Objectives To define the procedure-specific surgical anatomy of the pre-symphyseal region relevant to W-plate fixation by characterizing the soft-tissue layers, identifying critical neurovascular structures, and defining quantitative safe zones for dissection and plate placement. Methods Fresh-frozen adult cadavers underwent standardized low Pfannenstiel dissections reproducing the Over-the-Rectus Extrapelvic (OREX) exposure required for W-plate fixation. Pre-symphyseal soft-tissue layers were sequentially dissected from the skin to the anterior pubic symphysis. The locations of critical neurovascular structures relative to the pubic midline and pubic tubercles were recorded, together with anatomical layers, dimensions of the prepubic ligamentous-aponeurotic complex, soft-tissue thickness, sex-related anatomical differences, and surgical safe zones. Results Three reproducible anatomical layers were identified in ten specimens. The superficial layer contained the pre-symphyseal fat pad and superficial epigastric vessels. The intermediate layer contained the spermatic cord or round ligament, ilioinguinal and genitofemoral nerves, and suprapubic artery, with these critical structures located at a mean distance of approximately 3.2 cm from the midline. The deep layer was consistently formed by the Pyramidalis–anterior pubic Ligament–Adductor longus Complex (PLAC), which covered the anterior pubic symphysis and measured a mean of 4.6 × 3.1 cm. No critical neurovascular structure crossed the central trajectory corresponding to W-plate placement. Female specimens demonstrated greater preperitoneal soft-tissue thickness, whereas lateral surgical safe zones were narrower in male specimens. Conclusion The pre-symphyseal region demonstrated a reproducible three-layer surgical anatomy with a predictable distribution of critical neurovascular structures. Quantitative anatomic mapping defined procedure-specific safe zones for extrapelvic W-plate fixation and provided practical guidancefor surgical exposure, implant positioning, and avoidance of iatrogenic injury. Level of evidence Level IV, therapeutic study
Background Surgical fixation of pelvic ring fractures carries a substantial risk of postoperative complications, particularly surgical site infection, yet the relative contribution of fracture pattern and associated soft tissue injury to this risk remains incompletely defined. Objective To describe the rate and spectrum of complications following surgical fixation of pelvic ring fractures and to identify factors independently associated with these complications, with particular attention to acute surgical site infection. Methods Retrospective, single-center cohort study of 126 patients who underwent surgical fixation of pelvic ring fractures between December 2014 and November 2024, reported in accordance with the STROBE statement. Candidate demographic, injury-related, and treatment-related exposures were compared against a composite primary outcome (any postoperative complication) and against acute infection using Fisher’s exact test, Pearson chi-square test, the Mann-Whitney U test, and multivariable logistic regression. Results Overall, 39 of 126 patients (31.0%) experienced at least one postoperative complication; chronic pain (22.2%) and acute surgical site infection (16.7%) were the most frequent individual components. In bivariate analysis, the presence of a Morel-Lavallée lesion at baseline was significantly associated with both the composite outcome (OR 12.65, 95% CI 1.42–112.27, p = 0.011) and acute infection (OR 12.12, 95% CI 2.06–71.37, p = 0.007); Young-Burgess fracture pattern was also associated with infection (p = 0.018). After multivariable adjustment for infection, a Morel-Lavallée lesion (adjusted OR 17.69, 95% CI 2.46–126.95, p = 0.004) and combined-mechanism fracture pattern (adjusted OR 8.25 versus anteroposterior compression, 95% CI 1.91–35.58, p = 0.005) remained independently associated with infection. Neither the presence, technique, nor surgical approach of posterior ring fixation was associated with any complication type, and time from injury to definitive fixation (median 13 days) showed no significant association with either outcome. Conclusion A Morel-Lavallée lesion identified at initial evaluation was associated with postoperative complications in bivariate analysis and, together with a combined-mechanism fracture pattern, remained an independent predictor of surgical site infection after multivariable adjustment. No statistically significant association was identified between posterior fixation technique and complication risk. Level of evidence III, retrospective cohort study.
