LAUSR

PURPOSE The existing classification systems of tibial plateau fracture (TPF) are suboptimal for clinical use and academic communication. A more comprehensive and universal classification system with the capability to analyze all patterns of TPF is urgently required to guide the clinical practice. This study aimed to analyze the incidence and fracture characteristics of TPF using a computed tomography-based "four-column and nine-segment" classification. METHODS According to the differentiated morphological characteristics, tibial plateau and proximal fibula were divided into four columns, which were subdivided into nine segments. Tibia plateau injury index (TPII) was innovatively introduced to represent the extent of injury. A total of 698 consecutive adult patients with 704 affected knees were included (377 females, 321 males, mean age 51.6 ± 12.9 years). Fracture mapping was retrospectively analyzed according to the new-style classification system based on the CT imaging. RESULTS 371 (53.2%) left knees and 321 (46.0%) right knees were injured solely and 6 (0.9%) cases sustained bilateral injuries. The rates of one-column, two-column, three-column and all-four-column injuries were 30.5%, 31.5%, 28.0% and 9.9%, respectively. On average, 2.2 ± 1.0 columns and 3.6 ± 2.1 segments were involved, the mean TPII was 5.7 ± 3.0. The rates of mild, moderate and severe comminuted fractures were 50.0%, 37.5% and 12.5%. The most frequently affected columns were lateral column (572, 81.3%) and intermedial column (524, 74.4%), and the less frequently involved columns were the medial column (219, 31.1%) and fibular column (218, 31.0%). The most frequently affected segments were the posterolateral segment (465, 66.1%), anterolateral segment (453, 64.3%) and posteromedian segment (379, 53.8%). The least frequently involved segment was tubercle segment (85, 12.1%). CONCLUSIONS The novel "four-column and nine-segment" classification will be a beneficial classification system for clinical diagnosis, statistical analysis and prognostic judgment of tibial plateau fractures.