Who would need a joint replacement and why?
Joint replacement is recommended for those who suffer with progressive joint pain and loss of function despite conservative treatment. Joint pain and loss of function is commonly due to arthritis. This is essentially damage to the joint by degeneration (wear and tear); autoimmune or inflammatory (e.g. rheumatoid arthritis); trauma (e.g. fractures); and infection.
I specialise in knee and hip replacement (arthroplasty) and revision surgery of those joint replacements that have failed in time.
What are the alternatives to a joint replacement?
Alternatives can be divided into surgical and non-surgical treatments.
1. Weight loss and exercise
Our knees experience almost 5x our body weight in pressure. If your weight is 100kg; your knee will experience close to 500kg of pressure. Over time; this can result in osteoarthritis (a wear and tear type of arthritis). Obese people a 1 in 3 risk of developing arthritis for this reason.
Patients are recommended to lose weight through exercise/physiotherapy and diet. For every kilogram of weight a patient is able to lose, 5 kilograms of pressure are taken off their joints.
Exercise helps by strengthening the muscle around your joints, improving joint flexibility, strengthening bone, preventing fatigue and releasing endorphins to assist with pain management. This helps reduce stress around the joints from stability
2. Pharmaceutical analgaesics/acupunture
Arthritis is painful. Over the counter analgesics such as paracetamol, NSAIDs (Non-Steroidal Anti-Inflammatory Drugs) e.g. ibuprofen and stronger prescription drugs such as morphine or codeine may be required. Nerve and mood altering drugs may even be required for severe pain. Other non-pharmaceutical options such as acupuncture can also be effective
3. Knee injections
Hyaluronic injections (mimics joint fluid) and steroid injections typically provide relief for a short to medium term and carry a risk of infection. Other forms of injections such as stem cells and platelet-rich plasma have also been promoted and are purported to modify the disease which is akin to a cure. However, they are expensive, not Medicare-approved and their results have not been proven inconclusively.
Arthroscopy is not generally helpful if pain is due to arthritis. However, if there are mechanical symptoms due to a loose body, eg. fragments of wear and tear within the knee or unstable fragments of a torn meniscus, Arthroscopy can be helpful.
2. Knee Osteotomy
Knee osteotomy is generally reserved for young patients or those who have a very limited disease on one part of their joint. The aim is to realign the mechanics of the joint (e.g. knee) by fracturing the bone. The indication is very limited but can be effective for the right patient. Unfortunately, knee osteotomies can fail if arthritis develops on other parts of the knee. Eventually, this will need to be converted to a total knee replacement.
What happens during the surgery?
Joint surgery is a long process, however the upmost care is taken to ensure patient safety and that the procedure is performed without complications.
Patients are required to fast for at least 6 hours before surgery.
Patients are checked on admissions:
• Identification is confirmed
• Consent sighted
• Imaging studies available to confirm the diagnosis
• Routine medical check up e.g. BP to ensure fitness for the day of surgery
• Site preparation by shaving and application of antiseptics
• Site is marked with the surgeon to ensure correct side
• Anaesthetist to administer spinal or General anaesthesia supplemented with a regional block
• Time out is done in theatres with the entire surgical team to ensure correct patient, correct side, correct procedure, and highlight allergies and confirm prosthesis availability.
• Surgery is then done. This usually takes 45-60 minutes
• Patient is then brought to recovery
• Physiotherapy is commenced to encourage weight bearing and commence joint mobilisation
• Wound healing generally takes 2 weeks
• Knee bending should at least by 90 degrees by week 6 otherwise manipulation under anaesthesia is required
• Can commence driving in about 4-6 weeks
• Can return to work between 6-12 weeks
• Liming will be evident until such time that the joints have recovered normal range of motion
What are the potential complications?
Complications are common but with care, can be prevented and controlled. Potential complications include:
• Pain, bleeding, haematoma
• Blood clots (Deep Venous Thrombosis) and its dangerous sequalae of pulmonary embolism - is prevented by mobilisation, prophylactic anticoagulants and close monitoring
• Nerve and major blood vessel damage - A major nerve and blood vessel injury is disastrous but fortunately very rare. However, patients commonly feel a residual patch of numbness around the knee in knee replacement
• Fractures, dislocations (in the case of hip replacement) - Osteoporosis is also common in this age group and progresses over time if not managed. Hence the risk of fractures. Hip dislocations can be due to malposition of the prosthesis or patients not compliant with instructions imposed by the surgeon.
• Infection - The risk is low at about 1%. It is 3 fold higher in diabetics. It is important to be vigilant about infection and take precautions such as antibiotic cover during dental procedures as bacteria can be introduced into the blood stream.
• Stiffness - Rehabilitation is thereby important
• Loosening requiring revision surgery - this is generally due to arhtroplasty being done in young patients (younger than 60); obesity; and poor quality prosthesis (hard to identify which until 10 years of “trial"
What can be expected after surgery?
Hip and knee joint replacement surgery is a reliable and predictable treatment of hip and knee pain and loss of function due to joint disease. One study out of the US has shown that 98% of patients who were working before surgery were able to return to work after surgery. In the case of hip replacement for hip fractures, surgery can be life-saving.
Furthermore, our joint registry here in Australia has shown that some of the prosthesis used here in Australia have had very low rates of revision (about 5%) even at 15 years.