Research Summary

Bone Bruise Patterns After ACL Tears in Skiers vs Pivoting Athletes

Miranda Manier, BA

Key Highlights:

  • Bone bruises (BBs) in the lateral femoral condyle were significantly more prevalent in pivoting sports athletes than in alpine skiers after noncontact anterior cruciate ligament (ACL) tears.
  • No significant differences were found in BB depth or the prevalence of concomitant meniscal or collateral ligament injuries between the two groups.
  • Observer agreement was almost perfect for BB prevalence and substantial for both BB depth and associated injuries.
  • These findings, according to the study authors, support the need for sport-specific ACL injury prevention strategies tailored to biomechanical demands.

In a cohort study comparing magnetic resonance imaging findings in athletes with noncontact anterior cruciate ligament (ACL) tears, pivoting sports athletes were found to have a significantly higher prevalence of bone bruises (BBs) in the lateral femoral condyle (LFC; 85.2%) than alpine skiers (51.9%; P = .008). Despite this difference, there were no significant differences between the groups in BB depth or in the prevalence of concomitant medial/lateral meniscal or collateral ligament injuries.

This study was driven by the hypothesis that differences in ACL injury patterns across sports stem from sport-specific biomechanical mechanisms. Previous evidence has indicated that alpine skiers are more likely to experience isolated ACL tears, whereas pivoting sports athletes frequently present with associated meniscal damage. BBs, visible on MRI and reflective of the injury’s mechanical force and position, were leveraged as indicators of these underlying mechanisms. However, detailed comparative data on BB patterns and associated injuries in different sports had been limited prior to this investigation.

Researchers retrospectively analyzed 446 patients with ACL injuries treated between December 2016 and November 2020. After strict exclusion criteria and propensity score matching for age, sex, and body mass index, 27 alpine skiers and 27 pivoting sports athletes were included. BBs were assessed using the modified Whole-Organ MRI Score (WORMS) segmentation technique, and BB depth was classified according to the International Cartilage Repair Society system. Concomitant injuries were evaluated using established classification systems. Observer agreement was assessed with Fleiss κ values.

MRI revealed that BBs occurred in 92.6% of patients overall, with the lateral tibial plateau (90.7%) and LFC (68.5%) being the most affected sites. While BBs in the LFC were more prevalent in pivoting sports athletes, no between-group differences emerged for other anatomic sites or BB depth. Concomitant injuries were more common on the medial side (medial meniscus: 31.5%, medial collateral ligament: 18.5%) but showed no significant differences between sports. Observer agreement was nearly perfect for BB presence (κ = 0.95–1.00) and substantial for BB depth and concomitant injuries (κ = 0.64–0.94). Post hoc power analysis demonstrated 75% statistical power for the primary outcome.

Limitations of the study include its retrospective design and the inclusion of multiple sports within the pivoting group, which may have introduced heterogeneity. Additionally, the semiquantitative measurement of BB depth and the use of MRIs from multiple institutions may have limited sensitivity to detect nuanced differences.

“The prevalence of BBs in the lateral femoral condyle was higher in pivoting sports athletes than in alpine skiers after acute noncontact ACL tears,” the authors concluded. “This suggests that ACL injuries in pivoting sports are associated with higher lateral compression forces in a pivot-shift mechanism, whereas anterior tibial translation and tibial rotation may be the predominant loading pattern in alpine skiing.”

Reference:
Ubl ST, Vieider RP, Seilern Und Aspang J, et al. Bone bruise patterns after noncontact anterior cruciate ligament tears differ between alpine skiers and pivoting sports athletes. Am J Sports Med. 2025;53(7):1606-1613. doi:10.1177/03635465251332272