Femoroacetabular Impingement Syndrome (FAIS) is medical jargon to describe pathologic contact between the femur (your thigh bone) and acetabulum (on your pelvic bone). In other words, your thigh-bone has too much contact with your pelvis leading to hip pain and abnormal motion in the hip joint. Although prevalence varies across populations, FAIS is typically observed in adolescents and middle-aged adults. Before diving into this pesky condition, it’s important to understand the underlying anatomy…. Onward!
For this discussion, the hip is defined as the ball-and-socket joint between your thigh and pelvis. At the top of the femur, the femoral head (ball) fits into the acetabulum (socket) of the pelvis, which is actually comprised of three bones (the ilium, ischium, and pubis). Articular cartilage lines the inside of the acetabulum as well as covers the femoral head allowing for smooth, happy joint movement. Further deepening the socket and assisting in holding the head of the femur in place is the cartilaginous labrum. The joint capsule is comprised of a handful of ligaments blended with muscle fibers that help stabilize and protect the joint. Collaboratively, these structures function to allow a wide freedom of motion for your hip while ensuring your leg stays firmly attached to the rest of your body.
FAIS can be separated into two distinct types: CAM Impingement and Pincer Lesion Impingement based on anatomical variations within the body. CAM Impingement is most common in young athletic males and is caused an enlarged or abnormally shaped femoral head. Pincer Impingement is most common in middle-aged women and is caused by an abnormally shaped acetabulum essentially pinching the hip during movement. Although there are two distinct types, the majority of FAIS cases are in fact a hybrid of the two.
How do I know if I have FAIS?
Common symptoms associated with FAIS include:
- Decreased hip motion
- Hip Pain! Pain in the groin region or on the lateral aspect (side) of the hip
- Sharp, stabbing pain during deep squatting, sitting, running, and other athletic movements
- Others may experience a dull, annoying, aching sensation near their hip
- Occasionally there may be no pain at all!
To confirm a diagnosis of FAIS, you will need imaging (x-ray, CT, or MRI) of your hip.
Regardless of presentation, associated long-term effects of FAIS include articular cartilage damage, labral tears, early-onset osteoarthritis of the hip, sport hernias, low back pain, hip pain, knee pain, and ankle pain. Needless to say, it ain’t pretty folks.
How can I help myself now?
After sitting for about 20 minutes, our tissues begin to slowly deform to a new position due to the physiological phenomenon known as “viscoelastic creep”. Essentially, our body attempts to do us a favor by maintaining our preferred resting position. To break this heinous cycle, take micro-breaks from sitting (or at the very least change how you’re sitting by shifting your legs or backside).
Another thing you can do right now is start stretching. Spend 20 minutes a day stretching your hamstrings, quadriceps, hip flexors, hip rotators, and hip extensors. Be diligent and be patient as achieving flexibility can take up to 2 – 3 weeks to see results.
If you’ve progressed to the point of “stiff old man hips” or pain during just about any motion you perform, conservative care has been shown to improve symptoms. Primary treatment goals to combat FAIS are to improve joint motion of femoroacetabular (hip) joint, strengthen weak or inhibited hip musculature, and correct faulty movement patterns or biomechanics through corrective exercise.