• A D Caterson, D C Olthof, C Abel, and Z J Balogh.
• Department of Traumatology, John Hunter Hospital and University of Newcastle, Lookout Rd, New Lambton Heights NSW, 2305, Australia.
• Injury. 2021 Apr 1; 52 (4): 941-945.

AimThis paper evaluates computer tomographic morphology of partial ligamentous lesions of the sacroiliac joint. We hypothesised that in antero-posterior compression (APC) injuries the anterior superior portion of the sacroiliac joint (SIJ) should open up the most as suggested by the vector forces outlined in the Young and Burgess classification.MethodsAll patients who underwent operative fixation of a ligamentous APC pelvic injury between July 2009 and December 2015 in a single Level-1 trauma centre were included. Patients were case matched (1:1) to controls without pelvic injury. SIJ width was measured by two independent reviewers at the anterior superior and anterior inferior part of the SIJ. Wilcoxon ranged test was applied for analysis.Results70 patients (35 cases, 35 controls) were evaluated. Median inferior and superior SI joint widths were 5.27 (IQR 3.68-7.80) and 4.05 (IQR 3.13-5.31) mm in cases versus 2.24 (IQR 1.83-2.50) and 2.44 (IQR 2.14-2.65) mm in controls, respectively. The difference between the inferior and superior SI width in cases was larger than in controls (p-value < 0.01, median of -0.22 mm in the control group versus 1.51 mm in the cases).ConclusionOur data suggests that the inferior part of the SIJ opens up after injury more, relative to its superior portion. The vector of the force involved in rotationally unstable pelvic injuries is unlikely to be antero-posterior if the force causes the SI joint to widen up inferiorly first. This should be considered in SIJ fixation and challenges the APC mechanism in pure ligamentous rotationally unstable pelvic ring injuries.Copyright © 2020 The Authors. Published by Elsevier Ltd.. All rights reserved.

19 keywords...

hide…