title: Soft-tissue stabilizers of the distal radioulnar joint: an in vitro kinematic study.
abstract: OBJECTIVE
  Distal radioulnar joint (DRUJ) stability is dependent on osseous anatomy, soft-tissue stabilizers, and muscle activity. The relative importance of DRUJ soft-tissue stabilizers remains controversial and has not been examined in the more physiologic setting of simulated muscle loading in the intact specimen. The purpose of this study was to examine the role of static stabilizers on the kinematics of the DRUJ during active simulated motion.
  
  
  METHODS
  Twelve cadaveric upper extremities underwent computer-controlled, simulated, active forearm rotation. Joint kinematics were measured in the intact specimen and after sequential sectioning of soft-tissue stabilizers including the dorsal and palmar radioulnar ligaments (RULs) and the triangular fibrocartilage (TFC), dorsal and palmar capsule, ulnocarpal ligaments (UCL), extensor carpi ulnaris (ECU) subsheath, pronator quadratus (PQ), and the interosseous membrane (IOM).
  
  
  RESULTS
  After sectioning of soft tissues significant changes in the DRUJ kinematics were observed. With a distal to proximal sectioning sequence significant alterations in kinematics were not identified until sectioning of the IOM; with a proximal to distal sectioning sequence intact DRUJ kinematics were maintained until the final soft-tissue (RULs and TFC) sectioning.
  
  
  CONCLUSIONS
  Sectioning of all soft-tissue stabilizers produced significant DRUJ instability and abnormal joint kinematics. The RULs and TFC play a key role in DRUJ kinematics because they can help to maintain normal joint rotation in the absence of all other soft-tissue stabilizers. With the preservation of other soft-tissue stabilizers, however, the RULs and TFC are not essential for the maintenance of normal kinematics of the DRUJ.
authors.affiliation: Department of Surgery, University of Western Ontario, Ontario, Canada.
authors.forename: Wade T
authors.initials: WT
authors.lastname: Gofton
authors.forename: Karen D
authors.initials: KD
authors.lastname: Gordon
authors.forename: Cynthia E
authors.initials: CE
authors.lastname: Dunning
authors.forename: James A
authors.initials: JA
authors.lastname: Johnson
authors.forename: Graham J W
authors.initials: GJ
authors.lastname: King
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001696:Biomechanical Phenomena; D002102:Cadaver; D005260:Female; D006801:Humans; D008023:Ligaments, Articular / Q000502:physiology / Q000601:surgery; D008297:Male; D008875:Middle Aged; D011403:Pronation / Q000502:physiology; D011884:Radius / Q000502:physiology* / Q000601:surgery; D013484:Supination / Q000502:physiology; D014457:Ulna / Q000502:physiology* / Q000601:surgery; D016474:Weight-Bearing / Q000502:physiology; D014955:Wrist Joint / Q000502:physiology* / Q000601:surgery