Hip MRI — Labral Tears, Impingement & Avascular Necrosis

Hip MRI

From young athletes with groin pain to the occult fracture missed on X-ray, MRI answers the hip questions plain films can’t.

Impingement & labrum

MRI assesses femoroacetabular impingement — cam (femoral head-neck bump) and pincer (acetabular over-coverage) morphology — and the acetabular labral tears that result, a common cause of young-adult groin pain and a target for arthroscopy.

MR arthrography improves labral tear detection and is often preferred when hip arthroscopy is being considered.

Avascular necrosis

MRI is the most sensitive test for avascular necrosis (osteonecrosis) of the femoral head, detecting it before X-ray change or collapse — the classic serpentine “double-line sign.” Early diagnosis matters for joint-preserving treatment. Risk factors include steroids, alcohol and prior fracture.

Occult & stress fractures

In an older patient with hip pain after a fall and a normal X-ray, MRI reveals occult neck-of-femur fractures (marrow oedema/fracture line) that would otherwise be missed. It also detects stress fractures in athletes and sacral insufficiency fractures.

Reference: Sutter R, Pfirrmann CWA. Update on femoroacetabular impingement imaging. and MRI of osteonecrosis reviews.

Educational summary for clinicians; protocol choice follows local practice. Not medical advice.