Analysis of the orbital posterior ledge in an orbital fracture

Abstract

Orbital posterior ledge (PL) serves as the posterior limit for surgical instrumentation and important landmark for final plate position. The involvement and role of PL in an orbital fracture is not fully understood. The study aim is to determine the prevalence of PL involvement in orbital fracture cases. We provide further analysis to the radiographical features and possible predictors associated with its involvement in both pure and impure fracture. A retrospective cross-sectional analysis was performed based on orbital fracture computed tomography (CT) records in tertiary level hospital. Demographic data was retrieved, and analysis of PL conditions and morphometric measurements were performed to various dispositions of its independent radiographic variables. Statistical analysis involved parametric and non-parametric statistics, followed by regression analysis to determine predictors for PL involvement in an orbital fracture. The prevalence of PL fracture was 38.46%, and commonly found in impure fracture type. Demographic findings showed similarity to previous orbital fracture findings in Malaysia. Fracture aetiology was mainly due to motor vehicle, followed by assault, sports, and fall injury. The mean PL location is at 34.9mm in male compared 34.0mm in female. Factors associated with PL fracture includes muscle changes and loss of orbital floor inclination. Inferior displacement was the commonly observed in PL fracture. Male patient has slightly increase in anterior- posterior distance of PL compared to females. Involvement of PL is associated with race, presence of muscle changes, loss of orbital floor inclination and when fracture is due to motor vehicle accidents. This study is clinically relevant as it allows structured and timely analysis of orbital fracture based on the involvement of the PL and its correlation with other radiological parameters.