Total hip replacement is one of the most successful procedures in orthopaedic surgery to alleviate pain and improve quality of life. In Australia alone about 20,000 of these procedures are performed every year with an overall 95% success rate. After the procedure patients are able to return to activities and pursuits that were not previously possible.
Prof Jegan Krishnan and Dr Sunil Reddy are leading Joint replacement surgeons in Adelaide and offer the most up to date technology in hip replacement surgery including minimally Direct Anterior approach THR.
What causes problems with the hip joint?
Deterioration of the hip joint and consequent pain and swelling is mainly caused by severe arthritis, either osteoarthritis (the wearing away of cartilage in the joint) or inflammatory arthritis. It can also be caused by avascular necrosis, a condition where bone tissue deteriorates due to lack of blood supply, which can result from for example injury (‘trauma’) or from abuse of alcohol, steroid use or from decompression sickness (‘the bends’).
During the procedure the surgeon replaces diseased and damaged bone and cartilage in the natural hip joint with an artificial joint. As with the natural joint, the artificial joint is in two parts - the ‘femoral prosthesis’ which forms the ball of the ball and socket joint (called the ‘femoral head’) and the ‘acetabular prosthesis’ which replaces the socket (‘acetabulum’).
The operation takes around 90 minutes, during which the patient is put under either spinal or general anaesthesia and receives a femoral nerve block to relieve pain during and after the surgery.
THR can be performed through any of the three approaches – Posterior, direct lateral and direct lateral. All of them have their pros and cons. We offer Direct anterior approach THR in suitable patients and will discuss the options with you at the time of consultation. This would enable you to make an informed decision and work towards the best possible outcome.
Different approaches to perform Total Hip Replacement Surgery
- Posterior approach: Approaching the joint from the back of the hip. Worldwide this is the approach most used by Orthopaedic Surgeons. It is an excellent and reproducible approach but involves detaching the posterior capsule and some muscles / tendons that are repaired later. There is increased incidence of hip dislocation compared to other approaches, some of which require reoperation.
- Direct lateral approach: Requires detachment and later reattachment of the hip abductor tendon. Limp and gait abnormalities are more common with this approach which usually resolves with time.
- Direct anterior approach (DAA): Though this is not a new approach, its benefits in THR have been more widely realised in the recent few years. A summary of this approach, merits and challenges are discussed further below.
All of the above approaches have a long history and can be safely used to perform THR. The recently popularised DAA - THR too has been in use for over 20 years, especially in Europe. Introduction of efficient instrumentation, use of proprietary surgical tables by some surgeons and better surgeon training have allowed its increasing use in hip replacement surgery.
In most cases, where the patient is younger than about 75 years, no form of bone cement is usually needed, as the implants are coated with a special material to allow the prosthesis to integrate naturally with the bone, creating a bond that lasts a long time. This approach is called 'uncemented THR'. Where patients are elderly or suffering from osteoporosis a 'hybrid THR' is performed where surgical cement is used to bond the bone and the femoral implant.
Please see our section on Total Hip Replacement Rehabilitation Protocol to learn more about postoperative recovery and rehabilitation.
As with all surgical procedures there are some risks associated with total hip replacement. These are...
- Infection (0.6% risk).
- Nerve injury causing numbness/weakness in affected leg.
- Blood clot (DVT or embolism).
Risks specific to this procedure include...
- Joint dislocation.
- Leg length discrepancy.
- Fracture of thigh bone during / after procedure.
- Loosening of artificial joint components (where bonding fails or there is wearing of the polyethylene component, or osteolysis).