Knock Knees and Flat Feet in Children by sdfwerte

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									Knock Knees and Flat Feet in

     Dr Gillian Wilson
Knock Knees / Genu Valgum
          • Legs are bowed
            inwards in the
            standing position.
            Bowing occurs at or
            around the knee. On
            standing with knees
            together, the feet are
            far apart.
                  Normal Development
• Most children are “bowlegged” from birth until
  around 3 years old, then become “knock kneed”
  until age 4 to 5, and straighten towards adult
  alignment by age 6 to 7.
                         Investigations 1
• Measurement of intermalleolar distance. i.e
  Distance between two malleoli when the knees are
  gently touching with legs in adduction.
• Up to 3 and a half inches (9 centimeters) with
  child lying down is acceptable.
• 75% of children aged 2 - 4 years have some
  degree of intermalleolar separation.

• Intermalleolar separation under 3 inches is
  normal at any age.
• Periodic observation and measurement if
  less than 3.5 inches.
• If > 3.5 inches, need AP X-Ray with both
  legs on same film for knee deformity, hip
  and ankle joints and view of both long
       Indicators of Serious Disease
• Pronounced
• Short stature
• Other skeletal
• Intermalleolar
  separation greater than
  3.5 inches
• Developmental
• Miscellaneous syndromes e.g Rickets (Alk
  Phos raised, with x-ray changes)
• Rare Genetic disorders e.g Cohen
• Nutritional conditions e.g Vitamin C
• Autoimmune e.g RA
• Degenerative e.g OA
                             When to refer

•   Age > 7 with knock knee
•   Unilateral problem i.e Asymmetry of legs
•   Intermalleolar distance > 3.5 inches (9 cms)
•   Associated symptoms e.g Pain, Limp

• No evidence that shoe modification, splints,
  or exercises affect condition
• No evidence to justify surgical intervention
  under 6 inches of intermalleolar separation.
• Surgical options:
      Medial epiphyseal stapling at 10 to 11
      Corrective osteotomy at maturity.
                 Flat Feet / Pes Planus
• Arch of the foot is
  low. Medial arch is
  lost. There may be
  some valgus and
  eversion deformity of
  the foot.
                   Normal Development
• Flat feet are normal
  when learning to walk.
• Medial arch does not
  develop until 2nd / 3rd
  year of life.
• Normal arch functions
  as a shock absorber.
• Ask patient to stand on
• If medial arch restores
  itself when standing
  on tiptoe or when foot
  is unloaded, no action
  is needed.

• 2 Groups:

  – Pain free feet with normal mobility and muscle

  – Painful, stiff, hypermobile feet with abnormal
    muscle power i.e weak or spastic feet.
                    Causes of Flat Feet

• Loose - ligamented flat foot:
  – Commonest type.
  – Always bilateral.
  – Arch looks normal when non weight bearing /
    standing on tip toe.
  – Laxity can often be demonstrated in other
            Rare Causes of Flat Feet

• Rocker bottom foot : Congenital vertical
• Coalition Syndrome: Peroneal spastic flat
• In both, subtalar joint movement is limited.
• In peroneal spastic flat foot, attempting to
  invert hind foot produces painful spasm of
  peroneal muscles.
               Rare Causes of Flat Feet

• May be part of a more generalized condition

  –   Severe joint laxity
  –   Cerebral Palsy
  –   Peroneal spastic flat foot
  –   Downs Syndrome

• No proven benefit from insoles, shoe
  modification, foot exercises.
• Spasmodic type :
  – Hindfoot fusion for pain relief.
  – Subtalar arthrodesis corrects deformity.

• Knock Knees:
  – less than 3 inches intermalleolar separation is
    normal at any age.
  – Refer if age >7. Asymmetry, intermalleolar
    distance > 3.5 inches, short stature, pain or
  – Remember normal developmental stages.

• Flat Feet:
  – Test by standing patient on tip toes.
  – Refer if painful, stiff, hypermobile with
    abnormal muscle power.
  – Waiting time for Orthopaedic OPA at
    Birmingham Childrens Hospital is less than 4
    weeks, but > 13 weeks for physiotherapy.

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