What is the treatment for a sacrum microfracture?

Treatment for Sacral Microfracture

Most stable, minimally displaced sacral microfractures should be treated non-operatively with immediate weight-bearing as tolerated, pain management, and clinical follow-up without routine bracing, as this approach results in healing with minimal additional displacement in 99% of cases. 1

Initial Diagnostic Confirmation

• MRI without IV contrast is the preferred imaging modality if radiographs are negative or equivocal, as it provides excellent sensitivity for detecting stress fractures and bone marrow edema that characterizes microfractures 2
• CT without contrast can be used when MRI is contraindicated or equivocal, though it is less sensitive than MRI for early stress injuries 2
• Radiographs miss approximately 35% of sacral fractures and should not be relied upon alone for excluding microfractures 3

Treatment Algorithm Based on Fracture Stability

For Stable, Non-Displaced Sacral Microfractures (Most Common)

• Immediate foot-flat mobilization with weight-bearing as tolerated is the recommended approach, as research demonstrates 99% healing rates without additional displacement 1
• Pain management should be optimized to facilitate early mobilization and prevent complications of prolonged bed rest 4
• Bracing with a lumbosacral orthosis or TLSO is optional and primarily indicated for pain control in elderly patients with insufficiency fractures, not routinely required for all microfractures 3
• Activity modification should be implemented, with gradual return to full activity as pain resolves 2

For Unstable or Displaced Fractures

• Surgical fixation is necessary for rotationally or vertically unstable sacral fractures, which can be identified by associated pelvic ring disruption 3
• Spinopelvic fixation allows immediate weight-bearing in vertically unstable patterns 3
• Surgical options include percutaneous iliosacral screws, posterior tension band fixation, or lumbopelvic fixation depending on fracture pattern 5

Follow-Up Protocol

• Repeat radiographs should be obtained at 1 week after the patient has ambulated 50 feet to assess for any displacement 1
• Subsequent clinical follow-up at 4-6 weeks and 10-12 weeks is appropriate, with imaging only if symptoms persist or worsen 1
• Most patients can be followed clinically until pain-free, at which point controlled increase in activity is permitted 2

Critical Pitfalls to Avoid

• Do not assume bracing alone is sufficient for unstable fractures that require surgical fixation, as this leads to poor outcomes 3
• Do not miss associated posterior pelvic ring injuries that would change the fracture from stable to unstable and necessitate surgical intervention 3, 6
• Do not delay diagnosis with repeat radiographs in 10-14 days when MRI is available, as this increases morbidity without benefit 2
• Recognize that neurological deficits correlate more with overall pelvic instability than specific sacral fracture patterns, occurring in up to 63.6% of unstable central fractures 6

Special Populations

• Elderly patients with osteoporosis should be evaluated for bone mineral density and considered for osteoporosis treatment to prevent subsequent fractures 4
• Pregnancy-related sacral insufficiency fractures are rare but managed similarly, with MRI preferred over CT to avoid fetal radiation exposure 2
• Patients on bisphosphonate therapy are prone to progression from incomplete to complete fractures and require closer monitoring 2

When Conservative Management Fails

• If pain persists or worsens with mobilization attempts, or if displacement >5mm occurs on follow-up imaging, surgical intervention with closed reduction and percutaneous fixation should be considered 1
• Re-evaluation of original imaging is recommended to ensure the true etiology wasn't missed initially 2