Direct Anterior Approach for Total Hip Replacement

The Direct Anterior Approach (DAA) to perform hip replacement surgery is a minimally invasive approach with less in the way of muscle splitting or muscle cutting than other approaches to the hip. At every hip meeting I have been to in the past year there continues to be a lot of debate as to what the advantage is and whether there are longterm gains to be had. There certainly are those who oppose the idea of this being a good approach and this relates to data that is presented in relation to the ‘learning curve’ to safely perform the approach.

The learning curve is the number of procedures a surgeon would have to do to have a complication rate for the particular procedure or success rate, that would be the expected norm. Performing a hip replacement through a different anatomical route is not something that can always easily be achieved. How easy it is to switch from one approach to another depends a lot on the similarities between the anatomical planes and the actual technicalities of inserting the hip implants.

I think it is fair to say that the anatomical planes associated with the DAA are not ones that most surgeons are routinely exposed to and there is no doubt that the specific steps that are needed to insert a hip replacement through this approach are very different from other approaches. Complications that are sometimes presented associated with the learning curve are certainly of concern and indicate that appropriate training needs to be undertaken before the approach is adopted.

The benefits, in my view, of the DAA are quite significant in terms of the ease of recovery after hip replacement surgery. Patients require less in the way of strong pain killers and mobility returns with greater ease. Because the soft tissue envelope around the hip is preserved without cutting muscle, the joint is inherently very stable after surgery so fewer early post-operative restrictions apply.

One of the arguments used against the DAA demonstrating significant advantages is that most studies indicate that by 6 weeks or 3 months there is little difference as to which approach is used. This rather ignores the beneficial effect to the patient of that early recovery period which to many is the most significant element of having to undergo hip replacement surgery.
My experience using this technique for the majority of hip replacements over the past 6 years has been very positive with patients indicating that the recovery appeared much more straightforward than they anticipated. In particular, patients who are having their second side operated on, where they have undergone a different approach for their first side, find the difference very significant.

A further advantage which is important for many young patients, is that the surgery can be performed through a very cosmetic incision (so-called, bikini incision) which heals extremely well and is not very visible.

The Direct Anterior Approach has become increasingly popular for hip replacement surgery in the US, Australia and some European countries. In the UK there are rather few adopting this approach but I am sure that with time and as junior surgeons are increasingly exposed to this approach during training it will become more widespread.