Total Knee Replacement (TKR) or Total Knee Arthroplasty replaces an arthritic knee joint with an artificial metal or plastic replacement.
It is one of the most successful operations available today and could mean the difference between leading a normal life or putting up with a debilitating condition.
Reasons a total knee replacement is performed include:
Prior to surgery you will usually have tried some conservative treatments such as simple analgesics, weight loss, anti-inflammatory medications, modification of your activities, canes, or physical therapy.
Once these have failed, it is time to consider surgery. Most patients who have TKR are between 60 to 80 years, but each patient is assessed individually and patients as young as 20 or old as 90 are occasionally operated on with good results.
How should I prepare for a total knee replacement?
Dr Coolican will send you for routine blood tests and any other investigations required prior to your surgery. You should also have a general medical check-up with your GP. You should have any other medical, surgical or dental problems attended to prior to your surgery.
What should I expect on the day of the surgery?
You will be admitted to the hospital, usually on the day of your surgery. Further tests may be required on admission.
You will meet the nurses and answer some questions for the hospital records. You will meet your anaesthetist, who will ask you a few questions. You will be given hospital clothes to change into and have a shower prior to surgery.
The operation site will be shaved and cleaned. Approximately 30 minutes prior to surgery, you will be transferred to the operating room.
What happens during a total knee replacement?
Each knee is individual and knee replacements take this into account by having different sizes for your knee. If there is more than the usual amount of bone loss, sometimes extra pieces of metal or bone are added.
Surgery is performed under sterile conditions in the operating room under spinal or general anaesthesia. You will be on your back and a tourniquet applied to your upper thigh to reduce blood loss. Surgery takes approximately two hours.
Dr Coolican will cut down to the bone to expose the bones of the knee joint.
The damaged portions of the femur and tibia are then cut at the appropriate angles using specialised jigs. Trial components are then inserted to check the accuracy of these cuts and determine the thickness of plastic required to place in between these two components. The patella (knee cap) may be replaced depending on what Dr Coolican determines would be most appropriate.
The real components are then inserted with or without cement and the knee is again checked to make sure things are working properly. The knee is then carefully closed and drains usually inserted, and the overlying skin dressed and bandaged.
What happens after a total knee replacement?
When you wake, you will be in the recovery room with intravenous drips in your arm, a tube (catheter) in your bladder and a number of other monitors to check your vital observations. You will usually have a button to press for pain medication through a machine called a PCA machine (Patient Controlled Analgesia).
Once stable, you will be taken to the ward. In general, your drain will come out at 24 hours and you will sit out of bed and start moving you knee and walking on it within a day or two of surgery. The dressing will be reduced usually on the 2nd post op day to make movement easier. Your rehabilitation and mobilisation will be supervised by a physiotherapist.
To avoid lung congestion, it is important to breathe deeply and cough up any phlegm you may have.
Dr Coolican will use one or more measures to minimise blood clots in your legs, such as inflatable leg coverings, stockings and injections into your abdomen to thin the blood clots or DVT's.
Usually, you will remain in the hospital for 5-7 days. Then, depending on your needs, either return home or proceed to a rehabilitation facility. You will need physiotherapy on your knee following surgery.
You will be discharged on a walker or crutches and usually progress to a cane at six weeks.
Your sutures are sometimes dissolvable but if not, are removed at approximately 10 days.
What is the dental protocol following a total knee replacement?
ANTIBIOTIC PROPHYLAXIS IS REQIURED BEFORE ALL DENTAL WORK FOR 2 YEARS AFTER YOUR SURGERY
If allergic to penicillin, recommend clindamycin 3 capsules (450mg) 60 minutes before dental treatment.
What is the rehab after a total knee replacement?
A lot of the long term results of knee replacements depend on how much work you put into it following your operation.
When you go home you need to take special precautions around the house to make sure it is safe. You may need rails in your bathroom or to modify your sleeping arrangements, especially if they are up a lot of stairs.
Bending your knee is variable, but by 6 weeks should bend to 90 degrees. The goal is to obtain 110-115 degrees of movement.
Once the wound is healed, you may shower. You can drive at about 6 weeks, once you have regained control of your leg. You should be walking reasonably comfortably by 6 weeks.
More physical activities, such as sports previously discussed, may take 3 months to do comfortably.
You will usually have a 6 week check up with your surgeon who will assess your progress. You should continue to see your surgeon for the rest of your life to check your knee and take X-rays. This is important as sometimes your knee can feel excellent but there can be a problem only recognized on X-ray.
You are always at risk of infections especially with any dental work or other surgical procedures where germs (Bacteria) can get into the blood stream and find their way to your knee.
If you ever have any unexplained pain, swelling or redness or if you feel generally poor, you should see your doctor as soon as possible.
What are the risks and complications of a total knee replacement?
As with any major surgery, there are potential risks involved. The decision to proceed is made because the advantages of surgery outweigh the potential disadvantages. It is important that you are informed of these risks before the surgery takes place.
Infection
Infection can occur with any operation. In the knee this can be superficial or deep. Infection rates vary. If it occurs, it can be treated with antibiotics but may require further surgery. Very rarely your new knee may need to be removed to eradicate infection.
Blood clots (deep venous thrombosis)
These can form in the calf muscles and can travel to the lung (pulmonary embolism). These can occasionally be serious and even life threatening. If you get calf pain or shortness of breath at any stage, you should notify your doctor.
Stiffness in the knee
Ideally your knee should bend beyond 100 degrees but on occasion, the knee may not bend as well as expected. Sometimes manipulations are required. This means going to the operating room where the knee is bent for you and under anaesthetic.
Wear
The plastic liner eventually wears out over time, usually 10 to 15 years and may need to be changed.
Wound irritation or breakdown
The operation will always cut some skin nerves, so you will inevitably have some numbness around the wound. This does not affect the function of your joint. You can also get some aching around the scar. Vitamin E cream and massaging can help reduce this.
Occasionally, you can get reactions to the sutures or a wound breakdown that may require antibiotics or rarely, further surgery.
Cosmetic appearance
The knee may look different than it was because it is put into the correct alignment to allow proper function.
Leg length inequality
This is also due to the fact that a corrected knee is more straight and is unavoidable.
Dislocation
An extremely rare condition where the ends of the knee joint lose contact with each other or the plastic insert can lose contact with the tibia (shinbone) or the femur (thigh bone).
Patella problems
Patella (knee cap) can dislocate. This means it moves out of place and it can break or loosen.
Ligament injuries
There are a number of ligaments surrounding the knee. These ligaments can be torn during surgery or break or stretch out any time afterwards. Surgery may be required to correct this problem.
Damage to nerves and blood vessels
Rarely these can be damaged at the time of surgery. If recognised they are repaired, but a second operation may be required. Nerve damage can cause a loss of feeling or movement below the knee and can be permanent.
Fractures or breaks in the bone can occur during surgery or afterwards if you fall. To repair these, you may require surgery.
You will have the opportunity to discuss your concerns thoroughly with your Dr Coolican prior to surgery.
General issues with any surgery
Medical complications include those of the anaesthetic and your general well being. Almost any medical condition can occur so this list is not complete. Complications include:
If you would like to know if a total knee replacement would be suitable in your specific situation, please book an appointment with knee surgeon, Dr Myles Coolican for an expert assessment.
For all appointments and enquiries, please call (02) 9904 6099
8:30am to 5:30pm - Monday to Friday
Level 2, The Landmark
500 Pacific Highway
St Leonards NSW 2065
Getting Here
© 2011-2024 Dr Myles Coolican