Revision hip replacement

Revision surgery of the hip (redo surgery) is becoming a more frequent problem as the number of patients with joint replacements continues to rise.
Surgery is often more complex, takes longer, has more complications and requires larger wounds, and specialist equipment and facilities.

The assessment and surgery for these conditions can be extremely demanding and should be performed by surgeons specifically trained to do this work. In experienced hands, results after revision surgery have continued to improve due to better understanding of the problems, better implants, and better equipment.

There is no absolute limit to the number of times a hip can be revised, and what usually stops us is extreme bone loss, persistent infection, or poor health of the patient. Patient recovery takes longer, and often requires expert rehabilitation.
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Causes of revision

Implants fail for many reasons, some of which are predictable. Ideally joint replacements should be followed up with X-rays and examinations at least every five years in order to pick up potential problems before they become more complex. Failing implants usually become painful, although some may present with dislocation of the joint, and infection. There is a spectrum of complexity, and we have listed these below.
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Infection
This occurs in about 1% of all primary joint replacements. It can present with pain, swelling, drainage of the wound, or may present many years down the line with painful loosening of the implants. Occasionally infection can come from a distant site such as dental surgery, chest infection, or urinary infection. Patients can become very unwell, requiring emergency surgery, but usually the onset of symptoms is slow.

Successful treatment usually requires eradication of the infection before a new hip can be considered. This means an initial operation to remove the infected implants, followed by a period of powerful antibiotic treatment, usually with a temporary hip in place. If the infection is successfully cleared, then a second operation can be carried out to implant a new hip replacement.

The treatment of infected joints is complex and requires expert management from both the surgeon and the infectious diseases physicians. Reconstruction is often difficult due to the destruction caused by the infection.

In our hands, (Piers Yates and Gareth Prosser) the chance of successful eradication of infection is more than 90%.
Dislocation
This occurs when the ball of the hip comes out of the socket. It is very painful, and the patient will come with a short and twisted leg.

The cause of this problem can be due to implant factors or patient factors. Implant factors include component malpositioning or wear. Patient factors include falls, twisting, and poor muscle strength. Careful assessment of the cause of the dislocation needs to take place before revision surgery is contemplated, otherwise recurrence of the problem is all too common.
Fracture
Fractures around joint replacements are the fastest growing cause of revision in Australia. It most commonly occurs in elderly patients with osteoporosis (thin bones), after a minor fall. Again, surgery can be difficult, and complications have traditionally been very high.

Surgeons familiar with both trauma and joint replacement are the best to deal with these, as they require both skill sets. Some patients will need full revision of the implants, and others can just have the fractures fixed.
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Component malposition
If the implants are not quite in the correct place, this can lead to dislocation, excessive wear, leg length inequality or pain. Revision is often needed for this conditions, and must address the cause fully.
Leg length inequality
A true leg length difference of more than 1cm is associated with significant pain and disability. This may be amenable to revision surgery, but is often associated with continued pain.
Loosening and wear
The majority of hip replacements that fail do so due to wear of the moving parts (bearings), which may be associated with bone loss and loosening of the components. These will usually become painful, but may result in fractures of the bone or dislocation of the joint.

Reconstruction techniques

Revision implants
Specialist implants are often required to deal with bone loss, instability and tissue loss.
Impaction bone graft
One very well proven way of restoring bone loss in revision surgery is by impacting bone from bone donors into the defects. Over time, this is then incorporated into the patients bone permanently. Although this is a demanding procedure, it has excellent results of over 20 years, and is the only reliable way of restoring bone.
Allograft
Sometimes the bone or tissue loss is so great that a large piece of donated bone needs to be fixed to the patient’s hip along with a new hip replacement. The surgery is highly specialised, but is associated with satisfactory results in the medium term.

Complications of revision surgery

These are essentially the same as for primary hip replacement, but more likely.
Infection 1–5%
Bleeding
Transfusion is much more likely depending on the complexity of the surgery. About 50% of patients will require a blood transfusion.
Thrombosis/Pulmonary embolus 1%
Dislocation 1–5%
Revision hips are much more unstable due to repeated soft tissue injury and muscle damage. We now have better ways of dealing with this, and the risk has reduced dramatically over the last 5 years.
Anaesthetic complications 1–5%
Depends on the extent of the surgery and the health of the patient.
Death 1–2% (in first year)
Risk to life is much higher with this kind of surgery than with primary joint.
Leg length discrepancy
In revision surgery, our ability to equalise the leg lengths is much more limited due to the reduced stability of the joint, and preexisting deficiencies and deformity. Again we have become much better at dealing with this over the last 10 years.
Loosening and Wear
These implants wear at least as fast as primary implants, and loosening is more common. Hence each revision is likely to last a shorter time than the implant that preceded it.
Fracture of the acetabulum or femur <10%
Fractures are much more common, usually during removal of the old implants. Experienced revision surgeons should be able to anticipate and deal with the majority of these.
Vascular injuries<1 in 1000
Nerve injuries<1 in 1000
Heterotopic ossification (HO)
Implant breakage
This is much more common in revision, but rarely requires additional surgery.

Orthopaedics WA offer the complete range of revision techniques and reconstruction options, including bone restoration techniques, enhanced recovery after revision joint, and minimal blood loss surgery.
See the frequently asked questions about hips. Also see the Related links on this page.