Pediatric Overuse Injuries: A Closer Look

Illustration by J.C. Leyendecker, Saturday Evening Post

The ringing in of the New Year is traditionally accompanied by pictures with some variation on the theme of a new baby’s arrival.  Witness the classic Saturday Evening Post cover accompanying this post.

For intentional or serendipitous reasons, we at CJSM have a habit of doing something of the same:  for two years running now the journal has our inaugural issue of the new year highlight studies looking into the phenomenon of overuse injuries in the pediatric athlete.  Our January 2014 issue was headlined by the American Medical Society for Sports Medicine (AMSSM) position statement on overuse injuries and burnout in youth sport, a study I got to follow up with an interview with lead author and then-President of the AMSSM, UCLA’s John DiFiori!

This year, one of our ‘Original Research’ papers comes from another AMSSM member, Andrea Stracciolini, from Boston Children’s Hospital.  She is the lead author on the paper, A Closer Look at Overuse Injuries in the Pediatric Athlete.

Landing on your doorstep in January:  not a baby from a stork but a pediatric overuse study by CJSM….2015 is going to be a good year!

Dr. Stracciolini and her team primarily set out to see whether there was a true difference in overuse injuries between male and female athletes after they had controlled for several confounding variables (e.g. BMI, presence of contact/collision in the sport, team vs. individual sport, etc.)

AMSSM Annual Meeting, Hollywood, FL April 14 – 19, 2015

She and her co-authors did a 10 year retrospective review of referrals to their tertiary level sports medicine clinic (at Boston Children’s Hospital), looking at individuals who were aged 5 to 17 on presentation.  Their initial look revealed that there were 121 047 total unique patients in this cohort, and so they drew a 5% random sample for further analysis.  “Because of budget and time constraints,” they were able to analyze only 3813 of the approximately 6000 charts (N = 6000 would represent approximately  5% of the total charts meeting initial inclusion criteria).  The authors excluded all visits for injuries sustained as a result of ‘everyday accidents’ (e.g. falls, riding a bike recreationally, etc.) and were left with 1614 unique patients in the final sample:  1614 patients aged 5 to 17 who presented with an injury from sport.  A large, and representative sample of pediatric sports injuries.

On chart review, the dependent variables they looked at included primary diagnosis, body part injured, and injury classification (a dichotomous variable:  acute/traumatic or overuse).  Independent variables included anthropometric data (gender, BMI, etc.), and sport(s) played.  Sports were further divided by the American Academy of Pediatrics contact classification hierarchy (contact/collision, limited contact,  or non-contact).

Some of the findings confirmed what is known in the literature and what many of us see in our day-to-day practices.  Fifty-two percent of the injuries in this cohort were overuse, a figure similar to those quoted in the AMSSM position statement on overuse injuries from January 2014.  Females sustained significantly more overuse injuries than males (63% to 40%).

One of the more interesting findings of the study is something I do not fully grasp ‘statistically,’ so to speak.  Noting that there were markedly different proportions of males vs. female athletes in sports with/without contact (e.g. an American football cohort would almost exclusively be comprised of males), and that this would be likely to influence the dichotomous measure of whether an injury were due to ‘trauma’  or ‘overuse,’ the group did a ‘decomposition analysis’ to “…investigate the extent to which these differences are responsible for differences in the likelihood of being treated for an overuse injury….”   They found that 45.9% (nearly half) of the difference in the proportion of females vs. males sustaining overuse injuries was attributable to their differences in background and activity characteristics [e.g. intrinsic (BMI) and extrinsic (type of sport played)].  In their discussion, the authors state that the remaining almost 50% of the sex difference “…can likely be explained by biological differences, both those previously documented in the existing literature, and those yet to be discovered.”

“Yet to be discovered” = more research!!!!!  That’s a good thing.  Differential landing patterns in women vs. men, the effect of progesterone on concussion susceptibility, gender-based sociological and psychological differences–there is interesting literature out there on how young men and women differ in injury susceptibility, but, yes indeed, there is surely a lot ‘yet to be discovered.’

As I wrap up a post that figures the work of AMSSM members prominently and that ends with an emphasis on the research yet to be done in sports medicine, I think it’s a good time to remind you all of the 24th annual AMSSM meeting, coming up soon in Hollywood, Florida (April 14 – 19, 2015).  I know Dr. Stracciolini is an AMSSM member, and I’m hoping her research will be among the presentations given.  I’ll want to ask her about the ‘decomposition analysis’ that was done in the study so I can understand it better, and I want to pick her brain on what she thinks may be directions in which her research will lead.

Many of us from CJSM will be there.  We hope to see you there too!