When is a spine fracture considered unstable and indicated for orthosis (orthopedic support device)?

Spine Fracture Stability and Indications for Orthosis

A spine fracture is considered unstable when there is significant vertebral collapse, angulation, canal compromise, neurological deficit, or disruption of the disco-ligamentous complex, and orthosis is indicated for unstable fractures without neurological deficit or as an adjunct to surgical management in selected cases. 1

Determining Spine Fracture Stability

Spine fracture stability can be classified into three grades:

Grade 1 Unstable Fractures

• Deformity of the spine may increase if not stabilized
• No immediate risk of neurological injury
• May be managed conservatively with orthosis 2

Grade 2 Unstable Fractures

• Neural involvement may occur if not stabilized
• Significant risk factors include:
  • Significant vertebral collapse
  • Substantial angulation
  • Significant canal compromise 1
  • Disruption of disco-ligamentous complex

Grade 3 Unstable Fractures

• Already have neurological involvement
• By definition, all fractures with neurological deficit are unstable
• Generally require surgical intervention 2

Specific Fracture Patterns and Stability

Thoracolumbar Spine

• Burst fractures with significant vertebral collapse, angulation, canal compromise, or neurological deficit are considered unstable 1
• Burst fractures without neurological deficit are relatively stable and can be managed non-operatively 1
• Rotationally unstable patterns (APC-II, LC-II) and vertically unstable disruptions (APC-III, LC-III, VS, CM) require surgical fixation 1

Cervical Spine

• The Subaxial Injury Classification (SLIC) System provides excellent reliability for grading instability in cervical spine injuries 1
• Fractures in patients with diffuse idiopathic skeletal hyperostosis (DISH) are considered highly unstable with high risk for neurological injury 3

Indications for Orthosis

When to Use Orthosis

• Stable fractures with pain management needs
• Grade 1 unstable fractures without neurological deficit 2
• As an adjunct to surgical management in selected lateral compression patterns with rotational instability (LC-II, LC-III) 1
• Selected cases of DISH-associated fractures when surgery is contraindicated 3
• Vertebral compression fractures may benefit from bracing for symptomatic relief, though evidence is limited 4

When Not to Use Orthosis

• Neurologically intact patients with thoracic and lumbar burst fractures can be managed either with or without external bracing with equivalent outcomes 1
• Grade 3 unstable fractures generally require surgical intervention rather than orthosis alone 2
• Unstable cervical spine injuries are better managed with halo vest than soft collar, Miami J, or Minerva brace if surgical intervention is not an option 5

Effectiveness of Different Orthoses

Cervical Spine

• Halo vest provides the best immobilization for unstable upper cervical spine injuries 5
• Soft collars provide minimal stability for unstable cervical spine injuries 5
• Miami J and Minerva braces provide moderate control in the sagittal plane and better control of rotation 5

Thoracolumbar Spine

• Thoracolumbar sacral orthosis (TLSO) has controversial efficacy 6
• Prolonged brace use is associated with diminished lung capacity, skin breakdown, and paraspinal muscular atrophy 6
• No significant difference in pain and functional outcomes between patients treated with or without TLSO for stable fractures 6

Complications of Prolonged Immobilization

Prolonged immobilization with rigid collars can lead to significant complications after 48-72 hours:

• Pressure sores requiring skin grafting
• Increased intracranial pressure in patients with co-existing head injury
• Airway problems
• Difficult central venous access
• Poor oral care leading to bacteremia
• Failed enteral nutrition
• Gastrostasis, reflux, and aspiration 1

Surgical vs. Conservative Management

• Immediate surgical decompression and stabilization is indicated for patients with neurological deficits or spinal instability 4
• Single-stage posterior transpedicular approach can benefit patients with unstable lumbar spine injury and incomplete neurological involvement 7
• Patients with stable fractures without neurological deficit can be managed conservatively 1

Patient Considerations with Orthosis

• 43% of patients report that braces interfere with activities of daily living
• 73% of patients discontinue brace use earlier than advised
• 60% of patients would prefer not to use a brace if given the option 6
• Average increase in hospital length of stay waiting for bracing is three days 6

In summary, spine fracture stability assessment should guide treatment decisions, with unstable fractures requiring more aggressive management. Orthosis use should be limited to specific indications, as prolonged immobilization carries significant risks and patient compliance is often poor.