What is the appropriate treatment for a patient with a sacrum fracture, potentially with underlying osteoporosis or other comorbidities?

Treatment of Sacrum Fractures

For patients with sacrum fractures, initial management should prioritize conservative treatment with pain control, protected weight-bearing, and osteoporosis management, reserving surgical intervention for displaced fractures, pelvic instability, or neurological deficits. 1

Initial Diagnostic Confirmation

Before initiating treatment, ensure accurate diagnosis as sacral fractures are frequently missed on plain radiographs:

• Plain radiographs miss approximately 35% of sacral fractures due to overlying bowel gas, soft tissue, and sacral curvature 2
• MRI without contrast (rated 9/9 by ACR) is the gold standard for definitive diagnosis, showing hypointense T1 and hyperintense T2 signal with edema appearing within hours of injury 3, 4
• CT without contrast is superior to radiography and should be obtained if MRI is unavailable or contraindicated 2

Conservative Management (First-Line for Most Patients)

Most sacral fractures, particularly insufficiency fractures in osteoporotic patients, heal successfully with nonoperative treatment 1, 5:

Pain Management and Mobilization

• Provide adequate analgesia to facilitate early mobilization and prevent complications from prolonged bed rest 4
• Implement protected weight-bearing with assistive devices as tolerated 1
• Average time to complete pain relief is 3-6 months with conservative management 5

Osteoporosis Treatment (Critical Component)

• Order dual-energy X-ray absorptiometry (DXA) scan immediately to assess bone density 4
• Initiate osteoporosis treatment including calcium, vitamin D supplementation, and bisphosphonates or other anti-resorptive agents as indicated 1
• Address underlying risk factors including corticosteroid use, vitamin D deficiency, and metabolic bone disorders 1

Monitoring

• Follow clinically until pain-free, then gradually increase activity in a controlled manner 3
• Repeat imaging is typically unnecessary unless symptoms persist or worsen 3

Surgical Indications

Operative intervention is indicated for specific high-risk scenarios 6, 1:

Absolute Indications

• Displaced fractures with pelvic instability (TILE C classification) - these carry a 32.6-63.6% risk of neurological deficit depending on fracture zone 7
• Neurological deficits present in 15.1% of all sacral fractures, with rates increasing to 42.9% in transforaminal fractures and 63.6% in central fracture types 7
• Progressive neurological deterioration requires urgent surgical decompression 6

Relative Indications

• Severe, intractable pain unresponsive to conservative management after 6-8 weeks 1
• Bilateral fracture lines, comminuted fractures, or avulsion fractures - these are additional risk indicators for neurological impairment 7
• Lumbopelvic dissociation requiring spinopelvic stabilization 6

Surgical Options

• Minimally invasive sacroplasty for insufficiency fractures with persistent pain 1
• Iliosacral screw fixation or transsacral bar fixation for unstable fractures without spinopelvic dissociation 1
• Lumbopelvic fixation for fractures involving the lumbosacral junction 6, 1
• Open neural decompression when neurological deficits are present 6, 7

Special Populations

Pregnant Patients

• MRI without contrast (rated 9/9) is the imaging modality of choice - avoid radiation and gadolinium 3
• Pregnancy-related sacral fractures occur in the third trimester or postpartum due to transient osteoporosis 3
• Treatment is conservative with protected weight-bearing and calcium/vitamin D supplementation 3

High-Energy Trauma Patients

• Assess for hemodynamic instability immediately - systolic BP <90 mmHg, shock index >1, or transfusion requirement of 4-6 units indicates instability 8
• Evaluate for concomitant injuries - 89.4% have additional body region injuries, including urethral injury in 7-25% of pelvic ring fractures 8, 7
• These patients typically require operative stabilization due to associated pelvic ring disruption 6, 7

Functional Outcomes and Prognosis

Conservative and operative management yield similar functional outcomes at one-year follow-up 9:

• Mean Majeed score of 75.4 (moderate outcome) and ODI score of 10.6 (mild disability) at minimum one-year follow-up 9
• 40% of patients experience sexual dysfunction (30% females, 50% males) regardless of treatment method 9
• Complete pain relief occurs in approximately 69% of conservatively managed patients, with substantial relief in an additional 12% 5
• No significant difference in neurological deficits or sexual dysfunction between operative and conservative management for appropriate fracture patterns 9

Critical Pitfalls to Avoid

• Do not dismiss vague pelvic or low back pain in elderly patients as "arthritis" without imaging - sacral insufficiency fractures have insidious onset with nonspecific symptoms 8, 2
• Do not rely solely on plain radiographs - they have only 15-35% sensitivity in early stress fractures and miss 35% of sacral fractures 3, 2
• Do not overlook neurological examination - clinical exam has only 81% sensitivity for spine fractures, and neurological deficits may be subtle 8, 2
• Do not forget to assess for concomitant pelvic fractures - patients with sacral fractures often have pubic rami fractures that affect stability classification 2, 7
• Do not neglect osteoporosis treatment - addressing the underlying bone pathology is essential to prevent future fragility fractures 4, 1