Hallux Rigidus: Relevant Anatomy and Pathophysiology.

Hallux rigidus is a painful condition of the great toe characterized by restriction of the metatarsophalangeal joint arc of motion and progressive osteophyte formation. Precise cause of hallux rigidus remains under debate. Anatomic variations and historical, clinical, and radiographic findings have been implicated in the development and progression of hallux rigidus. Radiologic findings associated with hallux rigidus include metatarsal head osteochondral defects, altered metatarsal head morphology, and an elevated hallux interphalangeus angle measure. Associated historical findings include a positive family history and history of trauma to the joint. An understanding of relevant anatomy and pathophysiology is essential during the approach to hallux rigidus treatment.