What is the treatment for a sacral fracture?

Treatment of Sacral Fractures

The treatment of sacral fractures should primarily involve conservative management with pain control, bed rest to avoid load, and slow mobilization until the patient is pain-free, after which controlled activity increase can begin. 1

Diagnostic Approach

Before initiating treatment, proper diagnosis is essential:

1. Initial Imaging:

   • Radiographs should be the first imaging study for suspected sacral fractures
   • AP and lateral lumbar spine and AP pelvis radiographs are standard
   • Note: Radiograph sensitivity is low (15-35%) due to overlying bowel gas, fecal material, vascular calcifications, and sacral curvature 1

2. Advanced Imaging (when radiographs are negative or inconclusive):

   • MRI without contrast (nearly 100% sensitivity) is the preferred next imaging study 1, 2
   • CT scan (69-87% sensitivity) is particularly well-suited for sacrum and pelvis evaluation 1
   • Cross-sectional imaging for hip fractures should include the sacrum, as sacral fractures can cause radiated hip/groin pain 1

Treatment Algorithm

Conservative Management

For most sacral fractures, especially stable, non-displaced fractures:

• Pain Management:

  • Non-steroidal anti-inflammatory drugs, analgesics, or opioids as necessary 1
  • Note: Treatment may take many months 1

• Activity Modification:

  • Bed rest to avoid load 1
  • Slow full mobilization 1
  • Follow clinically until pain-free, then increase activity in a controlled manner 1

• Hospitalization:

  • Required for approximately 10% of cases 1

Surgical Management

Surgical intervention is indicated for:

• Significantly displaced fractures
• Fractures with neurological compromise
• Unstable fractures

Surgical options include:

• Percutaneously placed iliosacral screws
• Posterior sacral "tension band" fixation
• Lumbopelvic fixation for certain fracture patterns 3

Special Considerations

Fracture Classification and Neurological Implications

Sacral fractures can be classified into zones that predict neurological deficit risk 4:

• Zone I (ala sacralis only): 24% risk of nerve injury
• Zone II (involving foramina but not central canal): 29% risk of nerve injury
• Zone III (involving central canal): 57-60% risk of nerve injury, often bilateral and severe

Osteoporosis Management

For patients over 50 with fragility fractures:

• Evaluate systematically for subsequent fracture risk
• Ensure adequate calcium (1000-1200 mg/day) and vitamin D (800 IU/day) intake 1
• Consider pharmacological treatment with:
  • First-line: Alendronate or risedronate (oral bisphosphonates)
  • For oral intolerance: Zoledronic acid (IV) or denosumab (subcutaneous)
  • For severe osteoporosis: Consider teriparatide 1

Post-Radiation Therapy Fractures

For patients with radiation-induced insufficiency fractures:

• Preventive therapy before radiation should include BMD evaluation and risk factor assessment
• Vitamin D, calcium, bisphosphonates, and in selected cases, hormone replacement therapy may be prescribed 1
• Specific bone therapies can improve fracture repair 1

Follow-up Care

• Regular clinical assessment until pain-free
• For patients with osteoporosis: Regular BMD assessment and continued drug therapy 1
• Attention to patient-reported musculoskeletal symptoms
• Physiotherapy may be required for rehabilitation 1
• For patients with suspected insufficiency fractures, imaging studies (particularly MRI) should be prescribed to differentiate from metastases 1

Pitfalls and Caveats

• Sacral fractures are often missed on initial assessment due to low sensitivity of radiographs
• Overreliance on the "Honda" or "H" sign on bone scintigraphy can lead to missed diagnoses, as only 63% of patients with sacral insufficiency fractures demonstrate this sign 1
• MRI patterns showing only edema without fracture lines can be confused with metastatic disease 1
• Long-term morbidity, including residual pain and neurological deficits, may persist despite appropriate treatment 5