Hip FAI Overview
Femoroacetabular impingement (FAI) is a condition that may result in pain and damage to the hip joint due to an abnormal shape of the bones that make up the hip. The condition has only been recently appreciated in the medical community, and our knowledge of this disease has grown significantly over the past decade. The hip joint is a “ball and socket” type joint comprised of two bones – the femoral head (ball) and a part of the pelvis called the acetabulum (socket). Normally these bones have a shape that allows for smooth motion of the hip without any excessive contact; however, certain patients have a misshapen ball (which is not perfectly round), a socket which is too deep, or a combination of both. This mismatch creates and abnormal contact between the bones when the hip is moved and leads to damage to the labrum (rim of cartilage surrounding the acetabulum) and to the articular cartilage which coats then ends of the bones and allows for smooth motion of the hip. Over time as more and more of the cartilage is damaged a patient may eventually develop osteoarthritis of the hip joint, a condition where the cartilage is lost leaving bone rubbing against bone. While many people may have some evidence of impingement on X-rays, the symptoms are most pronounced in athletic patients who put their hip through a repetitive range of motion which is required for sports and athletic activities.
Although the exact mechanism of why certain patients develop FAI is still under investigation, it is thought to be due to a combination of genetic and developmental influences. Certain patients are born with misshapen hip (such as in developmental dysplasia) and some patients may have an injury to the hip while they are growing (such as in a slipped capital femoral epiphysis) which can lead to FAI later in life. Other patients who are active and undergo repetitive motion of the hip are thought to be at an increased risk of developing FAI. Hip surgeon Dr. Boykin specializes in the treatment of hip FAI for patients in Asheville, Arden, Fletcher and surrounding communities.
What are the Types of Hip FAI?
There are 2 types of FAI: Cam impingement and Pincer impingement. In the majority of symptomatic cases, patients have a mixed type impingement which includes a combination of a Cam lesion and a Pincer lesion; however, certain patients may suffer from either a Cam or Pincer in isolation.
- Cam Impingement: This type of impingement occurs as the result of an abnormal shape to the femoral head. The normally round ball has extra bone creating a “bump” on the ball which wears away at the articular cartilage and eventually causes tears of the labrum. The result is similar to the cam effect in mechanics, from which this condition takes its name.
- Pincer Impingement: the type of impingement occurs when the socket is deeper or extends further than normal. This traps the labrum between the ball and the socket when the hip is moved, causing a tearing and degeneration of the labrum followed by damage to the articular cartilage.
Symptoms of Hip FAI
Patients who have FAI on X-rays may not have symptoms for a long time until damage to the hip has started to occur. When FAI is severe enough to cause symptoms they are most commonly as follows:
• Pain deep in the groin
• Catching or locking of the hip
• A pinching sensation in the front of the hip when the hip is flexed and rotated
• Difficulty squatting down and coming back up
• Trouble competing in sports that require repetitive motion of the hip
How to Diagnose Hip FAI
Dr. Boykin will initially perform a history and physical exam where he will ask the patient the location of the pain, the pain level, what specific activities and movements cause pain, and what makes the pain better. He will then perform a detailed physical examination to assess for FAI, range of motion, tightness of the muscles around the hip, hip instability, and diseases of the lower spine. The classic test for FAI and anterior labral tears involves placing the hip in a position of flexion, internal rotation, and adduction to see if this causes the patient’s pain. Upon presentation all patients will have hip specific radiographs to examine for any bony abnormalities, FAI, or other causes of hip pain. In many cases, Dr. Boykin will order an MRI of the hip to examine the extent of damage to the articular cartilage, labrum, and other soft tissue structures surrounding the hip (which are not well seen on X-rays). This type of testing will allow Dr. Boykin to confirm the diagnosis as well as to determine the severity of the injury and to ensure that there are no other injuries in the hip joint (fractures, etc.).
Treatment Options for Hip FAI
Depending on the severity of the damage to the hip joint and the types of therapies that the patient has already tried, Dr. Boykin may first recommend non-surgical treatments. These include an initial trial of rest, activity modification, physical therapy to strengthen the hip and core muscles, and non-steroidal anti-inflammatory drugs. If these fail to provide relief, Dr. Boykin will then perform an injection of local anesthetic and steroids into the hip. This procedure serves a dual purpose: to provide a therapy to reduce the pain and as a diagnostic test to determine how much of the patient’s pain is from the inside of the hip joint. This is an important indicator as to how well the patient would respond to surgical treatment, if needed. In some cases, these treatment methods may be successful in completely alleviating the patient’s pain. If these non-operative treatment methods do not prove to be helpful, Dr. Boykin may begin to discuss surgical options with the patient.
What is Hip FAI Surgery?
FAI has only recently been appreciated as a source of hip pain and disability and therefore the surgical treatments for this have been evolving and improving. Initial surgical options for FAI included open surgery to dislocate the hip joint and treat the FAI and damage to the labrum and cartilage. While this procedure is successful, and may still be required in certain patients, newer techniques have allowed surgeons to accomplish the same goals with minimally invasive arthroscopic surgery. In the vast majority of cases, Dr. Boykin will perform an arthroscopic surgical approach to the hip using small incisions, a camera, and special instruments. During this surgery he will treat the FAI by removing the bump from the femoral head and recreating a round surface and/or removing the extra bone from the socket. He will then treat any tearing of the labrum and damage to the articular cartilage. Dr. Boykin strongly believes in preserving as much of the labrum and cartilage as possible; therefore, he uses a technique to repair the labrum rather than just take away the area of damage. If the labrum is damaged beyond repair, in most cases he will perform a reconstruction, rebuilding the labrum with tissue from the outside of the patient’s hip. Dr. Boykin will use his experience to determine which surgery a patient will better recover from to provide the patient with the best chance of returning to their activities. These procedures have been shown to be highly successful in active people, including professional athletes, back to their sports and activities.
For information regarding FAI, labral tears, or any other hip-related injury, feel free to contact Dr. Robert Boykin, orthopedic surgeon treating patients in Asheville, Arden, Fletcher and surrounding North Carolina communities.