The relationship between posterior tibial slope and anterior cruciate ligament injury.

INTRODUCTION The aim of this study was to identify an increased posterior tibial slope as a possible risk factor for anterior cruciate ligament injury. MATERIAL AND METHODS Sixty patients were divided into two groups (with and without anterior cruciate ligament rupture). The posterior tibial slope on the lateral and medial condyles was measured by sagittal magnetic resonance imaging slices by means of computerized method using circles to determine tibial axis. RESULTS The patients with anterior cruciate ligament rupture had a statistically significantly (p = 0.06) greater posterior tibial slope on the lateral tibial condyle than the control group (6.68 degrees:5.64 degrees), and a greater slope on the medial condyle (5.49 degrees:4.67 degrees) in comparison to the patients with the intact anterior cruciate ligament. No significant difference in the average values of angles was observed between males and females with anterior cruciate ligament rupture, the average value being 6.23 degrees in men and 5.84 degrees in women on the lateral condyle, and 4.53 degrees in men and 4.53 degrees in women on the medial condyle. DISCUSSION AND CONCLUSION A statistically significant difference between the values of posterior tibial slope was observed between the groups with and without anterior cruciate ligament rupture, the sex having no affect on the value of the posterior tibial slope. The method of measuring angles should be unique.