If you decide to have knee replacement surgery, you may be asked to have a medical assessment before your surgery. This is needed to assess your health and find conditions that could interfere with your surgery or recovery. This will also correct any abnormalities such as high blood pressure and can detect conditions previously undiagnosed like diabetes.
Blood tests, a cardiogram, 2-D echo of heart, chest X-ray, urine examination will be needed. Occasionally, assessment of blood circulation in your leg is necessary with Doppler ultrasound scan.
Tell your orthopaedic surgeon about the medications you are taking. He will advise you which medications you should stop or can continue taking before surgery.
If you are overweight, you may be asked to try to lose some weight before surgery to reduce the stress on your new knee joint.
Although infections after knee replacement are not common, an infection can occur if bacteria enter your bloodstream. Since bacteria can enter the bloodstream during dental procedures, treatment of significant dental diseases (including tooth extractions and periodontal work) should be considered before your knee replacement surgery.
Individuals with a history of recent or frequent urinary infections should consider a urological evaluation before knee operation. Older men with prostate disease should consider a urologic evaluation and treatment before having knee replacement surgery.
Although you will be able to walk with crutches or a walker soon after surgery, you will need some help for several weeks with such tasks as cooking, shopping, bathing.
Normally two units of blood needs to be kept ready for transfusion during or after operation. Blood bank will require replacement donations from patient’s relatives and friends.
Preparing Your Skin:
Your skin should not have any infections or irritations before surgery.
You will most likely be admitted to the hospital on the day before your operation. After admission, you will be evaluated by your anaesthetist.. The most common types of anesthesia for knee replacement surgery are general anesthesia (which puts you to sleep throughout the procedure) or spinal (epidural) anesthesia (which allows you to be awake but anesthetizes your body from the waist down). Epidural anaesthesia is a very safe technique in which a thin plastic tube is inserted in the lower back, through which calculated dose of medication is injected during surgery, making only the legs numb. It is safe for elderly, those who have high blood pressure or heart trouble & during surgery it helps reduce bleeding. After the surgery, the tube is connected to a syringe attached to a computerized pump, through which small dose of pain relieving medication is injected, reducing pain after the surgery, eliminating the need for sedatives and allow early exercises. Intravenous antibiotics are started just before surgery and continued for about 5 days after surgery.
The surgery itself takes about 90 minutes. However preparation and anaesthesia before surgery and recovery after surgery will keep you in operation theatre for about three hours. Your orthopaedic surgeon will remove the damaged cartilage and bone surface, then position a new metal and plastic joint surfaces to restore the alignment and function of your knee.
Many different types of designs and materials are currently used in artificial knee joints. These consist of two basic components: the femoral component (made of a highly polished strong metal), the tibial component (made of durable plastic held in a metal tray), and a patellar component (also plastic). Special surgical cement will be used to fill the gap between the prosthesis and remaining bone to secure the artificial joint.
After surgery, you will be moved to the recovery room where you will remain for one to two hours while the recovery from anesthesia is monitored. After you awaken fully, you will be taken to your hospital room.
Your Stay in the Hospital :
Your hospital stay will vary depending on your recovery and walking. It normally varies from 7 to 14 days after surgery.
After surgery, you will feel some pain in your knee. Pain medication will be given to make you as comfortable as possible. To avoid lung congestion after surgery, you will be asked to breathe deeply and cough frequently. Frequently, a thin plastic tube (epidural catheter) is inserted close to your spinal cord while giving spinal anaesthesia. This catheter is maintained for a few days after surgery and pain-relieving injections are given through this tube. Leg exercises are started as soon as you are comfortable.
You will have no plaster on your knee but a bulky dressing will be applied for after surgery. On second day after surgery, the dressing is changed, any drain tubes are removed and a small dressing is applied. Knee bending is then started.
As soon as you have regained your thigh muscle power, you can commence walking. Most knee replacement patients begin standing and walking with the help of a walking support and a physiotherapist, 4 to 5 days after surgery. The physiotherapist will teach you specific exercises to strengthen your muscles and restore movement in your knee for walking and other normal daily activities.
Possible Complications After Surgery :
The complication rate following knee replacement surgery is low. Serious complications, such as joint infection, occur in less than 2 percent of patients. Major medical complications, such as heart attack or stroke, occur even less frequently. However, chronic illnesses may increase the potential for complications. Although uncommon, when these complications occur they can prolong or limit your full recovery.
Occasionally, blood clots may form in the leg veins or pelvis. Your orthopaedic surgeon may prescribe one or more measures to prevent blood clots from forming in your leg veins, such as special support hose, inflatable leg coverings, and blood thinning medications.
Your Recovery at Home :
The success of your surgery will depend in large measure on how well you follow your orthopaedic surgeon's instructions regarding home care during the first few weeks after surgery Wound Care You will have stitches or staples running along your wound. The stitches or staples will be removed about two weeks after surgery. Avoid getting the wound wet until it has thoroughly sealed and dried. A bandage may be placed over the wound to prevent irritation from clothing or support stockings.
Diet Some loss of appetite is common for a few days after surgery. A balanced diet, often with an iron supplement, is important to promote proper tissue healing and restore muscle strength. Be sure to drink plenty of fluids.
Activity : Exercise is a critical component of home care, particularly during the first few weeks after surgery. You should be able to resume most normal light activities of daily living within three to six weeks following surgery. Some discomfort with activity, and at night, is common for several weeks
Your activity program should include :
You may wish to have a physiotherapist to help you at home.
Blood Clot Prevention:
Follow your orthopaedic surgeon's instructions carefully to minimize the potential risk of blood clots in your leg veins, which can occur during first several weeks of your recovery.
Warning signs of possible blood clots include: pain in your calf and leg unrelated to your incision, tenderness or redness of your calf, swelling of your thigh, calf, ankle or foot. Warning signs that a blood clot has traveled to your lung include shortness of breath, chest pain, particularly with breathing. Notify your doctor immediately if you develop any of these signs.
Preventing Infection :
The most common causes of late infection following knee replacement surgery are from bacteria that enter the bloodstream during dental procedures, urinary tract infections, or skin infections. These bacteria can lodge around your prosthesis.
Following your surgery, you should take antibiotics prior to dental work, including dental cleanings, or any surgical procedure that could allow bacteria to enter your bloodstream. Warning signs of a possible knee replacement infection are:
Persistent fever (higher than 100 degrees orally), shaking chills, increasing redness, tenderness, or swelling of the knee wound, drainage from the knee wound, increasing knee pain with both activity and rest. Notify your doctor immediately if you develop any of these signs.
Avoiding Falls :
A fall during the first few weeks after surgery can damage your new knee and may result in a need for more surgery. Stairs are a particular hazard until your knee is strong and mobile. You should use a cane, crutches, a walker, or handrails, or have someone help you until you improve your balance, flexibility and strength.
Your surgeon and physiotherapist will help you decide what assistive aides will be required following surgery, and when those aides can safely be discontinued.
You may feel some numbness in the skin around your incision. You also may feel some stiffness, particularly with excessive bending. These differences often diminish with time and most patients find these are minor compared to the pain and limited function they experienced prior to surgery.
After knee replacement operation, you should be able to bend your knee to right angle (90 degrees) by 2-3 weeks. Restoration of full motion of your knee (heel touching buttock) is difficult to achieve. The motion of your knee replacement after surgey is predicted also by the motion of your knee before surgery. Most patients can expect to nearly fully straighten the replaced knee and to bend the knee sufficiently to go up and down the stairs and get in and out of a car. Since the scar is in front of the knee, kneeling can be uncomfortable but not harmful.
After surgery, make sure you also do the following: