Congenital pseudoarthrosis of tibia by Dr. Bipul Borthakur

1. CONGENITAL
PSEUDOARTHROSIS OF
TIBIA
Dr. Bipul Borthakur (Professor)
Dept of Orthopaedics, SMCH

2. INTRODUCTION
 Nonunion of tibia fracture that develops
spontaneously or after trivial trauma in a dysplastic
bone segment of diaphysis.
 usually develops in first 2 years
 misnomer
 Etiology is not clear.
 Incidence is 1: 250,000

3.  Strong association with NF type 1.
 55% of cases associated with NF.
 Some authors: association in nearly every instance.
 Fibrous dysplasia: 15% of patients with anterolateral
bowing.

4. NEUROFIBROMATOSIS
 NF-1: due to mutation on the gene coding for
NEUROFIBROMIN on chromosome 17.
 It negatively regulates Ras activity.
 Affects Ras-dependent MAPK( mitogen activated protein
kinase) activity-essential for osteoclast function & survival.

5. •
•6 or more café-au-lait macules
• Axillary or inguinal freckling.
• 2 or more neurofibromas or 1 plexiform neurofibroma.
• 2 or more Lisch nodules.
•Optic glioma.
•Distinctive osseous lesions.
•Family history

6. •Recent studies :Hyperplasia of fibroblasts
•Osteolytic fibromatosis
•Paley et al: it is not bony but periosteal
POINTS FAVOURING:
•Thick & harmartomatous periosteum
•Avascular & atrophic changes in bone
•Failure of remodelling

7. CLASSIFICATION
No universal classification
CAMURATI-1930
ADGLEY -1952
BOYD -1958
APOIL -1970
ANDERSON-1973
CRAWFORD-1986
CRAWFORD-1999
BOYD & ANDERSON commonly used

8. BOYD CLASSIFICATION
TYPE 1: Anterior bowing, defect at birth,
other congenital abnormalities
TYPE2: Mc type
 Anterior bowing & a hourglass constriction.
 Spontaneous #s or after minor trauma.
 Commonly occurs before 2 years
 HIGH RISK TIBIA.
 Associated with NF-1
 Poorest prognosis

9. TYPE 3 :
Congenital cyst.
• Anterior bowing may precede or follow the
development of #.
TYPE 4 :
• Originates in a sclerotic segment.
• Medullary canal obliterated.
• Insufficiency or stress # develops
and gradually extends.
• Prognosis is good.

10. TYPE 5 :
• Pseudarthrosis of tibia with dysplastic fibula.
• Prognosis good if confined to fibula only.
• Lesion resembles type 2
TYPE 6 :
• Occurs as an intraosseous neurofibroma or
schwannoma .
• Extremely rare.

11. CRAWFORD CLASSIFICATION
 1-Non-Dysplastic
 Anterolateral bowing with increased density &
sclerosis of medullary canal.
 2-Dysplastic
 2a Anterolateral bowing
with failure of tabularization.
 2b Cystic changes.
 2c Frank pseudarthrosis.

12. DIAGNOSIS
CLINICAL FEATURES:
 cutaneous signs of NF
 anterolateral bowing of tibia.
 bowing usually at junction of middle & distal third.
 Associated with skin dimple, limb shortening, dysplasia
of fibula & ankle valgus.
 Usually unilateral.

13. IMAGING
MRI:
 Extent of disease
 Preoperative planning.
 Hyper intense on T2-weighted images and hypo intense on
T1-weighted images.
CT SCAN
 Confirm radiographic findings.
TOTAL BONE SCINTIGRAPHY
 Level of the pseudarthrosis .

14. PREOPERATIVE MANAGEMENT
 KAFO
 Clamshell orthosis
 DISCONTINUE:
 Tibia straightened
 Medullary canal reconstituted
 Adequate cortical thickness
 Skeletal maturity

15. TREATMENT OPTIONS
 Internal fixation and graft
 Ilizarov
 BMP
 Electrical stimulation
 Amputation
AIMS:
 1. Achieve union
 2. Prevent refracture
 3. Correct limb length inequality
 4. Correct associated growth abnormalities
 5. Prevent ankle deformity and arthritis.

16. STRATEGIES TO ACHIEVE UNION
 Microvascular graft transfer-vascularized fibula
 The Ilizarov technique
 Bone grafting with internal fixation-plating or IM devices.
 Excision of the pseudarthrosis should be an integral part of
the procedure.
STRATEGIES TO PREVENT REFRACTURE
 Splint the limb in an orthosis until skeletal maturity.
 Retain an intramedullary nail until skeletal maturity.

17.  STRATEGIES FOR DEALING WITH SHORTENING OF
THE LIMB
Minimize the extent of shortening.
Limb equalization procedures
STRATEGIES FOR MINIMIZING VALGUS DEFORMITY
OF THE ANKLE
Ensure union of fibular pseudarthrosis.
Retaining an IM rod that crosses ankle.

18. BONE GRAFTING
MCFARLAND:
 Corticocancellous graft from opposite tibia
 Placed posteriorly
VASCULARISED FIBULAR GRAFT
fibula along with vascular pedicle.
Transferred into the gap created.
Vessels anastomosed to local vessels.

19.  Procedure of choice for gaps > 3cm.
 92%- 95% union rate
 Refracture.
 Langenskiold procedure to prevent ankle valgus.
 In addition weakness may ensue in the donor leg due to
resection of origins of flexor muscles.
 PERIOSTEAL GRAFTING: has been tried

21. INTRA MEDULLARY FIXATION
 Resection, shortening and fixation with an IM rod &
autogenous bone grafting.
 Union 85%.
WILLIAMS TECHNIQUE
 Threaded male and female components of the rod
 Can be placed antegrade & brought out the bottom of
the foot.
 After retrograde insertion back in to the proximal tibia -
male end is unscrewed and removed from bottom -
female threaded rod left intraosseously in tibia or across
the ankle in talus/calcaneus.

22. ILIZAROV TECHNIQUE
 Provides excellent stability
 Complete resection of pseudo-arthrotic part.
 Enables weight bearing which aids healing
 Compression of pseudo-arthrosis
 Limb lengthening procedures can be done

23. BONE MORPHOGENIC PROTEIN
 BMP2
 BMP7
 ELECTRICAL STIMULATION
 Limited to the earlier phases when union is the primary
goal.

24. AMPUTATION – Maybe the better option in some
situations
McCARTHY CRITERIA
 Failure after 3 surgeries
 LLD 5cm or more
 Deformed foot
 Prolonged hospitalization
 High medical costs

25. COMPLICATIONS
1. REFRACTURE
 14% to 60%.
 Anatomic alignment minimizes the risk.
 IM rod and external bracing -protection against re-
fractures.

26. 2. MALALIGNMENT
 Procurvatum
 valgus deformity
3. LIMB LENGTH DISCREPANCY
 Residual limb length discrepancy common
 Growth abnormalities noted with CPT.

27. 4. ANKLE VALGUS
 Progressive ankle valgus is a problematic
postoperative donor-site morbidity of a vascularized
fibular graft in children.
 Tibiofibular metaphyseal synostosis (Langenskold
procedure) useful.

29. 5. ANKLE STIFFNESS
 Progressively regresses after IM removed from
ankle.
 Pain secondary to degenerative changes of ankle-
limitation of activity and shoe modification.
 Severe pain – ankle arthrodesis

30. CONCLUSION
 Challenging for the surgeon
 Poor tendency to heal
 Excision of the hamartomatous tissue and pathological
periosteum is the KEY.

31. “yogasthaḥ kuru karmāṇi saṅgaṃ tyaktvā dhanañjaya
siddhyasiddhyoḥ samo bhūtvā samatvaṃ yoga ucyate”
By being established in Yoga, O Dhananjaya, undertake actions,
casting off attachment
and remaining equipoised in success and failure. Equanimity is
called Yoga.
THANK YOU.