Femoral Acetabular Impingement (FAI) Treatment: Get Back to Pain-Free Movement

Femoroacetabular impingement (FAI) is a clinical condition characterized by abnormal contact between the femoral head and acetabular rim during hip motion. This mechanical disorder typically affects young, active adults and can lead to significant hip pain and functional limitations.

There are three primary types of FAI: cam, pincer, and mixed. Cam impingement results from an abnormal femoral head-neck junction, creating an aspherical shape that causes abnormal contact with the acetabulum during hip flexion and internal rotation. Pincer impingement occurs due to excessive acetabular coverage of the femoral head, leading to early contact during hip motion. Mixed impingement combines both cam and pincer morphologies.

Common presenting symptoms include groin pain, particularly with hip flexion and internal rotation. Patients often report pain with prolonged sitting, getting in and out of vehicles, and during athletic activities. The pain typically develops gradually and may be accompanied by clicking, catching, or locking sensations in the hip.

Physical examination typically reveals limited hip internal rotation and flexion. The FADIR test (Flexion, Adduction, Internal Rotation) often reproduces symptoms. The FABER test (Flexion, Abduction, External Rotation) may also be positive. Impingement testing is typically positive, reproducing the patient’s familiar pain.

Diagnostic imaging begins with plain radiographs, including anteroposterior pelvis and lateral hip views. Key radiographic findings include alpha angle measurement for cam morphology and center-edge angle for pincer morphology. MRI arthrography provides detailed evaluation of labral pathology and articular cartilage damage, which commonly accompany FAI.

Initial treatment focuses on conservative measures including activity modification, physical therapy, and anti-inflammatory medications. Physical therapy emphasizes core strengthening, hip mobility, and modification of aggravating activities. When conservative treatment fails, surgical intervention may be considered.

Arthroscopic surgery is the primary surgical approach for FAI. The procedure aims to address both bony abnormalities and associated soft tissue pathology. Cam lesions are resected to restore normal femoral head-neck offset, while pincer lesions are addressed through acetabular rim trimming. Associated labral tears are repaired or debrided as needed.

Post-operative rehabilitation typically involves a structured protocol lasting 4-6 months. Initial focus is on protected weight-bearing and gentle range of motion exercises, progressing to strengthening and eventual return to sport-specific activities.

Outcomes following appropriate treatment are generally favorable, with most patients experiencing significant improvement in pain and function. However, the presence of advanced articular cartilage damage at the time of diagnosis may predict poorer outcomes. Early recognition and appropriate management are crucial to prevent progression of joint damage and development of early osteoarthritis.

Prevention strategies include proper training techniques, avoiding excessive hip flexion activities, and maintaining appropriate hip strength and flexibility. Athletes in high-risk sports should be educated about early recognition of symptoms and proper biomechanics.