Drupal
Athletic development specialists dedicated to the art and science of excellence in movement

MRI's Show Poor Correlation Between Pain and Damage in Lower Extremities

 

“My knee has been hurting whenever I run for the past few weeks.  I think there could be a tear, so I want an MRI for a definitive answer.”

As we noted in the Nine I’s of Running Injuries, “Imaging” is a late stage on the highway toward surgery for many runners.  Exits ramp exist on this highway but many athletes bypass them willingly.  Imaging is often a sign of desperation when no one can figure out the problem.  The answer is rarely simple and often requires a mix of medical, rehab, and training interventions to achieve lasting results.     

Now, I’m just a coach, not a surgeon.  We often interact with athletes in the abyss between training and medical care.  Yes, this gap is truly an abyss as athletes look in many directions but can’t find a way out.  The medical profession often looks down upon the coaching business (sometimes for good reason) which impedes communication.  Heck, the medical profession often looks down on ITSELF with many surgeons believing their craftsmanship is above the need for post-surgical rehabilitation! 

The abyss can be confusing: some days it hurts to get out of bed; other days you can make it through a medium distance run.   Uncertainty leads to a craving for answers, and what can be more certain than the modern marvel known as the MRI?!?  While MRI’s have saved many lives from potentially fatal conditions, the images can be TOO sensitive for orthopedic issues, leading to false positives.   

Eminent shoulder surgeon Dr. James Andrews recently examined shoulder MRI’s of thirty one pain free Major League Baseball pitchers and found abnormal cartilage in 90 percent.  He famously noted, “If you want an excuse to operate on a pitcher’s throwing shoulder, just get an MRI.”  Additionally, there’s also a whole morass of medical standards of care and associated legal issues that clutter the process…but no, I’m not gonna put my lawyer badge on and try to explain them... 

Modern patients also believe they are getting substandard care if they don’t get an MRI.  As we’ll discuss below, the evidence shows a poor correlation between pain and damage.  However, because the shoulder is seen as more delicate than the knee, it’s a legitimate question whether the same thought process applies to running injuries…

Fukuta (2002) examine knees in a sample of one hundred fifteen ASYMPTOMATIC (No pain!) patients ranging from age 13 through 76.  Specifically, authors noted discoid menisci in fifteen subjects and subchondral changes in thirteen subjects over the age of forty.  Prevalence of abnormalities increased with age.  Conclusion: “Considerable prevalence of meniscal abnormalities in asymptomatic Japanese subjects!”  This study just happened to be from Japan, but there’s no reason to believe any other country’s results would be different (unless we Americans are wimpier when it comes to pain!).

We’ve all heard the old wives tale that running is bad for your knees…but is it true?  Shellcok (1991) examined a sample of twenty three ASYMPTOMATIC marathon runners to include a total of ninety two meniscal horns (four per runner).  In this sample, 2% of the horns showed tears (9% of the runners in the sample) and 45% showed signs of degeneration.  But wait…does all that degeneration mean that running is bad for your knees?...

Other studies (Crues 1987) have shown that 20% of ASYMPTOMATIC non-runner athletes and 16% of nonathletes (also ASYMPTOMATIC) had meniscal tears.  53% of the meniscal horns in the non-runner athlete sample showed signs of degeneration.  In short, it isn’t just runners who have knee damage without pain.  In fact, asymptomatic non-runners showed greater damage (slightly).   There are different degrees of damage ranging from small abnormalities thru a complete tear, but the link between damage and pain is incomplete with respect to the knee.  Knee damage is part of aging, but pain does not have to be. 

Take home points from these studies:

1)      Multiple asymptomatic populations show damage, sometimes significant damage

2)      As noted by Shellock, running may actually lead to “damaged” adaptations in the soft tissue that protect the body from additional damage.  One theory is that abnormalities whether thickening or partial tears may serve functional roles adaptive to that particular repetitive use activity.  This is only a theory, but could a partial tear be a way to increase mobility?  No one has a definitive answer, but it underscores the importance of considering the entire picture. 

Wait, there’s more!…Beattie (2005) examined a sample of forty four volunteers age 20-68 with no history of knee pain.  All but one showed evidence of at least one knee abnormality.  Twenty seven (61.4%) showed abnormalities in at least three of the four regions of the knee.  Conclusion:  “Meniscal degeneration or tears…are highly prevalent in asymptomatic individuals with the medial anterior and posterior horns being the most commonly affected regions.”  In short, if something hurts, there’s a good chance something was damaged before it became painful.  What definitive answers will the MRI provide if the structure was likely damaged to begin with?      

Similar caution is required for lower leg issues, although bone injuries and stress fractures are different animal than the soft tissue problems discussed above.  Bergman (2004) studied the lower legs of elite college runners and concluded “Signs of a tibial stress reaction were found on MRI in 43% of the 21 asymptomatic college distance runners in this study. The presence of these changes was not found to be a predictor of future tibial stress reactions or stress fractures. Our findings underscore the importance of correlating MRI findings with clinical findings before making therapeutic decisions.”  In other words, look at the whole situation and not just the image itself.

Conclusion

When people are desperate for “definitive answers” from the MRI it often means they didn’t ask the right questions or see the right people early in the process.   With repetitive use pain, we’re not talking about people getting run over by 300lb linemen!  Yes, there are times when imaging and surgery are needed, but athletes too often rely on the imaging out of desperation. 

Pain is the perception of threat by the brain, whether real or imagined.  If two people can have the same imaging yet have different pain presentations, the answer is not necessarily found in the image itself.   Consider all factors of movement, pain, and structure when making decisions.  Train smart and ask the right questions early, and you can avoid confusion later.   

Note: thanks to Neuroscience and Pain Science for Manual Physical Therapists for organizing many of these citations. 

References

Shellock FG, Deutsch AL, Mink JH, Kerr R.  Do asymptomatic marathon runners have an increased prevalence of meniscal abnormalities? An MR study of the knee in 23 volunteers.  AJR Am J Roentgenol. 1991 Dec;157(6):1239-41.

Stahl R, Luke A, Ma CB, Krug R, Steinbach L, Majumdar S, Link TM.  Prevalence of pathologic findings in asymptomatic knees of marathon runners before and after a competition in comparison with physically active subjects-a 3.0 T magnetic resonance imaging study.  Skeletal Radiol. 2008 Jul;37(7):627-38. Epub 2008 May 8.

Fukuta S, Masaki K, Korai F.  Prevalence of abnormal findings in magnetic resonance images of asymptomatic knees.  J Orthop Sci. 2002;7(3):287-91.

Crues JV 3rd, Mink J, Levy TL, Lotysch M, Stoller DW.  Meniscal tears of the knee: accuracy of MR imaging. Radiology. 1987 Aug;164(2):445-8.

Beattie KA, Boulos P, Pui M, O'Neill J, Inglis D, Webber CE, Adachi JD.  Abnormalities identified in the knees of asymptomatic volunteers using peripheral magnetic resonance imaging.  Osteoarthritis Cartilage. 2005 Mar;13(3):181-6.

Bergman AG, Fredericson M, Ho C, Matheson GO.  Asymptomatic tibial stress reactions: MRI detection and clinical follow-up in distance runners.  AJR Am J Roentgenol. 2004 Sep;183(3):635-8.

Kolata, Gina.  Sports Medicine Said to Overuse MRI’s.  New York Times.  2011Oct 28.

Comments

reply

This really answered my problem, thank you for the post! Keep it up.

My Page : Knee pain

Reply

Thanks for reading.  Glad you found it helpful.

Post new comment

The content of this field is kept private and will not be shown publicly.
CAPTCHA
This question is for testing whether you are a human visitor and to prevent automated spam submissions.
Image CAPTCHA
Enter the characters shown in the image.