Femoroacetabular impingement (hip impingement)

Femoroacetabular impingement (hip impingement)

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What is femoroacetabular impingement?

Femoroacetabular impingement (FAI), also called hip impingement, is a condition where the femoral head and the hip socket don't match appropriately, which can lead to premature contact between these two structures when the hip is placed in certain positions. Over time, this repeated contact can cause damage to the labrum (O-ring type structure which surrounds the hip socket) or the underlying cartilage.

  • Kathleen J. Maguire, MD: Femoroacetabular impingement, which we call FAI for short, is a condition where there is mismatch in the shape of the hip joint. There's some abnormality between the socket and the ball so that when patients bring their hip into flexion, they're making premature contact, which can result in pain, it can result in limitations in terms of motion. With everyday activities, patients can experience clicking or popping in the front of the joint. Patients often will come in with what we call the C sign. They say they can't quite pinpoint it exactly, but they'll cup their hand in a C shape around their hip and say it kind of hurts right there. And having hip pain, I often describe it's like having a really bad toothache. Every single motion that we do, again, up and down stairs, sitting at school, being able to drive, it can really be a challenge just with everyday life. Wudbhav N. Sankar, MD: The pain can typically start low grade, maybe just a little bit with activity, but if it gets worse, and it can start bleeding into normal life and creating pain with even upright activities like walking and climbing stairs. Kathleen J. Maguire, MD: So some people, unfortunately, are more prone to developing hip impingement. We know that males are more commonly affected than females. We also know that patients who are athletes or involved in particular sports are more likely to develop hip impingement. Wudbhav N. Sankar, MD: It's a 60 to prone internal. 30 of pro external FAI really is a diagnosis that has to be made by putting together all of the information. You need to have a good physical exam to see how the hip moves, how a person's walking, what their range of motion is like. You have to get nice quality X-rays to get good understanding of how the hip looks in three dimensions. Sometimes we need advanced imaging studies like CAT scans or MRIs as well to make the diagnosis, and one of the key parts of making the diagnosis is actually getting a good history. Understanding how the patient is feeling, what type of pain they have, what kind of activities are painful, and what positions are most problematic. And that's really key for making an accurate diagnosis. Kathleen J. Maguire, MD: A lot of patients will come to me with hip pain and groin pain and hip impingement and this really can affect not only their ability to participate in sport, but just their ability to get through the day without discomfort. And getting those kids back to their tip top playing shape and getting them back on the field is a really big part of what I do. So typically when a patient presents to us with FAI we do start with non operative management. That means that we talk about activity modification, prescriptions for medication, sometimes really strong anti inflammatories that can help to kind of relax agitated or inflamed muscles around the hip. And we get patients into a physical therapy program to really provide a specific protocol that's just for kids who present with FAI. In addition to doing physical therapy, we also provide ultrasound guided injections. We're able to place a medication that helps not only with pain, but also inflammation inside the joint itself or in the surrounding musculature of the hip. So the injection really provides, we say, a window of opportunity to maximize physical therapy, to build strength, stability of the pelvis and the hip to hopefully prevent need for a surgery. We start to talk about surgery for patients who have failed non operative interventions. Hip arthroscopy is a minimally invasive way to manage a number of conditions inside the hip. I think it offers a lot of benefit because it is minimally invasive. It's done through small portal sites. We don't have to make large incisions. We don't have to dissect through a large amount of musculature. I tell a lot of the kids, it's like playing a video game. You're kind of watching what's going on inside the hip up on a screen, and then we're able to do all of our work kind of outside the body. So a lot of patients can forego a larger surgery, which unfortunately can mean a longer recovery, by having hip arthroscopy done. Wudbhav N. Sankar, MD: So in certain circumstances, hip arthroscopy is not going to be enough. So in situations where the socket is abnormally rotated, over the front, then the best thing to do is actually periacetabular osteotomy, which is an operation that detaches the hip socket and reorients it into a better position. Similarly, if there are rotational problems on the femur bone, then sometimes we have to do what's called a derotation osteotomy, and that's a procedure where the femur bone is actually cut, rotated it into a better position and then fixed with either a rod or a plate. Now some of these procedures seem and sound pretty drastic, but there are certain situations where it is the better treatment option, so they can get back to the field and back to their activities as soon as possible. It's important to see a pediatric orthopedist who has a specialty in femoroacetabular impingement. Kids have unique skeletons that are growing, and any kind of treatment really needs to focus on the unique aspects of the pediatric skeleton. Kathleen J. Maguire, MD: I really impress upon the kids that surgery is the first step to recovery, it's certainly not the last. So after surgery, most of our patients will undergo a long post operative course of physical therapy, that really is to get their strength back, getting them going up and down stairs, working on their agility, their flexibility. All those types of things that hopefully will help not only get them back on the field, but help prevent another injury in the future. Wudbhav N. Sankar, MD: After treatment for FAI, our expectation, and certainly the expectation of our patients, is that they get back to an active lifestyle. Kathleen J. Maguire, MD: A lot of our athletes are very active now, and they want to continue to be active. Keeping them out of pain and keeping them as functional as they want to be is really, really important to me. It's why I do what I do Wudbhav N. Sankar, MD: When they have that smile on their face and they come back for their post operative appointment and they've been able to do what they haven't been able to do for several months or years, that's when I just go home with a great feeling. That's exactly why I wake up in the morning and come to work.
Transcript Transcript

Symptoms of hip impingement

Some people with FAI can live active lives and never experience pain or hip problems. Others, especially athletic and active people, may develop pain in the hip or thigh that is usually worse in a seated position. Clicking, popping or a pinching sensation may be felt deep in the hip joint.

Diagnosis

A diagnosis of FAI may be suspected after a detailed history and physical examination. X-rays can help evaluate the shape of the ball and socket to look for possible causes of impingement. The findings on X-ray are often subtle, however, and may be missed by practitioners who are unfamiliar with the condition.

Advanced imaging helps our doctors better understand what’s going on deep inside your hip socket. We may recommend specialized advanced imaging studies, which are all available at CHOP:

  • 3-D reformatting imaging — computed tomography (CT) scans that combine X-rays and computer technology to create three-dimensional models of the hip anatomy
  • Delayed gadolinium-enhanced MRI of cartilage (dGEMRIC) — imaging where an MRI scan is dedicated to detecting early cartilage breakdown and allows mapping of areas of early osteoarthritis or focal cartilage injury
  • Radial hip reconstruction — MRI reconstruction technique that takes slices of the hip joint circumferentially around the ball and socket and allows for more accurate identification of areas of potential femoracetabular impingement compared to conventional radiography

Treatment for FAI/hip impingement

Treatment may include non-surgical options such as activity modification, physical therapy, injections and anti-inflammatory medications. For those patients that don’t respond to non-operative treatment, hip arthroscopy or a surgical dislocation of the hip may be recommended.

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Why choose CHOP

CHOP’s Hip Preservation Program focuses on hip conservation in young adults to stop continued damage and prevent the need for premature hip replacement.

Related specialties and programs

Young Adult Hip Preservation Program

Hip Disorders Program

Orthopedic Center

Sports Medicine and Performance Center

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When Morgan was 11, longstanding hip issues began to severely limit her mobility and ability to play her favorite sport, soccer. Here, she describes the experience in her own words.
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