Lower Limb Alignment in Anterior Cruciate Ligament–Deficient versus –Intact Knees

Abstract

Purpose. To compare anatomic lower limb features of anterior cruciate ligament (ACL)–deficient versus –intact knees in Chinese subjects. Methods. Anatomic lower limb features (mechanical axis, tibiofemoral angle, posterior tibial slope, notch width index, and hip neck-shaft angle) of 25 men and 3 women aged 18 to 39 (mean, 26) years with ACL-deficient knees, and 16 men and 4 women aged 24 to 31 (mean, 28) years with ACL-intact knees were compared using radiography. Results. The notch width index (0.26 vs. 0.29, p=0.02) was significantly smaller in ACL-deficient than ACL-intact knees. Conclusion. Small notch width was associated with a thin ACL and can be regarded as an anatomic intrinsic risk factor for ACL injuries.