gms | German Medical Science

Objectives: Computed tomography (CT) is a useful modality in characterizing tibial plateau fractures. In prevenient studies we analyzed CT scans of tibial plateau fractures and summarized the data in a frequency map. We could emphasize the importance of a systematic preoperative CT evaluation. We could show that the complexity of the fractures concerning the joint surface is not sufficiently covered in the common classifications, especially the dorsal involvement.

The frequency map introduced in 2016 is a tool for a systematic evaluation of CT scans in clinical practice. The purpose of this study was to create a new CT based classification system of tibial plateau fractures to offer a better comparability in clinical studies and to apply it as a prognostic tool to estimate clinical progress.

Methods: Two hundred and eight tibial plateau fractures treated between Jan.2013 - Feb.2016 were retrospectively included in this single center study and evaluated in a CT based frequency map.

The frequency map was templated onto an axial intact subarticular tibial plateau. Therefore we separated the joint surface in 3 lateral, 3 medial and 3 tibial spine areas and counted the frequence of involvement. Based on this data we created a CT scoring and classification system. GT-Scoring system: Every affected area counts as one and with impression one point is added per involved area. The GT-Score is devided in mild (1-3), moderate (4-6) and severe (over 7). The GT-Type refers to the involved compartments (lateral, tibial spine, medial). Type I is an affection of one compartment, type II two compartments and type III three compartments. The combination of score and type results in the classification.

Results and Conclusion: This study included 92 female and 118 male patients (average age 55) with a tibial plateau fracture. 126 fractures were Schatzker type 1, 2 or 3; 58 were Schatzker type 4 and 21 were Schatzker type 5 or 6. 45 % showed an impression.

According to the GT classification we had 69 mild, 106 moderate and 32 severe fractures.

The 69 mild fractures are divided into 59 type I, 6 type II and 4 type III. The 106 moderate fractures are divided into 55 type I, 30 type II and 21 type III. And the 32 severe fractures are divided into 0 type I, 10 type II and 22 type III.

The mean k values for interobserver reliability using Schatzker Classification systems were 0.62 representing "substantial agreement," whereas the mean k values were 0.89, representing "excellent agreement" applicating the GT classification on CT scans.

We developed a classification system which offers a simple and systematic way for CT grading of tibial plateau fractures. Moreover the application of the frequency map provides a visual guideline for choosing the surgical approach. A CT based classification system is necessary to compare different studies in these complex fractures. The GT classification has to prove its clinical prognostic value in future studies.