Role of posterior tibial slope in ACL deficient Indian population

PurposePosterior tibial slope (PTS) is a bony factor contributing to the anteroposterior stability of knee. It is believed that increased PTS has been associated with ACL injury. The aim of this study is to identify an increased posterior tibial slope as a possible risk factor for ACL injury in Indian population.MethodsProspective case control study was conducted in Bajaj orthopaedic sports clinic, Delhi. 55 patients were included, in which 27 patients with ACL tear were included in case group “A” and remaining 28 patients with intact ACL in control group “B”. Inclusion criteria: Age - 15-55 years, group “A” - patient diagnosed with ACL tear clinically and radiologically on MRI knee and presented within 3 months of injury, group “B” - patient with intact ACL and got their MRI knee done for other knee pathologies. Exclusion criteria: Age >55 years, poor quality MRI, advanced osteoarthritis classified as >grade 2 in Outerbridge classification, multiple ligamentous instability, non-Indian and Patient with ACL tear presenting >3 months after injury. Using MRI, PTS was calculated and compared individually for medial and lateral tibial condyle.ResultsThe average PTS in case group was 3.95 and 4.74 for medial and lateral tibial condyle respectively. PTS in control group was less than case group with mean value of 0.03 and −0.38 for medial and lateral condyle respectively with statistically significant outcomes (p value <0.05) both for medial and lateral slope.ConclusionIn Indian population, increased PTS can be concluded as a significant risk factor in ACL injury. Though, posterior tibial slope cannot be considered as an isolated risk factor.