SURGICAL TIMING

When indicated based on shared decision making with the patient, several studies have demonstrated benefit of early reconstruction. Range of motion was not affected by early verses delayed surgery: Baba (2019) <1 month, 2-3 months or >3 months; Herbst (2017) <48 hours vs after acute inflammatory phase; Bottoni (2015) <21 days vs >6 weeks; Chua (2020) <3 weeks vs > 3 weeks.

With respect to general patient satisfaction and function there was no convincing evidence that early versus later reconstruction had an impact on outcomes. Two studies (Baba 2019, Signorelli 2016) did show that instrumented laxity was less with early reconstructions compared to late reconstructions.

Regarding the presence of meniscus injury at time of ACL reconstruction several high quality studies, (Newman 2015, Anderson 2015, Mok 2019) and many lower quality studies, (Hur 2017, Everhart 2019, Baba 2019, Brambilla 2015, Keyhani 2020, Chavez 2020, Kawashima 2020, Krutsch 2017, Stone 2019, Chen 2019) showed that early ACL reconstructions had less meniscus injury than late ACL reconstructions at the time of surgery. The Newman (2015), Keyhani (2020), and Anderson (2015) studies showed that a delay of > 3 months was a predictor of more severe meniscus injury. The Everhart (2019) study showed that a delay of greater than 8 weeks resulted in an increased incidence of meniscus tears, while the Mok (2019) study showed that reconstructions performed within 12 months have fewer meniscus tears. They did not investigate whether the increased risk may have occurred prior to the 12-month point. The Kawashima (2020) study noted increased meniscus tears in reconstructions performed >5 months post-injury.  Chavez (2020) noted an increase in meniscus tears in reconstructions performed >6 months after injury. The Newman (2015), Krutsch (2017), and Hur (2017) studies also showed that the meniscus injuries in the early reconstructions were more likely to be repairable then those in late reconstructions with variable definitions of early vs late reconstruction. Chen (2019) demonstrated that meniscus tears occurring after the injury MRI were increased in reconstructions performed >12 months post-injury. The Stone (2019) study found that reconstructions performed after >12 months had increased risk of subsequent medial meniscus tears. Snoeker (2020) showed that early ACL reconstruction resulted in fewer subsequent medial meniscus tears in the 5 years following surgery compared to delayed reconstruction.

With respect to the presence of articular cartilage damage at time of ACL reconstruction two high quality papers (Anderson 2015, Newman 2015) and several lower quality studies (Brambilla 2015, Chavez 2020, Everhart 2019, Kawashima 2020, Senorski 2019) showed that late ACL reconstructions had increased articular cartilage damage compared to early reconstructions at the time of surgery.  The Anderson (2015) study showed this to occur as early as 3 months, while the Everhart (2019) study showed it to occur at 5 months. Brambilla (2015) showed that there was less intra-articular damage (meniscal and chondral) in reconstructions performed <3 months after injury compared to >12 months.  Chavez (2020) showed increase in chondral damage if reconstruction performed > 6 months, while the Kawashima (2020) study demonstrated increased chondral damage after 5 months. Senorski (2019) showed that older patients who waited > 1 year for reconstruction had greater risk of long-term osteoarthritis.

Benefits/Harms of Implementation

Delaying ACL reconstruction after an ACL injury increases the risk of meniscal and chondral damage which could increase the risk of long-term post-traumatic osteoarthritis in the knee.

Outcome Importance

If surgical decision making includes proceeding with an ACL reconstruction after an acute ACL injury, earlier reconstruction may decrease the risk of meniscal and chondral damage in the knee, and thus long-term degenerative changes in the knee.

Cost Effectiveness/Resource Utilization

Earlier surgery does not increase cost and may decrease cost by reducing overall time in rehabilitation and recovery, with quicker return to activity, sports, and work, as well as reducing the likelihood of needing concomitant meniscal and articular cartilage procedures, which often add implant cost.

Acceptability

Younger and more active patients should be treated as expeditiously as possible for this reason. Older, less active patients who may do well with nonoperative treatment of ACL tears can be considered differently.

Feasibility

Performing ACL reconstruction within 3 months of an acute ACL tear is feasible in most settings.

Future Research 

Prospective studies controlling for confounders to continue to define the ideal time for surgical intervention after an ACL injury would be valuable. Studies to assess the cost effectiveness of early versus late ACL reconstruction would also be informative.