in Serum Biomarkers of Cartilage Turnover After Anterior Cruciate Ligament

Svoboda SJ, Harvey TM, Owens BD,
Brechue WF, Tarwater PM, & Cameron KL. American
Journal of Sports Medicine
. 2013;
Epub ahead of print. doi:

Take Home Message: While young
physically-active cadets experience biochemical changes that reflect cartilage
turnover during a four-year period, a cadet with an ACL injury may have more pronounced
changes.  These changes may provide
insight for detecting individuals at risk for OA and developing interventions
to prevent this.

Knee injuries, such as anterior
cruciate ligament (ACL) and meniscus injuries, are very common in athletic and
physically-active populations and may increase the risk of osteoarthritis (OA).
Biochemical changes after a knee injury may provide insight into the onset of OA,
allowing for earlier diagnosis and potential intervention. The authors of this case-control study compared biochemical
markers before and after an ACL injury among a group of 45 cadets or
active-duty military personnel and compared this injured group with 45 healthy
controls (matched to the injured group by age, sex, height, and weight). Both
groups had blood collected when they entered the United States Military Academy
and at graduation (~4 years later). On average, the ACL injury occurred ~2
years after entering the academy (2 years before graduation). The authors
analyzed four markers of cartilage synthesis and degradation. Approximately 87%
of participants were male (mean age = 20) and 13% were female (mean age = 19). Overall
both groups tended to have lower levels of biochemical markers of cartilage degradation
and synthesis at graduation compared with baseline; however, a knee with an ACL
injury may be more likely to have biochemical changes that are reflective of
cartilage turnover.

This study demonstrated that an
individual who suffers an ACL injury will have biochemical changes over time
and that these changes may be greater than those in a healthy control.  These changes may provide insight as to why
ACL-injured participants are at risk for OA.  The average time between injury and follow-up in
this study was approximately 2 years; however, an ACL injury could have
occurred anywhere between 4 years before follow-up to just one month before
follow-up, which creates a gap of knowledge regarding when changes may be initiated
and if they are activity dependent.  Among
the uninjured cadets, there was a slight decrease in biochemical markers over time,
which warrants a closer look as to whether physical-activity levels and age
were influencing these changes.  Clinically,
we need to understand if there is an optimal time to potentially thwart OA
onset and how best to mitigate its progression.  It would be interesting if the authors could
continue to follow these participants to see who develops OA in the future. In
the meantime, this study provides further evidence that as clinicians, there is
a potential for us to make an immediate difference on the long-term health of
individuals who suffer a knee injury. 

Questions for Discussion: Do
you think that we have enough information to potentially develop OA prevention
strategies? What do you think may be the next logical steps in trying to
prevent OA progression?
by: Nicole Cattano
by: Laura McDonald

Related Posts:

Svoboda SJ, Harvey TM, Owens BD, Brechue WF, Tarwater PM, & Cameron KL (2013). Changes in Serum Biomarkers of Cartilage Turnover After Anterior Cruciate Ligament Injury. The American Journal of Sports Medicine PMID: 23831890