Osteoarthritis Prevalence Following
Anterior Cruciate Ligament Reconstruction: A Systematic Review and
Numbers-Needed-to-Treat Analysis

Luc
B, Gribble PA, & Pietrosimone B. Journal
of Athletic Training. 40(3)
Published online first June 2014. doi: 10.4085/1062-6050-49.3.35

Take Home Message:  There
is very little evidence that an anterior cruciate ligament (ACL) reconstruction can reduce the risk of knee
osteoarthritis (OA).     

The
primary goal of an ACL reconstruction is to restore stability and return a
patient to a physically active life in the short term.  While many patients successfully return to
physical activity, it remains less clear whether an ACL reconstruction can help
prevent a patient from developing knee OA. 
This systematic review aimed to determine if patients who underwent ACL
reconstruction had lower knee OA prevalence than patients who tore their ACL but remained ACL
deficient.  The authors assessed 38
studies, including 2837 total patients. 
Analyses revealed that the 2500 patients who had an ACL reconstruction
had a slightly higher OA prevalence (44%) than the 337 patients who remained
ACL deficient (37%). Hence, patients with an ACL reconstruction are 1.29 times more
likely to have knee OA later in life.  The
overall prevalence rates for an isolated ACL injury revealed that ACL
reconstructed patients had higher OA rates (42%) than ACL deficient patients
(29%).  However, when there was a
concomitant meniscal injury that required meniscectomy, ACL reconstruction
patients had slightly lower OA prevalence (52%) than those who remained ACL
deficient (59%) when there was a concomitant meniscal injury.  The authors found that a patient with an ACL
reconstruction was more likely to have knee OA later in life if s/he had an
open patellar tendon reconstruction (47%) or patellar tendon autograft (47%)
compared with a patient who remained ACL deficient. In contrast, a patient who
received a hamstrings autograft reconstruction (29%) may be less likely to have
knee OA later in life.

This
is another study that fails to provide support for the prophylactic value of
ACL reconstruction to prevent knee OA.  Particularly
if a patient suffers an isolated ACL injury s/he may have more of a decision to
make now.  As clinicians, we need to
understand the potential long-term effects of knee injuries in order to best
educate our patients.  Surgery might not
always be necessary.  This type of
research may provide support to trying to conduct rehabilitation first to
determine if conservative management and remaining ACL deficient will be
sufficient to accomplish the short-term goals of the patient.  It is unclear if these results can be applied
to today’s ACL surgical techniques because they are continually evolving (graft
selection, single vs. double bundle) and we don’t have long term data on these
newer techniques.  It would be
interesting to be able to follow more ACL deficient patients longitudinally to
determine whether they are true copers, become less physically active, or if
they have repetitive giving-way episodes. 
The meniscus seems to be a critical factor in OA risk, and giving-way
episodes could threaten the integrity of the meniscus.  There were a small number of patients that
were followed for over 19 years following injury, and those who remained ACL deficient
had slightly higher OA prevalence rates than those that had reconstruction done;
however, the sample size was small and this demonstrates an area that needs
further investigation. It is going to be extremely important to follow more
patients longitudinally longer to determine the long-term outcomes.  There may be a reason to have a slight shift
in sports medicine thinking, just because an ACL is torn, does not necessarily
mean that it needs to be fixed.  High OA
prevalence rates post-knee injury mean that patients are likely to be living
with a chronic disease that will negatively affect their lives.  These changes are occurring after they leave
our care, but as sports medicine clinicians and researchers, we need to find
mechanisms to best mitigate these long-term negative outcomes after a knee
injury.

Questions for Discussion:  Have
you ever advised or worked with any ACL patients who decided to remain ACL
deficient?  If you personally suffered an
ACL tear today, would you consider conservative management – why or why not?
    
Written
by: Nicole Cattano
Reviewed
by: Jeffrey Driban

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Luc, B., Gribble, P., & Pietrosimone, B. (2014). Osteoarthritis Prevalence Following Anterior Cruciate Ligament Reconstruction: A Systematic Review and Numbers-Needed-to-Treat Analysis Journal of Athletic Training DOI: 10.4085/1062-6050-49.3.35