Thin cortical translucent area of the iliac wing: morphometric analysis and implications for surgical safety

BACKGROUND: The iliac wing is a frequently used fixation site in the surgical management of pelvic and acetabular fractures. Achieving safe implant placement in this region necessitates a comprehensive understanding of local morphology. However, the morphometric characteristics and surgical safety margins of the thin cortical translucent area (PLA) located in the central iliac wing have not been sufficiently defined. This may pose a significant challenge in evaluating the risk of cortical perforation, particularly during implant placement. This study aimed to evaluate the morphometric characteristics of the PLA and its relationship to fixation corridors. METHODS: Fifty-one unpaired dry hip bones were examined. The thin cortical translucent region was identified using photoluminescence. Photograph-based measurements were conducted utilising ImageJ software on standardised photographs. Dimensions, area, distances to reference landmarks and relationships with the iliac pillar and supraacetabular corridors were assessed. The safe angular deviation range for anterior inferior iliac spine (AIIS)-origin screw fixation was calculated. Cortical thickness was measured using a digital thickness gauge. RESULTS: , respectively. Mean distances to the anterior superior iliac spine, posterior superior iliac spine, iliac crest and acetabular roof were 62.12 ± 19.84 mm, 71.03 ± 12.17 mm, 19.88 ± 11.61 mm and 56.02 ± 9.09 mm, respectively. The safe angular deviation for AIIS-origin screw fixation was 16.94° ± 4.43°. The central cortical thickness was 2.07 ± 1.60 mm (range 0.3-5.9). CONCLUSIONS: The PLA is a clinically important region characterised by marked central cortical thinning and individual variability. Individualised morphometric assessment and preoperative imaging may help define safer zones for fixation planning and donor-site procedures. LEVEL OF EVIDENCE: Level V.