This provides information for you and your family regarding total knee replacement surgery. The goals are to restore your knee to a painless, functional status, and to make your hospital stay as beneficial, informative and comfortable as possible.
Normal Knee
The knee joint is formed where the thighbone (femur) meets the shinbone (tibia). A smooth cushion of articular cartilage covers the end surfaces of both of these bones so that they slide against one another smoothly. The articular cartilage is kept slippery by joint fluid made by the joint lining (synovial membrane). The fluid is contained in a soft tissue enclosure around the knee joint called the joint capsule.
The patella, or kneecap, is the moveable bone on the front of the knee. It is wrapped inside a tendon that connects the large muscles on the front of the thigh, the quadriceps muscles, to the lower leg bone. The surface on the back of the patella is covered with articular cartilage. It glides within a groove on the front of the femur
Total Knee Replacement
The main reason for replacing any arthritic joint with an artificial joint is to stop the bones from rubbing against each other. This rubbing causes pain. Replacing the painful and arthritic joint with an artificial joint gives the joint a new surface, which moves smoothly and without causing pain.
Total knee replacement is a surgical procedure in which injured or damaged parts of the knee joint are replaced with artificial parts. The ends of the thigh bone (femur) and the shin bone (tibia) are removed, and sometimes, the underside of the kneecap (patella) is removed. The artificial parts are cemented into place. Your new knee will consist of a metal shell on the end of the femur, a metal and plastic trough on the tibia, and, if needed, a plastic button in the kneecap.
Who is a candidate for a total replacement?
Total knee replacements are usually performed on people suffering from severe arthritic conditions. Most patients who have artificial knees are over age 55, but the procedure is performed in younger people as well.
The circumstances vary somewhat, but generally you would be considered for a total knee replacement if you have any of the below :
• You have almost daily pain.
• Your pain is severe enough to restrict not only work and recreation but also the ordinary activities of daily living.
• You have stiffness of your knee.
• You have instability (constant giving way) of your knee.
• You have deformity (lock-knees or bowlegs).
This is an elective surgery, it is not a matter of life or death. The decision to proceed with total knee replacement surgery is ultimately yours, it is you who must accept the risks and potential complications..
What can I expect from an artificial knee?
An important factor in deciding whether to have total knee replacement surgery is understanding what the procedure can and can’t do. An artificial knee is not a normal knee, nor is it as good as a normal knee.
If replacement provides you with pain relief and if you do not have other health problems, you should be able to carry out many normal activities of daily living. About 90 percent of patients with stiff knees before surgery will have better motion after a total knee replacement. More than 90 percent of individuals who undergo total knee replacement experience a dramatic reduction of knee pain and a significant improvement in the ability to perform common activities of daily living. But total knee replacement won’t make you a super-athlete or allow you to do more than you could before you developed arthritis.
| PATIENT EXPECTATIONS | SURGEON EXPECTATIONS |
| 100% pain relief | 90-100% pain relief |
| 100% normal walking pattern | Trace of limp to 100% normal walking |
| Able to run and jump. | Should avoid running or jumping |
| Able to bend knee fully | Can bend to around 120-125° |
| The knee will "last forever" | The knee will last for about 15-20 years |
| The knee will never get infected | Occasional knees will get infected! |
How successful is total knee replacement surgery ?Results are generally very good, most people are relieved of nearly all of their knee pain. Approximately 90% of total joints will last 15-20 yrs depending on patient use and activity levels. This may vary from person to person.
The goals of total knee replacement are, in order of priority :
1. pain relief
2. standing and walking that is not limited by the knee
3. improved knee motion
4. improved knee strength
How long do artificial knees last?
About 90 % of total knee replacements are successful up to 15-20 years. The major long-term problem is loosening. This occurs because either the cement crumbles (as old mortar in a brick building) or the bone melts away (resorbs) from the cement.
Preparing for Surgery
Preparing for a total knee replacement begins a few weeks ahead of the actual surgery date. Maintaining good physical health before your operation is important. Activities which will increase upper body strength will improve your ability to use a walker or crutches after the operation.
Pre–op Medical Check-up :
During your pre-op visit, lab tests will be advised to insure that you are in good general health. Chest xrays and an ECG are obtained if you have not had one taken for six months or if otherwise indicated. If at any time you become ill, such as with a cold or flu, you need to call your doctor. Remember, we want you to be in your best possible health !
The doctor will also make sure that a urinary tract infection is not present. Urinary tract infections are common, especially in older women, and often go undetected. Teeth need to be in good condition. An infected tooth or gum may also be a possible source of infection for the new knee. The orthopaedic surgeon may ask you to see a medical doctor.
You may be instructed to stop taking your anti-inflammatory medications (Ibuprofen, aspirin, etc ) one week before surgery. Bring a written list of past surgeries and of the medications and dosages that you normally take at home.
A physician will also review your medical history and the medications that you take. He will listen to your heart and lungs, and do a general physical exam. He will check for any type of infection. If infection is found, surgery is generally delayed until the infection is cleared.
Will I need blood?
Most patients don’t require a blood transfusion after a single side total knee replacement. If needed it, there is always blood available in the blood bank.
What are the risks of total knee replacement? Total knee replacement is a major operation. The effect of most complications is that you must stay in the hospital longer.
The most common complications are not directly related to the knee and usually do not affect the result of the operations. These complications include urinary tract infection, blood clots in a leg, or blood clots in a lung.
1. Infection
Infection can occur following any type of surgery. In order to minimize the potential for infection to occur at the time of surgery, antibiotics are given before & after surgery. Infection following total knee replacement is of special concern because of the prosthetic components. The prosthetic components have no blood supply and this makes them susceptible to infection. If the prosthetic components become infected, additional surgery is almost always required in order to treat the infection.
2. Persistent Pain
While more than 95% of patients have complete or nearly complete relief of pain following total knee replacement, there are some patients with some persistent pain. In many cases, the pain resolves with time. In other cases, a specific cause for the pain can be identified and treated.
3. Blood Vessels and Nerves
There are several major blood vessels and nerves around the knee. Rarely, a major blood vessel or nerve is injured during total knee replacement surgery.
4. Blood Clots
Blood clots can form in the large veins of the legs and pelvis following major surgery, such as total knee replacement. It is possible for such a clot to break loose from the vein and travel to the heart. The clot can pass through the heart and into the lungs. This is called a pulmonary embolus. In order to prevent this from happening, blood thinners are prescribed post operatively
5. Other Medical Complications
In a few patients, due to the advanced age & co-existing medical problems, there may be some medical complications like Hematemesis ( GI Bleed, etc), breathlessness, etc. This may necessitate a stay in the ICU for monitoring & so on.
Myths & Facts about Total Knee Replacement Too Old ?
Knee replacement is safe and successful at any age. With modern & regional anesthesia, infection fighters, and the skill of experienced joint surgery specialists, you don’t “have to live with the pain.”
Too Young ?
Today’s super-metals make artificial joints last longer than ever before. When performed properly, knee replacement can be expected to last 15-20 years. When the first knee replacement wears out, another newone can be put in. It’s much like re-treading a tire or recapping a tooth.
Too Overweight ?
For people with knee arthritis, it’s almost impossible to lose weight when even simple walking is too painful. In fact, it’s much easier to exercise and lose weight when knees are pain-free after a knee replacement.
Too Long To Recover ?
Patients are usually allowed to walk within 24 hrs after surgery. Discharge from the hospital is around the 3-4 post-operative day. Healing and recovery after knee replacement is generally complete in about 4 weeks.
Restricted Range of motion ?
With the new generation designs, patients can even sit cross-legged following TKR(Though floor sitting is not advisable !)
Limitations of Total Knee Replacement Technology
In many ways, a total knee replacement is similar to a set of automobile tires. How long the knee replacement lasts is related to the type and amount of use, and not simply how long it has been implanted.
Although it is anticipated that a total knee replacement will last for many years, some fail sooner than expected. The main causes of failure are loosening, wear, osteolysis and component breakage. Fortunately, these occurrences are rare. Unfortunately, they can occur and generally necessitate additional surgery.
Fracture of the bone around a total knee replacement can also occur and surgery may be necessary to stabilize the fracture.
Loosening, wear and osteolysis generally occur slowly over time. The patient may not initially experience any pain or other symptom indicating a problem. For this reason, it is generally recommended that all total knee replacements be evaluated with x-rays on a yearly basis. This way, problems can be detected and treated early and, therefore, more easily.
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