Bone morphology features associated with knee kinematics may not be predictive of ACL elongation during high‐demand activities

Abstract

Purpose Bony morphology has been proposed as a potential risk factor for anterior cruciate ligament (ACL) injury. The relationship between bony morphology, knee kinematics, and ACL elongation during high-demand activities remains unclear. The purpose of this study was to determine if bone morphology features that have been associated with ACL injury risk and knee kinematics are also predictive of ACL elongation during fast running and double-legged drop jump. Methods Nineteen healthy athletes performed fast running and double-legged drop jump within a biplane radiography imaging system. Knee kinematics and ACL elongation were measured bilaterally after using a validated registration process to track bone motion in the radiographs and after identifying ACL attachment sites on magnetic resonance imaging (MRI). Bony morphological features of lateral posterior tibial slope (LPTS), medial tibial plateau (MTP) depth, and lateral femoral condyle anteroposterior width (LCAP)/lateral tibial plateau anteroposterior width (TPAP) were measured on MRI. Relationships between bony morphology and knee kinematics or ACL elongation were identiied using multiple linear regression analysis. ResultsNo associations between bony morphology and knee kinematics or ACL elongation were observed during fast running. During double-legged drop jump, a greater range of tibiofemoral rotation was associated with a steeper LPTS (β = 0.382, p = 0.012) and a deeper MTP depth (β = 0.331, p = 0.028), and a greater range of anterior tibial translation was associated with a shallower MTP depth (β = − 0.352, p = 0.018) and a larger LCAP/ TPAP (β = 0.441, p = 0.005); however, greater ACL elongation was only associated with a deeper MTP depth (β = 0.456, p = 0.006) at toe-of. Conclusion These indings indicate that observed relationships between bony morphology and kinematics should not be extrapolated to imply a relationship also exists between those bone morphology features and ACL elongation during highdemand activities. These new indings deepen our understanding of the relationship between bony morphology and ACL elongation during high-demand activities. This knowledge can help identify high-risk patients for whom additional procedures during ACL reconstruction are most appropriate.

Tibial spine volume is smaller in ACL‐injured athletes compared to healthy athletes

“…Posterior tibial slope has been reported to correlate with the occurrence of ACL injury [12][13][14]23]. However, recent data suggest that the posterior tibial slope may not be associated with ACL elongation and, therefore, injury risk during in vivo activities [16]. Historically, it has been accepted that the tibial ACL footprint is attached to a part of the tibial spine [17,25].…”