Postoperative radiographic assessment of acetabular fractures - A comparison of plain radiographs and CT scans

Objectives: This investigation was designed to compare computerized tomography (CT) and plain radiography for detection of articular step and gap deformity after healing of operatively treated acetabular fractures. Design: Retrospective review of CT and plain radiographic images of 15 patients treated operatively for a displaced acetabular fracture. Setting: Level 1 trauma center. Main Outcome Measures: Ability of CT scans and plain radiographs to detect residual articular steps and gaps after healing of acetabular fractures managed by open reduction and internal fixation. Results: Using standardized evaluation techniques, more patients were found to have residual articular incongruities on CT scans (8 with step and 7 with gap) than on plain radiographs (1 with step and 6 with gap). In addition, a step deformity on CT scan correlated with a gap deformity and as the size of the step deformity increased, so too did the size of the gap deformity. Conclusions: Based on our data, computerized tomography is more likely than plain radiographs to allow detection of residual articular incongruities in healed acetabular fractures. The authors believe that CT scans improve the evaluation of articular reduction and that this information can be used to further evaluate surgical technique and provide insight as to the impact of residual articular incongruity on the development of hip arthrosis.