Importance of Postreduction CT Scans in Posterior and Transverse Posterior Wall Acetabular Fracture-Dislocations.

Abstract

Objectives: To report the frequency of patients with pre-reduction and postreduction computed tomography (CT) scans associated with acetabular fracture-dislocations and the change in position of associated intra-articular fragments occurring with joint reduction.

Methods:

Design: Retrospective case series.

Setting: Regional Level 1 trauma center.

Patient selection criteria: Patients who sustained Arbeitsgemeinschaft fur Osteosynthesefragen/Orthopedic Trauma Association 62A1 and 62B1 posterior wall or transverse posterior wall acetabular fracture-dislocations with pre-reduction and postreduction CT imaging from February 2020 to July 2023.

Outcome measures and comparisons: Intra-articular fragments were identified, and change in position (fossa to cranial, intra-articular to extra-articular, etc.) was noted from pre-reduction to postreduction scans. Operative reports and postoperative CT scans were reviewed to determine the frequency of fragment retrieval.

Results: One hundred nineteen (30.2%) of 394 patients meeting fracture pattern inclusion criteria received a CT scan before hip reduction. Of the 394 patients, 100 (25.9%) had pre-reduction and postreduction CT scans and were studied [average age of 35.5 years (range 16-87 years), 59 male patients]. Forty-five (45%) of 100 patients had pre-reduction CT imaging demonstrating the presence of intra-articular fragment(s). Thirty (66.7%) of 45 patients with a pre-reduction intra-articular fragment had an intra-articular fragment location change during the reduction. Of the 55 patients who did not have an intra-articular fragment on pre-reduction imaging, 28 (50.9%) had at least 1 intra-articular fragment on the postreduction CT. Complete fragment retrieval was performed in 71.4% of patients.

Conclusions: The study demonstrated that 30.2% of patients with posterior wall and transverse posterior wall acetabular fracture-dislocations received a CT scan before hip reduction. It was common to find intra-articular fragments on the postreduction CT in patients who did not have them on the pre-reduction CT. Obtaining and scrutinizing the postreduction CT scan provided accurate knowledge of the location of all osseous fragments associated with the fracture-dislocations, which facilitated thorough preoperative planning, intraoperative implementation, and hopeful long-term patient outcomes.

Level of evidence: Prognostic Level IV. See Instructions for Authors for a complete description of levels of evidence.