Genu varum

and Genu valgum

Etiology – Incidence – Diagnosis

R. Ganger, MD, PhD

Orthopaedic Hospital Vienna – Speising (www.oss.at)

Department of Pediatric Orthopaedic Surgery (F. Grill)

Lower Limb Development

Frontal plane alignment:

• Physiologic variations: the range of normal knee angles

changes with age

• Account for the greatest number of referrals

(including torsional problems) of children to orthopaedists

- Genu varum: bow legs

- Genu valgum: knock knees

Lower Limb Development

Frontal plane alignment:

• Genu varum: bow legs

• Genu valgum: knock knees

Lower Limb Development

Frontal plane alignment:

• Genu varum: bow legs

• Genu valgum: knock knees

Newborn 6 months 18 months

30 months 4-6 years

Lower Limb Development

Frontal plane deformities:

• Genu varum or Genu valgum outside normal range (+/- 2 SD)

• Normal or abnormal

• History: inquire about the onset

• was there an injury, illness

or infection?

• is the deformity progressing?

• is the general health good?

• are other familiy members affected?

Lower Limb Development

Frontal plane deformities:

• Genu varum or Genu valgum outside normal range (+/- 2 SD)

• Normal or abnormal?

- Body height and body proportion

- Other present deformities

- Unilateral or bilateral

- Leg length difference

- Laboratory examination: metabolic?

Lower Limb Development

Frontal plane deformities:

• Genu varum or Genu valgum outside normal range (+/- 2SD)

• Warnings:

- Asymmetrical deformity

- Progression

- Pain

- Leg length difference

Lower Limb Development

Frontal plane alignment:

• Standard imaging: AP-long leg standing radiogram,

patella pointing straight forward

incorrect correct

Lower Limb Development

Frontal plane alignment:

• Standard imaging: Teleradiogram

Normal alignment

but LLD:

left side: - 3 cm

Lower Limb Development

Frontal plane alignment:

• The majority of children with bow legs before age of 2 yrs. and

knock knees presenting before 6 yrs. will resolve spontaneously

Natural history:

• benign

• selfcorrecting deformity

Correction devices (twister cables, night splints, shoe wedges)

are unnecessary.

Anual clinical checks are recommended.

Lower Limb Development

Frontal plane malalignment:

• The minority of children with unilateral deformity, progression,

leg length discrepancy and pain need further investigation.

Pathological genu varum / valgum:

• M. Blount

• Rickets, Vit.D - resistent rickets,

• Deformities after infection, trauma,

tumor.

Lower Limb Development

Frontal plane malalignment:

• M. Blount

Lower Limb Development

Frontal plane malalignment:

• Epi-, metaphyseal dysplasia:

Lower Limb Development

Frontal plane malalignment:

• Pseudoachondroplasia:

Lower Limb Development

Frontal plane malalignment:

• posttraumatic:

Lower Limb Development

Frontal plane malalignment:

• after infection:

Lower Limb Development

Frontal plane alignment:

Goal:

• Physiological deformities are best observed

• Pathological deformities are treated surgically to achieve

straight legs at same length

Lower Limb Development

Normal lower limb alignment: Diagnosis

Frontal plane:

• Mechanical axis

Lower Limb Development

Normal lower limb alignment: Diagnosis

Frontal plane:

• Anatomical axis

Lower Limb Development

Normal lower limb alignment:

Frontal plane:

• Mechanical axis

versus

• Anatomical axis

Femur:

difference of 6°

Tibia:

same

Lower Limb Development

Normal lower limb alignment:

Sagittal plane:

Lower Limb Development

Lower limb malalignment: Diagnosis

Deformity analysis:

Frontal plane:

• Varus, valgus, translation

Sagittal plane:

• Antecurvation, recurvation, translation

Axial plane:

• Rotation, lengthening or shortening

Lower Limb Development

Malalignment test acc. to Paley and Herzenberg:

• Identify the source(s)

of the

mechanical axis

deviation

Femoral deformity

Lower Limb Development

Malalignment test:

• Identify the source(s)

of the

mechanical axis

deviation

Tibial deformity

Lower Limb Development

Malalignment test:

• Identify the source(s)

of the

mechanical axis

deviation

Femoral and tibial

deformity

Lower Limb Development

Tibial mechanical axis planning:

Frontal plane:

Lower Limb Development

Tibial mechanical axis planning:

Frontal plane:

Lower Limb Development

Tibial mechanical axis planning:

Frontal plane:

• Digital planning

with

TraumaCad

program

Lower Limb Development

Tibial mechanical axis planning:

Frontal plane:

• Digital planning

with

TraumaCad

program

Lower Limb Development

Tibial mechanical axis planning:

Frontal plane:

• Digital planning

with

TraumaCad

program Deformity: 4°

Correction: 8.5°

With Auto Alignment:

MAD 7mm med

Individual Alignment:

MAD 1mm med

Lower Limb Development

Tibial mechanical axis planning:

Frontal plane:

• Digital planning

with

TraumaCad

program

Lower Limb Development

Tibial mechanical axis planning:

Frontal plane:

• Digital planning

with

TraumaCad

program

Thank you for your attention!