Thursday, August 17, 2017  



A Surgeon's Perspective

The Minimally Invasive Direct Anterior Approach Total Hip Replacement: A Surgeon’s Perspective

By Tyler C. Wind, MD
Orthopaedic Surgeon
Northern Neck Bone & Joint Center

Total hip replacement is among the most common and successful procedures performed by orthopaedic surgeons.  Each year, thousands undergo this operation and are able to rid themselves of debilitating pain and return to the active lifestyle they desire.  From a patient’s perspective, this procedure is often life changing but selecting a surgeon and understanding the various details can be overwhelming.  It is my hope that this article will provide you with a surgeon’s perspective on the most recent major advancement in hip replacement—the minimally invasive direct anterior approach.

During the 11 years I have been training in orthopaedic surgery, I have seen many innovations in the field. I spent four years in medical school at the University of Virginia, six years in residency in Charleston, SC, and now a year of specialized fellowship training with Dr. Joseph Moskal, who is widely considered a leading authority on hip and knee replacement. Much like computer technology, the medical field is constantly changing. Procedures that were performed when I began my training have been enhanced by modern and improved versions. Dr. Moskal often reminds me of the need to stay current and keep learning. He shares that among the procedures he currently performs, the vast majority did not even exist when he finished training 20 years ago. Out of all the advances I have witnessed so far, none are more revolutionary than the direct anterior approach.

Traditionally, total hip replacement has been performed through either a posterior or direct lateral approach. In a posterior approach, the incision is located on the backside of a patient’s leg and the joint is approached from behind. A direct lateral approach, as the name implies, is a method through which the surgeon reaches the hip joint from directly on the patient’s side. With a direct anterior approach, the hip joint is reached through an incision on the front of the patient’s leg.

History of Anterior Total Hip Replacement

Although the direct anterior approach has recently become popular, it is not a completely new procedure. Variations on the approach are commonly used for numerous other orthopaedic procedures. In fact, the approach has been used, albeit very infrequently, by some surgeons for hip replacement for years. However, utilizing this technique for hip replacement was previously difficult to say the least. It was not until recently that innovative technologies allowed us to realize the full benefit of this revolutionary procedure.

People often say that necessity is the mother of invention and this certainly holds true for anterior hip replacement. Most would agree that the innovator responsible for this advancement is Dr. Joel Matta, an orthopaedic surgeon in California. My mentor, Dr. Moskal, serves alongside Dr. Matta at the courses surgeons attend to learn the anterior approach. Over the past year, I have had the chance to travel the country with Dr. Moskal and learn Dr. Matta’s techniques and rationale for developing the anterior approach. Dr. Matta frequently says that he worked hard to develop the technology to perform this procedure because he was unhappy with the results of its predecessors. “Posterior hips dislocate and lateral hips limp,” he often says to the audiences. What Dr. Matta is referring to is the fact that in the literature the posterior approach is often associated with a higher rate of dislocation, which often requires reduction, bracing, and/or revision surgery and is one of the most dreaded complications following hip replacement. Meanwhile, direct lateral hip replacement requires you to remove muscles and replace them with sutures at the end of the case. This may lead to a limp after surgery. While the majority of these patients still did well, there was definitely room for improvement.

Advantages of the Anterior Hip Replacement

Before starting my fellowship, I had been doing posterior and direct lateral hips for six years.  Given my experience with all approaches, in my opinion the anterior approach has numerous advantages.  Both the posterior and direct lateral approaches require you to cut muscles.  The anterior approach is the only way to do a hip replacement without harming any muscles.  Through this approach, you incise the skin and then spread the muscles apart to expose the hip joint. Cutting muscles is what creates the higher rate of dislocation and the limping associated with the traditional approaches.

A study published earlier this year showed that when you compare the different approaches, the anterior approach causes less trauma to the body.  Furthermore, many authors believe the anterior approach causes less pain. Having performed total hips through all approaches, I couldn’t agree more. Patients are experiencing less pain and that not only leads to a more pleasant experience, but also to a more rapid recovery.  The anterior hip replacements I have done over the past year with Dr. Moskal have recovered faster than any I have seen previously. The national average for length of stay in the hospital after a total hip replacement is about four days. The majority of our healthy patients are discharged on the day after surgery while the vast majority of all patients go home by post-operative day two. Getting out of the hospital sooner is important because patients are much happier and feel they can heal better at home. Furthermore, it has been shown that going home earlier decreases your risk of getting an infection. Most importantly, I feel the early discharge only one or two days after surgery is indicative of the decreased pain, increased function, and shortened recovery time enjoyed by direct anterior hip patients. While traditional hip replacement patients have “hip precautions,” which are positions and motions you are not allowed to do with your hip, anterior approach patients are more stable and usually do not require strict hip precautions.

While the short-term benefits are extremely important, there are several long-term benefits as well. First and foremost is component position. Studies have shown that the anterior approach allows surgeons to more accurately position the components of a hip replacement. It is well known among orthopaedic surgeons that component position is by far the most important factor in preventing dislocation and improving the longevity of a hip replacement. With improved component position, the anterior approach will decrease the rate of dislocation and lead to a longer lasting hip replacement.

Yet another benefit is the ability to more accurately reproduce the patient’s leg length. Very commonly after a posterior or direct lateral approach total hip the patient will have a leg length discrepancy, where one leg is longer than the other. These procedures require surgeons to make an educated guess about the length of the legs and if they miss by as much as a few millimeters, it may have a negative impact on the patient’s outcome. With the anterior approach, you are able to use x-rays in the operating room to fine-tune your leg length so it is reliably reproduced in every patient.

While studies are great, the real proof that anterior approach is superior to the alternatives lies with the patients. One year ago I was resistant to throwing out my previous experience with other approaches and switching to the anterior. However, after seeing the procedure and how the patients do after surgery, the results are undeniable and I would be doing a huge injustice to my patients if I didn’t offer this procedure. During my fellowship,  a study was conducted on our patients who had one hip done through a traditional approach and the other done through an anterior approach. These patients answer questions such as: which side hurt more; how quickly they recovered; and which one they liked better. The results are overwhelmingly in favor of anterior hips with 97% of patients saying they had less pain, a faster recovery, and preferred the anterior approach.

The Future of the Anterior Approach

Patients often ask surgeons “What would you do if you were me?” I can say without hesitation, I would choose the direct anterior procedure for myself or my family.  Familiarity and proficiency with the anterior approach would be one of my primary criteria when selecting a surgeon.

In late August, we will open the doors to the Northern Neck Bone & Joint Center. As part of that practice, we will be launching a comprehensive joint program. For patients desiring a joint replacement, there will be pre-operative education as well as a joint replacement class. We will be doing in-home assessments in order to determine an appropriate discharge plan.  A hospitalist will see you pre-operatively to make sure you are optimized for surgery and assist with the medical side of your post-operative care. A detailed and specially developed physical therapy program will be in place to help you maximize your outcome. Riverside Tappahannock Hospital is investing substantially in equipment, including an innovative operating room table, which facilitates anterior total hip replacement. I will be bringing with me the complex pain control protocols as well as techniques and drugs that decrease blood loss and lower your risk of blood clots. No stone will be left unturned and our patients will have all the advantages and luxuries enjoyed by patients at the busiest joint centers.

While I would love the opportunity to care for anyone with hip pain, it is my hope that you will consider the benefits of the anterior approach regardless of which surgeon you choose. Furthermore, I urge you to find a surgeon who is dedicated to doing the approach regularly and has extensive experience with hundreds of cases. Studies show that it takes about 50-100 of these replacements before a surgeon becomes comfortable with the procedure and I speak from experience in saying that it was a difficult procedure to learn but the improved patient outcomes are well worth the dedication.

In summary, I have done hundreds of hip replacements through traditional approaches and over 300 minimally invasive direct anterior hip replacements. While I hesitated to set aside my previous experience with other approaches, the patient results with the anterior approach were so remarkable that I could not ignore them. I feel the anterior approach offers a minimally invasive alternative that allows surgeons to replace the hip without cutting any muscles. Furthermore, patients enjoy improved component position and accurate restoration of leg length.

If you are interested in the anterior approach I encourage you to learn more about the procedure. I would be happy to direct you to credible information and beginning in August, I will be doing a series of community seminars to share my experience with minimally invasive direct anterior total hip replacement. If you have any questions, please feel free to email me directly at DrTylerWind@gmail.com. For more information about the Northern Neck Bone & Joint Center, or to schedule an appointment, please call 804-443-8670.