An anterior cruciate ligament (ACL) tear is a risk factor for early osteoarthritis
(OA) onset. Generally, ACL reconstruction (ACLR) is associated with better outcomes.
However, there is a lack of evidence regarding the effect of operative versus nonoperative
treatment for preventing premature knee OA in isolated ACL tears while achieving good
functional outcomes.The purpose of the study was to compare the outcomes of ACLR to
primarily nonoperative management of isolated ACL tears. It was hypothesized that
the outcomes between treatment types would be similar.Systematic review; Level of
evidence, 3.This systematic review was registered on the International Prospective
Register of Systematic Reviews (PROSPERO) (registration No. CRD42021285901) and was
conducted according to the Cochrane Handbook guidelines. We systematically searched
for randomized and nonrandomized studies that compared ACLR with nonoperative treatments
in isolated ACL tears in 3 databases until October 25, 2021. The risk of bias and
quality of evidence of the included studies was assessed in accordance with the Cochrane
guidelines. The primary outcome was radiologic signs of OA, and the secondary outcomes
were functional parameters. Using the common effects model, we calculated pooled mean
differences (MDs) and odds ratios (ORs) with 95% CIs.Five studies-2 randomized controlled
trials (RCTs) and 3 retrospective non-RCTs-were included. There was a moderate risk
of bias in 2 studies and a serious risk of bias in 1 study. The quality of evidence
was rated low because of the higher risk of bias and inconsistency. Nonoperatively
treated knees showed a trend toward lower odds of developing radiological signs of
OA (OR, 1.84 [95% CI, 0.90 to 3.75]); however, surgically reconstructed knees had
significantly better stability (MD, -2.44 [95% CI, -3.21 to -1.66 ]) and a trend toward
better but clinically not meaningful Lysholm scores (MD, 2.88 [95% CI, -1.09 to 6.85]).
The qualitative synthesis showed that surgical reconstruction was protective against
subsequent injuries but not superior when returning to previous activity levels or
various functional tests.Findings indicated that there is no certain evidence that
ACLR for an isolated ACL tear is superior to nonoperative treatment. Clinicians should
consider nonoperative treatments with a well-designed rehabilitative program as a
primary option. However, these findings must be interpreted with caution because of
low study quality and high risk of bias.
