Related Experiment Video
Updated: Nov 12, 2025

A Method of Trigonometric Modelling of Seasonal Variation Demonstrated with Multiple Sclerosis Relapse Data
Published on: December 9, 2015
Os Trigonum Syndrome
Jeffrey E McAlister1, Usman Urooj2
1Phoenix Foot and Ankle Institute, 7301 East 2nd Street, Suite 206, Scottsdale, AZ 85251, USA.
Abstract:
This article offers an overview of os trigonum syndrome, complications, operative techniques, and the authors' preferred protocol. Os trigonum is an ossicle like many other ossicles in the foot and ankle. Individuals who require repetitive plantarflexion of the ankle for activity may develop symptoms of an enlarged os trigonum. Usually, symptoms will be isolated to the posteriolateral aspect of the ankle. Because of the normal anatomic route of the flexor hallucis longus tendon, its range of motion may also elicit pain to the posterolateral ankle. Conservative, as well as surgical including both endoscopic and open excision, has been described.
Related Concept Videos
Trigonometric Equations
Trigonometric Identities I
Trigonometry of Right Triangles
Trigonometric Identities III
Trigonometric Functions of Real Numbers
Trigonometric Identities II

