Background: Anterior Cruciate Ligament (ACL) is most vulnerable to injury post trauma amongst all the ligaments of knee joint. Anatomy of the proximal tibia has come under focus as one of the possible risk factors for ACL injury.
1.To determine whether greater Posterior Tibial Slope (PTS) measured on Magnetic Resonance Imaging (MRI) is a risk factor for ACL tear.
2.To observe the PTS – ACL relationship in both genders separately.
3.To observe PTS-ACL relationship after contact and non-contact injury.
4.To compare PTS measurements on lateral radiographs with MRI.
Study Design: Observational cross-sectional study.
Materials and Methods: MRI knee of 160 patients with knee trauma was done. The PTS was measured on sagittal MRI and lateral radiograph. The data was analyzed for association of increased PTS and ACL tear. Final results on MRI were compared with lateral radiographs.
Statistical analysis used: Independent t- test.
Results: The mean PTS on MRI of those with ACL injury was 14.3° compared with 9.9° for those with no injury (P = .001). The mean PTS on X-Ray of those with ACL injury was 14.4o compared with 8.6o for those with no injury (P = .001). Majority of patients with ACL tear has PTS more than 12o.
Conclusion: Greater PTS angle is a risk factor for ACL injury. ACL injury is influenced by the PTS than the nature of injury or gender. Both MRI and X-Ray proved useful to evaluate the PTS and identify the at-risk individuals for ACL tear.