Total Knee Replacement
What is Arthritis?
Arthritis occurs when the lining of the joint, called cartilage (a bit like a Teflon coating) is damaged and bone rubs on bone causing pain.
Most common arthritis is osteoarthritis due to gradual wear and tear. Sometimes it can be due to previous injury or inflammatory arthritis (Rheumatoid arthritis is the most common inflammatory arthropathy).
What will happen without Surgery?
- Arthritis of the knee usually, though not always, will get worse with time
- The symptoms in the knee can fluctuate however usually slowly gets worse
Alternatives to Surgery (see handout)
- Lifestyle modification – Including weight loss and avoiding aggravating activities
- Painkillers and anti-inflammatories
- Glucosamine and chondrotin sulphate
- Injection of steroid or viscosupplement
- Walking stick (use in the opposite hand)
- Elastic knee support
- Physiotherapy can help with weak muscles
- Heel raises and knee braces
Benefits of Knee Replacement
Our goal is to achieve less pain, improve the ability to walk and improve quality of life.
It does take a few months to recover however as it is a large operation.
What does the operation Involve?
Anaesthetic – There are many options and I will get you to discuss this with my anaesthetist.
Surgery – there is an incision at the front of the knee. The abnormally worn joint surfaces are removed and replaced with metal implants (usually made from Chrome Cobalt). A special plastic (polyethelene) is placed between the two metal implants. Occasionally a plastic button is placed on the back of the patella (knee cap).
Prior to Surgery
Usually prior to the surgery you will require some blood tests and attend a pre-admission clinic.
It is helpful (if possible) to begin the knee exercises prior to your surgery.
Hydrotherapy can be helpful and I can assist in arranging this.
These X-rays show arthritis of the knee – You can see the joint line is narrowed due to loss of cartilage.
What to Expect After the Surgery
Postoperative management includes controlling pain with medication, reducing the swelling with bandages and cold packs and reducing the risk of infection with antibiotics (generally for 24 hours following surgery).
I often use a drain in the knee to avoid the knee filling with too much blood. This is usually removed after 24 hours.
Your blood count will be checked in the first few days after surgery.
A blood-thinning medication will be given to help prevent blood clots in the legs.
Compression boots (devices that go around the legs and inflate periodically) or special support stockings are often used to aid in the prevention of blood clots.
The support stockings are usually worn for several weeks following surgery.
I encourage you to start moving the feet and ankles immediately after surgery.
You will have a catheter in your bladder for the first 24-48 hours. This helps you initially after the surgery and enables us to make sure you are getting enough fluids. I like to remove the catheter as soon as possible to avoid the risk of bladder infection.
It is common to begin physiotherapy, including exercise of the knee and trying to walk, as soon as one day after the procedure.
Most patients spend about five days in the hospital, during which they work with a physiotherapist to develop an exercise and rehabilitation program. Some patients continue their therapy at home while others may stay in a rehabilitation facility until they are able to perform daily activities independently.
The rehabilitation program generally includes: exercises to improve range of motion, gait training, thigh muscle (quadriceps) strengthening, and training in activities of daily life.
After several months of rehabilitation, patients are encouraged to maintain an active lifestyle. While high-impact sports such as running or contact sports should be avoided, patients can typically participate in activities like walking, cycling, golf and swimming.
Most people have a good recovery and have less pain and are able to mobilise more easily.
A knee replacement however never feels completely normal. Usually you will have about 90 to 120 degrees of bend in the knee. Kneeling is usually uncomfortable and not recommended especially if the knee cap has a plastic put on it.
A knee replacement can wear out. This depends on how active you are and your body weight. 90% of knees will last 10 years. I recommend X-rays every 3-5 years to check for problems.
Complications – The risks of Total Knee Replacement Surgery.
Joint replacement is a very successful procedure for alleviating pain and restoring quality of life. In approximately 95% of patients there is significant improvement in pain level and quality of like. Every procedure has some risk attached to it. In a small percentage of people surgery may not help the pain or can make their knee worse.
General Anaesthetic complications – These risks will depend on your general health and can be discussed with your anaesthetist.
- Bleeding – About 50% of patients will require a blood transfusion after a knee replacement
- Infection – This can result in loosening and failure of the knee replacement. Risk is about 2%. This ranges from a minor infection (superficial) to a serious infection (deep). It may require a number of operations to control infection
- Blood clots – Clots in the deep veins (risk 1 in 10) and occasionally can go to the lungs (pulmonary embolus) and make it difficult to breathe (1 in 200)
- Damage to major nerves risk 1 in 170
- It is common to get a numb patch at the front of the knee. This will become less noticeable with time
- Damage to major blood vessel to leg and foot risk 1 in 650
- Loosening without infection that requires further surgery risk 1 in 40 in first 10 Years
- Stiffness about 1 in 20 will require manipulation under another anaesthetic
- Complex regional pain syndrome rare complication causing generalised pain. Usually improves over many months sometimes years