An Overview: Hip Impingement

Dr. Danyal H. Nawabi, Orthopedic Surgeon, offers his expertise on hip impingement.

What is hip impingement?

Hip impingement, formally known as femoroacetabular impingement (FAI), is a common cause of groin pain in the young, athletic population. It also causes limitation of hip motion and is a well-established cause of osteoarthritis (OA) of the hip. The hip is a ball and socket joint that is formed by the ball at top of the thigh bone (femur) and the socket in the pelvis (acetabulum). The hip joint relies on a perfect spherical morphology for normal motion. FAI occurs due to abnormal contact between the femoral head (ball) and acetabular (socket) rim because of a misshapen non-spherical head (ball) articulating with a spherical acetabulum (socket). This results in injury to the labrum on the acetabular rim and also the cartilage in the acetabulum which, if left untreated, eventually leads to osteoarthritis.

How is it diagnosed?

Making the correct diagnosis is critical in the field of hip preservation. There are many causes of groin pain in a young active adult, and therefore the diagnostic process is complex. It is important for the physician to perform a thorough clinical assessment followed by specialized investigations. These include specific X-rays, MRI, CT scans with 3D modeling, diagnostic injections, and in some cases dynamic computer simulations.

What is involved in the procedure?

Treatment of FAI is targeted at addressing the bony abnormalities, either on the femoral or acetabular sides, to restore the hip joint to its normal shape. This eradicates the abnormal contact that occurs between the femur and acetabular rim, resulting in pain relief, increased motion, and prevention of further damage to the acetabular labrum and cartilage. At the same time, the damaged labrum can also be repaired. The entire procedure can be performed either by hip arthroscopy or open surgical hip dislocation.

What are the risks of surgery?

FAI surgery can be performed arthroscopically or through open approaches. The risks of arthroscopy include scuffing of the cartilage, nerve injury, fluid collection in the abdomen, thrombosis, infection, and heterotopic bone formation. The risks unique to surgical hip dislocation include trochanteric non-union, painful hardware, and wound complications. Although the overall risk of these problems is low, these surgeries are technically demanding and therefore the risks can be minimized by getting treatment from a well-trained surgeon at a high-volume center.

What are some forms of nonsurgical treatment?

Non-surgical treatments include physical therapy, active release therapy, acupuncture, non-steroidal anti-inflammatory drugs (NSAIDs), cortisone injections and viscosupplementation injections.

Dr. Danyal H. Nawabi is an Orthopedic Surgeon on the Sports Medicine Service at Hospital for Special Surgery. He specializes in the surgical treatment of sports injuries and arthritis of the hip and knee joints. He completed his fellowship training in sports medicine and joint replacement at Hospital for Special Surgery.

Topics: Orthopedics
The information provided in this blog by HSS and our affiliated physicians is for general informational and educational purposes, and should not be considered medical advice for any individual problem you may have. This information is not a substitute for the professional judgment of a qualified health care provider who is familiar with the unique facts about your condition and medical history. You should always consult your health care provider prior to starting any new treatment, or terminating or changing any ongoing treatment. Every post on this blog is the opinion of the author and may not reflect the official position of HSS. Please contact us if we can be helpful in answering any questions or to arrange for a visit or consult.


  1. I had a hip arthroscopy 6 weeks ago. Although the MRI showed a complete tear of the gluteus minimus, no tear was found. There was a significant amount of inflammation which the surgeon removed/cleaned out. I am still in terrible pain which I didn’t expect this far out.
    I started PT but the Dr. advised taking a few weeks off to let the pain die down. Is it normal to have this much pain at this point?
    I know there really is no normal with this procedure but do people experience this?
    Should I be worried or is there still hope?

    1. Hi Alan, thank you for reaching out. It would be best for you to consult with your treating physician who is familiar with your medical history so that they can determine the best course of treatment. If you wish to receive care at HSS, please contact our Physician Referral Service at 877-606-1555 for further assistance.

  2. i have a torn labrum with all these symptons-and live in connecticut-can i be treated by you in your facility?

    1. Hi Vin, if you wish to receive care at HSS, please contact our Physician Referral Service at 877-606-1555 for further assistance.

  3. i have had a hip replacement and have had pain in my lower back since the surgery on the same side as the hip.nobody can figure out the cause. i only have the pain when i stand or walk i do not have pain when i am sitting. i do not want to wind up in a wheelchair.

    1. Hi Rona, thanks for reaching out. It is best for you to seek an in-person consultation with a treating physician so they can better advise. If you wish to receive care at HSS, please contact our Physician Referral Service at 877-606-1555 for further assistance.

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