Hip Replacement Surgery
Arthritis is pain from a joint. It can be caused by a number of things, but most commonly it simply develops over time as a result of normal wear and tear.
Arthritis can broadly be divided into Osteoarthritis which is mechanical wear and tear, and Rheumatoid Arthritis, which is caused by the body’s own immune system attacking a joint.
While arthritis technically just means “joint pain” it is commonly used to describe the condition where a joint becomes painful, stiff and deformed as the normal joint cartilage wears away. In bad arthritis a patient can even begin to wear away the bone itself.
Sometime hip osteoarthritis can develop as a result of a joint fracture or injury in the past, as a result of the hip joint forming or growing incorrectly as a child – a condition called hip dysplasia, or as a consequence of a joint infection. For some people it runs in their family, and we are still discovering the genetic factors that can contribute to arthritis.
Rheumatoid arthritis is often diagnosed before there is significant and irreversible damage to a joint. It is generally managed with medicines by a GP and a Rheumatologist, and the newer generations of diagnostic blood tests and medicines for treating rheumatoid disease are extremely effective at preventing progression of joint damage. Patients may still progress over time to needing surgery, but this may be from simple wear and tear rather than the immune destruction of joints that we saw in the past.
Osteoarthritis is initially managed with non-surgical treatments. This commonly includes simple pain killers like paracetamol and anti-inflammatories. Physiotherapy can help, by keeping joints mobile and maximising the strength and coordination of the muscles that move and stabilise the painful joint. Moderate, low impact exercise is important for cartilage health, as well as general mind and body fitness, and should be continued as much as possible. Maintaining a healthy diet and weight will mean the joint has less to carry around, and weight loss can often extend the lifespan of a joint with early arthritis by many years.
Finally, when the non-surgical treatments aren’t working, joint replacement surgery can be considered.
When to have a hip replacement
A hip replacement is a routine and successful operation, but it is still major surgery with rare but serious potential complications, and should not be done until the expected benefits outweigh the risks.
Patients will reach the stage where their hip will prevent them walking any significant distances, will wake them at night, cause them pain most days, and simple pain killers like paracetamol and anti-inflammatories will no longer be enough to control the pain symptoms. It becomes hard to sit in a chair or a car for long periods, patients have troubles reaching their toes to cut their toenails or put on socks, and they limp heavily when they first stand up to start walking.
Recreational activities, tasks around home and work, and dressing and washing become challenging.
When the hip is beginning to make life a misery, that is when hip replacement should be considered.
What is a hip replacement
A hip replacement operation involves removing the worn out sections of the hip joint and replacing them with artificial parts. Commonly this involves cutting off the ball of the hip, removing the remaining cartilage from the socket, and leaving the rest of the tendons and bone alone.
A hemispherical shell with an inner lining of high density polyethylene plastic or ceramic is put into the socket, and a stem is put into the thigh bone (the femur)with a replacement metal or ceramic ball attached to the top.
Broadly there are two ways that the implants can be held in place. An acrylic cement can be used to create a strong connection between the bone and the replacement parts – this is called a cemented hip replacement, and may be most suitable for older patients with thinner or softer bones. Alternatively the implants can have a rough outer surface than allows a tight fit into the bone at the time of the surgery, and allows the bone to grow onto and permanently attach to the implants – this is called an uncemented hip replacement, and is the way I most commonly do a hip replacement.
Anterior vs posterior approach
There are a number of surgical approaches – how we get down to the hip joint to do the replacement. In recent years the Anterior approach has been popularised in Australia as a new and better way to do a hip replacement.
I am trained in both anterior and posterior approaches for hip replacement surgery, and choose which one to use individually for each patient.
The anterior approach is not actually new, and has been used widely in France for many decades, while the posterior approach was more common in England, which was mainly why it was the more common technique in Australia until recently.
While many people feel that the recovery from an anterior approach hip is a little faster, the scientific evidence doesn’t show a huge early difference, and by 3 months after the surgery there is no difference in recovery from either approach.
Both approaches have the same risks of complications, and ultimately an experienced surgeon will get excellent outcomes from whichever approach they are most familiar with. Patient should not try to seek one approach over another, but rather seek a well trained and experienced surgeon who does their chosen approach reliably and well. This will result in a long lasting and well functioning replacement, which is ultimately the goal.
The hip replacement experience
Hip replacement begins with a consultation with me at the clinic. I ask you about your hip and your health, examine your hip, and look at the xrays and scans your GP has done. I discuss what stage your arthritis is at, and what non-surgical or surgical treatment is best for you.
If a hip replacement is the best option I explain the process, the risks and the usual benefits of hip replacement surgery. We complete the booking and consent process and I give you forms to get blood test and additional xrays done, if they are necessary for surgical preparation.
On the day of the surgery you come to the hospital to be admitted. The anaesthetist will talk to you and discuss what anaesthetic is safest and best for you personally. Common options include a spinal anaesthetic combined with sedation, or a general anaesthetic. The anaesthetists are the trained and experienced experts at this and will guide you to the safest option, taking your experiences and preferences into account.
The operation usually takes roughly an hour, and afterwards you are in the recovery area for another 30-60 minutes before going up to the ward. Most patients spend 2-5 days in hospital after the surgery before going home. You can go home when your pain is controlled with tablet painkillers, and the physiotherapists think you are walking safely and can get yourself out of bed, into the shower, and on and off the toilet safely. This is most commonly on the third day after the operation.
On the first day after the operation we get blood test and an xray done to double check the position of the replacement parts. The physiotherapists assess you and take you for a supervised walk. The nurses will help you shower if you want.
What are the outcomes?
Hip replacement surgery is one of the most successful surgeries performed as far as improvement in function per dollar spent in treatment.
It has very high “Forgotten joint” scores in followup studies – which means patient routinely forget day-to-day that they have had a hip replacement done in the past. It is extremely common that patient will report that their arthritis pain is completely removed following the recovery from the surgery.
A hip replacement is not really designed to be run on regularly for exercise, but pretty much any other moderate physical and social activity is fine.
Depending on the age you are when you have a hip replacement the risk of wearing the hip out varies, but even in very young active patients we can generalise that 19 out of 20 hip replacements will still be functioning well 10 years after the surgery.
What are the risks?
As with any surgery, hip replacement has risks which we cannot always prevent or avoid.
Serious complications are rare, but include events like heart attacks or strokes during the surgery, infections in the replacement pieces, or even death during or after the operation.
More minor complications are more common, but also temporary or fixable, and include things like:
- The operated leg being longer or shorter than planned
- The hip replacement being prone to dislocating
- A fracture during the operation that requires fixing
- Injuries to ligaments or tendons that require repair.
- Injuries that cause nerves to stop working normally, temporarily or permanently
- Shallow infection at the surgical scar.
- A scar that is over-sensitive, or which is raised or discoloured after healing.
- Altered skin sensation near the scar that can be temporary or permanent
- Clots in the veins of the legs, or clots that form on the lungs.
- Pneumonia, stomach ulcer, or temporary bowel obstruction in response to the surgery.
In the long term the replacement pieces can wear down or work themselves loose, requiring further surgery. A major injury like a fall or a car crash can fracture around the replacement and require further surgery. Any infection that gets into the blood stream in the future can settle around the replacement pieces, and this can require further surgery. Sometimes some of the tendons around the hip will get inflamed in response to the hip replacement pieces and require treatment, which sometime is surgical.