内科: オープンアクセス
オープンアクセス

概要

A Comprehensive Look at Sacral Dysmorphism and a Review of Altered Safe Zones in Sacroiliac Screw Fixation

Samuel G. Eaddy, M.S.

Sacral dysmorphism (SD) is a congenital anomaly found in up to 54% of the population. This includes abnormalities within the lumbosacral joint and its surrounding structures, presenting increased risk in the surgical repair of posterior pelvic ring injuries. Iliosacral and transsacral screw fixation is greatly influenced by these anatomical variations, consequently altering surgical planning. A systematic review was performed with the following objectives: to determine the overall prevalence of SD; to summarize the implications of its anomalies in surgery; and to describe the altered safe zones that may be available to orthopaedic surgeons. Inclusion criteria included studies that reported the statistical prevalence of SD and their associated features. Data collected included patient demographics, prevalence of SD, quantification or classification of dysmorphic anatomy, and postoperative complications. Our analysis demonstrated a prevalence of 23% among 1,983 pelves in 11 studies. Among the seven known dysmorphic criteria, only three have been considered significant in the evaluation of screw placement. Approximately 95% of dysmorphic sacra can accept an S2 transsacral transiliac screw compared to 50% in normal counterparts. Additional evidence suggests viable fixation pathways in dysmorphic S3. These results led to the conclusion that SD is a relatively common condition that appears to present on a spectrum of severity, yet the variability in dysmorphic anatomy complicates the development of a universal solution to biomechanical fixation. Standard protocol suggests fixation of dysmorphic sacra at S2 when S1 is not viable, as lower sacral segments have been found to yield greater opportunity in this patient population.