title: Classification of proximal humeral fractures based on a pathomorphologic analysis.
abstract: BACKGROUND
  The purpose of this study was to analyze the pathomorphology of proximal humeral fractures to determine relevant and reliable parameters for fracture classification.
  
  
  METHODS
  A total of 100 consecutive acute proximal humeral fractures in adult patients were analyzed by 2 non-independent observers from a single shoulder department using a standardized protocol based on biplane radiographs and 3-dimensional computed tomography scans. A fracture classification system based on the most reliable key features of the pathomorphologic analysis was created, and its reliability was tested by 6 independent shoulder experts analyzing another 100 consecutive proximal humeral fractures.
  
  
  RESULTS
  The head position in relation to the shaft (varus, valgus, sagittal deformity) and the presence of tuberosity fractures showed a higher interobserver reliability (κ > 0.8) than measurements for medial hinge, shaft, and tuberosity displacement, metaphyseal extension, fracture impaction, as well as head-split component identification (κ < 0.7). These findings were used to classify nondisplaced proximal humeral fractures as type 1, fractures with normal coronal head position but sagittal deformity as type 2, valgus fractures as type 3, varus fractures as type 4, and fracture dislocations as type 5. The fracture type was further combined with the fractured main fragments (G for greater tuberosity, L for lesser). Interobserver and intraobserver reliability analysis for the fracture classification revealed a κ value (95% confidence interval) of 0.700 (0.631-0.767) and 0.917 (0.879-0.943), respectively.
  
  
  CONCLUSIONS
  The new classification system with emphasis on the qualitative aspects of proximal humeral fractures showed high reliability when based on a standardized imaging protocol including computed tomography scans.
authors.affiliation: Department of Traumatology and Sports Injuries, Paracelsus Medical University, Salzburg, Austria.
authors.forename: Herbert
authors.initials: H
authors.lastname: Resch
authors.affiliation: Department of Traumatology and Sports Injuries, Paracelsus Medical University, Salzburg, Austria; Department of Shoulder and Elbow Surgery, ATOS Clinic, Munich, Germany.
authors.forename: Mark
authors.initials: M
authors.lastname: Tauber
authors.affiliation: Department of Orthopaedic Surgery, George Washington University School of Medicine, Washington, DC, USA.
authors.forename: Robert J
authors.initials: RJ
authors.lastname: Neviaser
authors.affiliation: Department of Orthopaedic Surgery, George Washington University School of Medicine, Washington, DC, USA.
authors.forename: Andrew S
authors.initials: AS
authors.lastname: Neviaser
authors.affiliation: Division of Surgery, Oncology, Reproductive Medicine, and Anaesthetics, Imperial College London, London, UK.
authors.forename: Addie
authors.initials: A
authors.lastname: Majed
authors.affiliation: Division of Surgery, Chelsea and Westminster Hospital, London, UK.
authors.forename: Tim
authors.initials: T
authors.lastname: Halsey
authors.affiliation: Department of Traumatology and Sports Injuries, Paracelsus Medical University, Salzburg, Austria.
authors.forename: Corinna
authors.initials: C
authors.lastname: Hirzinger
authors.affiliation: Department of Orthopaedic Surgery, Khoula Hospital, Muscat, Sultanate of Oman.
authors.forename: Ghassan
authors.initials: G
authors.lastname: Al-Yassari
authors.affiliation: Orthopedisk Center, Sophiahemmet Hospital, Stockholm, Sweden.
authors.forename: Karol
authors.initials: K
authors.lastname: Zyto
authors.affiliation: Department of Traumatology and Sports Injuries, Paracelsus Medical University, Salzburg, Austria. Electronic address: philipp.moroder@pmu.ac.at.
authors.forename: Philipp
authors.initials: P
authors.lastname: Moroder
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D006801:Humans; D021621:Imaging, Three-Dimensional; D008297:Male; D008875:Middle Aged; D015588:Observer Variation; D015203:Reproducibility of Results; D012784:Shoulder Fractures / Q000145:classification* / Q000000981:diagnostic imaging*; D014057:Tomography, X-Ray Computed; D055815:Young Adult
keywords: Proximal humeral fracture; classification; interobserver reliability; pathomorphology; valgus; varus