Congenital ANOMALIES OF LOWER LIMB CVT

1. CONGENITAL PSEUDARTHROSIS OF
TIBIA
DR MUHAMMAD JUNAID
RESIDENT ORTHOPAEDIC SURGEON

2. Definition
Pseudarthrosis is a
false joint associated
with abnormal
movements at the site

3. Introduction
• Congenital pseudarthrosis of tibia refers to
nonunion of tibial fracture that develops
spontaneously or after trival trauma in a
dysplastic bone segment of tibia diaphysis.
• CPT is rare & Usually develops in first 2 yrs of
life.
• Etiology is unclear.
• Incidence is 1: 250,000
•There is a strong association of CPT with
neurofibromatosis type 1.

4. Pathology
• Unclear
• Recent studies have shown that there is
hyperplasia of fibroblast with the formation of
dense fibrous tissue.
•This invasive fibromatosis is located in the
periosteum & between broken bones ends
causing compression, osteolysis &
persistance of pseudarthrosis.

5. Pathology
• Paley et al theorized that pathology of
pseudarthrosis is not bony but rather its
periosteal in origin.
•This theory is supported by following
observation
Thickening with hamartomatous transformation
of periosteum. Appearance of strangulation of
bone with atrophic changes followed by
avascular changes.

6. Boyd classification
• Boyd divided CPT into 6 types :-
Type 1 :-
 Pseudarthrosis occurs with
anterior bowing.
 A defect in tibia present at
birth.
 Other congenital deformities
may be present which may
affect the management of
pseudarthrosis.

7. Boyd classification
Type 2 :-
 Pseudarthrosis occur with anterior bowing & a hourglass
constriction of
the tibia is present at birth.
 Spontaneous fractures or after minor trauma.
 Commonly occur before 2 yrs of age.
 Also known as HIGH RISKTIBIA.
 Tibia is tapered, rounded,
sclerotic & obliteration of
medullary canal.
 Most common type.
 Associated with NF-1
 Poorest prognosis.

8.  Boyd classification
Type 3 :-
 Pseudarthrosis develops in a
congenital cyst usually near the
junction of middle & distal third
of tibia.
 Anterior bowing may precede or
follow the development of
fracture.
 Recurrance of fracture is less
common after treatment.

9. Boyd classification
Type 4 :-
 Originates in a sclerotic segment of
bone.Without narrowing of tibia.
 Medullary canal is partially or
completely obliterated.
 An insufficiency or stress
fracture develops in the cortex of
tibia & gradually extends through
the sclerotic bone.
 Prognosis is good.

10. Boyd classification
Type 5 :-
 Pseudarthrosis of tibia occurs with a dysplastic
fibula.
 Pseudarthrosis of both bone may develop.
 Prognosis is good if the lesion is confined to
fibula.
 If the lesion progress to tibia then the natural h/o
usually resembles type 2.
Type 6 :-
 Occurs as an intraosseous neurofibroma or
schwannoma
 Extremely rare.

11. Johnston et al.classification
Guide about prognosis and treatment
1)Presence and absence of fracture
2) Age of 1st fracture (before or after age 4yr)
Under this classification scheme
Fractured tibia>>>>>>surgical
Intact tibia>>>>>>>> observation & splinting

12.  For those tibias that require surgery, the
treatment involves first resecting the entire
pseudarthrosis, leaving a bone gap and soft-
tissue defect that must be treated regardless
of the descriptive radiographic classification
before surgical resection.

13. Clinical features
 • Associated with anterolateral
bowing of tibia.
 • Bowing usually occurs at the
junction of middle & distal third.
 • Deformity may be associated
with skin dimple, limb
shortening, dysplasia of fibula &
ankle valgus.
 • Usually unilateral.
 • If cutaneous signs of
neurofibromatosis are present the
diagnosis is readily apparent.

14. IMAGING
Xray
Bowing,sclerosis,cyst,fracture
Magnetic resonance imaging
• extent of the disease
• preoperative planning in that the borders for resection can be
defined precisely.
•The area of the pseudarthrosis is hyper intense on fat-
suppressed andT2-weighted images and slightly hypo intense
onT1-weighted images with contrast enhancement after
administration of gadolinium.
Computed tomography scan
Confirm radiographic findings.
Total bone scintigraphy
Level of the pseudarthrosis .

15. Prophylaxis
• Once the diagnosis of a non resolving
anterolateral bowing of the tibia has been
made the first step is to prevent fracture if
possible.
• In an infant before walking age,no specific
treatment is needed other than education of
the caretakers.

16. • Once the child begins weight bearing
prophylactic bracing should be attempted
although there is no documentation that
such a program can prevent a fracture.
• A clam shell like orthosis that provides
circumferntial support is usually recommended.
• Protection of the unfractured tibia should be
continued indefinitely till skeletal maturity

17. AIMS
1. Achieve union
2. Prevent refracture
3. Correct limb length inequality
4. Correct associated growth abnormalities
5. Prevent ankle deformity and arthritis.

18. 1. Strategies to achieve union
1. Microvascular free fibular transfer.
2. the Ilizarov technique
3. Bone grafting with intramedullary nailing.
Excision of the pseudarthrosis should be an
integral part of the procedure.

19. 2. Strategies for minimizing the risk of refracture
• Splint the limb in an orthosis until skeletal
maturity.
• Retain an intramedullary nail until skeletal
maturity.

20. 3. Strategies for dealing with shortening of the
limb
● Minimize the extent of shortening by
obtaining union of the pseudarthrosis as early
as possible.
● Established shortening can be addressed by
limb equalization procedures

21. 4. Strategies for minimizing valgus deformity of
the ankle
● Ensure union of the fibular pseudarthrosis.
● Retaining an intramedullary rod that crosses
the ankle joint can also prevent ankle deformity
although the motion is lost.

22. SURGICAL OPTIONS
1.Vascularized fibular graft
2. External fixation
3. Intramedullary rod
4. BMP
5. Electrical stimulation

23. Intra medullary fixation
•The procedure of choice for the first attempt
to gain union entails resection of pseudoarthrosis ,
shortening and fixation with an intramedullary
rod and autogenous bone grafting.
•The procedure can be performed at any age
and rates of union of around 85% have been
reported

24. Williams technique
•Williams conceived the novel technique of
threaded male and female components of the
rod that when joined,can be placed antegrade
through the pseudoarthrosis site and out the
bottom of the foot.
• After retrograde insertion back in to the proximal
intra medullary of the tibia the male end is
unscrewed and removed from the bottom of the
foot with the female threaded rod left
intraosseously in the tibia or across the ankle in
talus/calcaneus.

26. •The undesirable effect of ankle immobilisation
by IM fixation is thought to be necessary evil
to adequately immobilise the small distal
fragment.
• As the tibia grows the foot and ankle may
eventually grow off the distal end of the IM
rod and thus allow ankle to regain motion

27. •The possibility of ankle valgus is also almost
inevitable especially if there is a fibular
pseudoarthrosis despite the acheivement of a
solid union.
• Limb length discrepancy is yet another untoward
event with shortening at maturity averaging as
much as 5 cm.
•Weak and stiff ankle and subtalar joint secondary
to cross ankle fixation producing a poorly
functioning foot.

28. •The need for fibular surgery remains
controversial. Researchers concluded that it is
crucial to resect a fibular pseud- arthrosis or, if
the fibula is intact, to perform a fibular
osteotomy in order to achieve optimal limb
alignment and union.

29. 1. Vascularized fibular graft
1.Vascularized fibular graft
• The procedure entails harvesting a long segment of the opposite fibula along with its
vascular pedicle.
•This is transferred into the gap created after radical excision of the pseudarthrotic segment.
•The vessels of the transferred fibula are anastomosed to the local vessels.The transferred
fibula is fixed securely to the tibia.

30. • Intra medullary fixation of the donated fibula
is contraindicated theoretically because of the
possibility of disturbance of blood supply of
the microvascular graft.
• Because the transfer brings tissue with its own
blood supply, free fibular vascularised transfer
has been recommended as procedure of
choice for gaps > 3cm after resection of
pseudoarthrosis.

31. Morbidity of the donor leg
•The distal end of fibula must be synostosed to
the tibia or the fibula of the donor site must
be reconstructed with bone graft to prevent
ankle valgus.

32. BONE MORPHOGENETIC PROTEIN
>>Multiple reports have documented the
successful use of recombinant human bone
morphogenetic protein (rhBMP) in the
treatment of congenital pseudarthrosis of the
tibia.
>>Both currently available forms (rhBMP-2 and
rhBMP-7) of this protein have been used. In each
series, BMP was used in conjunction with other
accepted forms of bony stabilization such as
intramedullary fixation.

33. ILIZAROV
>>Good results were reported with the Ilizarov
technique, but problems have included difficulty
transporting the proximal tibia, “docking”
malalignment, and poor quality of regenerated
bone, leading to refracture.
>>For most established pseudarthroses, initial
treatment should be intramedullary rodding
and bone grafting. The Ilizarov approach with
bone transport does offer the advantage of
maintaining or gaining tibial length.

34. Electrical stimulation
• Electrical stimulation doesnot correct existing
deformities and thus its appplication is
probably limited to the earlier phases of
pseudoarthrosis treatment when union is the
primary goal.

35. Amputation
 Rarely indicated
Factors favouring amputation:-
1. Shortening > 5 to 7.5 cm
2. Multiple failed procedures
3. Stiffnes & decrease function of limb that
would be more useful after amputation and
prosthetic fitting

36. COMPLICATIONS
STIFFNESS OFTHE ANKLE AND HINDFOOT
A stiff ankle should be expected until the
distal tip of the rod is proximal to the ankle
joint after longitudinal growth of the distal
end of the tibia. Even if stiffness persists, it
rarely hampers functional results.

37. REFRACTURE
Refracture is common in patients with
pseudarthroses, despite apparently solid
clinical and radiographic union.
Refracture can be managed with casting or
removal and replacement of the
intramedullary rod with additional bone
grafting. Because of the likelihood of
refracture, removal of the rod after union is
not recommended until skeletal maturity has
been reached.

38. VALGUS ANKLE DEFORMITY
>>The distal tibial fragment must be fixed so that
valgus deformity of the ankle is corrected at the
time of placement of the intramedullary rod.
>>Intraoperative fluoroscopy is useful for monitoring
this procedure.
>>Long-term bracing is mandatory during the
growth years to minimize progressive valgus ankle
deformity, or surgical treatment may be indicated.
>>Valgus deformity has been found to be
significantly more frequent when the fibula is left
intact than when fibular osteotomy is done (with or
without fibular fixation).

39. TIBIAL SHORTENING
>>Tibial shortening should be anticipated in
almost all these children.The maximal
projected shortening in the patients of
Anderson et al. was 4 cm. In selected patients,
tibial shortening can be treated by a well-timed
contralateral epiphysiodesis or limb lengthening
of the proximal tibia.
>>The Ilizarov technique may be useful initially in
severe cases with significant shortening and a
wide nonunion or in patients in whom
medullary nailing and standard bone grafting
procedures fail.

40. Take Home message
 Rare.
 Little or no tendency for the lesion to heal
spontaneously.
 Aims to obtain a long term bone union, to prevent
limb length discrepancies, to avoid mechanical axis
deviation, soft tissue lesions, nearby joint stiffness,
and pathological fracture.
 The key to get primary union is to excise
hamartomatous tissue and pathological periosteum.
 Surgical options such as intramedullary nailing,
vascularized fibula graft, and external fixator, have
shown equivocal success rate in achieving primary
union
 Amputation must be reserved for failed
reconstruction, severe limb length discrepancy and
gross deformities of leg and ankle..