Broadly, there are several methods that hip replacement surgery can be performed – the posterior, lateral, and anterior approaches. Each approach is respectively named after the location where the incision is made to gain access to the hip joint. In Singapore, the posterior approach is the most common, however, the Direct Anterior Approach (DAA) has emerged as an important technique used by surgeons subspecialised in hip surgery.
What is the Difference Between the Direct Anterior Approach and the Posterior Approach?
The posterior approach is more commonly performed than the direct anterior approach, as this is the method that most orthopaedic surgeons are familiar with in Singapore. The Direct Anterior Approach (DAA) is a far more technically challenging technique that requires specialised training to perform safely, and is routinely performed by only a relatively small number of surgeons locally.
The advantage of the Direct Anterior Approach is that it is a minimally invasive surgical (MIS) technique that typically does not involve cutting across the muscles around the hip joint. As a result of this muscle-sparing technique, patients who undergo DAA hip replacement have less pain, faster recovery, more rapid restoration of walking ability and better early hip function when compared to the posterior approach. In fact, many patients are able to walk on the same day after DAA hip replacement surgery!
In the posterior approach, several large muscles around the hip have to be cut for the surgeon to access the joint. Although these muscles will be repaired after the hip prosthesis has been implanted, a longer time is required for healing and recovery after the posterior approach when compared to the muscle-sparing Direct Anterior Approach. In addition, the prosthetic hip joint may have better stability when the operation is done via DAA, which could reduce complication rates and afford patients better outcomes.
How the Direct Anterior Approach Hip Replacement Surgery is Performed
Before the surgery, you will have a consultation with your surgeon to discuss the type of surgery and implant that would be most appropriate for your condition. A hip X-ray (and sometimes an MRI scan) will be performed to enable the surgeon to assess the extent of damage in your hip joint, and to plan for the surgery (if required).
During the surgery, anaesthesia will be administered so that you can be asleep and not feel pain throughout the procedure. In the Direct Anterior Approach (DAA), a short approximately 10cm incision will be made along the front of the upper thigh, and the hip muscles are gently spread apart (but not cut) to gain access to the hip joint. Once the hip joint has been accessed through this muscle-sparing technique, the areas of damaged bone and cartilage will be carefully removed to make space for the hip implant to be fitted in place. After the implant has been fitted, your surgeon will thoroughly assess the length, alignment, stability and movement of your new hip joint before completing the operation.
After the surgery, you will undergo physiotherapy and rehabilitation, and there is a good chance you will be able to walk with your physiotherapist on the same day. Since the Direct Anterior Approach is minimally invasive (MIS), the expected recovery time is 4-6 weeks or less, with early hip function after DAA having been shown to be superior to the posterior approach.