Angular Deformity

Normal development

 

1 year:  Bow legs / 15° varus

2 year:  Neutral 

3 year:  Knock knees / 10° valgus

 

3 year old knock knees

 

6 year:  Physiological valgus / 6° valgus

 

Normal valgus six year old

 

Note range ~ 15° either way at each age

- persistence of physiologic variations may occur

- especially in some families & racial groups

 

Salenius and Vankka

- chart of normal tibio-femoral variations by age

 

History

 

FHx

 

Examination

 

Unilateral / bilateral

- angular profile

- femorotibial angle

- inter-malleolar / intercondylar distance (quantify)

 

LLD / rotational profile / joint laxity

 

Height vs Age

 

X-ray

 

Erect AP Standing Long Leg view

- patella directed forward

- femur & tibia on same Xray

 

Indications

- if pathological form suspected

- asymmetry

- < 5th percentile

- severe deformity

- positive FHx

 

- other musculoskeletal abnormality

 

Causes of both Varus and Valgus

 

Trauma: Malunion / Partial physeal arrest

Rickets / Renal disease

JRA

Osteopaenia

OI 

 

NHx

 

Avoid dogmatic predictions

- clinical course variable

- not all cases resolve

 

Shoe wedges & other bracing ineffective

 

Prognosis

 

Uncertain

- genu valgum may cause CMP / PF Dislocations

- genu varum may cause OA Knee

 

Varus deformities

 

Physiologic Bow legs

 

1. Lateral tibial bowing

- occurs in first year of life

- nearly always resolves

 

2. Common Bowing

- involving the femur & tibia

- seen in second year

- prior to age 2 years, development of MFC lags behind lateral

- resolution occurs in most children

 

Management Physiological  

 

Bracing doesn't affect the NHx

- exclude pathological causes of deformity & reassure parents

 

Surgery 

- corrective osteotomy / epiphysiodesis / guided growth with 8 plates

- recommended for those children with persistence or worsening of physiologic varus

 

Pathological

 

Blount's

Rickets

Trauma - malunion / epiphyseal arrest

Infection - physeal damage

Skeletal dysplasia - achondroplasia / OI / enchondromatosis / metaphyseal chondrodysplasia

Anterolateral bowing - pseudoarthrosis

Fibrous dysplasia

JRA

 

Valgus Deformities

 

Physiological Valgus

 

NHx

- knock knees very common age 2-6

- starts at 2 years

- maximum 3-4 years

- usually resolves by 7

- may not always resolve

- minimal correction occurs > 8 yo

 

X-ray if

- asymmetrical / Unilateral

- progressive

- LLD

- intermalleolar distance > 10 cm

- outside normal parameters i.e. 15° either side normal for age

 

Bracing

- no evidence of efficacy

 

Surgical Indications

- > 15° valgus

- cosmesis

- poor gait / function

- avoided < 12 years

 

Options

- osteotomy / hemiepiphyseodesis / Guided Growth with 8 plates

 

Pathological Valgus

 

Traumatic

 

1.  Distal femoral physeal injury

- Usually SH I or II 

 

2.  Proximal tibial metaphyseal fracture / Cozen's

- tendency for valgus deformity

- reason why is uncertain

 

Theories

- rotation on xray hides valgus

- ST interposition

- overgrowth

 

Manage

- careful moulding cast into varus

- usually resolves over time

 

Infection - physeal injury

Congenital Posteromedial Bowing

Anteromedial Bowing - fibular hemimelia

Skeletal dysplasia - MED / pseudoachrondroplasia / Kneist

NMD - cerebral palsy / spina bifida

Lateral Condylar Hypoplasia

 

OI

 

Rickets

 

JRA