What is a pathologic vertebral fracture?

Pathologic Vertebral Fracture

A pathologic vertebral fracture is a fracture that occurs in a vertebra weakened by an underlying disease process rather than by trauma alone, commonly caused by neoplasms (primary bone tumors, infiltrative neoplasms like multiple myeloma, or metastatic disease), infections, metabolic disorders, or congenital conditions. 1

Definition and Causes

• Pathologic vertebral fractures result from vertebrae weakened by underlying disease processes that compromise bone integrity, occurring without adequate trauma 1, 2
• Common causes include:
  • Neoplasms: primary bone tumors (hemangioma, giant cell tumors), infiltrative neoplasms (multiple myeloma, lymphoma), and metastatic disease 1
  • Metabolic disorders including renal osteodystrophies 1
  • Congenital disorders such as osteogenesis imperfecta 1
  • Infections causing vertebral osteomyelitis 3
  • Tumor-like conditions causing bony remodeling (aneurysmal bone cysts, Paget's disease) 1

Clinical Significance and Impact

• Pathologic vertebral fractures can cause marked decline in physical activity and quality of life 1
• These fractures lead to general physical deconditioning, which may prompt complications such as:
  • Poor inspiratory effort leading to atelectasis and pneumonia 1
  • Venous stasis resulting in deep venous thrombosis and pulmonary embolism 1
• In the context of malignancy, pathologic vertebral fractures are considered skeletal-related events (SREs) that significantly impact morbidity and mortality 1, 4
• Successful management can improve quality of life, increase expectancy of independent living, and prevent superimposed medical complications 1

Evaluation and Assessment

• The Spine Oncology Study Group (SOSG) developed the Spinal Instability Neoplastic Score (SINS) to evaluate spinal stability in pathologic fractures 1
• SINS is a composite of clinical and radiographic data including:
  • Location of the fracture
  • Pain characteristics
  • Bone quality
  • Spinal alignment
  • Extent of vertebral body collapse
  • Posterolateral involvement 1
• Based on SINS, spinal segments are classified as:
  • Stable (0-6 points)
  • Potentially unstable (7-12 points)
  • Unstable (13-18 points) 1
• SINS has excellent interobserver and intraobserver reliability and can predict fracture progression after radiation therapy 1

Diagnostic Approach

• Initial evaluation includes assessment of neurologic deficits and imaging of the affected spinal segment 1
• Imaging is crucial to characterize the fracture and determine the extent of disease 1
• In cases with ambiguous imaging features, a biopsy should be performed to verify the etiology 1
• Clinical presentation of infectious pathologic fractures may include:
  • Severe back pain refractory to analgesic therapy
  • Persistent unexplained fever
  • Leukocytosis without other obvious infection focus 3

Management Options

• Treatment approach depends on the underlying cause, patient's symptoms, and spinal stability 1
• For neoplastic pathologic fractures, management options include:
  • Vertebral augmentation (VA) procedures (vertebroplasty, kyphoplasty) for pain palliation 1
  • Radiation therapy for local tumor control, particularly for painful lesions 1
  • Percutaneous thermal ablation (radiofrequency ablation, cryoablation) with VA for pain relief 1
  • Surgical intervention for spinal instability or neurologic compromise 1
  • Bisphosphonates and other bone-modifying agents to decrease risk of skeletal-related events 1, 5, 4

Treatment Considerations for Specific Scenarios

• For painful pathologic fractures with mechanical instability:
  • Vertebral augmentation provides rapid pain relief and structural reinforcement 1
  • Percutaneous cement-augmented posterolateral instrumentation may be needed for unstable fractures extending into pedicles or facet joints 6
• For asymptomatic pathologic fractures:
  • Treatment depends on life expectancy, performance status, and tumor burden 1
  • Observation and medical management may be sufficient for patients with limited life expectancy (<3 months) 1
  • Local intervention (surgery or radiation therapy) may benefit patients with high risk for spinal instability despite being asymptomatic 1

Pitfalls to Avoid

• Delaying diagnosis and treatment can lead to increased morbidity and mortality, especially in infectious causes 3
• Failing to perform early biopsy and culture in suspected infectious pathologic fractures 3
• Using vertebroplasty or kyphoplasty alone for mechanically unstable pathologic fractures extending into the pedicle and facet joints 6
• Overlooking the need for treatment of the underlying disorder that predisposed to the vertebral fracture 7

By understanding the nature, evaluation, and management options for pathologic vertebral fractures, clinicians can provide timely and appropriate interventions to improve patient outcomes, reduce pain, and enhance quality of life.