Femoroacetabular impingement surgery: why doctors believe it works

If you’ve been diagnosed with femoroacetabular impingement (FAI), or hip impingement, you may have been told that surgery is the only way to relieve your hip pain.

Your doctors may sound confident that surgery will solve your problems, but this article will explain what your doctor may not know and why you may want to be skeptical about going under the knife.

The basic problem with FAI surgery recommendations

Bonnie shares her story with FAI, hockey, and avoiding surgery.

Doctors and surgeons are generally people with good intentions, doing their best to help their patients. The best ones base their recommendations on evidence. In the case of femoroacetabular impingement, surgeons tend to base their predictions for success on early FAI studies, which claimed the surgery was helpful for patients.

The problem is that these studies do not actually show that: The evidence just isn't very good when you look at it critically.

These early studies claimed very high success rates for hip impingement surgery, but their measures of success simply weren’t aligned with most patients' expectations and desired outcomes.

What does success in femoroacetabular impingement surgery look like?

What would it take for someone with hip pain to call their hip surgery a “success”? Being able to walk one mile without pain? Walking one block without a limp? Being able to run a marathon or play an entire game of soccer without pain? Being able to lift your child without wondering if your hips can handle it?

People with hip pain have a lot of goals of varying physical intensity, based on their lifestyles and ambitions. But ultimately it’s safe to say that everyone with hip pain wants their hip pain to stop interfering with their pursuits and passions.

That’s why as personal trainers, we’re laser-focused on good form, strength, and mobility. When we work with people with the FAI diagnosis, we encourage them to keep their athletic passions in mind because that's what a happy, engaged life looks like.

Success is being able to pursue your passions without limitations due to hip function and pain.

When doctors and surgeons present femoroacetabular impingement surgery as an option, patients naturally assume that a surgeon is promising success on these same terms.

Some surgeons claim there’s a 90%-plus chance of success with FAI surgery. Patients naturally think, “great—that’s a 90% chance I can get back to enjoying my life and pursuing my passions!”

And, in reality, surgery does help some people! There are people who find that femoroacetabular impingement surgery and the rehabilitation afterward is a positive experience overall. They do end up getting back to the things they love doing. But there’s a big question we have to ask. Is FAI surgery actually as successful as surgeons claim? And are their ideas of success the same as yours, as someone with hip pain?

Realistic success rates for FAI surgery aren’t as high as surgeons claim

Haley talks about the result of her surgery for FAI and how her surgeon's idea of success compared with hers.

The truth is success rates for femoroacetabular impingement surgery are not as high as 90%. Or even 80%. [Read more on real success rates for femoroacetabular impingement surgery].

A 2016 study on FAI surgery in the Journal of Hip Preservation Surgery looked at three separate surgeons responsible for operating on 150 patients (159 hips) and follow up occurring over a 2-year period. After two years, the paper notes that “64% of patients were satisfied with their surgical outcome.” That's a majority being "satisfied."  

But that also means one out of every three patients was dissatisfied with the surgery. If you were buying a car, and someone told you that 33% of owners of this particular car did not like this car after two years, would you still be as interested in buying it? Probably not.

One out of every three patients was dissatisfied with the surgery.

3 things surgeons are missing in the hip impingement surgery research

In light of results like that, it may seem hard to believe doctors and surgeons will say surgery is such a surefire approach. It’s important to recognize that doctors and surgeons are not bad people deliberately lying to patients about outcomes.

They want to help their patients. But researchers relied on poor metrics (measures of success)—questionnaires and objective scores to determine success, believing that they’d eliminate the risk of bias in the studies.

Unfortunately, the scoring systems they use and their definition of success are actually quite open to bias, making these metrics deceiving at worst and misaligned with patient desires at best. 

1. The metrics used in FAI surgery studies are murky.

Watch how Alex got hip pain relief after two femoroacetabular impingement surgeries failed.

The 2016 study mentioned above offers a clear example. The study presents success scores using the nonarthritic hip score (NAHS), a hip health questionnaire that takes a patient’s answers to questions like “How much pain do you have walking on a flat surface?” and creates a numerical representation of their hip health.

The multiple-choice answers (“None,” “Mild,” “Moderate,” “Severe,” and “Extreme”) are by nature murky, though. What is the difference between "extreme" and "severe"? The patients’ perception of these words could drastically affect their score.

What the 2016 study found was after FAI surgery the average patient’s hip problems improved from the 'mild to moderate' range to the 'mild' range. That’s all. They still had hip problems. But because their scores had improved—however slightly—these were viewed as successful surgical outcomes. 

This average patient improved from problems in the 'mild to moderate' range to problems in the 'mild' range.

2. Pain questionnaires aren’t a reliable measure of surgical outcomes.

Another major flaw in the study is one that one of my blog readers with the FAI diagnosis pointed out: pain levels fluctuate! Sometimes pain is on one side. Sometimes it shifts to the other. Sometimes it’s pain on both sides. Sometimes it’s on the front. Sometimes it’s on the back.

It moves and changes day to day, week to week.

As he pointed out, on a bad day, he could score a 47.5 on the NAHS, but on a good day two weeks later, he could score a 75. And he most definitely would not consider the feeling of 75 a successful outcome following invasive surgery.

On one of his best days after soaking in a hot spring, he had no pain, was able to jog, and would have scored a 97.5 without any medical intervention whatsoever. The NAHS is a prime example of how these so-called “objective” measures of success are actually biased toward “success” for surgical studies.

3. The researchers' definitions of success don’t align with the results patients want and expect.

The actual improvements most patients experience from hip impingement surgery simply do not align with what they expect or desire. And the NAHS is not the only system with that problem.

A 2009 study on FAI surgery in the journal Clinical Orthopaedics and Related Research used another measure, the Harris Hip Score, with equally questionable findings.

According to these metrics, if a hip pain sufferer says they are able to “ignore” their pain, they earn top marks and their surgery would be considered a smashing success. And another patient who answers that their “marked pain with a severe limp” has been reduced to “mild pain with a slight limp” is also considered a success story for FAI surgery.

But these results don’t accurately reflect most patients’ expectations and desired outcomes from an invasive surgery. 

The early pioneers of FAI research also used another survey called the Merle d’Aubigné score. In an often-cited 2003 FAI study published in the Journal of Bone and Joint Surgery, researchers used it to evaluate whether a procedure that involves cutting the bones of the pelvis and using screws to create a more optimal position, could effectively treat FAI.

In this study, surgeons operated on 29 hips in 22 patients. When they followed up around 30 months later, they found the patients had better range of motion and an increased average Merle d’Aubigné score.

By these metrics, though, a patient with “mild pain when walking that disappears with rest” and the ability to walk “without a cane but with a slight limp” could score as  “GOOD,” deeming the surgery a success. While this may be an improvement from their preoperative symptoms, this is someone who still has obvious hip problems. They wouldn't be able to run up a flight of stairs, let alone pursue a sport.

In this scoring system, someone else with full mobility and the ability to walk normally but who still gets pain in other activities would be also be considered a surgical success. Based on the clients we see, this is a common and frustrating scenario for many people in the modern world.

Surgery isn’t your only option for treating FAI

At Upright Health, we are dedicated to educating and encouraging people with hip pain to look at the problem in a different way.

We encourage you to look at hip pain as an issue caused primarily by poor muscle function. We invite you to look at it as a problem that can be solved by retraining the muscles over time.

It's not a quick fix, but it's noninvasive and makes sense in the context of natural human function and healing.



About the Author

Matt Hsu is a trainer and orthopedic massage therapist. He fought a long battle with chronic pain all over his body and won. He blends the principles he learned in his journey, empirical observations with clients, and relevant research to help others get their lives back.