Abstract Background Animal models have long been considered an important modality for studying ACL injuries. However, to our knowledge, the value of these preclinical models to study sex-related phenomena associated with ACL injury and recovery has not been evaluated. Questions/purposes We asked whether (1) prominent anatomic and (2) biomechanical factors differ between female and male porcine knees, particularly those known to increase the risk of ACL injury. Methods Eighteen intact minipig knees (nine males, nine females) underwent MRI to determine the femoral bicondylar width, intercondylar notch size (width, area and index), medial and lateral tibial slope, ACL size (length, cross-sectional area, and volume), and medial compartment tibiofemoral cartilage thickness. AP knee laxity at 30°, 60°, and 90°flexion and ACL tensile structural properties were measured using custom-designed loading fixtures in a universal tensile testing apparatus. Comparisons between males and females were performed for all anatomic and biomechanical measures. The findings then were compared with published data from human knees. Results Female pigs had smaller bicondylar widths (2.9 mm, ratio = 0.93, effect size = À1.5) and intercondylar notches (width: 2.0 mm, ratio = 0.79, effect size = À2.8; area: 30.8 mm 2 , ratio = 0.76, effect size = 2.1; index: 0.4, ratio = 0.84, effect size = À2.0), steeper lateral tibial slope (4.3°, ratio = 1.13, effect size = 1.1), smaller ACL (length: 2.7 mm, ratio = 0.91, effect size = 1.1; area: 6.8 mm 2 , ratio = 0.74, effect size = À1.5; volume: 266.2 mm 3 , ratio = 0.68, effect size = À1.5), thinner medial femoral cartilage (0.4 mm, ratio = 0.8, effect size = À1.1), lower ACL yield load (275 N, ratio = 0.81, effect size = À1.1), and greater AP knee laxity at 30°( 0.7 mm, ratio = 1.32, effect size = 1.1) and 90°(0.5 mm, ratio = 1.24, effect size =
