Peds

Genu Valgum

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Genu Valgum, Knock-Knee

  • Physiology
  • Normal course
  1. Birth: Maximal varus
  2. Age 2 years: Neutral position
  3. Ages 3-4 years: Maximal valgus (>10 degrees)
  4. Age >10 years: Anatomic valgus at 6 degrees
  5. Valgus deformity persists more in girls than boys
  • Signs
  1. Knock-Kneed appearance
  2. Evaluate standing knee alignment
    1. Intercondylar distance
    2. Intermalleolar distance
    3. Tibiofemoral angle
  • Precautions
  1. Onset as teen is unusual and warrants referral
  2. Atypical acquired cases may result from Trauma, prior Osteomyelitis or Fracture
  • Differential Diagnosis (Pathologic Genu Valgum)
  1. Rickets
  2. Diastrophic dysplasia
  3. Morquio's Syndrome
  4. Ellis-van Creveld or Chondroectodermal Dysplasia
  5. Spondyloepiphyseal Dysplasia
  6. Pseudoachondroplasia
  • Complications
  1. Premature Osteoarthritis
  • References
  1. Rerucha (2017) Am Fam Physician 96(4): 226-33 [PubMed]