Understanding Hip Anatomy and Impingement

The hip is a ball-and-socket joint made up of the femoral head (the rounded top of the thighbone) and the acetabulum (the hip socket in the pelvis). The labrum, a ring of cartilage around the socket, helps stabilize the joint and allows smooth movement. Soft tissue structures, including the labrum and articular cartilage, are essential for proper joint mechanics.

In a healthy hip, the ball and socket move freely without friction. In femoroacetabular impingement, extra bone growth on the femoral head, the acetabulum or both causes abnormal contact during movement. This repeated contact can damage the cartilage and labrum.

Over time, this damage can result in:

• Labral tears
• Cartilage breakdown
• Hip stiffness
• Progressive joint degeneration

Types of Femoroacetabular Impingement

The types of hip impingement are categorized based on the location and nature of bony abnormalities in the hip joint. There are three main types of femoroacetabular impingement.

Cam Impingement

Cam impingement occurs when the femoral head is not perfectly round. The irregular shape prevents smooth movement within the socket and can damage the cartilage and labrum.

Cam impingement is more common in younger, active individuals and athletes. Conditions such as slipped capital femoral epiphysis can contribute to cam-type deformities.

Pincer Impingement

Pincer impingement occurs when extra bone extends over the rim of the acetabulum. This overcoverage can pinch the labrum between the rim and the femoral head, leading to labral damage.

Combined Impingement

Many patients have features of both cam and pincer impingement. Identifying the exact type helps guide treatment decisions.

Causes and Risk Factors

Femoroacetabular impingement often develops during adolescence as the bones mature. Certain athletic activities that involve repetitive hip motion may increase the risk of developing FAI.

Risk factors may include:

• High-impact sports
• Repetitive hip flexion movements
• Structural hip abnormalities
• Family history of hip conditions

Young athletes who participate in sports involving frequent twisting, squatting or deep hip flexion may be more likely to develop symptoms.

Symptoms of Hip Impingement

Symptoms of femoroacetabular impingement may develop gradually. In early stages, pain may be mild and mistaken for a muscle strain.

Common symptoms include:

• Groin pain, especially with activity
• Pain or stiffness in the groin or front of the thigh
• Pain that may extend to the outer hip or buttocks
• Pain with prolonged sitting
• Hip stiffness
• Decreased range of motion
• Pain when bending the hip past 90 degrees
• Clicking, catching or locking sensations

Pain often worsens with activities such as squatting, pivoting, climbing stairs, athletic participation or prolonged sitting.

How FAI Is Diagnosed

Getting hip impingement diagnosed starts with a thorough history and careful physical examination by an orthopedic hip specialist.

At OrthoTexas, evaluation typically includes:

Comprehensive Clinical Evaluation

• Review of medical history and symptoms
• Physical exam focusing on hip range of motion
• Specific impingement tests to reproduce symptoms

Imaging Studies

• X-rays to evaluate the shape of the femoral head and acetabulum and identify bony abnormalities
• MRI or MRI arthrogram to evaluate soft tissue structures such as the labrum and cartilage
• CT scans, including 3-D imaging when needed, to further define bony anatomy

Imaging may also help identify impingement sources outside the joint, such as the anterior inferior iliac spine. These studies help determine the severity of impingement and whether labral tears or cartilage damage are present.

Non-Surgical Treatment for Femoroacetabular Impingement

Hip impingement treatment often begins with nonsurgical care, particularly when symptoms are mild.

Nonsurgical treatment options may include:

• Activity modification
• Anti-inflammatory medications
• Targeted physical therapy
• Core and hip strengthening exercises
• Image-guided injections in select cases

Physical therapy is often a key component of treatment. It focuses on improving hip stability, strengthening surrounding muscles and correcting movement patterns to reduce stress on the joint.

Conservative treatment is typically recommended for several months before considering surgical intervention.

Surgical Treatment for FAI

If symptoms persist despite conservative care, surgical treatment may be recommended. The goal of surgery is to repair damaged tissue and correct the abnormal bone shape to reduce impingement and prevent further joint damage.

Hip Arthroscopy for Femoroacetabular Impingement

Hip arthroscopy is the most common surgical procedure for FAI. It is minimally invasive and typically performed on an outpatient basis.

During the procedure:

• Small incisions are made around the hip
• A camera (arthroscope) is inserted into the joint
• Specialized instruments reshape excess bone
• Damaged labral tissue may be repaired or reconstructed

By correcting the abnormal bone shape and addressing labral damage, hip arthroscopy can reduce pain and improve joint mechanics.

Hip Replacement for Advanced FAI

In cases where FAI has caused significant joint damage and advanced arthritis, hip replacement may be recommended. This procedure replaces the damaged joint surfaces to relieve pain and restore function.

A hip specialist will carefully evaluate the severity of joint damage and overall health before recommending hip replacement.

Recovery After FAI Surgery

Recovery depends on the extent of correction and whether labral repair was performed.

Rehabilitation typically includes:

• Temporary use of crutches
• Structured physical therapy
• Gradual return to activity

Athletes may require several months before returning to full sports participation. Early rehabilitation focuses on protected motion to support proper healing.

Complications of Untreated FAI

Leaving femoroacetabular impingement untreated can accelerate cartilage damage and increase the risk of osteoarthritis. Ongoing impingement may lead to worsening labral tears and progressive joint degeneration.

As joint damage progresses, daily activities may become increasingly difficult and in severe cases, joint replacement surgery may eventually be required.

Early evaluation and treatment are important to help preserve long-term hip function.

Expert Hip Care at OrthoTexas

Femoroacetabular impingement can significantly affect mobility and quality of life. OrthoTexas provides advanced diagnostic and treatment options, combining minimally invasive techniques with personalized care to help patients return to active living.