title: Ulnar-sided perilunate instability: an anatomic and biomechanic study.
abstract: A staging system for ulnar-sided perilunate instability is presented based on a series of cadaver dissections and load studies. Stage I: partial or complete disruption of the lunotriquetral interosseous ligament, without clinical and/or radiographic evidence of dynamic or static volar intercalated segment instability deformity; stage II: complete disruption of the lunotriquetral interosseous ligament and disruption of the palmar lunotriquetral ligament, with clinical and/or radiographic evidence of dynamic volar intercalated segment instability deformity; and stage III: complete disruption of the lunotriquetral interosseous and the palmar lunotriquetral ligaments, attenuation or disruption of the dorsal radiocarpal ligament, with clinical and/or radiographic evidence of static volar intercalated segment instability deformity.
authors.affiliation: Division of Orthopaedic Surgery, University of Texas Medical Branch, Galveston 77551.
authors.forename: S F
authors.initials: SF
authors.lastname: Viegas
authors.forename: R M
authors.initials: RM
authors.lastname: Patterson
authors.forename: P D
authors.initials: PD
authors.lastname: Peterson
authors.forename: D J
authors.initials: DJ
authors.lastname: Pogue
authors.forename: D K
authors.initials: DK
authors.lastname: Jenkins
authors.forename: T D
authors.initials: TD
authors.lastname: Sweo
authors.forename: J A
authors.initials: JA
authors.lastname: Hokanson
mesh_terms: D000328:Adult; D000368:Aged; D001696:Biomechanical Phenomena; D005260:Female; D006801:Humans; D007593:Joint Instability / Q000000981:diagnostic imaging / Q000473:pathology / Q000503:physiopathology*; D008023:Ligaments, Articular / Q000000981:diagnostic imaging / Q000473:pathology / Q000503:physiopathology*; D008297:Male; D008875:Middle Aged; D011859:Radiography; D014457:Ulna; D014955:Wrist Joint / Q000000981:diagnostic imaging / Q000473:pathology / Q000503:physiopathology*