The flexion, abduction, and external rotation (FABER) test is an orthopedic screening to check for problems with the scaroiliac joint, including the hips and sacrum of the pelvis. A medical professional can conduct the non-invasive test in a clinic or hospital setting, and it is very rapid. Other diagnostic tests a healthcare professional may use can include medical imaging studies of the joint to check for inflammation and malformations. People may also refer to this technique as Patrick's test, and it is usually part of a routine musculoskeletal exam.
In the FABER test, the medical professional has the patient lie on his back on a table. In this face-up position, the patient's arms and legs should relax on the surface of the table. The medical professional takes the involved leg and bends it while also rotating it so the inside of the knee faces up. He or she places the foot on the opposite knee. With the leg in position, the medical professional can apply gentle pressure to the opposite side of the hip to keep the pelvis in place, while pressing down on the knee to push the bent leg towards the table.
Healthy patients should not experience pain or strain during this test, and the knee will slowly drop to the surface of the table. If a patient has a joint problem, it can cause pain in the groin, buttocks, pelvis, or back. The location of the pain during the test is an important clue about what part of the body is involved. The healthcare professional can manipulate the leg in other ways to collect more feedback and information.
Using the outcome of a FABER test and a patient interview, the medical professional can start to explore possible locations and causes of joint pain. X-rays and other images can provide information about the extent of inflammation or injury. Together, all of this material will help the orthopedist develop an appropriate treatment plan. This may be as simple as rest to allow a sore area to recover, or could involve surgery to treat serious inflammation or deformation of the joint.
During the test, it is very important to anchor the pelvis so the opposite side does not ride up as the healthcare professional pushes the knee down. People doing the test at home to check for joint problems should ask for help to make sure they do it correctly. If the pelvis can shift, it may mask pain because the joint will not be stretched during the examination. This will result in a false negative.