title: Quantitative 3D-CT anatomy of hamate osteoarticular autograft for reconstruction of the middle phalanx base.
abstract: BACKGROUND
  Hamate osteoarticular autografts are difficult to obtain and it is unclear to what degree the graft matches the joint surface to be replaced and whether a direct ulnar approach might provide a more reliable graft than the standard proximal to distal approach.
  
  
  OBJECTIVE
  We modeled hemihamate osteotomies using quantitative three-dimensional CT (3D-CT) to measure the amount of hamate articular surface used and the match with the native volar base of the middle phalanx.
  
  
  METHODS
  In virtual hemihamate osteotomies (standard and direct ulnar) on CTs of 20 patients (11 men and nine women), we measured the percentage of hamate articular surface used for each finger, the match of the articular contour, and the percentage of hamate articular surface removed.
  
  
  RESULTS
  The autograft in the standard approach used an average of 26% of the hamate articular surface and had an average 75% match of the articular contour with the volar half of the middle phalanx base. A direct ulnar approach removed an additional small margin of dorsal ulnar hamate with an average maximum width of 2.5 mm and volume of 27 mm(3).
  
  
  CONCLUSIONS
  An osteoarticular allograft from the hamate to replace the volar half of the middle phalanx base uses less than 1/3 of the hamate articular surface even if the dorsal ulnar margin of the hamate is taken with the graft.
  
  
  CONCLUSIONS
  These data suggest that it might be feasible to make the deep cut from a direct ulnar approach.
authors.affiliation: Orthopaedic Hand and Upper Extremity Service, Harvard Medical School, Massachusetts General Hospital, Yawkey 2100, 55 Fruit St, Boston, MA 02114, USA.
authors.forename: Paul
authors.initials: P
authors.lastname: Ten Berg
authors.forename: David
authors.initials: D
authors.lastname: Ring
mesh_terms: D000328:Adult; D000368:Aged; D016025:Bone Transplantation; D003196:Computer Graphics; D003198:Computer Simulation; D005260:Female; D050278:Finger Phalanges / Q000000981:diagnostic imaging* / Q000601:surgery*; D051225:Hamate Bone / Q000000981:diagnostic imaging* / Q000637:transplantation*; D006801:Humans; D021621:Imaging, Three-Dimensional; D008297:Male; D008875:Middle Aged; D008953:Models, Anatomic; D010027:Osteotomy; D011237:Predictive Value of Tests; D011857:Radiographic Image Interpretation, Computer-Assisted; D019651:Plastic Surgery Procedures; D025321:Surgery, Computer-Assisted; D014057:Tomography, X-Ray Computed; D014182:Transplantation, Autologous; D014457:Ulna / Q000601:surgery; D055815:Young Adult