Direct Anterior Approach Total Hip Replacement

Over the last decade, direct anterior approach (also called anterior supine incision or ASI) total hip replacement has been gaining popularity in the United States.  The reasons for this surge in popularity can be traced to three factors.

More traditional posterior or anterolateral surgical approaches to total hip replacement have to cut muscles attached to the hip joint in order to expose the joint.  In ASI total hip replacement, no muscles are cut, which results in less initial postoperative pain and faster early recovery with a shorter hospital stay for many patients.  Most patients have a one-night stay after surgery, and are off crutches by about 2 weeks after surgery.

The ASI approach allows for the use of x-ray imaging during surgery to precisely position the components, and to ensure very accurate measurement of leg lengths.  Since component position is critical to optimal long-term function of the implant, and leg-length inequality is one of the most common reasons for repeat surgery after older methods of hip replacement, this use of precise x-ray control is very advantageous.

Dislocation of the prosthesis is one of the more frustrating and challenging complications of total hip replacement.  With other techniques, the reported rate of dislocation over the lifetime of the prosthesis is 3-5% (Medicare data).  To try and minimize this, many surgeons performing those older techniques will tell their patients never to bend more than a right angle at the waist, and not to scissor their legs.

Because no muscles are cut during the ASI approach, the dislocation rate is markedly less.  After more than 2000 total hips performed by surgeons at Orthopedic Specialists of Seattle, the dislocation rate is less than 0.1% (less than 1 in 1000).  We therefore put no restriction on patient motion after surgery.  Dr. Peterson’s only restriction for his patients is no running for exercise.

An excellent YouTube animation video of how the ASI approach is performed is available below. While this video was made in Omaha by Dr. Ajoy Jana, the technique used by Dr. Peterson is very similar in all regards.

The surgeons at OSS perform more ASI hip replacements than any other practice in the Northwest.  Dr. Peterson has been performing total hip replacements for over 20 years, and switched to the ASI approach for most cases several years ago after seeing the significant benefits for his patients.  He would be happy to discuss this remarkable new technique with you during your office visit.