Final answer:
The statement 'HAV is a triplane deformity' is false; Hallux Abducto Valgus, or bunions, are generally considered as a two-plane deformity affecting the transverse and coronal planes but not the sagittal plane.
Step-by-step explanation:
The question refers to HAV, which stands for Hallux Abducto Valgus. This is a type of deformity related to the big toe where the toe deviates towards the other toes (abducts) and the first metatarsal bone deviates away from the second metatarsal, creating an angular deformity. When considering the term 'triplane deformity,' this usually refers to a deformity occurring in three planes of space: the transverse, sagittal, and coronal planes.
However, HAV, commonly known as a bunion, typically presents as a two-plane deformity, involving the transverse and coronal planes but not typically extending into the sagittal plane. Therefore, the statement 'HAV is a triplane deformity' would be false.