title: Osteochondral fragments within the dorsal pouch or dorsal joint capsule of the proximal intertarsal joint of the horse.
abstract: The anatomy of the dorsal pouch of the proximal intertarsal joint (PIJ) and its communication with the tarsocrural joint (TCJ) was studied in 15 pairs of hocks from young and mature horses. The mediolateral length of the TCJ-PIJ fenestration was 14 to 29 mm. The potential volume of the dorsal pouch of the PIJ was 3 to 5 ml, and a recess extended 10 to 28 mm medial to the medial commissure of the TCJ-PIJ fenestration. In a correlated clinical study, osteochondral fragments were identified radiographically within the dorsal pouch (category 1) or dorsal joint capsule (category 2) of the PIJ in 17 horses undergoing arthroscopic surgery of the TCJ. In six horses with category 1 lesions, osteochondral fragments were found free within the dorsal pouch and were removed. In five horses, category 1 fragments were not located. All 11 horses were reported by owners to be sound after surgery. In seven horses, a minimally displaced fragment was identified at the distal aspect of the medial trochlear ridge, within the insertion of the synovium separating TCJ and PIJ (one horse had both types of lesions in the same hock). Five of the seven category 2 fragments were removed at surgery. Of the seven horses with category 2 lesions, four were training or racing, two were unsound, and one was still convalescing at the time of follow-up.
authors.affiliation: Department of Clinical Studies, University of Pennsylvania, School of Veterinary Medicine, New Bolton Center, Kennett Square.
authors.forename: P R
authors.initials: PR
authors.lastname: Stephens
authors.forename: D W
authors.initials: DW
authors.lastname: Richardson
authors.forename: M W
authors.initials: MW
authors.lastname: Ross
authors.forename: T S
authors.initials: TS
authors.lastname: Ford
mesh_terms: D000818:Animals; D005260:Female; D006734:Horse Diseases / Q000473:pathology*; D006736:Horses / Q000033:anatomy & histology*; D007592:Joint Diseases / Q000473:pathology / Q000662:veterinary*; D008297:Male; D013643:Tarsus, Animal / Q000033:anatomy & histology*