What is the treatment for congenital pseudoarthrosis of the tibia?

Treatment of Congenital Pseudoarthrosis of the Tibia

The optimal treatment for congenital pseudoarthrosis of the tibia (CPT) is surgical management with combined fixation techniques, specifically external fixation (Ilizarov) with intramedullary fixation, which achieves 84% primary union rate and 93.3% final union rate with a refracture rate of only 22.3%. 1, 2

Surgical Indications and Principles

• Surgery is indicated for all patients over 2 years old with CPT (100% consensus agreement) 1, 2
• Essential surgical principles include:
  • Complete excision of the pseudarthrosis site/hamartoma
  • Sufficient autogenous bone grafting
  • Proper method of fixation 1, 2

Treatment Algorithm

First-line Treatment Options:

1. Combined External Fixation with Intramedullary Fixation

   • 84% consensus agreement among experts 1
   • 84% primary union rate, 93.3% final union rate
   • Mean primary union time: 5.3 months
   • Refracture rate: 22.3%
   • Success probability: 65.3% 1
   • Allows simultaneous correction of deformities and limb length discrepancies 1, 2

2. Cross-union Technique

   • Creates tibiofibular fusion to increase stability
   • 100% primary union rate
   • Mean union time: 4.5 months
   • Refracture rate: 22.5%
   • Success probability: 77.5% 1, 2
   • Particularly promising for younger patients or those with high-risk anatomical features 2

Treatment Techniques NOT Recommended:

• Intramedullary rods (IMR) alone

  • 74% expert disagreement 1, 2
  • Primary union rate: only 67.7%
  • Extended union time: 12.6 months
  • High non-union rate: 17%
  • Very high refracture rate: 48.1% 1

• Fixed nails (Rush rods) alone

  • 74% expert disagreement 1, 2

• Telescopic nails (Fassier-Duval) alone

  • 53% expert disagreement 1
  • Note: When combined with other techniques, FDR shows better outcomes 1

• Locking compression plate (LCP) alone

  • Only 21% expert agreement 1, 2

Adjunctive Therapies

• Vascularized fibular grafting (VFG)

  • Consider as an alternative bone graft source in persistent non-union or refracture
  • 45% refracture rate 2
  • Success probability: 35.9% 1

• Bone morphogenic proteins (BMPs)

  • 89% expert disagreement for routine use 1, 2
  • No advantage in terms of initial union, time till union, or refracture rates 3

• Bisphosphonates

  • 84% neutral expert opinion 1, 2
  • Some theoretical benefit based on pathobiology 4

• Electromagnetic stimulation

  • 74% neutral expert opinion 1
  • Limited evidence from case reports 5

Post-Treatment Monitoring and Complications

• Long-term follow-up is crucial

  • Follow until skeletal maturity
  • Refracture can occur up to 18 years after initial fusion 1, 2

• Common complications:

  • Refracture (most common and serious)
  • Non-union
  • Limb length discrepancies
  • Ankle stiffness (more common with IMR alone) 2
  • Valgus deformity (highly associated with fibular insufficiency) 6

Important Considerations

• CPT is likely a primary periosteal disease and secondary bone disease 4
• Fibular involvement is common and affects treatment outcomes 2
• The pathobiology demonstrates increased osteoclasis and reduced osteogenesis 4
• The cross-sectional area of union with its two-bar linkage in cross-union techniques makes refracture less likely 4

Monitoring Parameters

• Ankle function
• Limb length discrepancies
• Deformity correction
• Signs of refracture 2
• Tibial alignment and stability 7