title: Quantitative 3-dimensional CT analyses of fractures of the middle phalanx base.
abstract: BACKGROUND
  Quantitative 3-dimensional computed tomography (3DCT) analyses can provide a more detailed understanding of fracture morphology. For fracture-dislocation of the proximal interphalangeal joint, the extent of fragmentation of the volar lip of the middle phalanx-a factor that might influence treatment-is not always apparent from radiographs. We hypothesized that there is no correlation between number of fracture fragments and the percentage of articular surface area involved in intra-articular fractures of the base of the middle phalanx using quantitative 3DCT analyses.
  
  
  METHODS
  We used 13 computed tomography scans with a slice thickness of 1.25 mm or less to create 3-dimensional models of 15 intra-articular fractures of the base of the middle phalanx in 13 patients. We resized 3-dimensional models of a non-fractured middle phalanx of the same hand to fit the fractured middle phalanx in order to approximate the size and shape of the fractured middle phalanx in its pre-injury state. We created a heatmap to demonstrate the location of the fractured articular surface.
  
  
  RESULTS
  With the number of scans available, we did not find a significant correlation between the percentage of articular surface area involved and the number of fracture fragments. The median percentage of articular surface area involved was 46 % (range, 21-90 %). The heatmap demonstrated that the radio-volar side of the articular surface seems to be more involved than the ulnar-volar side in intra-articular fractures of the base of the middle phalanx.
  
  
  CONCLUSIONS
  Quantitative 3DCT analysis of fracture fragments provides useful information that could facilitate surgery and analysis of complex fractures of the base of the middle phalanx.
  
  
  METHODS
  IV, Basic Science Study, Anatomic Study, Imaging.
authors.affiliation: Harvard Medical School, Orthopaedic Hand and Upper Extremity Service, Massachusetts General Hospital, Yawkey Center, Suite 2100, 55 Fruit Street, Boston, MA 02114 USA.
authors.forename: Stein J
authors.initials: SJ
authors.lastname: Janssen
authors.affiliation: Harvard Medical School, Orthopaedic Hand and Upper Extremity Service, Massachusetts General Hospital, Yawkey Center, Suite 2100, 55 Fruit Street, Boston, MA 02114 USA.
authors.forename: Dirk P
authors.initials: DP
authors.lastname: Ter Meulen
authors.affiliation: Harvard Medical School, Orthopaedic Hand and Upper Extremity Service, Massachusetts General Hospital, Yawkey Center, Suite 2100, 55 Fruit Street, Boston, MA 02114 USA.
authors.forename: Michiel G J S
authors.initials: MG
authors.lastname: Hageman
authors.affiliation: Harvard Medical School, Department of Orthopedic Surgery Hand & Upper Extremity, Brigham and Women's Hospital, 75 Francis Street, Boston, MA 02115 USA.
authors.forename: Brandon E
authors.initials: BE
authors.lastname: Earp
authors.affiliation: Harvard Medical School, Orthopaedic Hand and Upper Extremity Service, Massachusetts General Hospital, Yawkey Center, Suite 2100, 55 Fruit Street, Boston, MA 02114 USA.
authors.forename: David
authors.initials: D
authors.lastname: Ring
keywords: 3-dimensional; 3d; Analysis; Computed tomography; Finger; Fracture; Heatmap; Model; Phalanx; Pip joint; Quantitative