Direct Anterior Total Hip Arthroplasty
Anterior hip replacement is a hip replacement surgery performed through an anterior surgical approach. Traditionally, hip replacements have been performed through posterior or lateral approaches. Both of these surgical approaches involve dissection of muscles or tendons that are involved in a normal gait cycle – the process of walking. The anterior surgical approach is unique in that it involves minimal disruption to the muscles and tendons surrounding the hip joint, and as such, allows for quicker recovery from the hip replacement procedure.
Patients who suffer from moderate-severe hip arthritis are considered candidates for hip replacement surgery. Good candidates for anterior hip replacement surgery specifically will include patients with low-normal BMI or patients who do not have a large abdominal pannus that will create a skin crease around the area of the incision for an anterior hip replacement – this causes a bacterial reservoir to form over the area of the incision and increases the risk of superficial wound infection and possibly deeper joint infection. Patient anatomy can also influence the surgeon’s decision as to whether they feel that the patient is a candidate for anterior hip replacement surgery, if a patient has a naturally broad pelvis for example, gaining access to the femoral canal may prove challenging and would preclude these patients from being candidates for anterior hip replacement surgery.
Anterior hip replacement surgery requires general anesthetic – once this has been administered, a surgical approach using the anterior skin directly overlying the hip is used. The surgeon then parts the muscles in this area without cutting them and exposes the hip capsule. This will then be opened and the arthritic femoral head will be removed. The acetabulum will be prepared for its replacement component by grinding away the arthritic bone with a special tool, and once it is placed in position, it may be held in place with one or more bone screws.
Once this is completed, some further surgical dissection is necessary to expose the proximal femur and this includes releasing some of the capsule and tendons from the posterior part of the cut end of the femur.
Once retractors are placed and visualization of the proximal femur is adequate, other special tools can be used to determine the correct size of replacement component for each patient. X-rays are used to help determine the appropriate position and size of the implant intraoperatively. It is also used to help the surgeon determine that the length of the leg is equal to the other side once the right size component has been selected.
Once the surgeon is satisfied, he will place the final components and reduce the hip one final time and then surgically close the hip capsule.
The patient is able to bear weight on the operative leg immediately following the surgery (although adequate pain relief will be necessary for them to achieve this). For some patients, discharge from hospital later the same day is possible, others may require a single night stay in the hospital to recover and are usually home the following day.
Anterior hip replacement surgery is an area of major interest in current research institutions. The current best evidence indicates that, at 3-months post-surgery, the outcomes between anterior hip replacement and all other hip replacement techniques are equivalent with no obviously superior technique. However, in the first 6 weeks to 3 months, it is felt that the anterior hip replacement technique offers a quicker earlier recovery as compared to alternative techniques. As such, it is felt to be a superior technique in terms of early postoperative recovery, especially in younger patients who have greater physiological reserves to be able to cope with the stresses of surgery.
Ultimately, the difference in success rates long term is not known, as we do not have sufficient research data to inform us of this, but medium term the results indicate equivalent outcomes when compared to alternative surgical approaches.
Anterior hip replacement surgery is fast becoming a widely used and highly successful technique for performing hip replacement surgeries. The benefits of using this technique include enhanced early recovery, shorter stays in hospital and even shorter times for returning to work and recreational activities.
If you think, you may be a candidate for an anterior hip replacement, please arrange to see one of our specialist orthopedic surgeons who will be happy to see you in consultation and review your surgical options with you.