The process by which an impaired knee joint is substituted with an artificial material is referred to as total knee replacement. The knee is a type of axis joint which provides movement at the point where the thigh meets the lower leg. The longest bone of the human body, femur adjoins the lower leg (tibia) at the knee joint. The surgeon, during a knee replacement surgery, removes the damaged cartilage and bone from the knee. Then metal implants are fixed to the ends of the thigh and calf bones. In between the metal implants a plastic gaper is introduced which aids in free movement of the joints.
The posterior circulate ligament, the tissue that strengthens each side of the knee joint, is either retained, removed or substituted by a polyethylene post.
There is no single method by which we can find out which patients can be subjected to total knee replacement surgery. Sometimes, even though, it seems to be the only solution, doctors cannot go for it due to a lot of factors like age, weight, other serious health problems etc which can lead to serious outcomes after the surgery. So, many patients still remain skeptical about going for the replacement. There are certain symptoms which indicate knee replacement is probably the best solution like
1. Severe knee pain that makes everyday necessary activities difficult.
2. Pain which does not subside even after resting or taking medications.
3. Long-lasting knee irritation and distension that doesn't get better with rest or medications
4. An ankle in or out of your leg
5. Knee firmness
6. No pain relief from pain killers
The most common reason for knee replacement surgery is Osteoarthritis which is a degenerative joint disease.
Lower Vitamin D levels may cause greater knee pain and difficulty walking in patients with osteoarthritis.
Other conditions that cause knee damage include rheumatoid arthritis, hemophilia etc.
The main risk associated with total knee replacement includes blood clots that can occur at the site of surgery and can travel to the lungs (pulmonary embolism). Pulmonary embolism can cause pain in the chest while breathing, light headedness or low oxygen in the body, palpitations, dry cough etc. Other risks include urinary tract infection, nausea and vomiting (usually related to pain killers), chronic knee pain and stiffness, bleeding into the knee joint, nerve damage, blood vessel injury, and sometimes even re-surgery has to be done due to infection in the knee.. Furthermore, the risks of anesthesia include potential heart, lung, kidney, and liver damage.
Before surgery the nearby hip and ankle joints are examined and checked properly. Replacing a knee joint that is contiguous to a sternly damaged joint may not be successful as the nearby joint may become more painful if it is irregular. Furthermore, all medications that the patient is taking are thoroughly checked to avoid post operative complications... Blood-thinning and anti-inflammatory medications may have to be given depending on the patient's past medical history. Liver function, renal function and urine tests are mandatory as before any surgery. Blood test is done to check for anemia or any other infection. Chest X-ray and ECG are performed to rule out significant heart and lung disease that may create complication during or after surgery. Finally, a knee replacement surgery is less likely to have good long-term outcome if the patient is obese. Excess body weight simply puts the replaced knee at an increased risk of dislocation and makes recovery more difficult.
Another risk is encountered if patient's donor takes adequate rest thereby adding trauma to the replaced joint.
A maximum of three hours might be needed for the surgery. After surgery the patient is kept under observation and when the condition stabilizes, they are shifted to normal hospital room. One major setback for the surgery, like any other surgery is the passage of urine for which a catheter is required to be inserted until the patient can walk on his/ her own and at least go to the washroom.
Physiotherapy is seen to benefit patients who have undergone knee surgery to a great extent. Initially physiotherapy might seem very difficult, due to extreme pain in the site of operation, but with the help and guidance of a proper physiotherapist, the patient can easily get better results. Knee immobilizers are sometimes used which helps the patient to move their legs without much pain.
A unique device that can facilitate the recovery process to get faster is the continuous passive motion (CPM) machine. The machine is first attached to the operated leg. When the patient relaxes, the machine then constantly aids in the movement of the knee through various degrees of range of motion. This helps in better blood circulation and reduces the risk of tissue breakage at the site of operation. Patients can eventually start walking using walker and crutches.
1. Moderate light exercises under the supervision of a trained physiotherapist can shorten the recovery period.
2. Regular dressing of the operation site is very important. Any sign of redness, itching, blood clot or pus coming out from the site followed by fever, swelling or pain should immediately be reported to the doctor.
3. Any activity which puts strain on the replaced knee like running, weight lifting, swimming, rigorous exercise, and any difficult sport should be avoided otherwise the healing process may further delay.
Patients who have undergone knee replacement should inform doctors and dentists in future before undertaking any further treatment because the replaced joints are prone to infection by bacteria through any further surgery as well as through anywhere else in the body.
Antibiotics and painkillers will continue for a long time after the operation. Rarely, a second operation might be necessary for some patients whose replaced knee joint shows signs of loosening, fracture or break. In most cases the second operation might not be as successful as the first one and impose risks on the patients. Researchers are going on so that the implant of the artificial joint stays good for a longer period of time without posing any complication on the patient's body.