Video Analysis of 26 Cases of Second ACL Injury Events in Collegiate and Professional Athletes

Abstract

Background Significant effort has gone into the identification and quantification of the underlying mechanisms of primary ACL injury. Secondary ACL injury is observed in approximately 1/4 to 1/3 of athletes who return to sport following ACL reconstruction. However, little has been done to evaluate the mechanisms and playing circumstances surrounding these repeat injuries. Hypothesis/Purpose The purpose of this study was to characterize the mechanisms of non-contact secondary ACL injuries using video analysis. It was hypothesized that in video recordings of secondary ACL injury, athletes would exhibit greater frontal plane hip and knee angles, but not greater hip and knee flexion, at 66 ms following initial contact (IC) as compared to at IC and 33ms following IC. Study Design Cross-Sectional Study Methods Twenty-six video recordings of competitive athletes experiencing secondary ACL ruptures via noncontact mechanisms were analyzed for lower extremity joint kinematics, playing situation, and player attention. Kinematics were assessed at IC as well as 33 ms (1 broadcast frame) and 66 ms (2 broadcast frames) following IC. Results Knee flexion and knee frontal plane angles were greater at 66 ms than IC (p ≤ 0.03). Hip, trunk, and ankle frontal plane angles were not greater at 66 ms than IC (p ≥ 0.22). Injuries were distributed between attacking play (n=14) and defending (n=8). Player attention was most commonly focused on the ball (n=12) or an opponent (n=7). A single-leg landing accounted for just over half of the injuries (54%), while a cutting motion accounted for the remainder of the injuries (46%). Conclusion Secondary ACL injury was most likely to occur during landing or a sidestep cut with player attention external to their own body. Knee valgus collapse combined with limited hip motion was identified in the majority of secondary injuries. Level of Evidence Level IIIb

Reliability of Kinovea Program in Measuring Knee Joint Range of Motion

“…[14]; and Vargas et al [15] discussed the interrater reliability of Kinovea in measuring different joints ROM during functional activities, concluding results that agree with the results of the current study.…”

“…Also, supporting the results of current study, Vargas et al [15] used a subcohort from the total investigation sample (20 videos from a total of 26 videos). The studyapproved excellent interrater reliability of Kinovea program in measuring knee angle measurements (ICC = 0.975).…”

“…Also, measuring knee angle only at initial contact, 33ms, and 66ms after initial contact is not full knee ROM, while the current study results support Kinovea usual clinical application by approving its reliability in measuring full knee ROM. Vargas et al [15] used the same videos to discuss the interrater reliability of Kinovea in measuring knee angle at initial contact. Using the same videos to investigate reliability excludes the effect of video recording from different angles on end results reliability.…”

“…The Kinovea program reliability was investigated in measuring knee angle at running foot strike phase [13], walking initial contact phase [14], and while investigating the mechanisms of non-contact secondary ACL injuries [15]. However, those studies did not discuss a full knee excursion; so the aim of this study was to investigate the intrarater and interrater reliability of Kinovea program in measuring full knee ROM.…”