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:

• Adult hallux valgus
• Adolescent & juvenile hallux valgus

See also: 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:

• The proximal phalanx deviates laterally.
• The first metatarsal head deviates medially leaving the sesamoid complex laterally translated relative to the metatarsal head.
• 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.
• Medial MTP joint capsule becomes stretched and attenuated while the lateral capsule becomes contracted.
• Adductor tendon becomes a deforming force.
• Medial MTP joint capsule becomes stretched and attenuated while the lateral capsule becomes contracted.
• Lateral deviation of extensor hallux longus tendon (EHL) further contributes to deformity.
• Plantar and lateral migration of the abductor hallucis causes muscle to plantar flex and pronate phalanx.

See also: Adult Hallux Valgus