Postoperative Computed Tomography Scans of Acetabular Fractures Routinely Identify Indications for Revision Surgery.

OBJECTIVES: To investigate the utility of postoperative computed tomography (CT) scans in identifying indications for revision surgery after surgical fixation of acetabular fractures. DESIGN: Retrospective cohort study. SETTING: Urban level 1 trauma center. PATIENT SELECTION CRITERIA: Patients with surgically treated acetabular fractures with surgical fixation (open reduction and internal fixation or percutaneous fixation) with routine postoperative CT scans. OUTCOME MEASURES AND COMPARISONS: Primary outcome-revision surgery based on postoperative imaging, including intra-articular osteochondral fragments, implant complications, and malreductions. Secondary outcome-quality of reduction on radiographs versus CT scans. RESULTS: One hundred forty-eight patients were included. The revision surgery rate was 15.5% (23/148); indications included malpositioned implants (6.7%, n = 10), malreductions (5.4%, n = 8), and intra-articular loose bodies (3.4%, n = 5). Only 8.7% (2/23) of the indications for revision surgery were identified on postoperative radiographs, with the remainder being identified on CT scans. Revision surgeries were found to be associated with male gender (proportional difference: 19.6%, 95% confidence interval [CI]: 3.4%-29.4%; P = 0.04) and T-type fractures (PD 28.7%; CI, 9.0%-48.9%; P = 0.001). Revision surgery was not found to be associated with age, body mass index, posterior wall fractures, concurrent pelvic ring fractures, or surgical approach. On radiographs, 51.3% (n = 76/148) had anatomic reductions (<2 mm) compared with only 10.2% (n = 15/148) on CT scans. CONCLUSIONS: Indications for revision of acetabular fixation surgeries and poor reductions were frequently missed on plain radiography and identified on postoperative CT scans. This suggests that the use of advanced imaging such as intraoperative 3D imaging or postoperative CT scans may be beneficial. LEVEL OF EVIDENCE: Diagnostic Level IV. See Instructions for Authors for a complete description of levels of evidence.