Hip Arthroscopy - Stanford Hospital & Clinics - Stanford University Medical Center

Femoroacetabular Impingement (FAI)

(aka: Femoral Acetabular Impingement)

Femoroacetabular impingement or FAI is a condition where the bones of your hip joint come too close and pinch tissue or cause too much friction. Usually, the ball of the hip joint (femoral head) sits on the femoral neck similar to an ice cream sitting on a cone. The pinching and friction occurs when the femoral head and neck contact the socket (acetabulum), creating damage to the hip joint. The pinching or friction may cause damage to the labrum (a fibrous cartilage that lines the outer edge of the socket) and/or the articular cartilage (the white covering over the bony surfaces that results in the very smooth surface gliding of the joint).

Causes

FAI generally occurs as two forms: Cam and Pincer. The Cam form describes the femoral head and neck relationship as aspherical or not perfectly round. This loss of roundness contributes to abnormal contact between the head and socket as the hip goes through a range of motion. The Pincer form describes the situation where there is overcoverage of the socket or acetabulum relative to the ball or femoral head. This over-coverage typically exists along the front-top rim of the socket (acetabulum). The end result is that the labral cartilage gets “pinched” between the rim of the socket and the front part where the femoral head meets the femoral neck. The Pincer form of the impingement is typically the results of “retroversion”, where the socket is pointed backwards a bit (rather than the usual situation where it is angled forwards), or where the socket is too deep. Very often, the Cam and Pincer forms exist together. The cause of these bony variations is not known at this time.

Damage

FAI is associated with articular cartilage damage and labral tears and may result in hip arthritis at a younger age than usually occurs.

Who is at risk?

FAI is common in high level athletes, but also occurs in active individuals. While either type of impingement can occur in men or women at any age, most frequently the Cam type of impingement tends to affect young (20’s) male athletes, while Pincer tends to occur more commonly in women in their 30’s and 40’s who are athletically active. Sports associated with FAI include Martial Arts, Ballet, Cycling, Rowing, Golf, Tennis, Soccer, Football, Ice Hockey, Baseball, Lacrosse, Field Hockey, Rugby, Water Polo, and Deep squatting activities such as power lifting.

Symptoms

There may be no pain or symptoms
Pain or aching (usually located at the inner hip, or groin area), usually after walking, or prolonged sitting (such as in a car)
A locking, clicking or “catching” sensation within the joint
Pain sitting for long periods of time, like in a car
Difficulty putting on your socks and/or shoes
Difficulty walking up hill
Low back pain.
Pain at the SI (sacroiliac joint on back of pelvis), the buttock, or greater trochanter (side of hip).
It is often confused with other sources of pain, such as hip flexor tendinitis, pain from the back (disc or spine), testicular pain, sports hernia.

Evaluation

Your doctor will ask about your hip (your symptoms and how the pain started, for how long, etc) and perform an examination. Your doctor will move your hips and legs in different positions to assess your range of motion and evaluate the positions where your hip hurts.

To confirm a diagnosis you will likely get XRays of your hip. Often, you may undergo a special type of magnetic resonance imaging (MRI) called magnetic resonance arthrography (MRA).

Magnetic resonance arthrography (MRA) is a noninvasive, non-irradiating imaging technique that uses a magnetic field and radio waves to evaluate your hip. While XRays show bones well, the MRI is particularly good at showing the non-bony structures of the body, such as the labrum and articular carilage. Further, while XRays are like looking at shadows, the MRI allows evaluation of the tissues around the hip in slices (like slices of bread as opposed to seeing the whole loaf without what is inside) and allows viewing from different views. During magnetic resonance arthrography, dye (contrast material) is injected into the joint space to help make images more clear. Frequently, local anesthetic (numbing medicine) is added to the contrast material to help determine if the pain is coming from inside the joint. The MRI will also help eliminate certain causes of non FAI hip pain including avascular necrosis (dead bone) and tumors.

Sometimes your physician may order a CT or CAT scan. This study can help understand the exact shape of the bones of the hip, but not essential to the diagnosis of FAI. It is a balance of the relatively large amount of radiation to the pelvis/reproductive region due to the CT scan with the amount of information obtained. This concern of additional radiation is especially important when 3-D CT scans are performed, which are particularly good at giving the doctor an very realistic perspective of the shape of the bone.

Treatment

The underlying problem with FAI is a bony abnormality. This bony shape will not change with physical therapy or rest. However, the shape of the bones itself do not cause pain. Other structures that can be injured with FAI, such as the labrum, or articular cartilage may cause the pain in the hip. Neither the labrum or articular cartilage have much capacity to heal, but sometimes these structures, even when injured do not cause pain or other symptoms. Thus, for those with symptoms the initial treatment may involve rest and rehabilitation, while those that have symptoms that persist, arthroscopic surgery may be needed. The long term sequelae of FAI has not been conclusively proven, but there is much evidence that it may be a major cause of premature arthritis of the hip. It has also not been proven that surgery for FAI will prevent arthritis. However, removing the offending bone may help reduce further injury to the joint, while also reducing symptoms. The results of surgery are clearly better when there is no articular cartilage damage. Thus, most physicians familiar with this problem often recommend early surgical intervention for symptomatic patients with FAI.

Non-Operative

Nonoperative management of FAI can be attempted. However, it involves a change in lifestyle from active to less active and a commitment to maintaining hip strength. A good physical therapy program focusing on hip strengthening instead of stretching may be beneficial. Stretching associated with yoga and sometimes physical therapy may make the symptoms worse. Activity modification should involve avoiding activities that take the hip through extreme or full ranges of motion. Anti-inflammatory medications can also be attempted.

Surgery

Surgery for FAI can be performed using hip arthroscopy or open surgery. In hip arthroscopy, the hip is distracted and an arthroscope (a videocamera about the size of a pen) is used to look in the joint to see and treat damage that is found using two to five incisions that are about ¼” in size. Often, all of the components of FAI such as the labral tear, damaged articular cartilage, and bony changes between the ball and socket can be treated with the assistance of the arthroscope. Repair of a torn labrum as well as stimulating new cartilage growth (microfracture) are often possible with the arthroscopic approach. A hip arthroscopy involving labral debridement (no repair) and no bony decompression usually takes less than one hour. A hip arthroscopy involving labral/cartilage repair and FAI decompression usually takes about two hours. This is done as an outpatient surgery (go home the same day). This is the way it is performed here at Stanford.

The open surgical hip dislocation involves a single long incision (approximately 7 to 10 inches), cutting a bone of the upper thigh, and dislocation of the ball from the socket exposing all parts of the joint. This exposure allows treatment of labral tears and abnormal contact between the ball and socket. The open approach can typically be done in a few hours. Pateints usually stay in the hospital for several days after this approach.

Recovery from Surgery

The patient is on crutches after surgery. Recovery time from most FAI surgical procedures is 4 – 6 months to full, unrestricted activity. Your postoperative activity level will depend on your surgeon’s recommendation, the type of surgery performed, and the condition of the hip joint at the time of surgery.

FREQUENTLY ASKED QUESTIONS AND ANSWERS

Why does it occur?
Answer: No one knows if FAI is a condition that begins at birth (congenital) or develops during periods of growth (acquired). However, even though you may have the bony changes of FAI, you may not have symptoms unless you participate in activities that require large hip motions or motions at the extremes.

How did I get it?
Answer: Some experts believe that significant athletic activity before skeletal maturity increases the risk of FAI, but no one really knows. Contact and collision sports (i.e., football) are associated with Cam impingement.

Do I have arthritis if I have FAI?
Answer: Not necessarily. However, first evaluation is done with x-rays which would show significant arthritis. MRI scans may show loss of articular cartilage, but frequently, there is significant loss of articular cartilage inside the hip that is not seen on MRI or Xray.

Do I have FAI if my hip MRI was read as “Normal”?
Answer: At times, an MRI will be read as “Normal” but the clinical history, physical exam, and plain x-ray films indicate FAI. In this situation, further investigation with an arthroscopic surgery may be needed.

My diagnosis was made after many years of hip pain, is that common?
Answer: FAI was first described in the english literature in 1999. As such, it is quite new and physicians are still hearing about it for the first time. In fact, many physicians have heard of a hip labral tear but have not heard of FAI. In general, most patients with hip pain due to labral tears or FAI often have seen multiple doctors and have significant delays in diagnosis (on the average, almost 2 years) before the correct diagnosis and treatment is instituted.

I’ve been treated for a labral tear with a hip arthroscopy. Could I have FAI, too?
Answer: Hip labral tears are associated with FAI. If you have had your labral tear treated and are still having pain, you may have FAI. The success of labral surgery is much less if there is untreated FAI. Further, residual impingement may lead to further loss of hip cartilage.

Can my other hip be involved as well?
Answer: Yes, it is possible for both hips to have FAI.

I don’t have any pain, what should I do?
Answer: Some patients with FAI complain of stiffness and loss of hip range of motion without any significant pain. Progressive loss of motion in the hip can be associated with ongoing FAI. Speak to your physician about your options.

Is this the same condition as DDH (developmental dysplasia of the hip)?
Answer: DDH or developmental dysplasia of the hip is a different diagnosis than FAI. DDH generally refers to too little coverage of the ball by the socket. FAI generally refers to too much coverage of the ball by the socket. Both DDH and FAI are associated with labral tears and articular cartilage damage.

What type of doctor can treat it?
Answer: If one has a diagnosis of FAI or suspects FAI, one should be evaluated by an orthopaedic specialist who is adept in treating hip disorders. Your physician should have experience with either open surgical hip dislocation or hip arthroscopy.

How long can I wait before seeking treatment?
Answer: Typically, FAI that produces symptoms for more than 2 months should be evaluated for surgical treatment. A longer wait may lead to furterh damage of the joint.

Can I be treated with an injection of medicine or good physical therapy?
Answer: Generally, FAI is a chronic condition that does not typically respond well to hip injections or physical therapy over the long term. However, a good physical therapy program focusing on hip strengthening instead of stretching may be beneficial. The key is that stretching may make the symptoms worse.

If I don’t have surgery, could I ever play sports again? If I rested for a while and felt better, could I cause more damage if I go back to my normal activities?
Answer: Non-operative treatment is always an option. If you follow a conservative treatment plan of active relative rest, stretching and strengthening, the pain and swelling may go down. If however, you have a labral tear or articular cartilage damage, these generally do not heal. Usually, the pain and swelling will return once you return to your chosen sporting activity.

Can I just wait a few years and have a total hip replacement?
Answer: Yes. The postoperative rehabilitation of a total hip replacement (total hip arthroplasty) is significantly shorter than an FAI procedure. However, hip replacements have a limited longevity, especially for younger patients. The same is true for a hip resurfacing type of procedures. Both the resurfacing arthroplasty and the total hip arthroplasty involve removal of the damaged joint surfaces and replacement with man-made materials (i.e., metal, plastic, ceramic) which are subject to wear. The wear results in joint debris which may shorten the life of the replacement. Once your hip replacement fails or wears out, your revision hip replacement does not last as long or work as well as your first and has a higher complication rate. And each subsequent replacement will not work as well or last as long as the one before and has a higher complication risk associated with it. As such, the goal is to put off having a joint replacement as long as possible, so that the one you finally get is the only one you need. Once you go down the path of hip replacement, there is no turning back.

How long would I be out of work?
Answer: Sedentary work can be resumed in one to two weeks. Labor intensive work maybe 12 – 20 weeks.

How long until I could drive?
Answer: Once you have good control of your leg and you are not taking any narcotic medications. This is usually 1-2 weeks

Would there be any rehabilitation involved?
Answer: Yes, though the amount and duration depends on what is done for your hip.

How long before I can exercise?
Answer: Stationary bike is part of the recovery process and may begin as soon as a few days after surgery. However, you are not to go into a swimming pool or get the wounds wet until your sutures are removed (usually 10 – 14 days). You may have to wait 2 – 10 weeks before being able to put weight on the operative leg depending on what needed to be done in the hip.

During surgery, would I be put under complete anesthesia?
Answer: Yes but you don’t need to. Spinal anesthesia is possible but not recommended.

Would I have crutches after surgery, how long would I use them?
Answer: Yes, though how long depends on what is done. If only bone is removed from your hip you may be on crutches for 2 weeks and if we have to try to get new cartilage to grow in your hip, then you may need to be on crutches for 6 - 10 weeks. Your rehabilitation progress will determine the weaning process as well as the extent of the tear and/or associated problems.

Is it possible that I have damaged articular cartilage (the cartilage that lines the joint surfaces)? Would you find this out prior to surgery or during?
Answer: Yes. The ability to detect articular cartilage injury before surgery still is not perfected, even with MRI. As hip arthroscopy techniques become more refined the incidence and ability to treat cartilage problems are both increasing. The presence of cartilage lesions (articular cartilage) is identified at the time of surgery and is treated by debridement (cleaning it up) and/or microfracture (where we poke holes in the bone to stimulate growth of a scar cartilage to replace the lost articular cartilage).

Will surgery prevent further damage to the ligament/cartilage? What are the changes of reoccurrence?
Answer: Surgery is done to treat your symptoms, usually groin pain, as well as to reduce worsening of the tear. There is no guarantee that a recurrent tear will not occur nor is there any guarantee that surgery will prevent arthritis. Recurrent tears are, however, unusual. Also, it is not known whether removing the torn cartilage will prevent further damage.

What are the main risks of Arthroscopic FAI treatment?
Answer: Complications from FAI hip surgery are uncommon but include the following:

DVT (blood clot)
Infection
Femoral neck fracture (broken hip)
AVN of the femoral head (dead bone)
Heterotopic ossification (abnormal bone formation in soft tissues)
Nerve injury (Sciatic, LFCN, Pudendal)
Scarring/Adhesions
Continued Pain
Damage to the cartilage

How much could the pain subside without surgery?
Answer: The pain may come and go, but likely would not decrease significantly or for an extended period of time, especially if you continue with sporting activity, without surgical intervention.

What can I do to put less tension on the hip? Are there any exercises, stretches or devices to use to help me sleep better?
Answer: All activities, even rolling over in bed can cause hip stresses. The most important exercises are ones which create normal flexibility about your hip and normal, protective strength. In some situations, activities that require extremes in your range of motion of your hip, may cause the pinching of tissues, resulting in damage to the torn labrum and articular cartilage.

What is the percentage that I could feel worse after the surgery?
Answer: Feeling worse after surgery is always a possibility, however, the likelihood of that is very small.

Is there anything I can do to give me any relief now? Ice and heat seem to only do so much.
Answer: Pain medications can be ordered but are not recommended prior to surgery. Non-steroidal anti-inflammatories (Advil) and Tylenol mixed together are often better than either alone. However it is recommended that you not take anti-inflammatory medications for the 2 weeks prior to surgery.

Labral Tear

The hip labrum is a fibrous cartilage that is similar to the meniscus in the knee. This cartilage runs on the edge of the bony rim of the acetablum (the hip socket). The labrum deepens the socket adding stability to the hip joint, helps in the nutrition of the joint cartilage and helps cushion the joint itself.

Causes

Labral tears may be the result of trauma, degeneration or occur as a result of bony pinching. Degenerative tears occur after years of repeated minor injuries, “drying out” of the cartilage as we age and/or may be associated with arthritis of the hip. Traumatic injuries can occur with any sporting activity that causes rapid hip motion especially associated with sudden stops and turns such as football, soccer, tennis, rugby, baseball or softball or with extremes of motion, such as dance, rowing, golf and martial arts. Excessive bone on the acetabulum (hip socket) or on the femoral neck (below the ball of the joint) may lead to pinching and / or tearing of the labrum. Occasionally, a traumatic injury that causes a labral tear may be trivial and forgotten by the time of the diagnosis.

Symptoms

There may be no pain or symptoms
Pain or aching (usually located at the inner hip, or groin area)
A locking, clicking or “catching” sensation within the joint
Stiffness in the joint
Little-to-no-pain during normal daily activities

Evaluation

To confirm a diagnosis of a hip labral tear, you may undergo a special type of magnetic resonance imaging (MRI) called magnetic resonance (MR) arthrography.

Magnetic resonance arthrography (MRA) is a noninvasive, non-irradiating imaging technique that uses a magnetic field and radio waves to evaluate your hip. While XRays show bones well, the MRI is particularly good at showing the non-bony structures of the body, such as the labrum. Further, while XRays are like looking at shadows, the MRI allows evaluation of the tissues around the hip in slices (like slices of bread as opposed to seeing the whole loaf without what is inside) and allows viewing from different angles. During magnetic resonance (MR) arthrography, dye (contrast material) is injected into the joint space to help make images more clear. Frequently, local anesthetic (numbing medicine) is added to the contrast material to help determine if the pain is coming from inside the joint.

Treatment

The labrum does not have a blood supply to it that allows healing, but sometimes people with a torn labrum do not have any symptoms. Thus, for those with symptoms that are the result of a labral tear the initial treatment involves rehabilitation and those that have symptoms that persist, arthroscopic surgery may be indicated. The long term sequelae of labral tears is not known though it is assumed they can lead to arthritic progression. If the tear is the result of abnormal bone formation about the hip, hip arthroscopy is recommended to remove the causative factor (the excessive bone) of the labral tear, in addition to removing the labral tear.

Non-Operative

A course of physical therapy may be initiated along with activity modification. This includes exercises to help with strengthening of the hip and sometimes to help stretch the muscles about the hip.

Corticosteroid injections into the hip joint can help provide pain relief and reduce joint inflammation. These injections are performed under X-ray or ultrasound guidance.

Alternative Treatment Options

Glucosamine
Hyaluronic Acid
Non-steroidal Anti-inflammatory Medications (NSAIDs)

Operative

Arthroscopic surgery to repair or remove the torn tissue is usually recommended when symptoms do not allow a continuation of desired activities. The procedure is done on an outpatient basis (go home the same day) and full recovery normally occurs by eight to 12 weeks. If excessive bone is removed or if additional procedures need to be done at the same time, then rehabilitation and return to sports activities may be longer.

FREQUENTLY ASKED QUESTIONS AND ANSWERS

How long would I be out of work?
Answer: Sedentary work can be resumed in one to two weeks. Labor intensive work maybe eight to 12 weeks.

How long until I could drive?
Answer: Once you have good control of your leg and you are not taking any narcotic medications. This is usually 1-2 weeks.

Would there be any rehabilitation involved?
Answer: Yes, though the amount and duration depends on what is done for your hip.

How long before I can exercise?
Answer: Stationary bike and elliptical trainers are a part of the recovery process and may begin as soon as one week. However, you are not to go into a swimming pool or get the wounds wet until your sutures are removed (usually 10 – 14 days).

During surgery, would I be put under complete anesthesia?
Answer: Yes but you don’t need to. Spinal anesthesia is possible but not recommended.

Would I have crutches after surgery, how long would I use them?
Answer: Yes, though how long depends on what is done. If the procedure only involves removal of torn labral tissue, then you only need to be on crutches as long as you are limping (about 1 week). If bone is removed from your hip you may be on crutches for 2 weeks and if we have to try to get new cartilage to grow in your hip, then you may need to be on crutches for 8 weeks. Your rehabilitation progress will determine the weaning process as well as the extent of the tear and/or associated problems.

If I don’t have surgery, could I ever play soccer or other active, aggressive sports again? If I rested for a while and felt better, could I cause more damage if I go back to my normal activities?
Answer: Non-operative treatment is always an option. If you follow a conservative treatment plan of active relative rest, stretching and strengthening, the pain and swelling may go down. If however, you have a labral tear, these generally do not heal. Usually, the pain and swelling will return once you return to your chosen sporting activity.

Will surgery prevent further damage to the ligament/cartilage? What are the changes of reoccurrence?
Answer: Surgery is done to treat your symptoms, usually groin pain, as well as to reduce worsening of the tear. There is no guarantee that a recurrent tear will not occur. Recurrent tears are, however, unusual. Also, it is not known whether removing the torn cartilage will prevent further damage.

What is the percentage that I could feel worse after the surgery?
Answer: Feeling worse after surgery is always a possibility, however, the likelihood of that is very small.