The Reliability of Postoperative Radiographic Matta Grading for Quality of Reduction of Acetabular Fractures

Objectives: To assess the reliability of the postoperative radiographic Matta grading for quality of reduction of acetabular fractures. Design: An inter-reliability and intrareliability study. Setting: Level I trauma center. Participants: 15 independent observers of different levels of experience who evaluated 115 sets of postoperative acetabulum radiographs in 35 consecutive patients with displaced acetabular fractures between January 2017 and January 2019. Main Outcome Measurements: To assess the interobserver and intraobserver reliability of Matta radiographic grading for postoperative quality of reduction of acetabular fractures. Results: The overall interobserver agreement was excellent among all groups with an average absolute intraclass correlation coefficient (ICC) of 0.91 (95% CI 0.93-0.97). When stratifying the agreement based on experience, the orthopaedic trauma fellow subgroup had the highest rate with an ICC of 0.92. The overall intraobserver agreement was good with an ICC of 0.81 (95% CI 0.74-0.85). Conclusion: The Matta radiographic grading was a reliable tool for the evaluation of quality of reduction after surgical fixation of acetabular fractures with excellent interobserver and good intraobserver reliabilities among different levels of observers.