Total Knee Replacement surgery
Total Knee Replacement may be considered as a surgical treatment option for those patients experiencing ongoing and deteriorating knee pain and loss of knee function. The aim of a total knee replacement is to minimise knee pain, improve knee function, improve quality of life, allow you to return to the activities that you enjoy and improve varus (bow-legged) or valgus (knock-kneed) deformities.
One of the most common reasons for ongoing pain and difficulties with function (such as walking, climbing stairs, sitting for long periods or pain when lying down) is arthritis of the knee joint. Arthritis of the knee joint can cause severe knee pain with activities of daily living, moderate or severe knee pain when resting and inflammation of the knee joint. There are many types of arthritis of the knee, the most common being osteoarthritis, rheumatoid arthritis and post traumatic arthritis.
Osteoarthritis is degenerative arthritis and is common in people over the age of fifty. Osteoarthritis occurs when the cartilage of the knee joint wears away. The cartilage provides cushioning of the joint and if worn away leaves the bones of the knee joint to rub together, causing knee pain and stiffness.
Rheumatoid arthritis is a disease where the lining of the knee joint becomes thickened and inflamed. The inflammation in the joint can wear away the cartilage causing chronic pain and stiffness.
Post traumatic arthritis occurs after a severe injury to the knee such as a fracture or tears to the ligaments of the knee joint. This may cause damage to the knee cartilage over time causing knee pain and stiffness.
A total knee replacement procedure involves the removal of the damaged cartilage and bone within the knee joint replacing it with a prosthesis. The prosthesis has three components, a femoral component, a tibial component and a patella component. The femoral component is metal (cobalt chromium alloy) and shaped to fit the contour of the end of your femur (thigh bone). The tibial component is also made of the same metal alloy and is flat with a stem underneath. The tibial component sits on top of your tibia (shin bone). Both the femoral and tibial components are anchored to the bone by a special bone cement. A plastic (polyethylene) liner sits on top of the tibial component to provide cushioning in the same way in that the cartilage in the knee did. The polyethylene liner provides the bearing in which the femoral component glides against. The patella component comprises of a polyethylene button that is cemented to the undersurface of the patella.
Making the decision regarding proceeding to a total knee replacement is a collaborative one between the patient, general practitioner and your orthopaedic surgeon, Dr Prodger. The patient is able to make an informed choice to proceed following a thorough discussion of the benefits of surgery and the risks of surgery.
Frequently Asked Questions
The aim of Total Knee Replacement surgery is to minimise knee pain and swelling, improve knee function, improve knee deformities and improve quality of life. Approximately 90% of people who have a total knee replacement experience a significant improvement in their knee pain and are able to return to usual activities that they had been unable to perform for some time. Common activities that individuals are able to return to are walking, swimming, golf and cycling. It is expected that surgical improvements will continue for up to one year after surgery.
The main surgical risk after knee replacement surgery is infection. This occurs 1% of cases, and if the infection is deep in the knee joint, will require further surgery and prolonged antibiotics. To minimize the risk of infection pre and post operative antibiotics are given, skin is sterilized immediately before the surgery and dressings are changed in a sterile fashion. Despite these precautions the risk of infection is not zero.
Other risks include:
- DVT (deep vein Thrombosis)
- Post operative knee stiffness
- General risks of an anaesthetic such as chest infection.
All relevant risks will be discussed with you by Dr Prodger if considering a total knee replacement.
Yes, before your total knee replacement surgery you will be provided with an appointment time to attend a Pre-Admission Clinic at the hospital you are having your operation in. You will be contacted by the hospital and provided with an appointment time to come in, which is usually at least four weeks prior to surgery. During this appointment you will be reviewed by a multi-disciplinary team and may have a review x-ray of your knee, an x-ray of your chest, and a blood test.
There are a number of steps that you can take to prepare for your total knee replacement to ensure the best possible outcome. These are:
- Continue with regular exercise including strengthening and stretching activities such as walking, swimming and cycling.
- Ensure that your skin remains free from any cuts, scratches, boils or abrasions to limit risk of a skin infection.
- Cease smoking at least two weeks prior to surgery to minimise risk of Deep Venous Thrombosis.
- Maintain your weight and if discussed with your surgeon lose weight prior to surgery.
- Cease medications such as ASPIRIN, WARFARIN or Fish oil at least ten days prior to your surgery. If required Dr Prodger will liaise with your Cardiologist regarding blood thinning medication.
On return to the ward after surgery, the nursing staff will ensure your pain is well managed. Most individuals who have a total hip replacement will get out of bed, stand and walk the same day, or the next morning. A physiotherapist will aid in walking and instruct on exercises to start your rehabilitation. An intravenous cannula (“drip”) will still be in your arm to administer antibiotics for the first 24 hours.
Pain management is crucial to a successful recovery and a variety of techniques are used that will be discussed with you by both Dr Prodger and the Anaesthetist before your surgery.
Most patients are in hospital for 3-4 days following surgery, however once your pain is managed and you have reached all the goals the physiotherapist has set (getting in and out of bed, getting to the bathroom, climbing stairs etc.) you will be safe to go home. For some people this is as early as the next day, for others they may need extra time in a Rehabilitation Ward. This decision depends a lot on your general medical health and social support. It is usual for patients to be discharged home with a walking aid such as crutches or a wheelie walker.
You will be discharged home with staples in the surgical wound. It is important to keep your wound clean and dry following discharge home. The wound will be reviewed 10 – 14 days after your surgery and the staples removed at your follow up appointment with Dr Prodger. It is recommended that you wear compression stockings for four weeks after your surgery.
Although there are no specific knee precautions to adhere to following total knee replacement surgery, it is important to ensure that you prepare your home to minimise risk of a fall during your recovery and to assist you to regain independence with activities of daily living as soon as possible.
Some helpful ways to prepare your home for your discharge include:
- Sitting on a high, firm chair with armrests. A footstool is important for leg elevation to minimise swelling of the knee joint.
- Remove any rugs from the floor and secure electrical cords that may be a trip hazard.
- Rearrange furniture to allow for ease of access around the home with a walking aid.
- Consider using a shower stool or chair with armrests in the shower with a hand held shower rose for increased safety. Do not bend to reach feet, consider using long handle aids instead such as a long handle sponge.
- Consider using an over toilet frame to increase safety and independence rising and lowering from the toilet seat.
- Consider using long handle aids such as a long handle sponge, long handle shoe horn, long handle dressing stick and a long handle reacher to avoid bending to reach feet or the floor.
A knee replacement may become infected at any stage post operatively from day one post surgery to a number of years after surgery. To minimise the risk of an infection you can take the following steps:
- Take antibiotics prior to any dental work or medical procedure
- Ensure that you are reviewed by a general practitioner if you have a suspected urinary tract infection
- Contact your doctor if you have any signs of an infection such as swelling, warmth or redness around the joint or fever.
- You will take Aspirin for 6 weeks after surgery to minimize the risk of DVT (blood clot in the leg)
Whilst you are in hospital after your surgery you will be visited by a physiotherapist who will provide you with exercises for your knee, assist you with walking, and may prescribe you a walking aid such as a wheeled walker. Returning to your usual activities and the leisure activities you enjoy doing will take time and it is important that you are an active participant in your rehabilitation to gain the best outcome after your total knee replacement. It is recommended that a physiotherapist follow you up after your discharge from hospital to receive a rehabilitation program and advice on exercise and activity. Returning to low impact sports and activities such as golf or bowls may take up to 3 months after surgery.
By working with your physiotherapist our goal is for your new knee to bend to 90 degrees by six weeks after your surgery, however this can vary. The goal is for you to reach between 110 -115 degrees of flexion (bending) on completion of your rehabilitation. Improvements in your knee function can be expected for up to one year.
It is important to stay as active as possible following discharge from hospital after a total knee replacement. However it is recommended that you listen to your body and do not do too much, too soon. It is expected that you will have some good days and some bad days, but over time notice a gradual improvement in your pain, activity levels and knee function
Knee pain is usual for up to 3 months post surgery. It is important that your knee pain is well managed after surgery so that you are able to participate in rehabilitation activities to ensure that you regain optimal function of your knee joint.
It is usual to experience swelling for up to 3-6 months after their total knee replacement surgery. To manage this swelling it is recommended that the leg be elevated and ice applied. Compression stockings may also assist in managing any knee swelling.
It is recommended that patients do not drive a manual or automatic car for a minimum of six weeks after a total knee replacement. This is irrespective of the side of the surgery. After this time the patient can decide to return to driving when they feel confident and safe when in control of their vehicle.
For the first two to three months you will be encouraged to perform gentle exercise regularly, such as walking, swimming, hydrotherapy or use of an exercise bike. Following this you should be able to gradually return to the leisure activities you enjoy such as golf and bowls, however Dr Prodger can provide you with guidance on return to activities that are relevant to you.
High impact activities such as running, manual labour, heavy lifting and high intensity sports should be avoided – Dr Prodger can advise about particular activities that are relevant to you.
