Hi doctors, can you tell me what is hallux valgus deformity?

Complex... Deformity of the great toe and its metatarsal. The 1st metatarsal is deviated away from the rest of the forefoot bones (abducted), and the great toe (hallux) runs over the 2nd toe, sometimes overlapping/ underlapping it in the more severe cases.
A misnomer. For one. Hallux - big toe valgus - is a position on the frontal plane where an object is everted. In podiatry this is often the term used to describe a big toe being directed at the mpj towards the second toe. Sometimes referred to as a bunion (again, not entirely true.).
Bunion deformity. A bunion deformity with an external rotation of the big toe.

Related Questions

Can you please define hallux valgus deformity?

Bunion. It is a bony prominence on the inside of the foot at the big toe. It is a misalignment which causes the big toe to become angled toward the little toes - where the term hallux valgus comes from. It can create pain in shoes, problems with foot function and can be treated by conservative and surgical means. Not all bunions are the same. See a podiatrist and have your foot examined properly. Read more...
Bunion deformity. A bunion deformity with an external rotation of the big toe. Read more...