Direct Anterior Approach

Minimally Invasive Total Hip Replacement via the Direct Anterior Approach

The direct anterior approach (DAA), is a less invasive way of performing a total hip replacement. There are a number of ways in which the hip joint can be accessed; so-called posterior (through the buttock area), lateral (from the side), anterolateral (a bit more towards the front) and finally direct anterior. These different approaches have pros and cons in terms of which parts of the hip joint they can most easily expose for repair and reconstruction, such as the femur or the acetabulum. Any approach has the possibility that muscle may need to be split or tendons detached and so this needs to be allowed to heal after surgery and the more soft tissue that is interfered with the more restriction there may need to be afterwards.

The great advantage of the DAA is that access to the hip joint is between muscle planes, so no muscles need to be split or cut. In order to access the acetabulum and the femur certain capsular tissues do need to be released and specialised retractors and instruments are required but the overall impact on the surrounding soft tissues is minimised. A lot of interest has been generated with this approach because there does appear to be a trend to a quicker recovery than with other surgical approaches to the hip. One of the main features in my opinion is that there is less pain in the post-operative period which has a big impact on recovery.

Hip replacements need to be performed for a variety of conditions that end up with the hip joint becoming arthritic. This point is reached when the normal gliding surface of the joint, the articular cartilage, has worn out and this then leads to the pain and stiffness that leads patients to seek help. Some of these conditions, in particular those occurring in childhood, maybe associated with a lot of bone and soft tissue deformity. In these cases the DAA may not be the optimal approach to the hip because correcting these deformities and reconstructing the hip requires greater access in order to provide a well functioning joint.

Most cases of hip arthritis that we see tend not to be associated with major deformity, and so for the most part the DAA can be used as the approach of choice making the recovery easier and with the added advantage of the surgery being performed through a small cosmetic incision.

What are the advantages?

Accumulating evidence suggests that patients find the recovery after this approach to the hip rather easier than with others. The main reason is that there is less pain which makes it easier to start becoming mobile and exercising after the procedure.

What are the downsides?

With an incision in the front of the thigh, there can be some alteration in the skin sensation over the front and outer aspect of the thigh. This relates to the anatomy of the small nerves that provide sensation to the skin and their proximity to where the surgical incision is made. Some people experience more changes in the skin sensation than others, but over time the area affected always reduces significantly.

Will there be much scarring?

With the approach that Johan Witt uses, the incision is placed in a skin crease of the thigh which heals in a very cosmetic manner and would not usually be visible when wearing a bathing suit; so – called bikini incision.
Healed incision after direct anterior approach hip replacement

Does it make a difference in the longterm?

The most important factor for the longterm function of a hip replacement is that appropriate hip implants are used and that they are inserted correctly so as to reconstruct the anatomy of the hip. Beyond the early functional recovery we do not know if the approach itself makes a significant difference in the longer term.

Can this approach be used in all cases?

Other approaches may be more suited to reconstruct the hip if there is a large deformity that needs to be addressed in the femur or acetabulum. Sometimes particular hip implants may be needed that are better suited to a different approach.