Congenital anterolateral bowing and …Dept. of Pediatric Orthopedics Shizuoka Children’s Hospital Our Strategy of Dealing with Congenital Anterolateral Bowing and Pseudarthrosis

Congenital Congenital anterolateralanterolateral bowing and bowing and pseudarthrosispseudarthrosis of the tibia: of the tibia:

pathogenesis and treatment with pathogenesis and treatment with IlizarovIlizarov apparatusapparatus

Nobuhiko Haga, MDDept. of Pediatr. Orthop.,

Shizuoka Children’s Hospital,Shizuoka, JAPAN

Dept. of Pediatric Orthopedics

Shizuoka Children’s Hospital

Congenital Anterolateral Bowing and Pseudarthrosis of the Tibia (CPT)

EtiopathogenesisPathologyTreatmentPrognosis



Our Strategy of Dealing with Our Strategy of Dealing with Congenital Congenital AnterolateralAnterolateral Bowing and Bowing and PseudarthrosisPseudarthrosis of the Tibiaof the Tibia

Prevention of fracture or deformity progression with a PTB ankle-foot orthosis ↓

Massive resection of pseudarthrosis site, acute shortening, and fixation with Ilizarov apparatus, with proximal metaphyseal lengthening, at pre-school age

↓Prevention of re-fracture with an orthosis, preferably until skeletal-maturityAdditional surgery (deformity correction, equalization of length.…) if necessary



STUDY 1Histological Analysis of the Pseudarthrosis Site

STUDY 2Retrospective Study on the Efficacy of Preoperative Brace Treatment

STUDY 3Retrospective Study on the Treatment Course with Ilizarov Apparatus



STUDY 1STUDY 1

Histological Analysis of thePseudarthrosis Site



PatientsCPT: 9 cases(NF1: 6 cases)

Age at Operation: 5y10m

MethodsHistological analysis

Control: adult posttraumatic pseudarthrosis



Histology of CPTA B C

Case 1

X-ray H.E. Azan



Fibrous Cartilage in CPTCase 1

A B C

Case 1

H.E. Toluidine blue Toluidine blue



Osteoclasts in CPT

A B C

Bo

FbCa

H.E. TRAP TRAP



Osteoclasts not only on Bone Surfaces but also in Fibrous Tissues

Case 2 Case 2 Case 3



Bone Histomorphometry

Osteoclast Surface (%)[Oc.S/BS (%)]

Osteoclast Number (/mm)[N.Oc/BS (#/mm)]

Osteoclastsin Fibrous Tissues



Enhanced Osteoclastogenesis in CPT

N.Oc/BS (#/mm)

0

1

2

3

4

5

0

5

10

15

20

25 Oc.S/BS (%)

0

2

4

6

8

10 OCs in Fibrous Tissuue

7 / 9

1 / 9



Expression of RANK ligand in Fibroblastic Cells and Osteoclasts in

CPTA B C

Immunostaining for RANK ligand



Possible Pathophysiology of CPT

EnhancedOsteoclastogenesis

Pseudarthrosis

Increased Expression of RANK ligand in Fibroblastic

Cells



STUDY 2STUDY 2

Retrospective Study on theEfficacy of

Preoperative Brace Treatment



PatientsCPT: 7 patients(NF1--2, Fibrous Dysplasia--1)

Age at initiation of brace treatment: 4m-14m

MethodsRetrospective radiological analysis:

Measurement of tibial deformity(coronal and sagittal plane) PTB ankle-foot orthosis

allowing partial WB



Status of Tibia & Fibula Status of Tibia & Fibula before Brace Treatment

7m 5y2m

before Brace TreatmentPseudarthrosis atinitiation of brace Tx

Tibia & Fibula 3

Fibula only 1

None 3 patients

measurement of tibial deformityuntil tibial fracture or operation



Deformity of Tibia during Brace TreatmentDeformity of Tibia during Brace Treatment

CoronalCoronal--plane Deformityplane Deformity SagittalSagittal--plane Deformityplane Deformity

age (years) age (years)

varus (degrees) procurvatum (degrees)

0

10

20

30

40

50

60

70

0 1 2 3 4 5

TT

T

F

F

Op(F)

0

10

20

30

40

50

60

70

0 1 2 3 4 5

T

T

T

F

FOp

(F)



Deformity of Tibia during Brace TreatmentDeformity of Tibia during Brace TreatmentOblique-plane Deformity( = arctan tan2ap+arctan2lat )

0

10

20

30

40

50

60

70

0 1 2 3 4 5

T

(F)TT

FF

Op

age (years)

degrees



STUDY 3STUDY 3

Retrospective Study on theTreatment Course with

Ilizarov Apparatus



PatientsPatientsSix patients operated between 1992 and 2002

Sex: 4 boys and 2 girlsAffected Side: 3 in the right and 3 in the leftAssociated Problem: NF1--2 patients, Fibrous Dysplasia --1 patientAge at Operation: 3y4m - 6y1mFollow-up Period: 1y9m - 12y2m (mean 6y0m)



Treatment Course during Treatment Course during IlizarovIlizarov Procedure Procedure

yespremature consolidation of fibula, breakage of Ilizarov ring, knee & ankle contracture

186days70mm40mmyesyes5y2m6

yesfracture of ipsilateraldistal femur315days62mm50mmyesyes6y1m5

yesknee & ankle contracture, superficial infection210days50mm40mmyesno5y2m4

yes

delayed union at pseudarthrosis site, premature consolidation of fibula, deformity of elongated callus, knee & ankle contracture


nodeformity at pseudarthrosis site, equinus foot, deep infection


yessuperficial infection

214daysno15mmyesyes3y4m1

Fusion of Pseudarthrosis at IlizarovRemoval

Complications during Initial Treatment

Duration of IlizarovApplication

Proximal MetaphysealLengthening

Resection Length of Tibial Lesion

Preop. Pseud-arthrosisof Fibula

Preop. Pseud-arthrosis of Tibia

Age at Initial Surgery

Case



Treatment Course after Treatment Course after IlizarovIlizarov RemovalRemoval

3nono

6

6tibia valga (5 months after removal, PETS)re-fracture (21months after removal, Ilizarov external fixation)

bone graft for elongated callus and compression site5

4re-fracture (17 months after removal, Ilizarov external fixation)

distal tibio-fibular bone graft4

8re-fracture (3 months after removal, intramedullaryrodding), ankle valgus (17 months after removal, PETS),breakage of intramedullary rod (4 years after removal)

bone graft for elongated callus, ABMI

3

8failure of fusion (17 months after removal, intramedullary rodding, led to fusion), ankle valgus (5 years after removal, PETS)

imtramedullary rodding, ABMI2

3re-fracture (10 years after removal, Orthofix external fixation)

no1

Overall No. of Operations

Complications after Ilizarov RemovalProcedures at the time of Ilizarov Removal

Case

AMBI : autologous bone marrow injectionPETS : percutaneous epiphyseodesis using transphyseal screws



-10

-5

0

5

10

15

20

25

30

35

Case 1

Case 3

Case 4

Case 5

Case 6

0

5

10

15

20

25

30

35

Case 1

Case 3

Case 4

Case 5

Case 6

Final

Pre-Fx

IlizarovR

emoval

varus (degrees)

valgus

CoronalCoronal--plane Deformityplane Deformity SagittalSagittal--plane Deformityplane Deformity

Deformity of Tibia after Removal of Deformity of Tibia after Removal of IlizarovIlizarov ApparatusApparatus

procurvatum (degrees)

Final

Pre-Fx

IlizarovR

emoval



Deformity of Tibia after Removal of Deformity of Tibia after Removal of IlizarovIlizarov ApparatusApparatus

Oblique-plane Deformity

0

5

10

15

20

25

30

35

40

Case 1

Case 3

Case 4

Case 5

Case 6

degrees

Final

Pre-Fx

IlizarovR

emoval



Patient 6Patient 6

Pre-Op (5y2m) Initial Operation

Before Ilizarov Removal　　　　　　　　　Final (5y10m)



Patient 3 Patient 3 with rewith re--fracture and ankle fracture and ankle valgusvalgus

Pre-Op (5y0m) Before Ilizarov Removal Re-fx 3m after Removal

IM for Re-fx PETS for Ankle Valgus Final (10y9m)



DiscussionDiscussion

Osteoclastgenesis even in the fibrous area apart from bone surfaces

Massive Resection of Pseudarthrosis Site and

Acute Shortening

to obtain wide contact area and opening of the medullary canal

5/6 fusion

Ext. Fixationfor 6m-12m

Simultaneous proximal metaphyseal lengthening

High Re-fracture Rate(4/6)

S o l u t i o n ? ? ?probably MALALIGNMENT



Residual Challenges after Healing of Congenital Pseudarthrosis in the Tibia

Kristiansen LP et al.: Clin Orthop 20035/7 re-fracture7/7 axial deformity

Precise alignment check during external fixation

PETS for malalignment during follow-up period

to avoid MALALIGNMENT

Intramedullary roddingafter Ilizarov removal ??



Efficacy of Preoperative Brace TreatmentEfficacy of Preoperative Brace Treatment

EPOS Multicenter Study (2000, JPO-B)14 patients with intact tibia & anterior bowingprocurvatum 2-53 degrees (at presentation)

(plaster or splints)25-54 degrees (pseudarthrosis -)30-80 degrees (pseudarthrosis +)



ConclusionConclusion

1. In CPT, osteoclastgenesis is enhanced on the surface of the bone and cartilage and even in the fibrous area apart from bone surfaces.

2. Such possible pathogenesis leads to the necessity of massive resection of the pseudarthrosis site during surgery.In 5 patients out of 6, fusion was obtained after 6 to 12 months of treatment. But re-fracture occurred in 4 patients. Malalignment may be one of the factors of re-fracture.

3. Brace treatment before surgery was beneficial at least until fracture of the tibia.



AcknowledgementsAcknowledgements

Dept. of Pediatr. Orthop., Shizuoka Children’s HospitalK.Takikawa, A.Yozu, K.Okada

Dept. of Orthop. Surg., the University of TokyoI.Nakamura, K.Nakamura, T.Kurokawa

…and all members of KPOS for your warm welcome

Documents

Congenital anterolateral bowing and …Dept. of Pediatric Orthopedics Shizuoka Children’s Hospital Our Strategy of Dealing with Congenital Anterolateral Bowing and Pseudarthrosis