How is FAI diagnosed?
Impingement Test
As part of the physical examination, your doctor will likely conduct the impingement test.
For this test, your doctor will bring your knee up towards your chest and then rotate it inward towards your opposite shoulder. If this recreates your hip pain, the test result is positive for impingement.
Imaging Tests
Your doctor may order imaging tests to help determine whether you have FAI.
X-rays. These provide good images of bone, and will show whether your hip has abnormally shaped bones of FAI. X-rays can also show signs of arthritis.
Computed tomography (CT) scans. More detailed than a plain x-ray, CT scans help your doctor see the exact abnormal shape of your hip.
Magnetic resonance imaging (MRI) scans. These studies can create better images of soft tissue. They will help your doctor find damage to the labrum and articular cartilage. Injecting dye into the joint during the MRI may make the damage show up more clearly.
Local anesthetic. Your doctor may also inject a numbing medicine into the hip joint as a diagnostic test. If the numbing medicine provides temporary pain relief, it confirms that FAI is the problem.