Editing Navicular bone (section)

== Horse anatomy ==
{{Main|Navicular syndrome}}
The horse has a [[sesamoid]] bone called the navicular bone, located within the [[horse hoof|hoof]], that lies on the [[Anatomical terms of location#Hands and arms|palmar]] aspect of the [[Equine forelimb anatomy|coffin joint]] between the second [[Phalanx bones|phalanx]] and third phalanx ([[Equine forelimb anatomy#Distal phalanx|coffin bone]]).  The navicular bone in the horse is supported by the distal sesamoidean impar ligament and two collateral sesamoidean ligaments. The navicular bursa is located between the flexor surface of the navicular bone and the deep digital flexor tendon, which runs between the bursa and the distal phalanx.<ref name="Auburn">{{cite web|url=http://www.vetmed.auburn.edu/uploads/7e/32/7e32a4dd9c82d711e57c148824e3b84a/PV1110_waguespack_Surgical.pdf|title=Navicular Syndrome in Equine Patients: Anatomy, Causes, and Diagnosis|author=R. Wayne Waguespack, DVM, MS, DACVS R. Reid Hanson, DVM, DACVS, DACVECC|date=December 2010|work=Surgical Views|publisher=Auburn University|access-date=11 January 2013|url-status=dead|archive-url=https://web.archive.org/web/20121021022902/http://www.vetmed.auburn.edu/uploads/7e/32/7e32a4dd9c82d711e57c148824e3b84a/PV1110_waguespack_Surgical.pdf|archive-date=21 October 2012|df=dmy-all}}</ref>  The central tarsal bone in the [[hock (zoology)|hock]] of the horse is homologous and analogous to the navicular bone of the human foot, and thus the navicular bone in the horse is a different structure from the [[eponymous]]ly labeled bone in humans.<ref>{{Cite web |url=http://cal.vet.upenn.edu/projects/saortho/chapter_32/32mast.htm |title=Chapter 32, FRACTURE AND LUXATION OF THE TARSUS AND METATARSUS "Textbook of Small Animal Orthopaedics" written by Charles D. Newton, D.V.M., M.S. and David M. Nunamaker, V.M.D. J.B. Lippincott Company, 1985. |access-date=11 January 2013 |archive-url=https://web.archive.org/web/20130119014549/http://cal.vet.upenn.edu/projects/saortho/chapter_32/32mast.htm |archive-date=19 January 2013 |url-status=dead }}</ref>
  
The navicular region is an important structure in relation to lameness, particularly in the front feet, and is involved with a significant disease process called navicular disease or navicular syndrome. Recently much of the original literature concerning navicular disease has been called into question, particularly the significance of [[radiographic]] changes as a sole diagnostic criterion.<ref>Citing Clinical Anatomy and Physiology Laboratory Manual for Veterinary Technicians, Colville, Thomas and Bassert, Joanna M. 2008 Publ. Mosby/Elsevier, Canada. "Navicular Bone - The distal sesamoid bone of the horse. The navicular bone is located deep in the hoof behind the joint between the middle and distal phalanges."</ref> Navicular syndrome may be responsible for as much as 1/3 of all cases of lameness in horses, but radiographic changes in the navicular bone do not always provide a definitive diagnosis.  Newer imaging techniques have shown that damage to the soft tissues in the region may be significant contributors to lameness and that multiple causes may result in visible lameness.<ref name="Auburn"/>