon accurately evaluate your individual circumstance. You will be asked about current medications, as well as past injuries, infections and other disorders you may have experienced. And, of course, you will be asked to describe the pain in your knee.
Finally, our surgeon will take X-rays which will be used to further assess the condition of your knee joint. If you decide on total knee replacement surgery, these X-rays will also be used to help our surgeon select the best type and size of artificial knee.
Based on this examination, your surgeon will determine whether your are a candidate for total knee replacement. Although widely practiced, total knee replacement is a major surgical procedure and should only be considered when all other treatment methods have failed.
There are more conservative alternatives which you and our surgeon may want to consider. These include medications or injections for pain and inflammation, physical therapy, or other types of surgery.
The final decision about whether or not to have total knee surgery will be yours, so you will want to understand the risks involved. There are potential complications both during and after surgery. Generally, these include infection, blood clots, pneumonia, prosthesis loosening, and nerve damage. Our surgeon can answer your specific questions about these risks.
What Is It Like To Have Knee Replacement Surgery?
If you and our surgeon decide that total knee replacement is right for you, a date will be scheduled for your surgery. Several things may be necessary to prepare for surgery.
Because blood transfusions may be needed during your surgery, you may want to donate one unit of your own blood, or possibly two units if your surgeon feels it is needed. You can donate one unit per week before your surgery.
On the day of surgery, a small tube (intravenous line) will be inserted into your arm. This tube will be used to administer antibiotics and other medication during your surgery. You will then be taken to the operating room and given anesthesia.
After the anesthesia takes effect, your knee will be scrubbed and sterilized with a special solution.
The surgery will begin with an incision over the knee that will expose the joint. When the bones are fully visible to the surgeon, special, precision guides and instruments are used to remove the damaged surfaces and shape the ends of the bones to accept the implants.
The implants are then secured to the bones. It might also be necessary to adjust the ligaments that surround the knee in order to achieve the best possible knee function. When the surgeon is satisfied with the fit and function of the implants, the incision will be closed.
A special drain may be inserted into the wound to drain the fluids that naturally develop at the surgical site. A sterile develop at the surgical site. A sterile bandage will then be applied, and you will be taken the recovery room, where you will be taken to the recovery room, where you will be closely monitored. Your surgery will take between two to three hours, depending on your individual circumstances.
As your anesthesia wears off, you will slowly regain consciousness. A nurse will be with you, and may encourage you to cough or breath deeply to help clear your lungs. You will also be given pain medication. When you are fully awake, you will be taken to your hospital room. Your knee will remain swollen and tender for a few days.
What Can I Expect After Surgery?
When you are back in your hospital room, you will begin in a rehabilitation program designed specially for you. This program will help you regain strength, balance, and get you back to the activities you enjoy. It may include a machine, called a continuous passive motion machine, that automatically moves your leg.
Your physical therapist will help you perform appropriate exercises. About 24 hours after surgery, you will probably be asked to stand. Within the next 24 hours, you will begin to walk a few steps with the help of a walker.
You will be discharged as soon as our surgeon determines that you have recovered sufficiently. You can expect to stay in the hospital for about three days after your surgery. You may or may not be transferred to a nursing facility for a few more days, as determined by our surgeon. Your bandages and sutures will usually be removed before you leave the hospital.
At home, you will need to continue your exercises. Your physical therapist will instruct you about proper home care, and may continue to work with you.
Within six weeks after surgery, most patients are able to walk with a cane. You will probably feel well enough to drive a car within seven to eight weeks after surgery.
In most cases, successful total knee replacement will relieve your pain and stiffness, and allow you to resume many of your normal daily activities. But even after you have fully recovered from your surgery, you will still have some restrictions. Normal daily activities do not include contact sports or activities that put excessive strain on your knees. Although your artificial knee can be replaced, a second implant is seldom as effective as the first.