By Dr Udai Prakash, Chief Joint Replacement Surgeon.
Hip and knee replacement surgery has a dramatic effect on patients’ lives. It is generally recommended if conservative measures have been ineffective or are likely to be ineffective. Most patients are able to go back to their former active lifestyle as their pain is relieved and mobility restored. Age is not a bar to joint replacement surgery. Modern materials and techniques have largely overcome the problems of wear and loosening of the implant. This brief introduction to joint replacement surgery will give you a flavour of the different types of joint replacements of the hip and knee performed by our surgeons.
Total Hip Replacement
Total hip replacement is probably the most successful operation performed by any surgeon of any specialty.
It involves replacing both the acetabulum and the femoral head components of the ball and socket joint. It is indicated in painful conditions of the hip such as osteoarthritis, rheumatoid arthritis, avascular necrosis and certain fractures and in a vast majority of cases it results in a dramatic improvement in the quality of life. Modern hip replacements are made of materials like titanium or high grade stainless steel and contain bearings such as ceramics, cobalt-chrome and highly cross-linked polyethylene that make them very durable. Age is not generally a concern when considering someone for a hip replacement as long as they have the right level of fitness and the operation is done for the right indication. The probability of most good hip implants surviving 10 years is over 90%.
Total Knee Replacement
Knee replacement is a surgical procedure to replace the weight-bearing surfaces of the knee joint to relieve the pain and disability of osteoarthritis. It may be performed for other knee diseases such as rheumatoid arthritis and psoriatic arthritis. This is a well established procedure giving consistently good outcome with long term results often matching and sometimes exceeding those of total hip replacement. In general, the surgery consists of resurfacing the diseased or damaged joint surfaces of the knee with metal and plastic components shaped to allow continued motion of the knee. During the operation any deformities must be corrected, and the ligaments balanced so that the knee has a good range of movement and is stable. In some cases the articular surface of the patella is also removed and replaced by a polyethylene button. Functionally, most patients get back to their formal lifestyle including most non-impact leisure activities like golf.
Unicondylar Knee Replacement
This is an excellent procedure for limited arthritis or the knee. Usually performed through a smaller incision than total knee replacement, only the part of the knee that is diseased is resurfaced. The joint therefore feels and behaves more like a normal knee. Recovery is rapid and the patient is often discharged within 2 -3 days of surgery.
Hip Resurfacing is an alternative to hip replacement surgery in some patients. It is a bone conserving procedure that places a metal cap on the femoral head instead of amputating it. There is no long stem placed down the femur so it is more like a natural hip and may allow patients a return to many activities. It seems the ideal option for young individuals with severe hip osteoarthritis who are likely to outlive any prosthesis that they receive and who are keen to carry on with an active lifestyle. In the unlikely event of the resurfacing failing many years down the line the bone stock that has been preserved in the first instance makes the revision in most cases almost as easy as doing a primary hip replacement. According to the Australian Registry data for 2009, performance of hip resurfacing for men under 65 years of age is better than total hip replacement.
Revision Hip and Knee Replacement
Primary hip and knee replacements do fail in time for a number of reasons. Revising them is highly specialised surgery requiring extensive training and access to sophisticated equipment, implants and hospital facilities. In most cases the old prosthesis is removed and replaced with a new implant. The surgery is often long and the risk of complications is higher than after a primary operation. Patients tend to spend the first 24 to 48 hours after the procedure in the high dependency unit. Surgery may involve the use of ultrasonic devices to remove the old cement used for fixation of the prosthesis, bone graft and/or custom made implants. Identifying failing joint replacements and performing the revision early is crucial for a successful outcome and therefore a regular follow-up by an orthopaedic surgeon is advisable for all patients carrying a hip or a knee replacement.
Frequently Asked Questions
Q: When is joint replacement surgery recommended?
A:The reasons are many. Most patients with severe hip or knee pain as a result of advanced arthritis may be candidates for joint replacement. Joints can also get damaged due to previous injury or infection. There are many more indications including congenital disorders, childhood disorders leading to arthritis in later life, avascular necrosis etc.
Q:How long do joint replacements last?
A:On average a hip or knee replacement has a 90% chance that it will survive 10 years and a 80% chance that that it will last 20 years if done by a well trained surgeon at a specialist hospital. The survival is highly dependent on the quality of surgery and the implant used.
Q:What are they made of?
A:Modern joint replacements are made of many different materials – these include Cobalt-Chrome alloy, surgical grade stainless steel, titanium. Your surgeon should be able to give you more information depending on what joint you are having replaced. All joint replacements done at UDAI OMNI are imported at the moment.
Q:How long will I need bed rest for?
A:You will almost never need any bed rest. The aim of the surgery is to get you out of bed as soon as possible after surgery. You will need intensive physiotherapy during the recovery phase of 6-8 weeks.
Q: How long will I stay in the hospital?
A:On average a patient after joint replacement will stay between 5-7 days in the hospital.
Following complex joint replacement, the stay may be longer.
Q:Will I be able to sit on the floor?
A:Many patients can sit on the floor after joint replacement surgery whether it is the hip or the knee. However, your surgeon will guide you on this depending on what you are having done and the complexity of the surgery. Kneeling might be difficult after knee replacement surgery. Again, the quality of surgery is the key. If done well and if the patient is motivated, most activities of daily living are possible.
Q:Can I ride a scooter or drive a car afterwards?
A: Most patients can start driving after about 6 weeks but please discuss this with your physiotherapist or your surgeon.
Q: At what age is joint replacement recommended?
A: Joint replacement can be done at any age. Most patients are between 55 – 80 years of age but the range can be from teenage to over 90 years. As long as the patient is reasonably fit, joint replacement can be done. Your doctor should be able to advise on this.