Asymmetric Sacral Dysmorphism: Prevalence and Impact on Surgical Planning

To determine the prevalence and surgical relevance of asymmetry in patients with sacral dysmorphism.

Retrospective review.

Level 1 academic trauma center.

Included were patients between 16 and 85 years old with an operative pelvic ring injury (Orthopaedic Trauma Association/Arbeitsgemeinschaft für Osteosynthesefragen (OTA/AO) 61A-C) and a thin-cut pelvis computed tomography (≤2.0 mm) with 3D reformats. Sacral dysmorphism was defined by the inability to place a transiliac-transsacral screw in the upper sacral segment.

Asymmetry was assessed by evaluating side-to-side differences in neuroforaminal height, upper sacral segment pathway obliquity, and anterior-posterior pathway width.

The group of patients with asymmetric sacral dysmorphism was 52.9% female while the group with symmetric sacral dysmorphism and without sacral dysmorphism was 36.3% female and 44.3% female, respectively. The average age of the patients with asymmetric, symmetric, and no sacral dysmorphism was 43.0 years (range 16-89), 42.9 years (range 18-94), and 47.5 years (range 33-89), respectively. Of the 220 patients evaluated, there were 114 (51.8%) patients who demonstrated sacral dysmorphism. Among dysmorphic patients, 34 (29.8%) exhibited at least 1 feature of asymmetry. Asymmetric features included differences in neuroforaminal height, upper sacral segment pathway obliquity, and pathway width.

Approximately 30% of patients with sacral dysmorphism demonstrated asymmetric features, which can affect surgical planning. Recognition of asymmetric sacral dysmorphism is important for proper execution of posterior pelvic fixation.

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