Hip Replacement

The hip is a ball and socket joint lined with smooth cartilage which moves with less than one tenth of the friction of ice sliding on ice. Over time this cartilage can wear away, usually as a result of wear and tear. This is arthritis. Other causes of wear include trauma and sporting injuries, anatomic abnormalities in the hip or inflammatory conditions affecting the joints.

Hip replacement involves removing the diseased ball and socket joint and replacing it with prosthetic components. The ball is usually made of metal or a ceramic and is attached to a metal stem which sits in the femur (thigh bone). The socket is metal and has a liner made of plastic or ceramic where the movement occurs. When the damaged parts of the hip are removed and replaced with these prosthetic parts, the artificial joint relieves hip pain and stiffness and improves movement.

The replacement hip components are held in position either with special bone cement or are pressed into the bone. The uncemented components have a surface finish that encourages the bone to grow onto the prosthesis. There are certain groups of people where one type of fixation is better than another.

As the hip is a deep joint, it obviously needs a surgical approach to access. The ideal approach is safe, gentle on the tissues and allows good access to do the job. There are three common approaches, or “doors”, each with pros and cons to consider. One size does not fit all. The ‘best’ approach for different patients varies based on build, size, bone quality and the degree of deformity. Importantly, beyond around 6 weeks to 3 months there is no significant difference between the different surgical approaches to the hip provided they have been done well.

• The front door (Direct Anterior Approach)
  The anterior approach has been rising in popularity. It is a less invasive approach which goes between muscles rather than splitting muscles. It has a lower risk of dislocation and infection. The downsides of the anterior approach include a risk of numbness in the thigh. It is a more difficult approach. Dr Gieroba did fellowship training in this approach in Melbourne and has visited a number of leading surgeons. Because it is harder, it is associated with a higher risk of fracture during the surgery or loosening of components if not inserted correctly. Since the patient is flat on their back with the legs in special leg holders, it is easy to use X-Ray during the case and Dr Gieroba checks his handiwork in theatre in real time with an X-Ray to optimise component positioning and limb length.
• The back door (Posterior approach)
  If the anterior approach is a sports car, the posterior approach is a Landrcuiser. It goes anywhere. It can be extended up and down as needed for access and is the most common approach for revision hip replacement. It involves splitting the gluteus maximus and detaching the small muscles at the back of the hip. Advantages include that it is extensile to allow surgery on even the most complicated hips and anatomy. The downsides are that it splits muscle so it has a slightly higher risk of dislocation and infection but because of the improved access it has a lower risk of fracture and loosening. As the patient is on their side, the position of the pelvis is less predictable, so Dr Gieroba uses the Mako surgical robot for his posterior hips to help optimise component positioning and limb length.
• The side door (Lateral approach)
  This is the least common approach for Total Hip Replacement in Australia. Like the posterior approach it involves splitting the gluteus maximus but also the abductor muscles (gluteus medius and minimus). These muscles are very important for balance and trunk stability during walking.

Absolutely, a chart is shown below that briefly summarises the varying approaches to hip surgery

Aside from certain hip fractures, no one NEEDS a hip replacement. It is an elective procedure. People elect to have a hip replacement when their symptoms are severe enough. For most people the main symptom is pain and when the pain affects their quality of life, keeps them up at night or they are starting to rely on heavy duty pain killers then it is time to consider surgery.

• We try to get you up and walking even as soon as the day of the procedure, as this helps to improve mobility
• Your hospital stay can last anywhere from one to five nights depending on your mobility and pain
• You can expect to be using some sort of frame, stick or crutches for between 2 and 6 weeks
• If recovery goes to plan, you should be back driving by approximately 6 weeks

Yes. Hip replacement is a major operation and all surgery carries risk. The general risks of surgery include bleeding, infection and blood clots. Specific risks include dislocations, fractures, unequal limb length, ongoing pain and nerve or blood vessel injury. Dr Gieroba will talk to you about specific risks at your appointment.

All joint replacements in Australia are recorded and followed on the National Joint Replacement Registry (now following more than 1.8 million joint replacements!) which is based in the SAHMRI ‘Cheese Grater’ building right here in Adelaide. Longevity of hip replacements was more of an issue in the past. Now the situation is that after 20 years, more than 91% of hip replacements in Australia have not been re-operated on.

Of people who have had hip replacements, 89% are “satisfied” or “very satisfied” with their hip replacements. When all goes well, it is an excellent procedure for restoring quality of life.