Early and Delayed Surgery for Isolated ACL and Multiligamentous Knee Injuries Have Equivalent Results: A Systematic Review and Meta-analysis

Background: Early surgery for acute ligamentous injuries has recently shown good clinical and functional outcomes. Purpose: To assess the advantages of early vs delayed surgery in patients undergoing isolated anterior cruciate ligament (ACL) or multiligament-injured knee (MLIK) surgery. Study Design: Meta-analyses of Level 1, 2, and 3 studies; Level of evidence, 4. Methods: A systematic search was performed via PubMed, EMBASE, and Cochrane for studies reporting outcomes of timing of surgery after isolated ACL injury or in the MLIK setting using accelerated rehabilitation protocols. Two analyses were conducted to differentiate early and delayed treatment (3- and 6-week cutoffs). Collected outcomes included meniscal or chondral lesions, failure and reoperation rates, range of motion (ROM) deficits, other complications, muscle strength, instrumented laxity, and functional outcomes. Outcomes were reported in risk ratios (RR) or mean differences with 95% CIs. Results: For timing of isolated ACL surgery, 16 studies were included with 2093 patients. High-grade evidence indicated that there were no differences in meniscal or chondral lesions, failure and reoperation rates, stiffness, ROM deficits, complications, muscle strength, instrumented laxity, and functional outcomes between patients treated early and late (all P > .05). When including only studies that set no preoperative criteria for early surgery, the findings were similar. Regarding MLIK surgery, 14 studies were included with 1172 patients. Low evidence was noted for the following: patients treated early had significantly fewer meniscal injuries (RR, 0.7; P = .04) and chondral injuries (RR, 0.5; P < .001), while no differences were found in reoperation rates, complications, stiffness, ROM deficits, muscle strength, instrumented laxity, and functional outcomes between the groups. Other than higher Lysholm scores in the early group for the 3-week analysis (mean difference, 6.8; P = .01), there were no differences between cutoff analyses. Conclusion: This systematic review with meta-analysis found no differences in clinical and functional outcomes between early and delayed surgery for isolated ACL injuries. For MLIK injuries, there were also no differences in surgical outcomes between early and delayed surgery.