Association of Tibial Plateau Fracture Morphology With Ligament Disruption in the Context of Multiligament Knee Injury

Abstract

Background: We identified common morphologies of tibial plateau fractures that arise with multiligament knee injuries (MLKIs), and investigated the relationship of the fracture with ligament tears. We also evaluated the correlation of 3 tibial plateau fracture classification systems (Schatzker, AO, and Duparc).

Methods: Over a 2-year period, a single orthopaedic surgeon at our institution managed 90 MLKIs. Images of those knees with a tibial plateau fracture were retrospectively reviewed and classified per Schatzker, AO, and Duparc systems. Correlation among the 3 systems was evaluated using Spearman nonparametric correlation coefficient. Associations between fracture grading system and ligament tears were estimated using logistic regression. Associations between ligament tears and tibial plateau fracture location (medial vs lateral) were estimated using exact logistic regression.

Results: A total of 19 of 90 knees suffered tibial plateau fractures. There was reasonable correlation among the 3 tibial plateau classification systems. Increasing grade under the Schatzker system showed statistically significant associations with medial collateral ligament (MCL) (P = 0.056) and posterolateral corner (PLC) (P = 0.035) tears. Increasing grade under the Duparc system showed statistically significant associations with MCL (P = 0.032) and PLC (P = 0.058) tears. PLC tears had a statistically significant association with medial plateau fractures (P = 0.003); odds ratio of 121.1 (95% CI: 2.2-∞). MCL tears had a statistically significant association with lateral plateau fractures (P = 0.004); odds ratio of 18.4 (95% CI: 2.1-∞). Although not statistically significant, 8 out of 9 knees with a lateral plateau fracture demonstrated tear of the anterior cruciate ligament (ACL).

Conclusions: As the grade of designation increases within the Schatzker and Duparc tibial plateau fracture classifications, as does the likelihood of MCL and PLC tear. The majority of tibial plateau fractures that occur in the context of MLKI are either isolated to the medial or lateral tibial plateau. Medial tibial plateau fractures are associated with PLC tears. Lateral tibial plateau fractures are associated with MCL tears, and although not statistically significant in our small sample size, 8 out of 9 knees also demonstrated a tear of the ACL.