Iatrogenic Injury to the Sacral Plexus and Its Branches: A Critical Narrative Review of Procedural Anatomy, Localization and Prevention

After surgery near the posterior hip or pelvic sidewall, a new foot drop, posterior thigh sensory loss or change in bladder function raises different questions about the site of injury. This critical narrative review examines how the operative exposure and the distribution of a deficit can guide investigation and how strongly the available evidence supports prevention. We selected human anatomical studies, clinical cohorts, trials, evidence syntheses and professional guidance identified through database searches and citation tracking. After posterior pelvic fixation, distal segmental weakness prompts review of the screw trajectory, whereas isolated abductor weakness draws attention to the entry site and abductor tendons. After proximal hamstring repair, a posterior thigh cutaneous deficit implicates a different nerve from weakness below the knee. In pelvic surgery, evidence for preservation of urinary function concerns autonomic pathways and cannot establish protection of the somatic plexus. Across these settings, baseline neurological status, the unit counted and the timing of outcome assessment materially change estimates of harm. A severe or progressive deficit requires urgent assessment for a treatable structural cause. For stable deficits, targeted imaging and serial electrodiagnosis can refine localization and prognosis. Few studies connect a technical precaution to a sustained improvement in neurological function.