Introduction
  • Genu valgum is a normal physiologic process in children
    • therefore it is critical to differentiate between a physiologic and pathologic process
  • Epidemiology
    • distal femur is the most common location of primary pathologic genu valgum but can arise from tibia
  • Etiologies
    • bilateral genu valgum
      • physiologic
      • renal osteodystrophy (renal rickets)
      • skeletal dysplasia
        • Morquio syndrome
        • spondyloepiphyseal dysplasia
        • chondroctodermal dysplasia
    • unilateral genu valgum
      • physeal injury from trauma, infection, or vascular insult
      • proximal metaphyseal tibia fracture 
      • benign tumors
        • fibrous dysplasia
        • osteochondromas
        • Ollier's disease
  • Prognosis
    • the threshold of deformity that leads to future degenerative changes is unknown
    • deformity after a proximal metaphyseal tibia fracture (Cozen) should be observed, as it almost always remodels
Anatomy
  • Normal physiologic process of genu valgum
    • between 3-4 years of age children have up to 20 degrees of genu valgum
    • genu valgum rarely worsens after age 7
    • after age 7 valgus should not be worse than 12 degrees of genu valgum
    • after age 7 the intermalleolar distance should be <8 cm
Treatment
  • Nonoperative
    • observation
      • indications
        • first line of treatment
        • genu valgum <15 degrees in a child <6 years of age
    • bracing
      • indications
        • rarely used
          • ineffective in pathologic genu valgum and unnecessary in physiologic genu valgum
  • Operative
    • hemiepiphysiodesis or physeal tethering (staples, screws, or plate/screws) of medial side  
      • indications
        • > 15-20° of valgus in a patient <10 years of age
        • if line drawn from center of femoral head to center of ankle falls in lateral quadrant of tibial plateau in patient > 10 yrs of age  
      • technique
        • to avoid physeal injury place them extraperiosteally
        • to avoid overcorrection follow patients often
        • growth begins within 24 months after removal of the tether
    • distal femoral varus osteotomy  
      • indications
        • insufficient remaining growth for hemiepiphysiodesis 
      • complications
        • peroneal nerve injury
          • perform a peroneal nerve release prior to surgery
        • gradually correct the deformity
        • utilize a closing wedge technique