How to diagnose Femoroacetabular Impingement Syndrome (FAIS)

The term ‘femoroacetabular impingement syndrome’ was introduced to reflect the central role of patients' symptoms in the disorder.

To reach a diagnosis, patients should have the appropriate symptoms of FAIS, positive clinical signs and imaging findings to corroborate the diagnosis. 

Symptoms the patient may experience day-top-day include:

• Groin pain (most common symptom)

• Occasionally posterior hip pain (buttock pain)

• Pain may also refer to the lateral hip, thigh, lower back, or knee

• Pain is often provoked by deep hip flexion, twisting, pivoting, or changing direction

• Catching, clicking, or locking sensations

• A feeling that the hip or leg gives way, or buckles

• Stiffness

• Limited range of motion, particularly internal rotation

Clinical signs may include:

• Not negative FADIR and IR@90 tests

• Reduced hip muscle strength

• Reduced functional task performance

• Increased impingement in single leg squat

• Reduced trunk function

• Reduced dynamic balance

• Alterations in gait

• Poor range of motion

Imaging findings should also corroborate a diagnosis of FAIS. 

Plain radiographs (X-rays) should demonstrate something called cam morphology with increased alpha angle and reduced head-neck offset, and/or pincer morphology with acetabular overcoverage or retroversion.

An MRI should be utilised when assessment of labral or cartilage injury is required.