Lower limb alignment in anterior cruciate ligament-deficient versus -intact knees.

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.