From: Liu et al J Orthop Surg Res 2021 From: Banchhor et al Cureus 2022
Definition
Anterolateral bowing secondary to fibrous hamartoma in tibia
High risk of pathological fracture / nonunion / refracture
Epidemiology
Rare 1:200 000
50% have Neurofibromatosis type 1
Crawford classification
| Type I | Type II | Type III | Type IV |
|---|---|---|---|
|
Anterolateral bowing Thickened cortex |
Sclerotic bone Narrow canal
|
Central cyst Anterolateral bowing |
Fracture / pseudoarthrosis |
| May not fracture | Risk of fracture | High risk of fracture |
Bone ends thin and tapered
|
Natural history
Neurofibromatosis - virtually all will fracture by 2 years / consider prophylactic treatment
Skeletal maturity - risk of fracture / refracture lowers significantly
Brace
Indications
KAFO in walking child - attempt to prevent fracture and to delay surgery for 1 - 2 years
Patella tendon bearing cast in older child until skeletal maturity
Operative management
Principles
Fractures won't heal without surgery
Surgery - excise segment / bone graft / stabilize with nail / frame
Union difficult to achieve - graft resorption / recurrence / refracture
Options
Fixation - intramedullary rod / circular frame / combined
Bone graft - iliac crest / vascularized fibular graft
Cross union between tibia and fibula
Amputation
From: Singer et al JBJS Open 2019 From: Liu et al J Orthop Surg Res 2021
Results
Intra-medullary rod
- 34 patients with Type IV fractured congenital tibial pseuodoarthrosis
- treated with resection + IM nail with 12 year follow up
- 82% functional extremity at maturity
- 18% amputation
Combined frame + intramedullary rod
Liu et al J Orthop Surg Res 2021
- 15 patients with Type IV fractures
- treated with resection / telescopic rod / external fixator
- 100% union at average 4.5 months
Vascularized fibular bone graft
El-Gammal et al J Pediatr Orthop 2021
- 39 patients with CPT treated with vascularized fibular grafting
- 96% union at 3 months
- 51% stress fractures
- 54% tibial shaft deformities
Tibia / fibula cross union
- excision / stabilization / cross union between tibia and fibula in 39 cases
- 100% union with no refracture
Fibula pseudoarthrosis
Deng et al J Child Orthop 2021
- 36 patients with congenital tibial pseudoarthroses managed surgically
- increased proximal tibial valgus and ankle valgus in patients with fibular pseudoarthrosis
Intramedullary nails
Options
Fixed length nails
Telescoping nails - Fassier-Duval growing rod
Technique
Fassier-Duval surgical technique PDF From: Liu et al J Orthop Surg Res 2021
Anterior incision and excise hamartoma and sclerotic bone
- iliac bone graft +/- vascularized fibular bone graft
- resect + stability co-existing fibular pseudarthrosis
- stabilise with intra-medullary rod
- cast
- weight bear with patella tendon brace until maturity
Ilizarov technique / combined
From: Liu et al J Orthop Surg Res 2021
Technique
Resect pseudarthrosis
- apply 3-level ring fixator applied
- corticotomy of proximal metaphysis performed
- middle tibial segment moved distally
- pseudarthrosis compression / docking
- +/- intramedullary rod to prevent refracture
Tibia fibular cross union
From: Shannon et al Children 2021
Technique
Use periosteal excision / bone graft to deliberately obtain cross union between tibia and fibular