Etiology of the bunion.

The authors explain the sequential development of a bunion beginning with hallux abducto valgus, then hypertrophy of the dorsomedial tubercle, followed by proximal articular set angle adaptation. This manuscript emphasizes the importance of transverse plane motion and the pull of the tibial sesamoid metatarsal ligament, and adductor hallucis tendon in the formation of a bunion.