Reliability and Agreement of Different Spine Fracture Classification Systems: An Independent Intraobserver and Interobserver Study

OBJECTIVE: Currently, no spinal classification system has achieved universal acceptance. Therefore, it is important to choose a reliable classification within clinical practice. The objective of this study was to determine and compare the intraobserver and interobserver agreement of the Load Sharing Classification (LSC), the Thoracolumbar Injury Classification System (TLICS), and the AOSpine Thoracolumbar Spine Injury Classification System. METHODS: In this web-based intraobserver and interobserver study (www.spine.hostei.com), plain radiographs and computed tomographic scans of traumatic thoracolumbar fractures (T12-L2) were evaluated. By use of a questionnaire, fractures were classified according to the LSC, the TLICS, and the AOSpine classification. Data were analyzed with SPSS (Version 21, 76 Chicago, Illinois, USA). Intraobserver and interobserver agreement was determined by the Cohen k. Statistical significance was defined as P < 0.05. RESULTS: Data from 91 patients were classified twice by 7 board-certified spine surgeons. The intraobserver and interobserver reliability considering the LSC total score was noted as fair (intraobserver/interobserver reliability: k [0.26/0.22). Considering the resulting TLICS total score, a moderate intraobserver agreement (k = 0.41) was noted, whereas the interobserver results presented only fair reliability (k = 0.23). In contrast to the LSC and the TLICS, the AOSpine classification showed substantial agreement considering the fracture type (A; B; C) (intraobserver/interobserver reliability: k = 0.71/0.61) and moderate agreement considering the fracture subtype (e.g., A0; A1;.; B1;.) (intraobserver/interobserver reliability: k = 0.57/0.48). CONCLUSION: In conclusion, the reliability of the AOSpine fracture classification is superior to the TLICS and the LSC. Therefore, this classification system could best be applied within clinical practice.