Femoroacetabular impingement, or “FAI“, causes a sharp pain in the hip, most commonly in the front of the hip or groin.
It can come on suddenly and may not necessarily have an obvious mechanism of injury.
You may be more prone to hip FAI with bony changes around the hip.
Bony bumps can form on the pelvis or femur side of the joint.
These bumps get compressed when the joint moves to the end of its range, causing hip FAI.
A simple x-ray is commonly performed to screen for these bumps however this is often not useful.
You may have the bumps without FAI, and vice versa, so it doesn’t confirm the diagnosis.
And surgery is very rarely required to correct the bumps, so knowing that they’re present doesn’t change management.
The symptoms are flared when the leg moves in a combination of flexion (forward), internal rotation (twisting inwards) and adduction (tilting inwards).
These movements can occur with simple tasks such as doing up a shoelace, climbing stairs or getting out of a car.
This may also occur while running uphill or on tired legs or during pivoting in field sports such as football.
It’s worth noting that it’s the same positions that often cause clicky hips, although the two conditions aren’t related.
MY TOP 3 DO’S FOR A FAST FAI FIX
- Once accurately diagnosed, anti inflammatory meds usually have a significant effect within a few days
- It’s important to cease or pause the meds after a week or so. If the pain returns to the same intensity within a day, the meds are unlikely to be a solution for the injury. They’re just subduing it without resolving the reaction completely.
- Imaging isn’t typically required unless the pain is persistent, recurrent or extremely strong
- An MRI can be useful to confirm the diagnosis and screen for other pathologies like labral tears or bone stress injuries. The findings can also be used to guide the location of a cortisone injection if recommended
- Doctors often refer for screening x-rays but these have little clinical value in guiding management
- Exercises to improve hip strength and control must be done in safe positions, avoiding deep or unstable positions
- Full depth squats or deadlifts will build strength but can compress the injury, worsening the condition
- Staying in upper ranges and avoiding unstable movements (such as lunges) is recommended
- Stretching is not useful, despite the “tight” feeling around the hip, as it often adds to the compression
MY TOP 3 DON’T (BOTHER)…
- If you find a bony bump or labral tear on imaging, it doesn’t automatically mean you’ve found the culprit
- Both of these findings are present in people without hip FAI pain too
- X-ray is unable to differentiate between old or unrelated findings and findings that are causing symptoms
- MRI has the benefit of showing which structures are currently reactive, which can help to determine if a bump or labral tear is involved in the current presentation
- People often mistaken FAI for chronic hip flexor tightness or soreness after exercise
- As an acute (sudden onset) injury, FAI can feel like a pulled hip flexor or groin muscle
- You can differentiated hip FAI from strained muscles as FAI recovers quickly and responds well to anti inflammatory meds
- Another key feature to differentiate is that muscle injuries usually have a sore area found when you poke around. Hip FAI is too deep to have any palpable soreness
WHAT ELSE MIGHT BE CAUSING YOUR HIP PAIN?
- Hip labral tear
- This injury is almost impossible to differentiate from FAI except for a painful click (only present in labral tears, not FAI)
- Labral tears are on the same continuum as FAI and are both precursors to hip osteoarthritis
- Differentiating between hip FAI and labral tears is often unnecessary as the management plan for each condition is almost identical
- Hip flexor muscle strain or tear
- This injury is very similar in presentation to hip FAI – they both start suddenly, generate pain in the front of the hip and don’t like movements that bring the knee towards the chest
- With hip flexor strains, there’s often an area that’s sore to push on. By comparison, FAI doesn’t have any palpable soreness
- Lower back pain
- Back pain can refer to a number of areas, including the front of the hip
- It’s difficult to determine whether the back is causing anterior hip pain as there’s often concurrent back pain with FAI sufferers
- Hip osteoarthritis
- Hip OA is on the same continuum as hip FAI – that is, FAI is a precursor to the changes that lead to hip arthritis
- Hip osteoarthritis usually feels worse after prolonged rest or sleep but loosens up with activity. Conversely, FAI can loosen up slightly with activity but deteriorates with aggravating activities
- Psoas (hip flexor) bursitis
- This injury is an inflammatory reaction around a small pad in front of the hip and comes on slowly over a period of days or weeks, not suddenly like FAI
- Unlike hip FAI, it’s painful to push on the sensitive area with Psoas bursitis
- Inguinal hernia
- Lower abdominal strain
- Similar to inguinal hernia but with a more easily identified cause, this injury occurs after abdominal overload or excessive stretch
- The pain is higher up compared to hip FAI and doesn’t refer past the skin creases in the front of the hips
- Inguinal ligament strain or tear
- This injury can occur suddenly or over time and causes pain on or just above the skin creases in front of the hips
- There is usually a sore area to press on with inguinal ligament strains
- Inguinal ligament strains share many of the same aggravating activities with hip FAI and may be confused based on their presentation