The role of applying radiological modifiers to the Letournel classification and its clinical implications

Abstract

While the Letournel classification is the most widely used system for classifying acetabular fractures, it has some limitations, such as a limited inclusivity and a limited ability to guide surgical approaches. Introducing radiological modifiers to the Letournel classification could address those shortcomings. The main aim of this study is to identify these modifiers, determine their incidence relative to different acetabular fracture patterns, and explore their association with fractures that cannot be classified using the Letournel system. The secondary objective is to evaluate how these modifiers may improve their utility in guiding surgical approaches. The radiographs and CT scans of 236 acetabular fractures were retrospectively reviewed by 2 authors to classify the fracture and to detect the presence of the radiological modifiers, which are roof impaction, marginal impaction, head impaction, head fracture, intraarticular fragments, preoperative dislocation and its type, articular comminution, pelvic ring involvement, and quadrilateral plate involvement. Using the modifiers, the number of unclassified fractures was reduced by 90%. Some modifiers were more significantly common in the older age group. The presence of specific modifiers, such as roof impaction and intraarticular fragments, mandated the use of a different approach. We used surgical hip dislocation in 21(8.8%) cases based on specific modifiers, namely, femoral head fracture 11, roof impaction 6, and intraarticular fragment 2, pure impaction (unclassified) 1, and labral avulsion with posterior rim in 1. Infrapectineal plating was done in 14 cases (6 %) based on the presence of quadrilateral plate modifier. Identifying the characteristics of an acetabular fracture is essential for enhancing the value of its classification. Given the complex anatomy and varied injury patterns of the acetabulum, an accurate description that includes radiological modifiers-such as posterior wall involvement or quadrilateral plate displacement-provides a more comprehensive assessment. Integrating these modifiers into the Letournel classification improves its ability to predict prognosis and guides surgical planning more effectively.