Abstract
Objectives The aim of this study was to report the use of computed tomography (CT) for postoperative
evaluation of the accuracy of sacroiliac reduction and minimally invasive screw fixation
in a series of five cats.
Methods Medical records between January 2016 and March 2017 of cats presenting to the author's
institution were reviewed. Included were cats that had undergone minimally invasive
sacroiliac screw fixation with a complete medical record and pre- and postoperative
radiographs. Screw size was obtained from the medical records. CT images were acquired
prospectively and evaluated to assess joint reduction, relative screw size and screw
positioning.
Results Six sacroiliac luxations and 6 screws were available. Fixation was achieved with
either a 2.4 (n = 1) or 2.7 mm (n = 5), 316L stainless steel, cortical bone screw. Mean screw size as a proportion
of sacral diameter was 47.7%. Sacroiliac reduction >90% in the craniocaudal plane
and sacral screw purchase >60% of the sacral width were achieved in 3/5 cases. Mean
dorsoventral screw angulation was 1.6 degrees (range: −9.7 to 11.7 degrees) and craniocaudal
angulation was −4.5 degrees (range: −16.6 to 6.6 degrees). Complications included
screw loosening in the one case of bilateral repair and penetration of the neural
canal in one case which was not detected with postoperative radiographic evaluation.
Clinical Significance CT evaluation provides a useful method for the assessment of sacroiliac reduction
and the accuracy of screw placement.
Keywords
sacroiliac luxation - computed tomography - cats - minimally invasive approach - screw
fixation
