What is the treatment for a sacral fracture?

Treatment of Sacral Fractures

Stable, non-displaced sacral fractures should be managed non-operatively with pain control and early mobilization, while displaced fractures (>1 cm) or those with pelvic ring instability require surgical fixation. 1

Initial Treatment Algorithm

Non-Operative Management (Stable Fractures)

• Non-displaced or minimally displaced (<1 cm) sacral fractures should be treated conservatively with pain management and activity modification. 1, 2
• A lumbosacral orthosis (LSO) or thoracolumbosacral orthosis (TLSO) may be used primarily for pain control, particularly in elderly patients with insufficiency fractures, but is not routinely required for all stable fractures. 1, 3
• Gradual return to full weight-bearing activity should be permitted as pain resolves, with most patients followed clinically until pain-free. 3
• Chronic low back pain is rarely observed (7%) with conservative treatment of minimally displaced fractures, justifying this approach. 2

Surgical Fixation (Unstable Fractures)

• Fractures with displacement >1 cm, rotationally unstable pelvic ring injuries (Tile B), or vertically unstable injuries (Tile C) require surgical fixation. 1, 2
• Surgical techniques include percutaneously placed iliosacral screws, posterior sacral tension band fixation, or lumbopelvic/triangular fixation for certain fracture patterns. 4
• Spinopelvic fixation allows immediate weight-bearing in vertically unstable patterns. 1, 3

Fracture Classification Guides Treatment

Denis Zone Classification

• Zone I (transalar fractures): Lateral to foramina, lowest neurological risk (24% deficit rate in unstable injuries). 5, 6
• Zone II (transforaminal fractures): Through foramina, moderate neurological risk (29-43% deficit rate in unstable injuries). 5, 6
• Zone III (central canal fractures): Highest neurological risk (57-64% deficit rate), often bilateral deficits with bowel/bladder dysfunction. 5, 6

Tile Pelvic Ring Classification

• The rate of neurological deficits correlates more strongly with pelvic ring instability (Tile classification) than with specific sacral fracture patterns. 6
• Tile A (stable): Neurological deficits rare. 6
• Tile B (rotationally unstable): 10% neurological deficit rate. 6
• Tile C (vertically unstable): 32.6-63.6% neurological deficit rate depending on Denis zone. 6

Special Considerations for Neurological Deficits

• Neurological deficits occur in 15-35% of sacral fractures overall, with higher rates in unstable injuries. 6, 2
• Additional risk factors for neurological injury include avulsion fractures, comminuted fracture lines, and bilateral fracture patterns. 6
• Zone I and II injuries typically cause unilateral lumbar and sacral radiculopathies, while Zone III injuries cause bilateral deficits with bowel/bladder incontinence in 50% of cases. 5
• Neurological deficits generally improve spontaneously with time, though complete recovery occurs in only a minority of patients (approximately 10% of those with initial deficits). 7, 2
• Operative reduction and internal fixation may be beneficial for patients with unilateral root symptoms and displaced fractures. 5

Critical Pitfalls to Avoid

• Do not assume bracing alone is sufficient for unstable fractures requiring surgical fixation, as this leads to poor outcomes. 1, 3
• Do not miss associated posterior pelvic ring injuries that would change the fracture from stable to unstable and necessitate surgical intervention. 3
• Do not rely solely on plain radiographs, as they miss approximately 35% of sacral fractures; CT is superior for diagnosis. 1, 3
• Do not dismiss the need for surgical fixation in fractures displaced >1 cm, as conservative treatment of significantly displaced fractures results in persistent neurological deficits in 30% of patients. 2

Special Populations

• Elderly patients with osteoporotic insufficiency fractures: Typically managed conservatively with LSO/TLSO for pain control and evaluation for osteoporosis treatment to prevent subsequent fractures. 1, 3
• Pregnancy-related sacral fractures: Rare but managed similarly to other insufficiency fractures, with MRI preferred over CT to avoid fetal radiation exposure. 8, 3
• Polytrauma patients: Sacral fractures occur in 89.4% of cases with at least one additional body region injured, requiring comprehensive evaluation for associated injuries. 6