Biplane Fractures of the Distal Femur: A Proposed Computed Tomography-Based Classification and Surgical Management

Abstract

Abstract Introduction: Management of periarticular fractures requires a careful understanding of fracture characteristics and proper pre-operative planning. We suggest a new computerized tomography (CT) based classification system, which assists in planning surgical approaches and in implant selection, and provides an addition to the metaphyseal comminution along with the articular type. Materials and Methods: 50 patients with biplanar distal articular fractures were included in our study and were classified using the CT-based classification. The CT images and intra-operative photographs were reviewed by five independent orthopedic surgeons and one radiologist to assess the reliability of the classification system. Postoperatively, patients were followed up at regular intervals, and range of motion and the Knee Society Score were assessed at 6 months. Discussion: AO Muller’s classification gives a good idea of metaphyseal and intra-articular involvement, which is followed worldwide for plan of management and fixation. This is based on 2D images. The classification described here is based on CT imaging, in which the 3D configuration has subtypes based on fracture fragments involving both intra-articular and extra- articular, which helps in understanding the fracture configuration in 3D and also helps in fixation of the fracture. Results: According to our proposed CT-based classification, distal femur fractures are classified as uniplanar (A and B) and biplanar types (C, D, E, and F). Among the biplanar fractures, the severity of articular comminution increases from type C to type F. We found that among the biplanar fractures, Type D (three-part fracture) was the most common fracture type. We found that Type C fractures had the best outcome, whereas type F had the worst functional results. Conclusion: This CT-based classification system can assess the severity of the articular comminution, decide the surgical approach and implant selection, and grade the prognosis.