title: Dynamic in vivo evaluation of radiocarpal contact after a 4-corner arthrodesis.
abstract: OBJECTIVE
  To understand the mechanisms that preserve joint integrity after 4-corner arthrodesis (FCA).
  
  
  METHODS
  We investigated the long-term changes of the radiolunate articulation after an FCA for different motions of the wrist in a cross-sectional study that included wrists of 10 healthy participants and both operated and nonoperated wrists of 8 individuals who had undergone FCA on 1 side. The average postoperative follow-up period of the FCA group was 5.7 years. The radiolunate articulation was assessed from dynamic 3-dimensional distance maps during wrist motion. Contact surface area, centroid position of the articular area, and distance between radiolunate articular surfaces were measured and compared between healthy subjects and operated and nonoperated wrists of FCA patients.
  
  
  RESULTS
  The total radiolunate articulation area was larger in patients with FCA. The average radiolunate joint space thickness was preserved in the operated FCA wrists. The centroid of the articulation area was shifted radially and dorsally in FCA wrists.
  
  
  CONCLUSIONS
  Changes of the motion pattern of the lunate during radioulnar deviation and flexion-extension of the wrist after FCA can explain the shift of the centroid radially and dorsally.
  
  
  METHODS
  Diagnostic IV.
authors: Department of Plastic, Reconstructive, and Hand Surgery, Academic Medical Center, Amsterdam, The Netherlands; Orthopaedic Research Center Amsterdam, Department of Orthopaedic Surgery, Academic Medical Center, Amsterdam, The Netherlands; Department of Biomedical Engineering and Physics, Academic Medical Center, Amsterdam, The Netherlands. Electronic address: m.foumani@amc.uva.nl.
authors: Mahyar
authors: M
authors: Foumani
authors: Department of Plastic, Reconstructive, and Hand Surgery, Academic Medical Center, Amsterdam, The Netherlands; Orthopaedic Research Center Amsterdam, Department of Orthopaedic Surgery, Academic Medical Center, Amsterdam, The Netherlands; Department of Biomedical Engineering and Physics, Academic Medical Center, Amsterdam, The Netherlands.
authors: Simon D
authors: SD
authors: Strackee
authors: Department of Plastic, Reconstructive, and Hand Surgery, Academic Medical Center, Amsterdam, The Netherlands; Orthopaedic Research Center Amsterdam, Department of Orthopaedic Surgery, Academic Medical Center, Amsterdam, The Netherlands; Department of Biomedical Engineering and Physics, Academic Medical Center, Amsterdam, The Netherlands.
authors: Carlijn M
authors: CM
authors: Stekelenburg
authors: Department of Plastic, Reconstructive, and Hand Surgery, Academic Medical Center, Amsterdam, The Netherlands; Orthopaedic Research Center Amsterdam, Department of Orthopaedic Surgery, Academic Medical Center, Amsterdam, The Netherlands; Department of Biomedical Engineering and Physics, Academic Medical Center, Amsterdam, The Netherlands.
authors: Leendert
authors: L
authors: Blankevoort
authors: Department of Plastic, Reconstructive, and Hand Surgery, Academic Medical Center, Amsterdam, The Netherlands; Orthopaedic Research Center Amsterdam, Department of Orthopaedic Surgery, Academic Medical Center, Amsterdam, The Netherlands; Department of Biomedical Engineering and Physics, Academic Medical Center, Amsterdam, The Netherlands.
authors: Geert J
authors: GJ
authors: Streekstra
mesh_terms: D000328:Adult; D001174:Arthrodesis / Q000379:methods*; D001696:Biomechanical Phenomena; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D012667:Lunate Bone / Q000502:physiology; D008297:Male; D008875:Middle Aged; D010003:Osteoarthritis / Q000601:surgery; D011884:Radius / Q000502:physiology; D014955:Wrist Joint / Q000503:physiopathology / Q000601:surgery*
keywords: Four-corner arthrodesis; biomechanics of the wrist joint; dynamic imaging of the wrist; quantification of osteoarthritis