What is a Total Hip Replacement? (THR)
The hip is a “ball and socket” joint. The ball (femoral head) and socket (acetabulum) are lined by cartilage which acts like a shock absorber and normally allows smooth movement of the joint. In a normal adult hip joint, the cartilage makes up a space of about 6mm between the hip socket and femoral head. Cartilage cannot be seen on x-ray, but appears as a space between the two bones.
There are 4 main types of hip joint surgery.
Total hip replacement (THR): The most common type of hip joint surgery is the THR. In this procedure, joint function is restored by replacing both the hip socket and ball. The artificial replacement device is called a prosthesis.
Hemi-arthroplasty: only part of the hip joint is replaced – the femoral head.
Hip joint resurfacing: This bone conserving procedure results in the hip socket being replaced and a new smooth lining being placed over the femoral head.
Revision hip replacement: Part or all of a previous hip replacement is redone. This can vary from small adjustments through to big operations where the entire prosthesis is removed and replaced.
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Why would I need a Total Hip Replacement?
The main cause for a THR is arthritis. Trauma and congenital conditions can also be triggers. Arthritis comes in many forms including rheumatoid arthritis and osteoarthritis; however the latter is the most common cause for hip replacement surgery.
Osteo-arthritis results from wearing down of the cartilage surfaces, eventually causing bone to move on bone. This painful and debilitating condition is more likely to affect people as they get older or people who are inactive or obese.
A THR replaces your arthritic joint, replacing the damaged weight bearing surfaces. The design of a THR helps to
1. Eliminate pain
2. Minimise wear and tear
3. Improve motion and function
Who performs a THR and where?
A THR is performed in hospital by an orthopaedic (bone) surgeon. An anaesthetist will be present and an assistant surgeon will usually be in attendance. Most THR surgery in Australia is performed in private hospitals.
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Before the procedure
You will be asked to stop blood thinning medication and you should quit smoking before a THR or any major surgery. Blood thinners increase your risk of bleeding and smoking increases your risk of wound infections, pneumonia and blood clots. It can also slow down healing after surgery. Likewise, obesity can also lead to poor surgical outcomes. Weight loss achieved before surgery can reduce the risk of complications. Maintaining a healthy weight for life could reduce future wear and tear on the prosthesis and increase its “lifetime.”
Your anaesthetist will decide whether you need a general or spinal anaesthesia. This will be based on your risk factors. It is important to discuss your medical history, other health problems, the medications you take and any allergies you have. Both the surgeon and anaesthetist need to know these things if they are to deliver the best possible outcome from your surgery.
Some surgeons ask their patients to attend a hospital pre operative clinic where all of this is taken care of. It’s important to attend the clinic, have the pre op tests done and provide as much information as you can. It could help you to achieve the quickest recovery and best possible outcome from your procedure. It could even help save your life!
Use these helpful nib links to find out more about what you need to know about your hospitalisation. Be sure to ask questions if you don’t understand what is being asked of you, or if you want to know more about the procedure. You are the most important person in this whole process!
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THR – Brief description
There are two approaches to surgically replacing a hip.
1. Anterior Incision (or ‘minimally invasive’) approach
Although not commonly used in Australia, results overseas have been encouraging. The anterior approach uses a shorter cut and is said to cause less trauma to muscles and other tissues. It is thought to lead to a shortened hospital stay, less post-operative pain and a more rapid return to normal activities. However, like all newer techniques, many doctors are waiting to see the long term results of this type of surgery.
2. Posterior Incision
This is the more common approach. With the patient lying on their side, the worn out joint is opened and the femoral head removed. The hip socket is prepared to take the prosthetic socket and then the prosthetic socket is inserted. The surface of the prosthetic socket is lined by a smooth surface made of metal, plastic (polyethylene) or ceramic.
Next, the femur (thigh bone) is surgically prepared to take the stem of the femoral prosthesis. Once the stem is in place, a trial femoral head can be attached. The new ball and socket joint is then put through a range of movements to assess stability and leg length.
Once all adjustments are made, the trial femoral head is removed and the final prosthetic femoral head is applied to the stem. The joint is brought back into alignment and a drain is inserted into the site. The wound is then closed usually with absorbable sutures (stitches).
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Choices and Decisions
Talk to your surgeon
Apart from the surgical approach, the surgeon also needs to make a decision about the type of material/s the prosthetic components are made from. Put simply, the components can be made of plastic, metal or ceramic – and the components can interchange. This means that a patient can have a femoral stem, head, socket and liner made entirely of metal or a metal femoral stem and socket and ceramic femoral head and liner. However, the liner could be plastic!
Ceramic components are thought to be better suited to younger and more active patients, but some surgeons argue that a ceramic socket and head can lead to poor results if used together.
Confusing as all of this sounds, it really just reflects advances in technology and attempts to make better fitting and longer lasting prostheses.
Another decision the surgeon needs to make is whether either or both of the femoral stem and hip socket components will be cemented in place or uncemented (where bone in-growth locks the prosthesis into place). There are pros and cons to both fixation methods.
Although the surgeon is in the best position to decide which surgical approach, prosthetic components and fixation method to use, don’t be afraid to ask questions of the surgeon. After all it’s your body.
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Things you need to consider
You need to understand the pros and cons of the various alternatives and consider them against your expectations after the operation.
• Do you need to be active (returning to physical work, caring for young grandchildren, getting back to dancing or bush walking)?
• Are you looking at retiring or taking up a more sedentary occupation?
• How long will you be off work?
• How long before you can get in a car?
• How long before you can DRIVE a car? (there is a difference!)
Another decision to make at this time is whether you should enter a hospital-based rehabilitation programme after your surgery or whether you should return home with or without community-based rehabilitation.
Surgeons vary in their recommendations on these matters. Have the discussion with your surgeon. Talk to your GP and family members or carers. Find out what services are offered in the community. Be proactive in this decision. Not everyone needs hospital rehabilitation after hip replacement surgery.
Above all, have the discussion with your surgeon. Most are more than happy to discuss your reasonable concerns. If not, then find another surgeon.
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Risks and Side Effects
Hip surgery carries risk – this includes anaesthetic risk, infection risk, risk of hip joint dislocation, risk of blood clots and risk of bleeding. These conditions are preventable and treatable, but also depend on your cooperation with post-operative care (e.g. wearing compression stockings to prevent clots and keeping a pillow between your legs in bed to prevent dislocation).
Most total hip replacement surgery can be expected to result in good and comfortable hip function for 10-15 years and sometimes longer. On rare occasions the surgery doesn’t work. Increased pain and ongoing immobility can be the result. This can be caused by loosening of the prosthesis, joint infection or some other complication. Sometimes a repeat surgery is needed sooner than anticipated.
Although these factors are sometimes out of everyone’s control, you can minimise your risk by being in the best health possible before your operation and keeping your weight under control and staying fit after the procedure. You should follow all of the pre op and post op advice given by your doctor and the nursing and physio staff. But remember to ask questions if you are unsure about anything. Everyone involved in your procedure wants it to be a long term outstanding success.
Immediately after the operation
You will be sent to the recovery room whilst the anaesthetic wears off. You will then return to the ward with your pain relief taken care of. Your wound will usually have a waterproof film over it and you will be left to rest for the next day or so.
However, it is important to start mobilising as soon as you are able. This can help to reduce the risks of clots and chest infections. A physiotherapist will show you exercises to strengthen your muscles, safe positions to prevent hip dislocation and give advice about returning to sport or other activities. Your surgeon may want you to fully or partially weight bear as soon as you are comfortable.
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General tips after THR
Your surgeon and GP will give you all the information you need, but here are some general tips.
In the first 6 weeks –
To prevent hip joint dislocation
• Avoid crossing your legs.
• Avoid lying on the operated side but you can lie on the opposite
side provided you have a pillow between your legs.
• Avoid flexing your hip over 90 degrees. Only use high chairs to sit on.
In the longer term
• Keep your weight under control and keep physically fit if possible
• A hip check up every two years with an x-ray is a good idea.
• Antibiotic cover should be given if you have any major bowel, bladder or dental surgery – otherwise germs in the blood stream may attach to the hip prosthesis meaning it may have to be removed.
• Metal prostheses can set off airport security alarms.
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What does nib cover me for?
The hospital you choose, your health cover policy and hospital excess, and if you’re still serving waiting periods are just some of the things that affect how much your procedure will cost.
You should always contact nib BEFORE your procedure to ensure you’re covered.
Your out of pocket expenses may be minimised if you:
• Choose an nib agreement private hospital or public hospital
• Ask your doctor if they’ll treat you as an nib MediGap patient, and if other people performing the procedure (e.g. anaesthetist) will be using MediGap as well
More information about Going to Hospital
This procedure is INCLUDED on the following nib health insurance covers:
• Top Cover
• Young at Heart Mid
• Young at Heart Top
• Premier Plus
• Just Hospital*
* Benefit Limitations apply if you are new to Private Health Insurance. During your first 24 months of cover (but after standard hospital waiting periods have been served) this procedure is subject to ‘Benefit Limitations’. This means that the benefits payable on these services are limited to Public Hospital Benefits only.
This procedure is EXCLUDED on:
• Basic Saver
• Basic Plus
• Family Basic Saver
• Family Plus
• Mid Plus
Note: the belowcovers are no longer available for sale
At nib agreement private hospital and public hospitals, this procedure is fully covered on
• Gold
• Bodyguard
• Safeguard
• Couples Plus
• Singles Plus
• Premier 65% and Premier 85%
• Essentials
• Top Private Hospital
• Executive R
If you are on Public Hospital or Public Hospital Plus Extras, you will be fully covered for a stay in a shared ward of a public hospital, provided you are admitted as a day patient. If your admission requires an overnight stay, you may have out of pocket expenses.
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