Total Knee Replacement
Knee replacements are a successful operation which can give patients back a well functioning knee to carry out the activities in life they enjoy. It typically delivers excellent pain relief, a functional range of motion and a stable knee to stand up to the rigours of every day demands. It is an excellent option for those patients with significant knee arthritis who are troubled in every day activities.
Many patients are nervous to contemplate undergoing a knee replacement, as historically it has been a painful procedure to undergo. With modern anaesthetic techniques and accelerated rehabilitation, it is now an easier journey to recover from. It is a major procedure and requires dedication to the rehabilitation to achieve the desired outcome.
Read on to find out;
How do I know if I am ready for a knee replacement?
What can and can't I do with a knee replacement?
How long does a knee replacement last?
What should I expect while I am in hospital?
Am I ready for a knee replacement?
It is an excellent option for those patients with significant knee arthritis who are troubled in every day activities. Typically, patients are ready when they are having sleep disturbances and their walking distance is limited by knee pain. Other indications include when the knee can no longer be trusted due to giving way, significant stiffness or when the shape of the leg changes, impairing function. The vast majority of patients recover to be free of any painkillers with a comfortable, stable knee.
What can and can't I do with a knee replacement?
Patients can live a very active lifestyle with a well functioning knee replacement. They typically can walk unrestricted distances and partake in physical exercise such as cycling, swimming, pilates, gym strengthening to name a few. Running is not recommended on knee replacements as it can lead to premature wearing of the replacement bearing. Extreme bending of the knee is also not recommended such as sitting on your heels. Most patients who are considering a knee replacement have long given up these pursuits due to knee pain and stiffness.
How long does a knee replacement last?
Australia is a world leader in monitoring joint replacement longevity. The Australian National Joint Replacement Registry is an excellent source of information for patients. For most patients their knee replacement will last their lifespan. 92% of knee replacements are functioning well 20 years after surgery. The longevity is dependent on the age and activity of the patient with younger people having a higher risk of needing further surgery.
The table above shows the overall likelihood of requiring revision knee replacement surgery within 20 years ^
The table above shows the likelihood of requiring revision knee replacement surgery within 20 years according to age group at the time of the initial surgery^
^ Australian Orthopaedic Association National Joint Replacement Registry, Hip, Knee & Shoulder Arthroplasty, 2022 ANNUAL REPORT
Pre-operatively
Preparing yourself for a knee replacement is an important process. Optimising health and well being prior to the surgery will reduced the risks of the procedure. Undertaking a pre-operative exercise program to improve the knee function is an excellent way to hit the ground running in rehabilitation. Physiotherapy can be an effective treatment of knee arthritis, and is also a good way to prepare for the operation. Typically, 3 dimensional scans of the leg are undertaken, and you be required to have blood tests in the lead up to surgery. Further investigations may be required on a case to case basis. Dr Duff will discuss your individual requirements with you.
The Surgery
Dr Duff utilises robotic technology to assist in accurate placement of your knee replacement. The knee replacement is in essence a resurfacing of the knee joint with highly polished metal alloy and highly engineered plastic. It allows immediate weight bearing and movement of the knee.
Spinal anaesthetic has been proven to be the safest way to undergo a knee replacement and is used in combination with sedation and pain blocks to the knee and a multimodal approach to pain relief. Most patients sleep through their procedure even though they are not having a general anaesthetic. The wound is closed with dissolvable sutures. The spinal anaesthetic typically wears off 3-4 hours after the operation allowing the patient to stand up on the day of the surgery and begin moving the knee.
In Hospital
Most patients stay 3 days in hospital after a knee replacement but this depends on a number of factors. In many places in the world this procedure is now undertaken as day surgery or an overnight stay. Standing and walking a few steps is achieved on the day of the surgery. The knee is immediately strong to stand with full weight and to move through a comfortable range.
Recovery from knee replacement
The key to successfully recovering from a knee replacement is early movement and not overdoing things. 3 exercises are emphasised initially; one to straighten the knee, another to bend it and a floor pedalling device (like a bike pedal in front of a seat). Resting, cold therapy and compression are important to settle swelling and allow good movement.
Patients typically walk into the clinic at 2 weeks post op with 1-2 crutches. By 4-6 weeks most are driving cars and are off all pain killer medications. Activities such as golf and longer distance walking are achieved by most at approximately 12 weeks.
Risks
Knee replacement surgery is a major operation and carries risks like any medical intervention. The degree of risk does depend on the individual patient’s medical situation. Thankfully complications are rare. Dr Duff will speak to your individual situation during your consultation.