Management of Tibial Deformities by Using of Mono … Sebha Medical Journal, Vol. 6(1), 2007. Management of Tibial Deformities by Using of Mono-tube External Fixator Abdulrazag Shakshuki,*

70 Sebha Medical Journal, Vol. 6(1), 2007.

Management of Tibial Deformities by Using

of Mono-tube External Fixator

Abdulrazag Shakshuki,* Sedig ben Dalla,* Abdelhakim Zanati,*

Abstract:

The aim of this study is to evaluate the results of dome-shaped tibial osteotomy with mono-tub external

fixator in treatment of genovarus and other tibial deformities with or without leg length discrepancy.

And to understand the system of external fixator ... advantages, disadvantages and complications.

And is it a better solution that replaces other methods which used in treatment of tibial deformities.

Key words: Tibial deformities, external fixation, mono-tube.

Introduction:

These deformities are very common conditions

Which often worries the mother of her 1st

baby, and account for a substantial percentage

of referrals to the pediatric orthopaedic clinics.

Careful explanation of this condition to the

mothers is important at their initial stage. At

this stage of early life the varus knee or the

bowed leg appearance might be worse

specially when accompanied by some internal

rotation of the lower limb with increased

anteversion of the femoral neck.

Basically, these early deformities were called

normal physiological changes that happen

during childhood; geno-varum and tibial bow

added to mild degree of rotation start to appear

during the first year of life, and continue

during the toddler stage until the age of 4-5

years, were reversal to geno-valgum and of

course developed into beautiful straight legs

eventually.

It's important to stress the normality of this

state not only to the parents but also to the

following doctors in polyclinics. The problem

of deciding when the normal varus or

angulated leg becomes pathological is very

difficult,1 and widespread abnormalities can be

discussed as the primary pathology e.g :

1. Epiphyseal dysplasia.

2. Metaphyseal dysplasia of Blount's disease.

3. Osteogenesis imperfecta.

4. Postero-medial tibial angulation.

5. Antero-lateral tibial angulation (pre

pseudoarthrosis tibia).3

6. post-trumatic physis injuries.

Among this short four –year- experience study,

we review our acknowledgment and out come

treatment of tibial deformities referred to our

department by using mono tube external

fixator.

Regarding their physio-pathological and

therapeutic aspect, our treatment plan follow

the type of deformity, age of patient and

severity of angles measured (staging). The

treatment to correct this deformity started for a

long time by using Ializrov,4 and Wagner

external fixator.

Aetiology Pathogenesis: As the most other idiopathic congenital

anomalies of the extremities no clear causative

factor was determined. In deed, many

attributers suppose different aetiology, the

congenital postero-medial tibial angulation, in

fact, is related to abnormal intrauterine

position of the fetus which usually occur in the

middle and distal third of the tibia dominantly

unilateral deformity and often skin dimple over

the angle of bow (approximately 50%) as in

"fig. 1" added to proximity to the ankle makes

the deformity mimic calcaneo-valgus footl

,while antero-lateral tibial bowing is often

correlate to pseudoarthrosis of tibia. And

supposed primary due to abnormal vascular

system of tibial shaft or secondary to zone 2

{Streeter) congenital constriction band of the

leg as2 in "fig. 2". Pathological changes of

bony sclerosis and cystic changes or dysplasia

might support that. Neurofibromatosis is

associated with deformity in 30% of the cases.

*) Orthopeadic Department, Central Hospital, Tripoli, Libya.

Management of Tibial Deformities …… Abdulrazag Shakshuki, et al.


fig. 1: skin dimple fig. 2: congenital constriction band

Tibia vara (Blount's disease) of infantile

variety is more clearly defined by

developmental abnormalities as a result of

growth disturbance of the medial side of the

upper tibial growth plate. It's presence with

high incidence in west Africa and west

Indians. Those children are noted to walk

earlier and they also have lax ligaments and

joints.3 Cvolding and McNiel (1963) conclude

that this type of tibia vara is caused by failure

of growth of the postero-medial part of upper

tibial epiphysis. The other adolescent variety

developed at age of 8-13 years and those

children are above the 95th

percentile for height

and weight and usually unilateral.4

The post traumatic physis injury is another

cause of varus deformity (Tibia vara).

Excessive loading on mechanical axis of the

knee by early walking of overweight child with

physiological bowed legs may contributes to

the development of the infantile Blount's

disease, but this hypothesis has not been

proved.

Langenskiold (l964)5 Has classified tibia vara

into six stages (Table 1) according to

pathological changes seen on the radiographs.

That is very helpful to decide treatment should

be undertaken.

Table 1: (Langinskiold staging) and treatment regimens

Age Stage Treatment

<18mo 1-2 None

18-24mo 1-2 Frame/ blount brace (night)

2-3yr 1-2 Modified locked KAF*

3-8yr 3-5 Orthosis

3-8yr 6 Valgus rotational osteotomy

Resection of bony bridge

*KAF-Knee, Ankle, Foot.

Plan of Treatment and Follow-up:

Treatment methods as ordinary are described

into:

(1) Conservative regimen that includes all

cases younger than (3 years) and some cases

older than (3 years) with mild deformity. It is

processed in a way of short period casting

followed by long time bracing until the age

near the puberty.

(2) Surgical regimen includes:

a- cases do not respond to bracing with

progressive deformation.

b- For cases which primarily present with

sever deformity at late age and adults.

Physiological geno varum and tibial bow

rarely require treatment rather than family

education and regular observation, during

which radiographic angles and leg length

discrepancy are recorded. According to a chart

based on (Green-Andersoit) growth tables can

guides the time of possible surgical treatment.



In general tibio-femoral angle exceeds

(32degree), anatomical tibial angulation more

than (25 degree) with {Boyd) signs of

morbidity or significant cosmetic deformity

guiding toward the corrective surgery.

Despite dramatic appearance, the postero-

medial angular deformity is corrected

spontaneously in nearly all cases, some authors

recommend casting to hold the dorsiflexed foot

down to plantigrade position, but as actual

deformity is not related to the foot, this

maneuver was not logical and patients who are

never casted resolve as quickly as those who

are suffering from tibial curvature remodels

enough by the age of three that the leg appears

cosmetically acceptable, even if little bowing

may be evident on radiograph at 5-8 years.

Although this deformity needs no treatment,

long term follow-up indicates few numbers of

cases that will necessitate surgical correction

with the external fixator device, especially

with those complicated by leg length

discrepancy.6

Specific attention must be taken for the antero-

lateral tibial deformity as their critical outcome

might end by amputation of the limb, the

possibility of the fracture from birth until the

age of 8-10 years is still important prognostic

factor, (Boy d) classification is based on

bowing and the presence of cystic bone

changes, sclerosis, or dysplasia helps to prove

treatment time. Early treatment includes a total

contact brace to protect from fracture, and later

surgical corrective osteotomies with excision

of hamartomatous tissue or constriction band

and fixation with Mono Tube External Fixators

can improve the prognosis, bone grafting

insertion advised by many authors if fracture

occurs to minimize the high risk of tibial

pseudoarthrosis.6

Treatment of (Blount's) tibia vara is more

practical with high success rate regarding the

long term follow-up control.

Langinskiold staging-Table 1) shows two

groups of patient according to the affected part

of tibial physis, physial plate depression

recorded by radiographs "fig. 3"7.. Those

groups; in children under 3 years with stage 1

or 2 disease complete correction can be

achieved using long leg brace that exert valgus

force and unload the medial tibial physis.

Fig. 3: Epiphseal-methaphyseal angle in Blount's disease

while in stage 3 or more and even in failed

bracing of more than one year, the corrective

surgical osteotomy is indicated with long term

post-operative bracing until the age of maturity

is recommended.

In stage 6, tibia vara with depression of medial

articular surface an osteotomy to elevate the

entire medial platue is necessary. Also a

combination with epiphysiodesis and

lengthening may be required for sever cases.7

Over all these different management ways, the

only surgical option that involves such

deformities is the corrective osteotomy to re

aligned the angulation apart from fixation

device or casting procedure.

Material and Methodology:

This study started four years ago in

orthopaedic department central hospital-

Tripoli. It's applied for (33) cases of tibial

deformities ("7" cases with antero-lateral and

postero-medial angular deformity, "20" cases

of Blount's disease, "3" cases post-traumatic

geno-varum "3" cases of geno-varum due to

achondroplasia and metaphysial dysplasia ).

As in "fig.4", all of them were Libyans; male

to female ratio was about 5:1. The age

category is grouped into: below (3 years),

above (3 years), and adults. The diagnostic

tools obtained from clinical observation with



condition of the skin overlying deformities and

associated anomalies and by 2nd

tool which is

the radiographs on both A-P and Lat views and

control X-ray of the normal side in unilateral

cases. Three major angles were measured;

(Drennan's) metaphyseal-diaphyseal angle in

tibia vara, which is the angle between

metaphyseal beaks is perpendicular to the long

axis of tibia which is abnormally more than

(16 degree), another tibio-femoral angle is

between the anatomical axis of the tibia and

femur (Levin), which is normally less than (32

degree) in children "fig. 5".

The (3rd

) angle of tibial shaft deformities is the

angle drawn between the anatomical axis of

proximal and distal parts of tibia which isn't

more than (25 degree) for better prognosis.6

Fig. 4: •Blount's disease • Post. Traumatic geno.varus Fig. 5: Tibio-femoral angle (Levine)

• Antero-lateral & postero-medial angulation Meta-diaphyseal angle (Drennan’s)

• Achondroplasia & metaphysial dysplasia

Surgical Technique:

The correction of deformity carried out using

Mono Tube External Fixator starts by

osteotomy of the fibula first then insertion of

two parallel pins in the tibia just below the

joint line in adults and below epiphyseal plate

in children and insertion of another two

longitudinal pins distal to the osteotomy line

on the tibia.

Distal and proximal pins are fixed together by

a bar of Mono Tube External Fixator.

The dome shape osteotomy was done just

below the proximal pins of external fixator.

Then we can correct the angle of deformity by

moving of distal tibia (anterior or posterior and

medial or lateral). After correction of the

angle, we can fix the external fixator.

N.B.: we can adjust the deformity even after

surgery (postoperative) by manipulation of

external fixator and we can do the surgery

under image intensifier screen (TV. Screen).

Results:

Among (33) cases of pathological Tibial

deformities:

(a) Tibial vara (Blount's disease).

(b) Postero-medial tibial angulation.

(c) Antero-lateral tibial angulation.

(d) Other geno-varus.

(27) cases were males and (6) females of

different geographical distribution along Great

Jamahiria, age-severity relationship recorded

as 31% less than "3 years" old of mild and

moderate deformity, while 69% more than "3

years" and adults of moderate and sever

deformity.

(16 cases) were treated conservatively.

(17 cases~19 legs) were treated surgically.

Two of them were treated bilaterally (we

treated both legs) by using Mono Tube

External Fixator are shown as:

(12 cases) good correction

(3 cases) incomplete correction + leg length

discrepancy less than 4cm.

(2 cases) delayed union + no correction.

(2 cases) did not complete their follow-up.

0

5

10

15

20

Blount's disease A. L. & P. M.angulation

Post. Traumaticgeno.varus

Achondroplasia



0

5

10

15

20

25

30

35

40

45

Blount's disease P.M. bow A.L. bow other G.V.

corrective tibial osteotomy+monotube E.F outcome

Good

Fair

Bad

11%

11%

16% 62%

post. Operative complication with monotube E.F.

D. wound healing D. bone union leg length discrepancy no complication

* E.F- external fixator * P.M- postero-medial

* A.L- antero-lateral * G.V- geno-varus

Complications:

(1). Delayed wound healing: two cases.

(2). Delayed bone union: two cases.

(3). Leg length discrepancy less the 4cm: three cases.

(4). Compartment syndrome: no cases recorded.

(5). Bone infection: none.

(6). Neuro-vascular injury: none.

* E.F- external fixator

* D- delayed



Conclusion:

The most orthopaedic attributers agreed that

lower extremities disorders in general usually

can be easily diagnosed with a thorough

history and examination apart from speciality

unit, laboratory and radiographic studies

facilitate both diagnosis and treatment

planning, as many of these deformities in

children are physiologically normal and

require only family reassurance, instructions

closed to regular follow-up and observation.

By the way the adolescent tibia vara with

(Drennan's) angle of more than (16 degree)

should be corrected carefully to avoid early

progressive degenerative arthritis at adulthood.

The surgical treatment preferred in adults and

adolescent and recently many authors prefer

surgical treatment even in early life (4-5) years

old.1

The (Mono Tube External Fixator) can be

used to treat these deformities.

This method gives us more flexibility to

correct the deformities even after surgery

(post-operative) by re adjustment of external

fixator, and gives rapid return of joint motion,

earlier weight bearing and walking. By using

Mono Tube External Fixator we can correct

leg length discrepancy. Also Mono Tube

External Fixator augmented by autogenous

bone graft can be one of the best options.

Some cases:

(Preoperative) (Dome- osteotomy + monotube Ex. Fix.)

(Blount's disease) (Blount's disease) Preoperative Postoperative



Using of Mono-Tube External Fixator in correction bf postero-medial tibial angulation deformity

with leg length discrepancy.

Pre. Operative Post. Operative after healing & removal of Ex. Fix

Congenital anterior angulation of the tibia corrected with Mono-Tube External Fixator.

References:

1. Pappas AM. Congenital postero-medial

bowing of the tibia and fibula. J pediatric

ortho, 1984.

2. Morrissey RT. Congenital pseudoarthrosis

tibiae factors that effect Results dine ortho,

1982.

3. Johnston CE. Infantile tibia vara. clinc

ortho, 1990.

4. Tudisco C et al. Functional results at the end

of skeletal growth in 30 patients affected

by congenital ps tibiae. J pediatric ortho,

2000.

5. Langinskiold. Tibia vara, osteochondrosis

deformans tibiae, Blount's Dis clinic ortho,

1981.

6. Review of orthopaedics. Mark D. Miller,

M.D 4th

Edition, 2004.

7. Bwen JR-Lealy JL, Zahng Z. Partiale

epiphyseodesis at the knee to Correct the

angle deformities, clinc ortho, 1985.

8. Feldman MD, Schooenecker PL use of the

metaphyseal-epiphyseal Angle in

evaluation of the bowed legs. J Bone Jr

Surg, 1993.

Documents

Management of Tibial Deformities by Using of Mono … Sebha Medical Journal, Vol. 6(1), 2007. Management of Tibial Deformities by Using of Mono-tube External Fixator Abdulrazag Shakshuki,*