FAI & Labral Tear

Anatomy

The hip joint is the junction between the femur (thigh) bone and the pelvis and is referred to as a ball and socket joint. The head of the femur is the ball, and the socket is referred to as the acetabulum of the pelvis. The neck of the femur attaches the femoral head to the rest of the femur. Articular cartilage covers the femoral head and acetabulum allowing the bone to glide easily with one another. The labrum is a ring of fibrocartilage that goes about 270° along the rim of the acetabulum and helps to add stability to the hip by providing a suction seal affect. 

What is FAI?

Femoroacetabular impingement (FAI) is a term given to abnormal bony contact between the femoral neck and the rim of the acetabulum. The impingement is cause by abnormal bony morphology. If excess bone is present on the femoral neck it is referred to as cam impingement. If the excess bone is present along the rim of the acetabulum it is referred to as pincer impingement. Most patients with FAI have both cam and pincer morphology.

The abnormal bony contact can lead to pinching of the labrum and eventually lead to a labral tear. This can lead to some instability of the hip and if left untreated, may progress to osteoarthritis (a loss of articular cartilage).

FAI starts to develop during our rapid peak growth years. As bone is stressed, it often lays down more bone leading to more impingement. Repetitive motions involving positions of impingement (deeper hip flexion) make patients susceptible to developing FAI and labral tears. Activities involving repetitive hip flexion and athletic such as hockey, lacrosse, throwing athletes, hurdlers, football players, and weight lifters are examples of patients who might be more prone to develop FAI. However, FAI can also result from trauma or other genetic conditions involving the hip.

Symptoms of FAI and Labral Tear

• Pain in the front part of the hip (groin)
• Pain with activity especially with deeper flexion of the hip
• Mechanical symptoms of catching, clicking, locking, or feeling like something is stuck
• Reduced hip motion
• Can lead pain in the low back pain, sacroiliac (SI) joint, pubic symphysis, and may have an association with sports hernias
• Can lead to tendonitis of muscles that span the hip joint including adductors, hamstring, iliotibial (IT) band, and posterior musculature

Diagnosing FAI and Labral Tear

A thorough patient history and physical exam can help to identify patients with FAI and labral pathology and imaging studies including x-rays and MRI are used to help confirm the diagnosis

Treatment for FAI and Labral Tear

• Activity modifications and rest
• Anti-inflammatory medications
• Physical or pelvic floor therapy
• Injections

• Core decompression: For younger patients without collapse of the femoral head. Helps to decompress the area of dead bone and restore blood flow to the area allowing for new bone growth
• Total hip replacement