Anatomical Deformities in Hallux Valgus

• Hallux valgus deformity is a complex deformity of the first ray that frequently is accompanied by deformity and symptoms in the lesser toes.

• There are two forms of the deformity:
  1. Adult hallux valgus
  2. Adolescent & juvenile hallux valgus

See also: Ankle and Foot Anatomy

What are the anatomical deformities in Hallux Valgus?

• There are multiple changes in the bony and soft tissue anatomy as hallux valgus progresses:
  1. The proximal phalanx deviates laterally.
  2. The first metatarsal head deviates medially leaving the sesamoid complex laterally translated relative to the metatarsal head.
  3. Sesamoids remain within the respective head of the flexor hallucis brevis tendon and are attached to the base of the proximal phalanx via the sesamoido-phalangeal ligament.
  4. Medial MTP joint capsule becomes stretched and attenuated while the lateral capsule becomes contracted.
  5. Adductor tendon becomes a deforming force.
  6. Medial MTP joint capsule becomes stretched and attenuated while the lateral capsule becomes contracted.
  7. Lateral deviation of extensor hallux longus tendon (EHL) further contributes to deformity.
  8. Plantar and lateral migration of the abductor hallucis causes muscle to plantar flex and pronate phalanx.

See also: Adult Hallux Valgus