Understanding Hip Impingement: Causes, Symptoms, and Treatment Options

Hip impingement, also known as femoro acetabular impingement (FAI), is a condition that occurs when the ball-like top of your thigh bone (femur) doesn't fit smoothly into the cup-like socket of your pelvis (acetabulum). This can cause pain and decreased range of motion in your hip joint, and if left untreated, it may lead to early osteoarthritis, especially in people under 40 years old.

What Causes Hip Impingement?

There are two main types of hip impingement:

1. Cam impingement: This occurs when the ball at the top of the femur is not shaped normally, causing it to jam in the socket when the hip is bent.

2. Pincer impingement: This happens when the front rim of the socket (acetabulum) sticks out too far, causing the neck of the femur to bump into it during normal hip movement.

In some cases, both the ball and socket may be affected. Other conditions that can cause hip impingement include Legg-Calve-Perthes disease, slipped capital femoral epiphysis, and coxa vara.

Symptoms of Hip Impingement

Hip impingement may not cause symptoms in its early stages, but as the condition progresses, you may experience:

• Pain in the groin, especially when walking or flexing the hip

• Decreased range of motion in the hip

• Pain when sitting for long periods or walking up a hill

• Pain at night or when walking on flat ground (indicates cartilage breakdown and osteoarthritis)

Diagnosing Hip Impingement

To diagnose hip impingement, your doctor will consider your symptoms, perform a physical exam, and order imaging tests such as:

• X-rays to show irregularities in the shape of the ball, thigh bone, or excess bone around the socket rim

• MRI to reveal fraying or tears of the cartilage and labrum (cartilage along the socket rim)

• CT scan to help determine if surgery is necessary

Treatment Options for Hip Impingement

Treatment for hip impingement usually begins with non-surgical methods, including:

• Resting the affected hip

• Modifying activities to avoid painful movements

• Exercising to strengthen muscles that support the hip (as recommended by a doctor or physical therapist)

• Taking anti-inflammatory and pain medications

If these treatments do not relieve pain, your doctor may recommend hip impingement surgery. The type of surgery depends on the cause of the impingement and the extent of cartilage damage. In many cases, arthroscopic surgery can be performed using small incisions and a lighted scope. Early intervention increases the chances of a complete recovery, but even with cartilage damage, surgery may still reduce pain and improve range of motion.

In severe cases of cartilage damage, hip replacement may be the only effective treatment. However, experimental treatments like injecting parts of your own blood into the joint to stimulate cartilage growth show promise for the future.