Case Prep: Sacral Fracture / Spinopelvic (Lumbopelvic) Fixation

Case / Approach Snapshot

• Anatomy at risk: unstable columns, cord/roots, dura, vertebral artery or great-vessel/visceral structures by level, fracture lines, and fixation corridors.
• Operative steps: protect the spine during transfer/positioning, confirm levels and reduction goals, decompress when indicated, instrument/reconstruct stability, verify alignment and hardware, and plan ICU/brace/rehab needs; use the detailed operative sequence and approach notes below as the step-by-step source.
• Rescue plans: neurologic deterioration, reduction failure, vascular/visceral injury, durotomy, blood loss, hardware pullout, infection, and staged anterior/posterior stabilization.
• Figures: review Figures, Imaging & Video and the Curated Image Set; embedded local figures should remain open-access, public-domain, or otherwise reusable with attribution.
• Papers: review High-Yield Literature for seminal sources, modern reviews, and outcome data specific to this page.

One-Liner

[Age]yo [M/F] with a [Denis zone / U-type spinopelvic dissociation] sacral fracture following [high-energy fall/MVC] [± cauda equina/sacral nerve deficit] planned for [lumbopelvic (spinopelvic) fixation / iliosacral screw fixation / sacral decompression].

Figures, Imaging & Video

🎥 Operative video — search operative video on YouTube ▸ · The Neurosurgical Atlas ▸

🧭 Operative approach: Posterior thoracolumbar approach — posterior midline/paramedian exposure, lumbopelvic fixation, and closure principles.

Neurosurgical Atlas · AO Spine / Surgery Reference · Radiopaedia · PubMed Central — operative figures © linked; see media-sources.md

High-Yield Literature

• Spondylopelvic dissociation — Sullivan MP. The Orthopedic clinics of North America 2014. PubMed
• Traditional versus Minimally Invasive Spinopelvic Fixation for Sacral Fracture Treatment in Vertically Unstable Pelvic Fractures — Tsai YT. Journal of personalized medicine 2022. PubMed
• Percutaneous lumbopelvic fixation for pathologic sacral fractures and spinopelvic dissociation: patient series — Baksh N. Journal of neurosurgery. Case lessons 2023. PubMed
• Traumatic spinopelvic dissociation or U-shaped sacral fracture: a review of the literature — Yi C. Injury 2012. PubMed
• Minimally Invasive Spinopelvic Fixation for Unstable Bilateral Sacral Fractures — Koshimune K. Clinical spine surgery 2016. PubMed
• Spinopelvic fixation for vertically unstable AO type C pelvic fractures and sacral fractures with spinopelvic dissociation- A systematic review and pooled analysis involving 479 patients — Patel S. Journal of orthopaedics 2022. PubMed
• Robotic-Assisted Minimally Invasive Spinopelvic Fixation for Traumatic Sacral Fractures: Case Series Investigating Early Safety and Efficacy — Hardigan AA. World neurosurgery 2023. PubMed
• Lumbopelvic Fixation for Sacral Insufficiency Fracture Presenting with Sphincter Dysfunction — Maki S. Case reports in orthopedics 2019. PubMed
• Treatment of Unstable Sacral Fracture with Minimally Invasive Spinopelvic Posterior Fixation and an Internal Anterior Fixator in a 95-Year-Old Patient with Diffuse Idiopathic Skeletal Hyperostosis: A Case Report — Sasagawa T. Journal of orthopaedic case reports 2021. PubMed
• A Case of U-shaped Sacral Fracture After Longstanding Spinopelvic Fixation Treated With Percutaneous Sacroiliac Joint Fusion and Iliosacral Osteosynthesis — Ganeshan V. Cureus 2023. PubMed

Curated Image Set

Open-access figures are embedded from PubMed Central articles and kept unique to this guide.

Fig. 1. A Prone position on radiolucent table, marking of PSIS and greater trochanter on each side. B PSIS exposure: starting point located caudal and medial to PSIS (Anatomic entry point). C… Source: Does minimally invasive percutaneous transilial internal fixator became an effective option for sacral fractures? A prospective study with novel implantation technique — European Journal of Trauma and Emergency Surgery 2023; CC BY.

Fig. 2. A Awl used for penetration and creating screw tunnel. B Alternatively, oscillating drill could be used instead. C, D direction of awl in ventral and caudal direction. E Pedicular screw… Source: Does minimally invasive percutaneous transilial internal fixator became an effective option for sacral fractures? A prospective study with novel implantation technique — European Journal of Trauma and Emergency Surgery 2023; CC BY.

Fig. 3. A Showing Obturator view with awl insertion between the 2 tables. B Screw placement above sciatic notch in iliac view. C Tear drop view, D Iliac outlet view. E Obturator inlet. F True… Source: Does minimally invasive percutaneous transilial internal fixator became an effective option for sacral fractures? A prospective study with novel implantation technique — European Journal of Trauma and Emergency Surgery 2023; CC BY.

Fig. 4. Fracture reduction methods using pelvic reduction clamps applied over 4.5 cortical screws Source: Does minimally invasive percutaneous transilial internal fixator became an effective option for sacral fractures? A prospective study with novel implantation technique — European Journal of Trauma and Emergency Surgery 2023; CC BY.

Fig. 5. A Preoperative radiograph showing left fracture sacrum Denis type 2 in 40 years old male. B–H Postoperative radiographic views showing iliac screws accurate trajectory. I–K Final… Source: Does minimally invasive percutaneous transilial internal fixator became an effective option for sacral fractures? A prospective study with novel implantation technique — European Journal of Trauma and Emergency Surgery 2023; CC BY.

Fig. 6. A, B Preoperative radiograph showing left fracture sacrum Denis type 2 in 21 years old male. C–H Final follow-up different radiographs showing iliac screws accurate trajectory Source: Does minimally invasive percutaneous transilial internal fixator became an effective option for sacral fractures? A prospective study with novel implantation technique — European Journal of Trauma and Emergency Surgery 2023; CC BY.

Fig. 1. Computed tomography (CT) on admission (A) Three-dimensional CT reconstruction of the pelvis demonstrating bilateral sacral fractures, bilateral ischiopubic fractures, and right femoral… Source: Modified spinopelvic crab-shaped fixation using offset connectors for a H-shaped sacral fracture with a floating Roy-Camille type 3 transverse component: a case report — Acta Neurochirurgica 2026; CC BY-NC-ND.

Fig. 2. Schematic depiction of sacral fracture lines (red) The distal sacral fragment (asterisk), classified as Roy-Camille type 3, was a floating fragment. The right side involved Denis zone… Source: Modified spinopelvic crab-shaped fixation using offset connectors for a H-shaped sacral fracture with a floating Roy-Camille type 3 transverse component: a case report — Acta Neurochirurgica 2026; CC BY-NC-ND.

Fig. 3. Preoperative and intraoperative photographs (A) Preoperative photograph showing bilateral 5-cm incisions above the posterior superior iliac spine (PSIS) for placement of L5 pedicle… Source: Modified spinopelvic crab-shaped fixation using offset connectors for a H-shaped sacral fracture with a floating Roy-Camille type 3 transverse component: a case report — Acta Neurochirurgica 2026; CC BY-NC-ND.

Fig. 4. Reduction maneuver and buttress technique (A) Bilateral neurodissectors were inserted lateral to the dura into the transverse fracture site, with the tips positioned on the ventral… Source: Modified spinopelvic crab-shaped fixation using offset connectors for a H-shaped sacral fracture with a floating Roy-Camille type 3 transverse component: a case report — Acta Neurochirurgica 2026; CC BY-NC-ND.

History of Present Illness

• Chief complaint: Low back/pelvic/buttock pain, inability to bear weight, ± bowel/bladder/sexual dysfunction and saddle anesthesia (sacral nerve injury)
• Mechanism (high-energy: fall from height, MVC), associated pelvic ring/abdominal/GU injuries (polytrauma)
• U-type/H-type = spinopelvic dissociation (spine separated from pelvis — highly unstable)

Past Medical History

• Associated pelvic/visceral/GU injuries, osteoporosis (insufficiency sacral fractures in elderly — different management), anticoagulation
• Standard PMH

Imaging Review

CT Pelvis/Sacrum (with reconstructions)

• Denis classification (zone I lateral to foramina, zone II through foramina, zone III central/canal — highest neuro risk), transverse component (U/H-type = spinopelvic dissociation)
• Displacement, kyphosis, canal/foraminal compromise, pelvic ring integrity, sacral dysmorphism (screw planning)

  MRI

• Sacral nerve roots/cauda, hematoma, neural compression

  X-ray (pelvis, inlet/outlet views)

Labs

• CBC, BMP, Coags, type and crossmatch, trauma labs

Neurological Examination

• Sacral nerve roots: perianal sensation, rectal tone, bulbocavernosus reflex, bladder/bowel function, lower extremity motor/sensory; document baseline

Surgical Planning

Case Logistics, OR Needs & Orders

• OR table/bed: Jackson/Allen/open-frame radiolucent table, or ProAxis/hinged table when sagittal alignment adjustment is useful; keep abdomen free for venous decompression.
• OR setup: spine table with log-roll precautions, fluoroscopy/O-arm/navigation, traction/Mayfield when cervical, posterior/anterior implant trays, decompression instruments, cell saver/blood for large constructs, and IONM before positioning when feasible.
• Special needs: arterial line, Foley, type/cross, MAP augmentation for acute SCI per local protocol, no long paralytic when MEPs are needed, anticoagulation/reversal plan, and airway strategy for unstable cervical injuries.
• Immediate postop orders: serial ASIA/neuro checks, MAP goal/duration if SCI, CT/X-rays for hardware/alignment, brace/collar orders, drain care, DVT prophylaxis timing, bowel/bladder/skin care, and early rehab/SCI consult.

Diagnosis & Indication / Approach

• Indication: Unstable sacral fracture / spinopelvic dissociation, displacement/deformity, neurological deficit (decompression), inability to mobilize
• Spinopelvic (lumbopelvic) fixation: pedicle screws (L4-L5/S1) connected to iliac screws — bridges spine to pelvis for U-type dissociation
• Iliosacral (SI) screws: percutaneous, for certain zone I/II and pelvic ring; sacral decompression (laminectomy/foraminotomy) for zone III with neural deficit
• Coordinate with orthopedic trauma (pelvic ring)

Classification and Construct Choice

• Denis zone, Roy-Camille/U-type morphology, vertical instability, lumbosacral kyphosis, pelvic-ring injury, and neurologic deficit determine whether this is a pelvic screw case or a spinopelvic fixation case.
• Percutaneous iliosacral/transsacral screws may be enough for stable corridors without spinopelvic dissociation; U-type dissociation, vertical shear, severe comminution, or inability to mobilize usually needs lumbopelvic fixation.
• Decompression is most compelling for progressive deficit or imaging-proven root/canal compression; chronic complete sacral deficits may not recover, so decompression should be weighed against wound and stability needs.
• Decide early with orthopedic trauma who owns pelvic-ring reduction, anterior fixation, weight-bearing restrictions, and timing around abdominal/urologic injuries.

Imaging and Neurologic Checklist

• CT pelvis with inlet/outlet/sagittal reconstructions: sacral corridors, foraminal compromise, transverse component, kyphosis, comminution, and safe S1/S2 screw pathways.
• MRI when neurologic deficit is unexplained or root compression/epidural hematoma changes decompression urgency.
• Document saddle sensation, rectal tone, bulbocavernosus reflex, voluntary anal contraction, bladder scan/catheter status, and sexual function baseline when possible.

Position

• OR table/bed: Jackson/Allen/open-frame radiolucent table, or ProAxis/hinged table when sagittal alignment adjustment is useful; keep abdomen free for venous decompression.
• Prone, Jackson table, fluoroscopy (pelvis — inlet/outlet/lateral), IONM; careful with associated injuries

Key Surgical Steps (Lumbopelvic Fixation)

1. Posterior midline (and/or paramedian for iliac screws) exposure of lumbar spine and posterior pelvis
2. Pedicle screws at L4/L5/S1; iliac screws (entry at PSIS, aimed toward AIIS, between inner/outer tables — fluoroscopic “teardrop” view) ± S2-alar-iliac (S2AI) screws
3. Reduce the sacral fracture/dissociation (restore alignment, lumbosacral kyphosis)
4. Sacral decompression (laminectomy/foraminotomy) if neural compression/deficit — decompress sacral roots
5. Connect rods spine-to-pelvis, lock, confirm reduction/hardware (fluoroscopy/CT)
6. Decorticate/graft as appropriate, drain, closure
7. (± Iliosacral screws for pelvic ring, with ortho)

Critical Anatomy & Structures at Risk

1. Sacral nerve roots / cauda equina (zone III, foraminal) — bowel/bladder/sexual function
2. Iliac screw corridors — between inner/outer tables (avoid sciatic notch, hip joint, pelvic viscera/vessels)
3. L5 nerve root (anterior sacral ala), presacral vessels/structures, sacroiliac joint

Equipment

• Spinopelvic system (pedicle + iliac/S2AI screws, rods, connectors), fluoroscopy/navigation
• Decompression instruments, bone graft, cell saver, crossmatched blood

Monitoring

• EMG (sacral roots), SSEPs, MEPs

Anesthesia

• Arterial line, crossmatched blood, MAP support (if neural injury), prone precautions, coordinate trauma

Potential Complications

1. Sacral nerve injury / persistent bowel-bladder-sexual dysfunction
2. Hardware prominence (iliac screws — symptomatic), screw malposition (notch/joint/vessels)
3. Wound complications/infection (posterior pelvis, polytrauma), nonunion, loss of reduction
4. Blood loss, associated pelvic injury complications

Intraoperative and Postoperative Rescue

• Poor fluoroscopic corridor: stop and obtain better inlet/outlet/lateral imaging or navigation; sacral dysmorphism makes “standard” screw angles unsafe.
• Screw breach or triggered EMG change: remove/reposition, check CT if uncertain, and prioritize root safety over construct convenience.
• Reduction worsens neuromonitoring: release correction, raise MAP, reassess root/canal compression, and decide whether decompression is needed before final locking.
• Posterior wound risk: minimize dead space, consider drains/negative-pressure dressing in polytrauma or degloving injury, and coordinate timing if fecal/urogenital contamination exists.
• Persistent bladder/bowel dysfunction: involve urology/rehab early, trend post-void residuals, bowel program, and counsel that sacral neurologic recovery is variable and often slow.
• Hardware prominence/pain after union: evaluate fusion/fracture healing before elective iliac screw removal or revision to lower-profile S2AI fixation.

Operative Note Template

Preoperative Diagnosis: [Denis zone __ / U-type] sacral fracture with spinopelvic dissociation [± sacral nerve deficit]

Postoperative Diagnosis: Same

Procedure: Lumbopelvic (spinopelvic) instrumented fixation [L_-ilium] [with sacral decompression] for sacral fracture / spinopelvic dissociation

Surgeon / Assistant: [± orthopedic trauma] Anesthesia: General endotracheal EBL / Fluids / Blood products: [crossmatched] Adjuncts: Fluoroscopy (inlet/outlet/lateral)/navigation; EMG (sacral roots)/SSEP/MEP Implants: Pedicle screws (L4/L5/S1), iliac/S2AI screws, rods, bone graft Complications: None

Indications: [Age]yo [M/F] with an unstable [U-type] sacral fracture/spinopelvic dissociation after high-energy trauma [with sacral nerve deficit — bowel/bladder/saddle]. Associated pelvic/visceral injuries were managed with the trauma team. Risks discussed.

Description of Procedure: After consent and time-out, general anesthesia was induced and neuromonitoring (including sacral-root EMG) established. The patient was positioned prone on a Jackson table with fluoroscopy. A posterior midline [± paramedian] exposure of the lumbar spine and posterior pelvis was performed. Pedicle screws (L4/L5/S1) and iliac/S2-alar-iliac screws were placed under fluoroscopic inlet/outlet/lateral guidance, staying within bone and avoiding the sacral foramina, canal, and sciatic notch.

The sacral fracture/dissociation was reduced and lumbosacral alignment restored. [A sacral laminectomy/foraminotomy decompressed the sacral roots for the neurological deficit.] Rods connected the spine to the pelvis and were locked; reduction and hardware were confirmed on fluoroscopy/CT. Neuromonitoring remained stable.

Hemostasis was obtained, a drain placed, and closure performed in layers. The patient was transferred to the [ICU] with sacral-function monitoring.

Postoperative Plan

• ICU/floor per trauma, neuro checks (sacral function), MAP support if neural injury
• CT postop (hardware, reduction), weight-bearing per ortho/construct
• DVT prophylaxis (high risk — pelvic trauma), bowel/bladder management (urology), wound monitoring
• Rehab, follow-up imaging; counsel re: recovery of sacral function (variable)

Chief-Level Case Review

Use these as the senior-level mental model for Sacral Fracture / Spinopelvic (Lumbopelvic) Fixation:

• Decision point: Treat physiology while preparing the room: airway, reversal, transfusion, ICP/CPP, sodium/osmolality, temperature, and repeat imaging drive timing as much as the scan finding.
• Technical lever: Know the operative priority: decompression, hemorrhage control, debridement, dural closure, reconstruction, stabilization, or contamination control.
• Bailout: Plan for swelling and coagulopathy: bone flap decision, duraplasty size, drain/EVD need, hemostatic adjuncts, and ICU handoff should be decided early.
• Postop watch: Postop failure modes are predictable: expanding hematoma, malignant edema, seizure, infection, CSF leak, venous sinus injury, and missed associated spine/vascular injury.

Common Pimp Questions

Use these to pressure-test preparation for Sacral Fracture / Spinopelvic (Lumbopelvic) Fixation:

1. What neurologic level and root are responsible for the presenting deficit?
2. What is the decompression target and how will you know it is adequately decompressed?
3. What instability, deformity, bone-quality, or fusion variable changes the construct?
4. What vascular, visceral, dural, or neural structure is the main structure at risk?
5. What postop brace, drain, mobilization, MAP, antibiotic, and DVT plan should be ordered?

Attending Preference Variables

Items that commonly vary by surgeon or institution:

• Positioning frame, arms, traction, and localization workflow: [attending-specific]
• Navigation/robot/fluoro use, screw system, graft/biologic choice, and drain threshold: [attending-specific]
• Neuromonitoring modality and MAP goal for myelopathy, deformity, or cord-risk cases: [attending-specific]
• Brace, Foley, antibiotics, mobilization, and DVT prophylaxis timing: [attending-specific]