There are a number of different approaches used when performing hip joint arthroplasty. To date there is no compelling evidence in the literature to show one particular approach is vastly superior over the other but consensus of professional opinion favours either the posterior approach or the modified anterio-lateral approach (also known as the direct-anterior approach)
Over the past few years there has been a significant amount of debate over minimally invasive surgery hip. The results of surgeries using this technique have not necessarily proven to be better than the standard approaches and in fact some studies show an inferior outcome of MIS compared to the standard approach. The use of computer navigation in hip arthroplasty is another controversial subject since it hasn’t shown any significant evidence of a better outcome than using standard approaches. However, each approach has pros and cons and their are advantages and disadvantages for each.
The common approaches to the hip joint for Hip Replacement are:
The posterior approach: This approach accesses the joint through the back and taking the short external rotators off the femur. This approach gives excellent access to the acetabulum and preserves the hip abductors so the patient has less chance of a limp after surgery. Critics cite a higher dislocation rate, although repair of the capsule and the short external rotators negates this risk. Due to incisions through the posterior muscles recovery time can be slower.
The lateral approach: This is also commonly used for hip replacement. This approach requires elevation of the hip abductors (gluteus medius and minimus muscles) in order to access the joint. The abductors may be lifted up by osteotomy of the greater trochanter and reapplying it afterwards using wires. This approach has lesser chance of dislocation but the patients are more likely to develop a limp after surgery which could be permanent.
The anterolateral approach: This develops the interval between the tensor fasciae latae and the gluteus medius. Recently the direct-anterior approach, which utilises an interval between the sartorius muscle and the tensor fascia latae has become more popular especially with the use of a specialised table that allows for hip extension. The advantage of this approach is a small incision and no cutting to any muscle. It is also associated with less pain and faster recovery times. However, it is more technically demanding and requires stringent patient selection since it is very difficult to use this approach on obese or very muscular patients.
A/Prof Al Muderis believes the best approach is the one that the surgeon is most comfortable with performing as long as optimal visualisation of the joint anatomy is obtained using as minimal soft tissue dissection as possible with efficient time utilisation. The best approach will vary from patient to patient depending on their individual situation and needs.
Depending on the approach taken the procedure will vary slightly but the following is a basic overview of what to expect from hip replacement surgery:
An incision is made over the hip to expose the hip joint. The acetabulum (socket) is prepared using a instrument called a reamer. The acetabular component of the implant is then inserted into the socket. This can sometimes be reinforced with screws or occasionally cemented. The liner part of the prosthesis which is either made of plastic, metal or ceramic material is then placed inside the acetabular component.
The femur is then prepared. The arthritic femoral head is removed and the bone prepared to fit the new metal femoral component. The femoral component is then inserted into the femur. The femoral head component is then placed on the femoral stem. This can be made of metal or ceramic.
All components are fitted together and the muscles and soft tissues are carefully closed.