What are the management options for complications after Harrison rod placement?

Management of Complications After Harrison Rod Placement

The most effective management of complications after Harrison rod placement requires prompt identification of the specific complication and implementation of targeted interventions based on the type of complication encountered.

Common Complications

1. Rod Breakage

Rod breakage is a significant complication that occurs primarily due to mechanical factors:

• Causes:

  • Stress concentration at the ratchet-shaft junction (approximately 43.7% decrease in cross-sectional area) 1
  • Cyclic loading producing metal fatigue
  • Uneven stress distribution

• Management:

  • Rod-sleeve procedure is an effective method to prevent further breakage 1
  • Complete revision surgery with modern instrumentation systems may be necessary in cases with significant deformity progression

2. Metal Corrosion and Metallosis

Long-term complications can develop from metal-bone breakdown:

• Presentation:

  • Pain
  • Neurological deficits (thoracic outlet syndrome, hyperreflexia, peripheral muscle weakness)
  • Elevated serum metal levels (e.g., chromium) 2

• Management:

  • Serum metal level testing
  • Advanced imaging (CT/myelogram) to assess for adhesive arachnoiditis
  • Hardware removal if symptomatic and fusion is solid
  • Consider referral to neurology for management of neurological symptoms

3. Loss of Correction/Deformity Progression

• Management:
  • Radiographic assessment to determine the extent of correction loss
  • Revision surgery with modern instrumentation systems
  • Consider circumferential correction techniques using articulating rods and interbody devices for severe deformities 3

4. Hook Migration

• Presentation:

  • Progressive loss of correction
  • Pain at hook sites

• Management:

  • Reoperation to reposition hooks
  • Consider conversion to modern segmental fixation systems
  • Addition of segmental wires may reduce the incidence of hook migration 4

Surgical Management Options

1. Hardware Revision/Replacement:

   • Conversion to modern pedicle screw constructs
   • Addition of segmental wires to augment fixation 4
   • Use of articulating rods for complex deformity correction 3

2. Hardware Removal:

   • Indicated when hardware is painful or causing neurological symptoms
   • Should only be performed if solid fusion is confirmed
   • May be necessary in cases of deep infection or metallosis

3. Circumferential Approaches:

   • Combined anterior and posterior procedures for severe deformities
   • Use of expandable interbody devices to restore alignment 3
   • Articulating rods to facilitate safe correction of severe kyphosis

Monitoring and Follow-up

• Regular radiographic assessment to monitor for progressive deformity
• Clinical evaluation for neurological symptoms
• Consider metal ion testing in patients with suspected metallosis
• Long-term follow-up is essential as complications can develop decades after initial surgery 2

Special Considerations

• In pediatric patients with early-onset scoliosis, modern growing rod systems (e.g., magnetically controlled growing rods) should be considered for revision, though these also have a high complication rate (48%) 5
• Multidisciplinary approach involving spine surgeons, neurologists, and pain specialists may be necessary for complex cases

Pitfalls to Avoid

• Delaying intervention for symptomatic hardware failure
• Removing hardware without confirming solid fusion
• Underestimating the neurological impact of long-term metallosis
• Failing to recognize that seemingly minor symptoms may indicate serious complications

Harrison rod complications require vigilant monitoring and prompt intervention when symptomatic. Modern instrumentation techniques have largely replaced Harrison rods, offering better biomechanical properties and lower complication rates when revision is necessary.