| What is Knee Arthritis ?
Knee pain and stiffness often results from osteoarthritis (wear and tear of joint articular cartilage and bone), rheumatoid arthritis (an inflammatory joint disease) or an injury. Arthritis causes your articular cartilage to wear away. As a result of this the bone ends become rough and rub together causing pain. Your joint may also be inflamed and swollen. Although ageing is the factor most strongly associated with OA. However, previous injuries and consequent damage to articular cartilage will result in accelerated osteoarthritis. There may be a genetic tendency in some people that increases chances of developing osteoarthritis.
Why TKR is needed ? Articular cartilage i.e. joint surface , when worn out or , can not be regrown . Hence it has to be replaced. As we use dentures after losing teeth . Are there any alternatives to a TKR? Before suggesting surgery your doctor may have offered several alternative treatments including medication, physiotherapy, weight loss, walking aids or other operations. In some situations, Arthroscopy or osteotomy ( changing the angle of the bone ) may be sufficient . Some times replacing half the joint ( unicondylar ) may be required .Only when these treatments no longer control your pain will your doctor suggest a TKR. What is a Total Knee Replacement? A total knee replacement is a surgical procedure whereby the diseased knee joint is replaced with artificial material. The knee is a hinge joint which provides motion at the point where the thigh meets the lower leg. The thigh bone (or femur) abuts the large bone of the lower leg (tibia) at the knee joint. During a total knee replacement, the end of the femur bone is removed and replaced with a metal shell. The end of the lower leg bone (tibia) is also removed and replaced with a channeled plastic piece with a metal stem. Depending on the condition of the kneecap portion of the knee joint, a plastic “button” may also be added under the kneecap surface.
PATIENTS WHO CAN GET BENEFIT OUT OF A TOTAL KNEE REPLACEMENT
CONTRA -INDICATIONS:
Which patients should consider a total knee replacement? Total knee replacement surgery is considered for patients whose knee joints have been damaged by either progressive arthritis, trauma, or other rare destructive diseases of the joint. The most common reason for knee replacement is severe osteoarthritis of the knees. Regardless of the cause of the damage to the joint, the resulting progressively increasing pain and stiffness and decreasing daily function lead the patient to consider total knee replacement. Decisions regarding whether or when to undergo knee replacement surgery are not easy. Patients should understand the risks as well as the benefits before making these decisions. What are the risks of undergoing a total knee replacement? Risks of total knee replacement include blood clots in the legs that can travel to the lungs (pulmonary embolism). Pulmonary embolism can cause shortness of breath, chest pain, and even shock. Other risks include nausea and vomiting (usually related to pain medication), chronic knee pain and stiffness, bleeding into the knee joint, nerve damage, blood vessel injury, and infection of the knee which can require re-operation. Furthermore, the risks of anesthesia include potential heart, lung, kidney, and liver damage. Fortunately the cumulative risk is less than 1% at present . COMPLICATIONS AND RISKS:
What happens in the Preoperative period of TKR? Before surgery, joints adjacent to the diseased knee are carefully evaluated. This is important to ensure optimal outcome from the surgery. Replacing a knee joint which is adjacent to a severely damaged joint may not yield significant improvement in function. Furthermore, all medications which the patient is taking are reviewed. Blood-thinning medications such as warfarin (Coumadin) , clopidegrel and anti-inflammatory medications such as aspirin may have to be adjusted or discontinued prior to surgery. Even drugs taken for RA e.g. Salazopyrine , Methotrexate may have to be stopped. Patient is evaluated by physician and anaesthetist . Routine blood tests of liver and kidney function and urine tests are evaluated for signs of anemia, infection, or abnormal metabolism. Chest X-ray and ECG are performed to exclude significant heart and lung disease which may preclude surgery or anesthesia. Finally, it is less likely to have good long-term outcome if the patient’s weight is greater than 100Kgs Excess body weight simply puts the replaced knee at an increased risk of loosening and/or dislocation. A similar risk is encountered in younger patients who may tend to be more active, thereby adding trauma to the replaced joint. What happens in the postoperative period in TKR? A total knee replacement generally requires between one and a half hours of operative time. After surgery, patients are taken to a recovery room, where vital organs are frequently monitored. When stabilized, patients are returned to their hospital room. Passage of urine can be difficult in the immediate postoperative period, and this condition can be aggravated by pain medications. A catheter inserted into the urethra (a Foley catheter) allows free passage of urine until the patient becomes more mobile. Physical therapy is an extremely important part of rehabilitation and requires full participation by the patient for optimal outcome. Patients can begin physical therapy hours after surgery. Some degree of pain, discomfort, and stiffness can be expected during the early days of physical therapy. Knee immobilizers are used in order to stabilize the knee while undergoing physical therapy, walking, and sleeping. They may be removed under the guidance of the therapist for various portions of physical therapy. Patients will start walking using a walker or crutches. Eventually, patients will learn to walk up and down stairs . A number of home exercises are the patients physiotherapy starts on the next day of surgery. Attempts are made to bend the knee, stand with the walker and walk. Most patients walk on the next after surgery and make gradual progress with exercises. Patients generally go home once they are independent that is they are able to go commode on their own without taking anybody help and are able to use a dinning chair etc. This generally happens in 5 days. At this time, the patients are discharged. If only knee is replaced, the patients are able to climb stairs in 5 days. If both knees are replaced, they can take as long as 3 weeks. How does the patient continue to improve as an outpatient after discharge from the hospital? It is important for patients to continue in an outpatient physical-therapy program along with home exercises for optimal outcome of total knee replacement surgery. Patients will be asked to continue exercising the muscles around the replaced joint to prevent scarring (contracture) and maintain muscle strength for the purposes of joint stability. The wound will be monitored by the attending physicians and their staff for healing. Patients also should watch for warning signs of infection including abnormal redness, increasing warmth, swelling, or unusual pain. It is important to report any injury to the joint to the doctor immediately. Future activities are generally limited to those that do not risk injuring the replaced joint. Sports that involve running or contact are avoided, in favor of leisure sports, such as golf, and swimming. Swimming is the ideal form of exercise, since the sport improves muscle strength and endurance without exerting any pressure or stress on the replaced joint. Patients with joint replacements should alert their doctors and dentists that they have an artificial joint. These joints are at risk for infection by bacteria introduced by any invasive procedures such as surgery, dental or gum work, urological and endoscopic procedures, as well as from infections elsewhere in the body. Patients are recommended to take antibiotics before, during, and immediately after any elective procedures in order to prevent infection of the replaced joint. Though infrequent, patients with total knee replacements can require a second operation years later. The second operation can be necessary because of loosening, fracture, or other complications of the replaced joint. Future replacement devices and techniques will improve patient outcomes and lead to fewer complications. Total Knee Replacement at a Glance
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