Adolescent Bunion | Hallux Valgus

  • Medial prominence of the first metatarsal head
  • Often associated with hallux valgus
  • Not degenerative like in adults
  • Female > male

Aetiology

  • pronation of the forefoot, pes planus which lead to medial capsule stretching

Clinical

  • Female, 12-15 years of age
  • Prominent medial bursa on metatarsal head
  • Pain & difficulty with footwear
  • ROM – passively correctable
  • Heal Valgus & Pronation of the forefoot

Xray

  • AP & Lat weight bearing
  • Normal hallux valgus angle – 14-16°, normal IMA = <10°
  • Congruency of joint – if subluxation high probability of progression

Pathophysiology

  • Incongruency of joint predisposes to progression

Treatment

  • only treat if symptomatic
  • Non operative
    • Exhaust shoe modification, reassurance & stretching
  • Operative
    • avoid surgery in skeletal immature – recurrence
    • Soft tissue – reefing of the medial capsule & releasing lateral
    • Bony – realignment – usually for metatarsal primus varus – do it proximal to avoid growth plate
    • Akin for proximal phalanx realignment
    • Excise bunion

Complications

  • Frequent recurrence
  • AVN for distal osteotomy
  • Hallux Varus