Tibial Pseudoarthrosis



Anterolateral bowing


True bone dysplasia

- hamartomatous area in the tibia

- non union or potential non union through pathological fracture in this region


The defect in the bone is filled with mature, fibrous connective tissue

- not really a pseudoarthrosis

- by definition, a pseudarthrosis has a cleft lined by fibrocartilage containing fluid and bounded by a capsule

- the name is so firmly embedded in the literature that it is retained





- 1:200 000


M = F


50% have NF type 1

- 1-3% of NF have CPT




Cause unknown


Theories include

- intrauterine fracture

- localised vascular abnormality




Hamartomatous cuff present at site of lesion site

Even with NF, no clear histological evidence that fibrous tissue is NF


Crawford Classification


Type I: Non-dysplastic

- anterolateral bowing

- thickened sclerotic cortex


Type II: Dysplastic


IIA Anterolateral bowing

- wide medullary canal

- failure of tubularisation


IIB Cyst +/- Fracture


IIC Frank pseudarthrosis

- atrophied ends




Type 1:  Congenital anterior bowing

- defect present in tibia on x-ray

- rare


Type II:  Congenital anterior bowing with hourglass constriction of tibia

- tapered, rounded & sclerotic

- medullary cavity non continuous on xray

- spontaneous fracture or 2° minor trauma usually < 2 years

- most common & worst prognosis


Type III:  Fracture develops at site of bone cyst


Type IV:  Sclerotic bony segment

- segment may produce complete or partial obliteration of medullary canal

- no narrowing of tibia

- fracture develops like stress fracture


Type VCongenitally dysplastic tibia

- mild bowing ± pseudarthrosis 


Type VIIntraosseous NF or Schwannoma

- ± Pseudarthrosis

- Very rare





- virtually all will fracture by 2 years

- therefore reasonable to prophylactically treat involved segment if has NF


Management Algorithm


No Fracture / Type I or IIA 


Corrective osteotomy contra-indicated

- wll not heal

- must excise hamartoma


Brace all

- KAFO in walking  child

- PTB in older child until skeletal maturity


Prophylactic surgery

- NF 

- discuss excision + graft + stabilisation


Fracture / Type II B&C 



- won't heal non operatively

- treatment is surgical

- excise segment, graft & rod  / frame

- try to avoid until > 2 


Surgery timing

- controversial

- delay: shorter underdeveloped leg

- older patient: increased union rate

- brace till large enough or not controlled by AFO


Difficult surgery

- union difficult to achieve

- high refracture and recurrence rate

- increased with residual malalignment / provides an ongoing stress riser 

- failure of OT with graft resorption associated with amputation in 50%



- varies by type

- worse with tapering and sclerosis




Valgus deformity common

- sloping tibial epiphysis or fibular pseudoarthrosis

- can treat with guided growth


Surgical Options


1.  IM Rod


Several options 

- Sheffield / Fassier-Duval growing rod / Rush pin / Steinman pins

- use Steinmann pin, Rush nail or IM nail depending on size of patient & medullary canal



- anterior incision 

- excise hamartoma and sclerotic bone

- balance between bony resection & minimising LLD

- iliac bone graft

- stabilise with intra-medullary rod extending from calcaneum across STJ / AKJ into proximal tibial metaphysis

- with growth, rod migrates proximally & releases AKJ

- must graft & rod any co-existing fibular pseudarthrosis


Post operatively

- prolonged immobilisation

- spica cast for 6/12

- once united PTB till skeletal maturity

- rods left until skeletal maturity to avoid fracture




Vascularised Free Fibular Graft



- pseudarthrosis segment resected

- contralateral fibula as graft

- can use ipsilateral fibula if no pseudoarthrosis

- stability with external fixation



- valgus deformity of normal AKJ 2° overgrowth of distal tibial epiphysis

- distal fibula acts as tether 

- treat with tibia / fibula synostosis 

- avoid by using ipsilateral fibula

- only possible if fibula not involved


Ilizarov Technique



- pseudarthrosis resected


Bone transport

- 3-level ring fixator applied

- corticotomy of proximal metaphysis performed

- middle tibial segment moved distally 

- metaphyseal lengthening 

- pseudarthrosis compression / docking



- child > 5



- high rate of refracture after removal of frame


Electrical & US Stimulation


Independent use has unknown benefit 

- combine with graft / rod




"Should not be the operation of first resort or last resort"

- severe lesions with poor prognosis

- make early decision