An Updated Look at Femoroacetabular Impingement (FAI)

Over the weekend I posted a video at of a former (and hopefully future) division 1 lacrosse player that I’ve worked with over the last few months at Endeavor Sports Performance. What makes this player unique is that he’s undergone 4 hip surgeries (2 on each side) secondary to femoroacetabular impingement (FAI) and bilateral sports hernia surgery. The video alludes to the importance of recognizing individual limitations and teaching the athlete how to move within his or her own confines.

Working with this athlete also highlights the importance of understanding these so-called abnormalities. When he first came to Endeavor, light jogging wasn’t even an option. In other words, his range of motion was so poor, damage so significant, and overall comfort level with athletic movements so degraded that we really had to start slow. A few months later, he’s sprinting, cutting, and jumping explosively and without pain; he’ll be the first to tell you that he’s never felt better. My ability to effectively work with athletes like this stems directly from the amount of time I’ve spent studying the relevant research. I think this information is valuable for anyone that trains anyone, but if you work with hockey players, it’s absolutely essential. The amount of research in this area has exploded over the last decade; understanding the causes and implications of FAI will help you more effectively train players that present with these injuries (which is most) and help to prevent unnecessary complications.

Illustrating “normal” hip joint anatomy and FAI abnormalities

Below is a brief review of some of the current literature:

High prevalence of pelvic and hip magnetic resonance imaging findings in asymptomatic collegiate and professional hockey players

  • MRI findings from 21 professional and 18 NCAA D1 players; all were asymptomatic
  • 14 (39%) dysfunction of adductor-rectus abdominis insertions
  • 25 (64%) hip pathologic changes
  • 30 (77%) have MRI finding of hip or groin pathologic abnormalities

The prevalence of cam-type femoroacetabular deformity in asymptomatic adults

  • Retrospective analysis of CT scans from 419 randomly selected patients from 2004-2009 that were taken for problems unrelated to the hip
  • Of the 215 male hips (108 patients) analyzed, a total of 30 hips (13.95%) were defined as pathological, 32 (14.88%) as borderline and 153 (71.16%) as normal.
  • Of the 540 female hips (272 patients) analyzed, 30 hips (5.56%) defined as pathological, 33 (6.11%) as borderline and 477 (88.33%) as normal.
  • This highlights the prevalence of these injuries in asymptomatic individuals, especially men. This means that, in the general population, roughly 1 in every 3-4 men that you train will have an underlying hip abnormality. The prevalence of these findings in hockey players is drastically higher (see above).

Prevalence of cam-type femoroacetabular impingement morphology in asymptomatic volunteers

  • 200 asymptomatic individuals (111 females, 89 males; average age 29.4 years) had an MRI taken of their hips.
  • 14% of the volunteers had at least one hip with CAM impingement
  • 10.5% had CAM on either the right or the left side; 3.5% had CAM in both hips
  • 22 of 28 individuals (79%) who had CAM were men; only 6 (21%) were women.
  • 22 of 89 (24.7%) men had CAM impingement, compared with only 6 (5.4%) of 111 women.

Hip flexor muscle fatigue in patients with symptomatic femoroacetabular impingement

  • Comparison of hip flexor strength during submaximal isometric and repeated maximal dynamic contractions in those with and without FAI.
  • FAI participants exhibited significant hip flexor weakness compared to the controls
  • No changes were noted in fatigue indices between the two groups
  • Authors noted that those with FAI tend to have adductor and hip flexor weakness. It’s easy to look at these weaknesses and point to them as potential causes of FAI secondary to poor femoral head control. That said, it’s also worth noting that the bony overgrowth limits hip adduction and hip flexion and may cause weakness secondary to neurological inhibition, especially as bony end-range is approached.

Can we predict the natural course of femoroacetabular impingement?

  • Because FAI is so strongly associated with future osteoarthritis, these authors sought to determine whether age of total hip arthroplasty was related to certain radiographic findings and/or activities.
  • Given the complex and dynamic nature of these injuries, it’s not surprising that they weren’t able to find a relationship through their methods. That said, I think they hit the nail on the head with their conclusion: “Hence, considering the high prevalence of FAI-related radiographic findings, we conclude that not every radiographic abnormality requires treatment.”
  • This highlights the importance of not taking every positive radiographic finding and shipping the player off to the surgical table!

Treatment of athletes with symptomatic intra-articular hip pathology and athletic pubalgia/sports hernia: a case series

  • Analyzed 37 hips (average age: 25 years) with BOTH a sports hernia and FAI. Patients were athletes competing at the pro (8), college (15) elite high school (5) and competitive club (9) levels.
  • Evaluation occurred at an average of 29 months post surgery (wide range of 12-78 months though)
  • Of 16 hips that had athletic pubalgia (sports hernia) surgery as the index procedure, 4 (25%) returned to sports without limitations, and 11 (69%) subsequently had hip arthroscopy at a mean of 20 months after pubalgia surgery.
  • Of 8 hips managed initially with hip arthroscopy alone, 4 (50%) returned to sports without limitations, and 3 (43%) had subsequent pubalgia surgery at a mean of 6 months after hip arthroscopy.
  • Thirteen hips had athletic pubalgia surgery and hip arthroscopy at one setting. Concurrent or eventual surgical treatment of both disorders led to improved postoperative outcomes scores (P < .05) and an unrestricted return to sporting activity in 89% of hips (24 of 27).
  • While it’s impossible to make any accurate inferences, I’d be interested to see how these numbers may differ if the athletes were in sport programs with medical professionals that truly understood the implications of the abnormalities and could teach the players how to move within their limits.

In my experience, most players do very well when they understand the limitations in their joint anatomy and are taught how to move within these confines. Because the primary suggested mechanism underlying athletic pubalgia involves a tug of war across the pubic symphysis between the adductors and abdominals AND because those with FAI tend to have very dense/fibrotic adductors, many players will benefit from some soft-tissue work in this region, especially in the area of the proximal adductor magnus attachment. Also, because posterior capsule density can push the femoral head forward in the joint and put excess stress on the anterior/superior labrum, this is another area worth having a manual therapist look at. The manual method itself is less important than the proficiency of the therapist. It can be tough to find someone that is comfortable working in that area, but it is well worth the trouble when you do!

To your success,

Kevin Neeld

P.S. If you’re interested in learning more about hockey hip injuries and associated assessments and corrective strategies, I highly encourage you to check out my presentation “Hockey Hip Assessments: An In-Depth Look at Structural Abnormalities and Common Hip Injuries”, which is now available at Hockey Strength and Conditioning

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