Leg Length Discrepancy

Congenitally Short Femur

Incidence

 

20 - 30 % LLD

 

Features

 

Intact femur radiographically +

- foot at contralateral mid-tibial level

- cruciate ligament deficiency

- coxa vara

- hypoplastic lateral femoral condyle with resulting valgus knee

- sclerosed lateral cortex

 

Amount of femoral shortening is variable patient to patient

 

Shapiro Type 1 growth disturbance

- i.e. LLD increases with time

 

Examination

 

LLD

Genu valgum

Fat thigh

High riding patella

 

Foot held externally rotated

 

X-ray

 

Hypoplastic femur

Coxa vara

Lateral sclerosis

 

2 groups

 

Simple femur hypoplasia

 

Femoral hypoplasia with coxa vara

 

Management

 

Align early then lengthen in primary school years

 

1. Realignment may involve

 

Coxa vara

- proximal femoral valgising osteotomy

 

Valgus knee

- Supracondylar osteotomy / guided growth 8 plates

 

2. Lengthen tibia and femur

 

Caution for dislocated knee

- ACL deficient

 

3. Contralateral epiphysiodesis

 

 

 

 

 

 

 

Fibula Hemimelia

Definition

 

Deficiency of bony elements on lateral side of lower limb

- characterised by hypoplastic or aplastic fibula

 

Types

 

Terminal

- abnormal foot

 

Intercalary

- normal foot

 

Epidemiology

 

Most common congenital deformity of long bones

- M:F   2:1

 

May be associated with PFFD

 

Sporadic 

- tibial hemimelia can be inherited

 

Presentation

 

LLD

 

Femur

- PFFD with type C / severe

- always slightly short femur

 

Knee

- cruciate deficiency

- hypoplastic LFC / valgus knee

 

Tibia

- anteromedial bowing

 

Ankle 

- equino-valgus / ball and socket

- tarsal coalition

 

Foot

- small limb / foot

- absent lateral ray(s)

- lateral tarsal bones fused or absent

 

UL deficiency

 

Classification Coventry

 

Type 1:  Short or partial proximal absence unilaterally

 

1A:  Stable ankle joint ± ball & socket joint

1B:  Unstable anklejoint / equinovalgus

 

Fibular Hemimelia

 

Type 2: Complete absence unilaterally

- tibia short & bowed anteromedially, dimple at apex

- associated with lateral ray deformity & coalitions

 

Type 3:  Bilateral

- severe

- associated with PFFD & upper limb deficiency

 

DDx

 

Fibular hemimelia / dysplasia is a spectrum

- child may have only gracile fibular and short leg in tibia and femur

- attributed to fibula hemimelia as no ACL, short femur etc

- can be pseudoarthrosis of tibia

- realise when tibia fractures and then doesn't heal

 

Management Issues

 

1.  Foot / ankle deformity

 

Concept

 

If less than 2 rays or unstable ankle

- cannot salvage

- symes / BKA

 

Indication for Syme's Amputation

- severe deficient foot that will not serve any useful purpose

- grossly unstable ankle

- associated tibial deficiency such that LLD & unstable AKJ preclude leg lengthening

- associated PFFD 

 

2.  LLD 

 

Usually > 5 inches

- can predict based on difference at presentation 

- can treat if have normal foot

 

Usual Options

- < 3cm shoe lift

- 3-5 epiphysiodesis

- 5-10 limb lengthening

- 10-16 limb lengthening + epiphysiodesis

- > 16 amputate

 

Technique

 

5cm at a time

Usually start when child 7-8, can understand reason for operations

 

3.  Tibial bowing

 

Least important

- usually corrects

 

 

 

Growth Plate Arrest

Aetiology

 

Trauma

- most common

- SH 4

- high energy SH 2 / 1 i.e. distal femur

 

Infection

 

Thombotic / embolic

 

Ischaemia (arteritis)

 

Radiotherapy

 

Classification

 

1. Central

- tenting 

- slows longitudinal growth +/- angulation

 

2. Peripheral

- can lead to rapidly progressive angular deformity

- especially small bar

 

Distal radius premature lateral growth arrest

 

3. Linear

- especially SH4

- effect depends on site and size

 

X-ray 

 

To assess deformity (angular and LLD)

 

CT

 

To accurately map size and position of bar

 

Management

 

1.  Epiphysiolysis

 

Indications

- < 50% growth plate

- > 2 year growth

- healthy skin

 

Technique

 

Excision of bar and interposition graft (fat)

- excision with high speed burr

 

Peripheral

- via direct approach to growth plate

 

Central 

- more difficult

- via metaphyseal window (avoid damage to the perichondral ring)

 

2.  Epiphysiodesis 

 

Concept

- remove active part of growth plate

- prevent angular deformity

 

Technique

- use drill under II guidance

- 4.5 mm

 

3.  Osteotomy

 

Indication

- correct angulation post growth plate fusion / epiphysiodesis

 

 

 

Hemihypertrophy

Definition

 

Asymmetry between L and R side more than due to normal variation

 

Upper limb hemiatrophy

 

Prevalence

 

Difficult to determine because no precise definition

 

Difficult to differentiate hemihypertrophy from normal variation

- enlargement soft tissues & bones also

 

Incidence

- 1/13 000 combined

- 1/86 000 non-syndromic

 

Non syndromic hemihypertrophy associated with 4% incidence tumours

 

Aetiology

 

Unknown

 

Non-syndromic is sporadic

 

Clinical Features

 

Rarely apparent at birth

- thicker skin, more hair, accelerated bone age on involved side

- ipsilateral paired organs increased in size also

 

Associations

 

Non-syndromic hemihypertrophy

 

Inguinal hernias

 

Genitourinary

- renal cysts

- cryptorchidism

- sponge kidney

- horseshoe kidney

 

Scoliosis

- non-structural

- compensatory to pelvic obliquity

 

Syndromic hemihypertrophy

 

Associated with cutaneous and vascular lesions

 

Classification

 

Total 

- involvement of ipsilateral paired organs

 

Limited 

- also divided as per extent of involvement

  

Classic hemi - UL & LL

Segmental - UL or LL

Facial - head and neck only

Crossed - opposite UL & LL

 

Diagnosis

 

Normal population may differ up to 1-2 cm in length and circumference

 

Rush and Steiner 1946

- 1000 US army recruits

- 23% equal leg lengths

- 77% 0.75 cm

- 15% > 1 cm

 

1cm difference

- in adolescent within normal

- in infant in pathological range   (4.2%)

 

Hemiatrophy V's hemihypertrophy

 

Compare length of L and R tibia and femora with normal standards

 

Hemiatrophy 

- no association with tumours

 

Non-syndromic hemihypertrophy / Beckwith-Weidermann syndrome

- are at increased risk for intraabdominal tumors 

 

DDX of non-syndromic hemihypertrophy

 

1. Beckwith- Weidmann syndrome

2. NF

3. Klippel-Trenaunay-Weber syndrome

4. Proteus syndrome

5. Malignant tumours

6. Olliers

7. Fibrous dysplasia

8. Poliomyelitis

9. Spastic hemiplegia of CP

10. Russell-Silver synd (short, cafe-au-lait spots, clinodactaly, hemiATROPHY)

11. JCA or haemophilia (secondary to hyperaemia)

12. XRT

13. Conradi-Hunnerman (chondrodysplasia punctata)

 

(5 - 13 may have contra-lateral shortened limb)

 

50% of hemihypertrophy will have syndrome

 

Beckwith-Weidermann Syndrome

 

Features

 

Pre / postnatal overgrowth, birth weight > 90 %

- neonatal hypoglycaemia

- macroglossia

- hemihypertrophy occurs in 13%

 

Predisposition for embryonal tumors (Wilms)

 

Aetiology

 

Genetic abnormality Chr 11 p15

- near gene for IGF -II

- AD transmission but most sporadic

 

Management

 

Need abdominal US

 

BWS with hemihypertrophy c.f. BWS without hemihypertrophy 

- risk embryonal tumour

- 27 V's 9%

 

Neurofibromatosis

 

NF1 may have overgrowth digit or limb

 

Klippel-Trenaunay-Weber

 

Characteristed by Hemihypertrophy + vascular malformations

 

AV Malformation Arm

 

Problems

- varicose veins

- port-wine nevi

- cutaneous and subcutaneous capillary haemangiomas

- cavernous haemangiomas

 

Proteus Syndrome

 

Name after Greek god who could change shape

 

Vascular + lymphatic malformations + lipomas

 

Features

- haemangiomas

- lipomas

- lymphangiomas

- macrocephaly

- hyperostosis skull

- overgrowth long bones

 

 

LLD Aetiology

A.  General Conditions

 

Hemi-hypertrophy or atrophy

 

Idiopathic

Klippel-Trenaunay-Weber syndrome

Proteus syndrome

Beckwith-Weiderman syndrome

Russel-Silver syndrome (atrophy)

 

Skeletal dysplasia

 

Chondrodysplasia punctata

Ollier's / Maffuci's

Multiple hereditary exostoses

NF

Fibrous dysplasia

 

Neurological

 

Closed HI

Polio

Spina bifida

CP

Spinal dysraphism / tumor / injury

Peripheral nerve injury

 

B.  Specific Regions

 

Tumour / trauma / infection / radiotherapy physis

 

Hip

- PFFD

- Coxa vara

- SUFE

- DDH

- Perthe's

- Tom Smith arthritis / post septic arthritis

 

Femur

- congenitally short femur

 

Leg

- fibula hemimelia

- tibial hemimelia

- bowing

 

Foot

- CTEV

 

Effect of LLD

 

Initially thought gives pain in back and contralateral knee and hip

- this may be debatable

 

1.  Short leg gait

- increased energy expenditure is the only proven effect of LLD

 

2.  Back 

- pelvic tilt and secondary scoliosis

- initially compensatory

- can become fixed

- ? causes LBP - now thought no different from general population

- most children's spines adapt (not so with adults)

- up to 2 cm easily tolerated

 

3. Contralateral Hip 

- uncovering of hip on long leg side in stance

- AKA long leg arthropathy

- ? increased OA 

- no evidence 

 

4.  Contralateral Knee 

- ? increased knee pain in athletes

 

Growth

 

2° Proliferative Zone chondrogenesis

 

Proximal Femur

- 3mm / year

- 15% leg

 

Distal Femur

- 9mm  / year

- 37% leg

- 70% of femur

 

Proximal Tibia

- 6mm / year

- 28%

- 60% tibia

 

Distal Tibia

- 3mm / year

- 20%

 

Growth Cessation

 

14-15 Girls

16-17 Boys

 

Relationships

 

LL vs Chronological Age

- steady growth occurs

- growth spurt in early adolescence

 

LL vs Skeletal Age 

- Green & Anderson curves

- Growth vs Skeletal age

- shows no growth spurt

- because growth spurt & maturation spurt occur together

 

Skeletal Age & Chronological Age

- maturation can occur at different rates

- if early, are tall early & stop growing early

- can have spurt where mature more than age

- pass through skeletal ages more quickly

 

History

 

Determine cause

Determine deformity

 

 

 

LLD Assessment & Quantification

Quantification of LLD

 

X-ray

 

1. Teleroentgenogram

- single exposure both legs

- long film with ruler

- Parallax errors

 

2. Orthoroentgengram

- same long Xray

- separate exposures hip, knee & AJ 

- eliminates parallax error

- problem artefact 

 

3. Scanogram

- similar separate exposures

- film moved between exposures

- smaller film

- multiple exposures

 

CT scan

 

Software measures distances 

- accurate to 0.2 mm

- legs must be in same position

- fast

 

Skeletal Age

 

1. Greulich- Pyle Atlas

 

Xray Left hand (non dominant)

- correlated with Green- Anderson table LL

- less accurate < 6

- improved accuracy by focusing on hand bones rather than carpal bones

 

2. Tanner- Whitehouse Atlas

- more refined

- 20 landmarks graded L Hand

- more accurate

- can't use as not correlated with LL

 

Prediction of Growth

 

Note that all methods have an inherent error of 12 months

- gives accuracy to 1.5 cm

 

Need > 3 measures 4/12 apart for all methods

- If inadequate data wait till older or wait till skeletally mature

- If acquired event caused LLD, can plot onto graph

 

1.  Menelaus "Rule-of-thumb" Method

 

Less accurate

- based on chronological age

- only valid from age ten

- convenient / easy / simple

 

Basic rules

- girls stop growing at 14 

- boys stop growing at 16

- distal femur 9 mm 

- proximal tibia 6 mm 

- distal tibia / proximal femur 3 mm 

 

Calculate how much growth lost from fusion of physis / Predict effect of epiphysiodesis

- Effect = Physis rate x years of growth Left

 

2.  Green & Anderson tables

 

Growth remaining method

- uses skeletal age

- requires graph

- estimates growth potential in distal femur and proximal tibia at various skeletal ages

- separate charts for girls and boys

 

3.  Moseley

 

Straight - Line Graph Method  

- uses Green & Anderson data

- applied to a chart

 

At least 3 measurements each time

1.  Length long leg

2.  Length short leg

3.  Skeletal age

 

Do so 3 times separated by 3-6 months

- accuracy improves with increased plotting

 

Plot the points for long and short leg on a vertical line for chronological age of either boy or girl

- create 2 lines for short and long leg over time

- line of best fit

- gives LLD at maturity at right of graph

 

Technique

- plot Long leg length on long leg line against skeletal age

- plot Short leg length on short leg line against skeletal age

- able with at least 3 measures to create line of best fit

- extend lines to maturity

- difference is LLD

 

Growth rate of each leg = slopes

- parallel or divergent 

- AKA static or progressive

 

Then use Menelaus rule of thumb to determine appropriate age for epiphysiodesis

 

4.  Paley multiplier

 

State of the art

- 2000

- take LLD for boy or girl

- multiplier for chronological or skeletal age

- predicts LLD at maturity

 

Patterns of LLD

 

Adds to difficulty

- static

- progressive

- regressive

 

Shapiro 

 

1982 5 developmental patterns

- 75% types I and II

 

I Increasing

- LLD increases at constant rate

- hemihypertrophy / atrophy

- tibial pseudoarthrosis

 

II Increasing plateau

- similar early, but annual rate of increase diminishes thereafter

- Perthes

 

III  Plateau

- discrepancy increases, then stabilises

- fracture femur

- DDH

- Polio

 

IV Increasing- decreasing

- similar to III, then late increase at end of growth

- DDH

- hemihypertrophy

 

V Decreasing

- Initial increase, steady, then decrease

 

Progressive LLD

 

Progression Rate = Change LLD / Time

 

Final LLD

- add Current LLD to Prog Rate x Time to Skeletal maturity

 

 

 

 

 

 

LLD Examination

Four Physical Outcomes

 

1.  Symmetrical Stance & Level Pelvis 

 

A.  LL Equality

- components equal with no deformity

 

B.  Components equal with bilateral symmetrical deformity

- eg bilateral varus knees

 

2.  Symmetrical Stance with Oblique Pelvis 

 

Uncompensated LLD

 

3.  Asymmetrical Stance & Level Pelvis 

 

A. Fully Compensated LLD

- flexed contralateral knee 

- equinus ipsilateral ankle

 

B. Sagittal deformity with ipsilateral sagittal compensation

- FFD knee with equinus & hip flex OR

- fixed equinus with flex knee & hip OR

- FFD hip with equinus & flex knee

 

C.  Coronal deformity with contralateral coronal deformity

- valgus of knee & contralat varus of knee

 

4. Asymmetrical Stance with Oblique Pelvis 

 

A.  Partly compensated LLD

- partly flexed contralateral knee

- partly equinus of ipsilateral ankle

 

B. Coronal hip deformity with sagittal compensation

- fixed hip adduction with contralateral knee flexion / ipsilateral equinus

- fixed hip abduction with ipsilateral knee flexion / contralat equinus

 

C.  Sagittal deformity with coronal compensation

- FFD knee c ipsilateral hip abduction

- fixed equinus c ipsilateral hip ADD

 

Leg length Examination

 

1.  Look

 

Posture

- flexed knee

 

Signs hemihypertrophy

- NF
- haemangiomas / lipomas (Proteus, Klippel-Trenau-Weber, Beckwith)

 

Scars

- trauma, infection

 

2.  Gait

 

Children

 

Compensate well 

- walk on toes short leg usually / equinus

- flexion long knee uncommon as energy++

 

Adults

 

Compensate less well

- walk with bilateral heel-toe gait

- vaults over long leg

- excess sagittal head motion

 

3.  Measure LLD
 

A.  Functional LLD

- on blocks

- heels flat, nil knee FFD (if able)

- correct pelvic tilt

- should correct scoliosis

 

Conclusion

- if can make pelvis stable

- ASIS equal

- blocks are a quantitative measure of functional LLD

 

B.  Apparent LLD

 

Lying on bed

- measure from xiphisternum to medial malleolus

- no correction for contractures

 

C. Real / True LLD

 

Must correct for deformity in coronal and sagittal plane

 

Exclude

- hip adduction / abduction contracture

- hip FFD

- knee FFD

 

Scenarios

1.  Hip FFD

- pillow under both thighs

2.  Knee FFD

- pillow under both knees

3.  Hip adduction contracture won't correct to neutral

- measure each leg crossed over the other

4.  Hip abduction contracture won't correct to neutral

- place both legs in similar position

 

If there is a contracture, perform the above measures

- then meaure the intercalated segments

- from ASIS to medial joint line

- medial joint line to medial malleolus

 

4.  Identify site of shortening

 

Galeazzi

- must not forget can have small foot / old calcaneal fracture / wasted buttock

- hips and knees flexed

- side by side

- look for tibial / femoral shortening

 

If shortening above knee, find out if shortened above greater trochanter

- i.e. hip deformity

 

Bryant's triangle

- line perpendicular to GT and ASIS

- distance between

- quantify in fingerbreadths

 

Nelaton's line

- line from ischial tuberosity to ASIS

- GT should be on or below line

 

Klisics line

- GT to ASIS

- should aim to umbilicus

- will be more parallel

 

5.  Other

 

Examine knee stability

- can have problems lengthening femur if ACL deficient

- i.e. fibula hemimelia

 

 

 

 

 

LLD Management

Goals

 

1. Equal leg lengths

- goal is mild to moderate isolated discrepancy

 

2. Unequal leg lengths

- goal with paralysis / equinus foot

- aim 1-2 cm short for clearance

 

3. Level Pelvis

- should use blocks to estimate functional correction

 

4. Vertical LS Spine

- vertical spine more important than level pelvis

 

5. Equalisation with Prosthesis

- goal with excessive LLD

- usually femur < 1/2 normal length or LLD >15cm

 

Principles

 

Correct coexisting deformity first

- can decrease discrepancy

 

May require correction of other problems first

- release of contractures

- correct angular deformity

- correct spinal deformity

- excision of bony bridge

- completion of partial arrest

 

Treatment guidelines by projected discrepancy

 

0 - 2 cm

- no treatment, heel raise

 

2- 6 cm

- shoe lift, epiphysiodesis

- maximum subtalar joint can take

 

6 - 15 cm 

- lengthening + epiphysiodesis

 

> 15 cm 

- amputation

 

Prosthesis

 

Shoe Lift / sole raise

 

Good treatment if 2-5 cm

- aim is to improve gait

 

Note

- > 5 cm ankle sprains

- joint unable to cope

- need patten boot (steel reinforcements of STJ)

 

Guidelines

- 0 - 1.5cm heel raise

- 1.5 - 5cm heel and sole raise

- 5 - 12cm patten and boot

- 12 - 20cm patten and AFO / prosthesis

- 20+cm prosthesis

 

Epiphysiodesis

 

Advantage

 

Often treatment of choice

- low morbidity

- accurate

- can shorten at level of deformity

 

Disadvantage

 

Operate on normal leg

- get loss of height & proportions

 

Indications

 

Anticipated LLD 2-6 cm

 

If > 6 cm LLD 

- excessive height loss

- knees at different level 

 

Phemister Technique

 

Create bony bridge

- medial & lateral approaches

- access window removed

- physis excised with curette

 

Percutaneous Technique 

 

Under II guidance

- percutaneous incision

- medial and lateral drilling into physis

- angle drill anterior and posterior

- entry points anterior, middle and posterior

- see white growth plate on drill

 

Complications

 

Continued longitudinal growth or angular deformity

- failure to eliminate growth plate

 

Femoral Shortening

 

Indications

 

Maximum 2 - 6 for reasons above

 

Consider if

- too old, insufficient growth remaining

- can't predict LLD and wait til maturity

 

Usually performed over a nail

 

Tibial Shortening

 

Easier 

Max 3cm

 

Growth Stimulation

 

Stimulate physis by hypervascularity 2° irritative

- insert vicryl into growth plate

- moderate success

 

Leg Lengthening

 

See Limb Lengthening

 

 

 

 

 

Limb Lengthening

Definition

 

Concept of distraction osteogenesis

 

Popularised by Ilizarov in the Soviet Union 

- initially in the 1940's

- popularised in the 1980's

- also created the circular fixator

 

Corticotomy

- low energy osteotomy

- attempt to minimise damage to blood supply and periosteum

- avoid use of saw

- minimise thermal necrosis

 

Callotasis

- gradual incremental distraction of a fracture callous after a latency period

- intramembranous ossification in zone of distraction

- type 1 collagen with osteoid laid on collagen

 

Advantage

 

Maintains height & proportions

- Avoids operating on normal side

 

Disadvantage

 

Difficult

- steep learning curve

- complication rate 10 - 250%

 

Indications

 

General rules

- LLD 6-15 cm

- over 15 cm risks outweigh benefits

- < 20% limb

- 5cm in femur / 5 cm in tibia

 

Limitation is due to muscles / ligaments / nerves

- can repeat at staged procedures

- i.e. 5 cm per bone at any given time

 

Site 

 

Site of deformity best

 

Metaphyseal lengthening easiest

- large cancellous surface area

- thin cortex

- best blood supply

 

Contra-indications

 

Mentally or medically unstable

- long and demanding process

- 12 months or more

 

Unstable joints

 

Associated neurology

- Weakness /  Insensate

 

Technique

 

1. Osteotomy & Frame / Nail

2. Latency Period

3. Distraction Period 

4. Consolidation Period

 

Maintaining blood supply via periosteum is the key

 

1A.  Osteotomy with Periosteal Preservation

 

Open Corticotomy

 

Drill-holes & closed osteoclasis / Di Bastiani

 

Used in the femur

- percutaneous skin incision

- multiple drill holes first to weaken bone

- osteotome to complete

- apply force to complete fracture

 

Usually stablise initially with temporary external fixator

- perform osteotomy

- insert nail / ISKD

- remove frame

 

Tibial technique with Gigli saw

 

Proximal corticotomy in metaphyseal bone

- below tibial tuberosity

- frame on initially to stabilise

- incision lateral crest tibia, elevate periosteum lateral tibia

- incision medial border tibia, elevate periosteum medial tibia

- pass artery clip between periosteum and bone on one side

- pass wire on other side, retrieve with clip

- pass suture, then pass gigli saw

- perform subperiosteal corticotomy, periosteum intact

 

Wagner Osteotomy

 

Contra-indicated now

- osteotomy and acute resection

- distraction

- bone grafting and plating

- superceded by lizarov techniques

 

1B. Devices

 

Need stable device or risk non-union with fibrocartilage

 

Uniplanar Device 

- Wagner, Orthofix

- simple

- no angular correction

- "Cantilever Loading"

- problems with pin loosing

- often necessary in femur

 

Ilizarov

- multiplanar correction

 

IM nail  / ISKD

 

Self lengthening nail

- movement of leg induces lengthening mechanism

- maximum of 5 cm

- if only want 3 cm, lengthen 2cm before insertion

 

Advantage

- all internal 

- no pin site complications

- easier for patient

 

Disadvantage

 

Runaway nail 

- lengthens too quickly

- cause contractures and nerve injury

- nothing can be done about this

- incidence 5%

 

Jammed nail 

- take to theatre to unblock

- may have to debride callus if lengthening too slow

 

2.  Latency period 

 

Usually 1/52

- allow callus to form before distraction

- reduce latency period in child as may start to ossify

- increase latency period in diabetics / steroids

 

3.  Distraction Period

 

Rate / Regenerate

 

Optimum 1mm / day turning 4x / day

- balance premature union vs non union

- slower in adults / diabetics

- i.e. 2-3 x day

 

Stop if

- poor new bone formation

- nerve palsies

- joint subluxation

- joint contracture 

 

4.  Consolidation

 

1 month per cm or

Double the distraction period

 

Complications

 

Pin infection

 

Management

- early oral antibiotics

- patient should have script at home

- take if pin site appears red or begins leaking fluid

- increase frequency of pin site cleaning

 

Prevention

- tight well tensioned pins

- don't place pins throught muscle

 

Nerve  injury

- demyelinate if lengthen > 6%

 

Contractures

- muscle elongates poorly

- max 1mm / day

- congenital LLD more susceptible than acquired

 

Risk

- T achilles contracture in tibia

- FFD / adduction femur

- knee FFD

 

Device failure

- broken pins, loss of position

 

Fracture

- inadequate consolidation before device removal

- 10 - 15% incidence

- can result in loss of length or angular deformity

 

Premature Consolidation

- unable to distract

- break pins / wires

 

Poor regenerate

- inadequate latency period

- too rapid distraction

- poor blood supply

 

Joint subluxation

- ligamentous insufficiency

 

Delayed or non union

- constant observation

 

Bone growth impairment

- damage to physis

- likely secondary to pressure

- best if delayed until after skeletal maturity

 

Psychological Stress

 

Distraction Physiolysis

 

Concept

- tibial lengthening by distraction across physis

- similar results to metaphyseal lengthening

 

Indications

- need extra length in skeletally immature

 

Complication

 

Physeal injury risk

 

Chondrodiastasis if < 1mm / day

 

 

 

Tibial Hemimelia

Definition

 

Paraxial deficiency of skeletal elements on medial aspect of lower limb

 

Epidemiology

 

Only skeletal deficiency with a documented familial occurrence 

- AD

 

1/ 1 000 000

 

Bilateral 30%

 

Clinical

 

Leg short +++

 

Tibial Anterolateral Bowing

 

Foot fixed in severe varus

- can mimic CTEV

- sole facing perineum

 

Knee

- FFD

- may be unstable

- no quads mechanism

 

Associations

 

Cleft hand

Reduplication of toes

CDH 20%

 

Classification

 

MRI to assess extent of proximal failure

 

1.  Unilateral Complete Type 1

 

No proximal tibial remnant

- usually foot abnormalities

- distal femur is hypoplastic & ossification delayed

- knee is featureless / unstable

 

Tibial Hemimelia Complete

 

Management

- amputation early

- around 1 year before child gets attached to it

 

2.  Unilateral Partial Type II

 

Well developed proximal tibia & knee joint

 

Tibial Hemimelia Partial

 

Management

 

A.  Knee

- proximal tibiofibular synostosis to prevent proximal migration

- fuse distal fibula to end of tibia

- then either symes or fuse fibula into calcaneus

 

B.  Ankle foot

- distal tibial deficiencies

- get equinovarus deformity similar to club foot

- tibiofibular synostosis

- then either keep foot if good or Symes

 

3.  Bilateral

 

Management

 

A.  Bilateral through knee amputation

 

B.  Can try to make fibula into tibia and perform symes on one side

- Brown procedure

- need good quadriceps