Treatment of Anterior Cruciate Ligament Tears should be Individualized
The umbrella review by Blom et al.  showed that arthroscopic anterior cruciate ligament (ACL) reconstruction had similar patient-reported outcomes to non-operative care. However, the conclusion was based on the only randomized controlled trial (RCT) by Frobell et al. in 2013  and must be interpreted with caution. Although there was no difference in KOOS scores, this subjective score had the ceiling effects (i.e., the item was too easy for patients with ACL tears).  And IKDC subjective score and Lysholm score were not assessed in that RCT; how could figure 3 of the umbrella review indicate no difference in those functional scores. We should also notice that an updated RCT  showed that the early surgery group had a significantly better IKDC subjective score than the rehabilitation and delayed surgery group.
Meanwhile, for the Tegner score, less than 25% of the “active adults” were able to return to their pre-injury activity levels , which is inconsistent with the recent meta-analysis reporting a 48.9% rate of return to pre-injury levels of performance and 73.2% rate of return to sport after ACL reconstruction.  The objective indexes (percent of normal Lachman test or pivot-shift test, which represented some part of the IKDC objective score) in the rehabilitation group were inferior to the reconstruction group (p < 0.001) . Meanwhile, as reported by James et al., nonoperative management resulted in high rates of residual knee instability and moderately low rates of return to sports in pediatric patients. 
Moreover, for another part of the IKDC objective score, the osteoarthritis grade has concluded no difference between reconstruction and rehabilitation.  However, the five-year endpoint in this only RCT may be too early to result in no difference. A recent systematic review indicated that with proper anatomic ACL reconstruction, the lower osteoarthritis prevalence would be presented with more than ten years of follow-up.  Indeed, operative and non-operative treatments were acceptable treatment options for ACL tears.  Meanwhile, ACL repair other than reconstruction would be another operative choice, reducing the osteoarthritis incidence.  So, for patients with ACL tears, treatment of anterior cruciate ligament tears should be individualized. We still need a long way to get the best treatment based on more RCT evidence comparing operative and non-operative treatment for different patients with different ages, expectations, and goals.
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Competing interests: No competing interests