Hips

Revision Hip Replacement (RHR)

Revision total hip replacement is performed when the original primary total hip replacement has worn out or loosened in the bone. Revisions are also carried out if the primary hip replacement fails due to recurrent dislocation, infection, fracture or very rarely, ongoing pain and significant leg length discrepancy.

The revision total hip replacement is a more complex procedure, often because there is a reduced amount of bone to place the new total hip into. Extra bone may be required and this is usually received from a bone bank. Bone bank (allograft bone) is safe and has been irradiated to eliminate any chance of disease transmission. There are also artificial bone substitutes that may be used.

Revision total hip replacement takes longer than a standard total hip replacement and has a slightly higher complication rate. The prosthesis may also not last as long as a primary hip replacement. Surgery is usually performed through the same incision but may need some extension.

Post-operative care:

When comfortable the physiotherapist will get you up and start your rehabilitation. You will be shown exercises to strengthen the muscles of the hip joint and you will also be shown the positions that you may keep your leg in and positions that will avoid hip dislocation. Initially you may start with a walking frame but then you will progress to crutches and a walking stick. Depending on your surgeon’s preferences you will either fully or partially weightbear. The wound will have a waterproof dressing over it,  which will allow you to shower. It is important to mobilise as soon as you are comfortable as this will prevent complications such as deep vein thrombosis and chest infections.

To help protect your hip for the first 6 weeks after your total hip replacement.

• Do not bend your operated hip more than 90. Don’t lean forward when sitting, to reach anything!

• Avoid sitting on low chairs, stools or toilets or in car seats where your knees are higher than your hips.

• You should avoid crossing your legs or putting your operated leg across the midline of your body

• You should avoid lying on the operated side but you may be able to lie on the opposite side with a pillow between your legs.

• Avoid driving

• Avoid Crossing your legs

• Avoid lifting heavy items

• Avoid heavy housework

• Avoid lying on the operated side

• Avoid reaching towards your feet to dry them, put on footwear etc

Risks of hip replacement surgery:

Any operation that requires a general anaesthetic has certain risks attached to the general anaesthetic. In addition, there are also small risks attached to spinal or epidural anaesthesia. These risks will be discussed in more detail with your anaesthetist but the chances of having a major anaesthetic complication in New Zealand are one in 40,000.

Anaesthesia complications

As anybody undergoes general or regional anaesthesia (epidural anaesthesia) there are always risks associated with it. The risks of course are magnified if you have abnormal general medical conditions in addition to your older age, which may have affected the functions of your vital organs such as heart, lungs and kidneys. Therefore a complete evaluation of those systems has to be performed before you are taken to the Operating theatre

Specifically regarding hip replacement risks include the following:

Deep vein thrombosis and pulmonary embolus: You are given medication (injections) to thin your blood and prevent these complications. Other measures include TED stockings and calf compressors.

Infection: Superficial wound infections may occur early on and deeper infections can occur at a later stage. The incident of infection is less than 1%. Infections are usually treatable with antibiotic treatment. You are given antibiotics before the operation and for the first two days to prevent infections from happening. Very rarely, if a joint has a deep infection that cannot be controlled with antibiotic therapy, the joint requires removal and a second joint re-implanted at a later stage.

Leg length discrepancy: It is not unusual for there to be up to 1cm leg length discrepancy following a Hip replacement. This is quite easily tolerated. The reason there may be a discrepancy is to ensure that the hip joint is appropriately tensioned so that it does not dislocate. Initially you may think that you have a longer leg but this is often due to muscle contracture which over time will loosen up and your leg lengths will even out.

Hip dislocation: The risk of hip dislocation is usually less than 1 or 2%. Provided the components are placed correctly and the appropriate post-operative precaution measures adhered to, it is unlikely that the hip will dislocate.

Fractured femur: Very rarely the femoral bone may fracture at the time of surgery and this is usually treated immediately. It is also uncommon to fracture following a total hip replacement unless you have been involved in a bad accident.

Loosening of the prosthesis: As mentioned, over time the prosthesis may loosen if the bone does not grow into it sufficiently or if the bearing surface wears out to produce areas around the prosthesis, leading to loosening. Should a prosthesis loosen, then it can be revised. If only the bearing surface wears out, then usually only the bearing surface requires revision which is a much smaller operation. Patients who have metal on metal articulating surfaces have a slightly higher metal iron level in their blood. This has been extensively researched over the past 30 years and there have been no increased incidents of cancer or any other problems.

Damage to nerves and vessels: It is unusual to damage any major nerves or blood vessels following a hip replacement. However nerve palsy can develop if the nerve is stretched during surgery. Those with hip dislocations from childhood are at higher risk of nerve injury.

Haematoma: Occasionally a bleed may occur around the hip joint following the operation that may require drainage.

Scarring: Some patients tend to scar more than others and it may be that the scar that you have will be quite thickened (keloid).

Long-term swelling: Occasionally the operated leg may remain a little swollen for a number of months but in general this tends to resolve.

Trochanteric bursitis: Occasionally following hip replacement surgery one can experience inflammation at the side of the hip joint which usually settles with either a cortisone injection or anti-inflammatories.

Joint stiffness: Very rarely extra bone can form around your hip joint which will cause it to stiffen up again (heterotopic ossification). This is usually painless but may cause some stiffness.

General advice after hip replacement surgery:

1. You should have a regular check every two years with an x-ray.
2. If you have had any major bowel, bladder or dental surgery, antibiotic cover should be given prior to the surgery.
3. Metal prostheses can activate security alarms at airports.