Deformity of the great toe due to medial deviation of the 1st metatarsal and lateral deviation of the toe itself

Aetiology

• Exact aetiology unknown
• Higher incidence in females
• Familial tendency but no direct genetic link
• Incidence increases in age but can occur in adolescence
  • Hallux valgus in late adolescence usually has a strong family history
• Commoner in rheumatoid arthritis and other inflammatory arthropathies as well as some neuromuscular diseases (multiple sclerosis, cerebral palsy)

Clinical features

• Usually bilateral
• May be painful due to joint incongruence
• May be unable to wear closed shoes - bursa and/or nerve damage
  • A widened forefoot may cause rubbing of the foot with shoes resulting in an inflamed bursa over the medial 1st metatarsal head → bunion
• The great toe and second toe may rub causing ulceration and skin breakdown
• In severe cases, the hallux may override the second toe
• Joint pain indicates OA
• Transfer metatarsalgia or poor balance indicates defunctioned 1st ray (segment of the foot composed of the first metatarsal and first cuneiform bones)

Management

• Conservative - wearing wider and deeper shoes to prevent bunions, the use of a spacer in the first web space to stop rubbing between the great and second toes
• Surgical management - osteotomies to realign the bones and soft tissue procedures to tighten slack tissues and release tight tissues
  • Indications: failure of conservative management, lesser toe deformities, lifestyle limitation, overlapping, functional limitation
  • Any surgery may alter the biomechanics of the foot - 30% of patients are not satisfied so surgery should not be performed for cosmetic reasons alone
  • Some patients complain of pain in the metatarsal heads (metatarsalgia) after surgery
  • Surgical correction in adolescents carries a risk of recurrence of the deformity later in life