Management of Tibial Protrusion
Immediate Recommendation
For tibial protrusion in the context of congenital pseudarthrosis of the tibia (CPT), the optimal surgical approach is combined external fixation (Ilizarov method) with intramedullary fixation, which achieves the highest success rate (65.3%) and lowest complication profile. 1
Clinical Context and Timing
When to Operate
- Surgical intervention is indicated when patients are over 2 years old 1
- Earlier intervention may be considered if severe deformity causes knee instability or functional impairment 1
Surgical Goals
The primary objectives are to achieve 1:
- Bone union and maintenance of union
- Correction of deformities
- Prevention of refracture
- Equalization of limb length
- Functional, pain-free lower extremity 2
Recommended Surgical Approach
Core Surgical Principles (100% Expert Consensus)
All surgical management must include 1:
- Complete excision of the pseudarthrosis site
- Sufficient autogenous bone graft (typically from iliac crest)
- Proper method of fixation
Optimal Fixation Strategy
Combined External and Intramedullary Fixation (84% Expert Agreement) 1:
- Achieves 65.3% success rate (primary union without refracture)
- Non-union rate: only 6% (24/400 tibias)
- Mean primary union time: 8.2 months
- Prevents refractures and axial deformities more effectively than single-modality approaches
Alternative Approaches Based on Clinical Scenario
Cross-Union Technique 1:
- Success rate: 77.5%
- Particularly promising for younger patients or high-risk anatomical features
- Focuses on tibiofibular fusion to increase stability
- 26% expert agreement as viable option
Vascularized Fibular Graft (VFG) 1:
- Non-union rate: 7.3% (21/288 tibias)
- Success rate: 35.9%
- Can substitute for autogenous bone graft with proper fixation
- Consider when conventional grafting has failed
Techniques to AVOID as Sole Fixation
Intramedullary Rods Alone (74% Expert Disagreement) 1:
- Primary union rate: only 67.7%
- Non-union rate: 17%
- Refracture rate: 48.1% (unacceptably high)
- Mean union time: extended to 12.6 months
- Associated with instability, ankle stiffness, and limb length discrepancies
Other Single-Modality Approaches with Poor Outcomes:
- Rush rods alone: 74% expert disagreement 1
- Telescopic nails (Fassier-Duval) alone: 53% expert disagreement 1
- Locking compression plate alone: 74% neutral/uncertain 1
Special Considerations for X-Linked Hypophosphatemia (XLH)
If tibial protrusion occurs in the context of XLH-related lower limb deformities 1:
Timing Considerations
- Delay osteotomy until after skeletal maturity when possible to reduce complication rates
- Exception: Severe deformities causing knee instability require earlier intervention
- Guided growth techniques should commence early (after 12 months) if deformity persists despite maximized medical therapy
Surgical Approach for XLH
- Osteotomies at sites of major deformity with correction in all three planes
- Options include acute correction with internal fixation or gradual correction with external fixation
- Caution: 57% of patients experience at least one complication; 29% develop recurrent deformity 1
Adjuvant Therapies (Limited Evidence)
NOT Recommended
Recombinant human BMPs (rhBMP-2 and rhBMP-7): 89% expert disagreement due to lack of conclusive benefit 1
Uncertain Benefit (Neutral Consensus)
- Bisphosphonates: 84% neutral 1
- Electric/electromagnetic stimulation: 74% neutral 1
- Low-intensity pulsed ultrasound: 63% neutral 1
These adjuvants are generally complementary to primary surgical procedures, not substitutes 1
Postoperative Management
Follow-Up Protocol
- Radiographic assessment at 12 months post-surgery (or earlier if deformity worsens) 1
- Functional assessment using validated tools (PODCI or 6-minute walk test) 1
- Intermittent assessments until skeletal maturity 1
- Long-term follow-up is critical: Refracture has been reported up to 18 years after fusion 1
Expected Outcomes with Optimal Technique
- Overall mean primary union rate: 83.3% 1
- Mean final union rate: 87.5% 1
- Average refracture rate: 33.2% (varies significantly by technique) 1
Critical Pitfalls to Avoid
- Using intramedullary fixation alone: Results in nearly 50% refracture rate 1
- Operating too early in XLH patients: Increases complication and recurrence rates 1
- Inadequate excision of pseudarthrosis tissue: Compromises union 1
- Insufficient long-term follow-up: Late refractures can occur years after apparent healing 1
- Relying on adjuvant therapies as primary treatment: Evidence for BMPs and other biologics remains inconclusive 1