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- Clinical photo showing anterolateral bowing
- Concern of Pseudoarthrosis or Tibial hemimelia
- Triple assessment to evaluate severity and confirm NF
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- AL bowing, possibly fracture
- Ddx - infection, tumor
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- Etiology not fully understood, associated with NF-1
- Presence of fibrous harmatoma at the pseudoarthrosis site, originating from abnormal periosteal growth
- Harmatoma restricts blood flow to pseudoarthrosis site and impairs local circulation; also has increased osteoclastic properties.
- Harmatoma may actually occupy the entire medullary cavity of the tibia, and thus not just a local problem but affect the entire tibia
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- Original literature suggested that fibula involvement results in poorer prognosis but a multicenter study indicated that patients with fibula involvement achieved successful union more frequently.
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- 10% of NF 1 has AL bowing
- 50% of AL bowing has NF
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- Crawford Classification
- Type 1 = bowing
- 2 = hourglass constriction
- 3 = cysts
- 4 = obliterated (penciling)
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- Cells composing the harmatoma not fully characterised
- Majority of cells in fibrous harmatoma were fibroblasts lacking a basement membrane in the stationary phase.
cho2008.pdf1675.3KB
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- Brace at all times during weight bearing till skeletal maturity
- Surgery for Pre-fracture is highly controversial.
- Avoid osteotomy due to poor leading. Only do if there is a fracture.
- If fractures ➔ need surgery
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- Goal = resect pseudoarthrosis fibrous harmatoma, achieve union, limb length and alignment. Many techniques described
- Paley’s Cross-union surgery involving 4 components:
- Aim to achieve cross union between fibula and tibia
- 1. Excision of pseudoarthorsis fibrous harmatoma, Internal fixation with growing rod and plates,
- 2. bone grafting - between tibia and fibula to achieve cross union
- 3. BMP-2
- 4. IV Zolendronic Acid
- Eventually may have shortening ➔ may need proximal tibia lengthening
- Other options - ex fix, free vascularized fibular grafting
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- Indications - failure to achieve bony union after 3 surgeries
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- Will NEED surgery as very limited potential of healing
- Paley’s Cross Union Surgery
