title: Biomechanical effect of triquetral and scaphoid excision on simulated midcarpal arthrodesis in cadavers.
abstract: OBJECTIVE
  To examine the biomechanical effects of triquetral and scaphoid excision on wrist motion and radiolunate contact characteristics in a cadaveric model after simulated 4-corner arthrodesis with rigid internal fixation.
  
  
  METHODS
  Ten fresh-frozen cadaveric upper extremities were studied. For all surgical manipulations, the motion was measured and contact characteristics were assessed using ultralow prescale pressure-sensitive film.
  
  
  RESULTS
  Compared with the intact specimen, simple 4-corner arthrodesis with scaphoid retention led to a significant decrease in flexion (-23%), extension (-69%), radial deviation (-129%), and ulnar deviation (-25%), but no significant change in radiolunate contact characteristics. After 4-corner arthrodesis with scaphoid excision, there was a significant increase in radial deviation (+213%) without significant change in radiolunate contact characteristics, but average radial deviation was still less than in the intact specimen. After further excision of the triquetrum, radial deviation increased significantly (+238%), to a mean value 5% greater than that of the intact state, but at the cost of a significant increase in mean radiolunate contact pressure (+44% compared to the intact state).
  
  
  CONCLUSIONS
  When performing 4-corner arthrodesis, scaphoid and triquetrum excision may improve motion at the cost of increased mean radiolunate contact pressure.
authors.affiliation: Department of Orthopaedic Surgery, Baylor College of Medicine, University of Texas, Houston, TX 77030, USA.
authors.forename: Razvan G
authors.initials: RG
authors.lastname: Scobercea
authors.forename: Jeffrey E
authors.initials: JE
authors.lastname: Budoff
authors.forename: John A
authors.initials: JA
authors.lastname: Hipp
mesh_terms: D000368:Aged; D001174:Arthrodesis / Q000379:methods*; D001696:Biomechanical Phenomena; D001860:Bone Plates; D002102:Cadaver; D050824:Carpal Joints / Q000601:surgery*; D006801:Humans; D016059:Range of Motion, Articular / Q000502:physiology*; D021361:Scaphoid Bone / Q000601:surgery*; D051221:Triquetrum Bone / Q000601:surgery*; D014955:Wrist Joint / Q000502:physiology* / Q000601:surgery