Risk Factors Associated With a Noncontact Anterior Cruciate Ligament Injury to the Contralateral Knee After Unilateral Anterior Cruciate Ligament Injury in High School and College Female Athletes: A Prospective Study

Abstract

Background: The incidence of contralateral anterior cruciate ligament (CACL) injuries after recovery from a first-time anterior cruciate ligament (ACL) disruption is high in women; however, little is known about the risk factors associated with this trauma. Hypothesis: Patient characteristics, strength, anatomic alignment, and neuromuscular characteristics of the contralateral uninjured leg at the time of the first ACL trauma are associated with risk of subsequent CACL injury, and these risk factors are distinct from those for a first-time ACL injury. Study Design: Case-control study; Level of evidence, 3. Methods: Sixty-one women who suffered a first-time noncontact ACL injury while participating in high school or college sports and underwent measurement of potential risk factors on their contralateral limb soon after the initial ACL injury and before reconstruction were followed until either a CACL injury or an ACL graft injury occurred, or until the last date of contact. Results: Follow-up information was available for 55 (90.0%) of the 61 athletes and 11 (20.0%) suffered a CACL injury. Younger age, decreased participation in sport before the first ACL disruption, decreased anterior stiffness of the contralateral knee, and increased hip anteversion were associated with increases in the risk of suffering a CACL injury. Conclusion: A portion of CACL injury risk factors were modifiable (time spent participating in sport and increasing anterior knee stiffness with bracing), while others were nonmodifiable (younger age and increased hip anteversion). The relationship between younger age at the time of an initial ACL injury and increased risk of subsequent CACL trauma may be explained by younger athletes having more years available to be exposed to at-risk activities compared with older athletes. A decrease of anterior stiffness of the knee is linked to decreased material properties and width of the ACL, and this may explain why some women are predisposed to bilateral ACL trauma while others only suffer the index injury. The risk factors for CACL injury are unique to women who suffer bilateral ACL trauma compared with those who suffer unilateral ACL trauma. This information is important for the identification of athletes who may benefit from risk reduction interventions.

Risk Factors for Contra-Lateral Secondary Anterior Cruciate Ligament Injury: A Systematic Review with Meta-Analysis

“…Of the 44 included studies, nine [ 53 , 57 , 59 , 61 , 67 , 68 , 70 , 85 ] were excluded from the meta-analysis due to being the only study reporting on a specific factor or using specific statistics that were not possible to calculate to odds ratios. The caracteristics and results of these studies are reported in online resource 2.…”

“…A few studies have previously pointed to a possible role of hip and knee movement patterns and moments during functional tasks, as well as hop performance, for the risk of sustaining second ACL injuries (graft rupture and C-ACL injury combined) [ 30 , 39 , 113 ]. There is nevertheless limited evidence for lower extremity strength as a contributing factor to C-ACL injury risk [ 53 , 66 ] (Online resource 2). Given that demographic factors such as sex, age and family history cannot be changed, studies on risk factors that are modifiable are encouraged.…”

Screening Tests for Assessing Athletes at Risk of ACL Injury or Reinjury—A Scoping Review

“…Of the eight studies reporting joint laxity measures, five studies found an association with ACL (re)injury in at least one of the metrics assessed [ 14 , 15 , 33 , 46 , 60 ], while two found none [ 18 , 52 ]. One study was excluded from the analysis because of a potential risk of bias [ 27 ].…”

“…One study was excluded from the analysis because of a potential risk of bias [ 27 ]. An association between the following metrics and ACL (re)injury was found for: (1) anterior knee stiffness (a 1 SD decrease in anterior stiffness of the knee was associated with a 2.37-fold increase in the risk of CACL injury) [ 33 ]; (2) generalized joint laxity (little finger extension and thumb opposition test were positive in the ACL injured) [ 14 ]; (3) side-to-side differences in knee laxity (for every 1.3-mm increase, the odds of ACL injury increased four-fold (95% CI, 1.68–9.69), and side-to-side difference in anterior knee laxity of 3 mm or greater had an OR of 2.4 of sustaining a contralateral ACL injury) [ 46 , 60 ]; and (4) decreased general joint laxity (GJL) (based on the Beigtohn GJL scale, where a larger number indicated a higher GJL; cases: 1.8 (1.3); controls: 2.7 (2.2)) [ 15 ]. No association was found for generalized laxity measures [ 18 , 46 ] or knee laxity in the sagittal plane [ 14 , 15 , 18 , 33 , 52 ].…”

“…Measures of joint morphology and anthropometrics were addressed in 18 studies [ 14 , 15 , 18 , 21 , 26 , 28 , 29 , 32 , 33 , 35 , 37 , 38 , 39 , 43 , 44 , 45 , 51 , 55 ], of which we excluded three from the analysis because of the potential risk of bias [ 26 , 28 , 29 ]. The following metrics were the most common: four studies assessed femoral notch width [ 14 , 43 , 44 , 45 ], five investigated the tibial slope [ 21 , 43 , 44 , 51 , 55 ], and another five examined height and weight [ 15 , 33 , 35 , 38 , 39 ].…”