AST classification of proximal humeral fractures: introduction and interobserver reliability assessment

  • Christian CunyEmail author
  • Cedric Baumann
  • Julien Mayer
  • Didier Guignand
  • M’barek Irrazi
  • Aboubekr Berrichi
  • Nicolas Ionescu
  • Francis Guillemin
Original Article



This article introduces an alphanumeric AST (Articular, Surgical neck, Tuberosities) classification of proximal humeral fractures, based on the number, localization, and displacement of articular and extra-articular fragments. All possible cases of proximal humeral fractures can be assessed from a single figure using this classification. The aim of the study was thus to describe the AST classification and to assess interobserver reliability.


This classification is based on a single figure, allowing an easy description of the anatomic variants of different proximal humeral fractures. The severity of the fracture is determined by the fragment displacement in angular degrees and the major linear displacement in millimeters. AST reproducibility was assessed and compared with Neer, AO, and Duparc classifications, commonly used in clinical practice. The interobserver agreement was measured with Cohen’s kappa coefficients and their 95% confidence intervals.


Thirteen independent observers analyzed a total of 64 X-rays. Overall kappa coefficients were 0.34, 0.29, 0.24, and 0.25 for AST, Neer, AO, and Duparc classifications, respectively.


The AST classification, which is easier to use because it is based on only one figure, is at least as reproducible as other proximal humeral fracture classifications.


Proximal humeral fractures Classification Interobserver reliability 



We would like to thank the physicians who participated in this study for their extraordinary help, and for the reading, classification, and analysis of four different classifications of a total of 64 X-rays of proximal humeral fractures: Dr Beau—Metz, Dr Berrichi—Metz, Dr Boughrebi—Amiens, Dr Camus—Dunkerque, Dr Dujardin—Orléans, Dr Favreul—Lyon, Pr Galois—Nancy, Dr Ionescu—Metz, Dr Irrazi—Metz, Dr Kany—Toulouse, Dr Khalife—Metz, Pr Roussignol—Rouen, Dr Schenk—Strasbourg, Dr Schwartz—Colmar, Dr Scarlat—Toulon, Dr Seboiu—Metz, Pr Simon—Lyon, Dr Travers—Lyon, as well as the talented Mrs L. Collette—Bruxelles, for the figures.

Conflict of interest

The authors have no conflict of interest to declare.


  1. 1.
    Bahrs C, Schmal H, Lingenfelter E, Rolauffs B, Weise K, Dietz K et al (2008) Inter- and intraobserver reliability of the MTM-classification for proximal humeral fractures: a prospective study. BMC Musculoskelet Disord 9:21PubMedCrossRefGoogle Scholar
  2. 2.
    Brorson S, Bagger J, Sylvest A, Hrøbjartsson A (1995) Neer’s classification system: a critical appraisal. J Trauma 38:257–260CrossRefGoogle Scholar
  3. 3.
    Brorson S, Bagger J, Sylvest A, Hrøbjartsson A (2002) Improved interobserver variation after training of doctors in the Neer system. A randomised trial. J Bone Joint Surg Br 84:950–954PubMedCrossRefGoogle Scholar
  4. 4.
    Brorson S, Hróbjartsson A (2008) Training improves agreement among doctors using the Neer system for proximal humeral fractures in a systematic review. J Clin Epidemiol 61:7–16PubMedCrossRefGoogle Scholar
  5. 5.
    Edelson G, Kelly I, Vigder F, Reis ND (2004) A three-dimensional classification for fractures of the proximal humerus. J Bone Joint Surg Br 86:413–425PubMedCrossRefGoogle Scholar
  6. 6.
    Mahadeva D, Mackay DC, Turner SM, Drew S, Costa ML (2008) Reliability of the Neer classification system in proximal humeral fractures: a systematic review of the literature. Eur J Orthop Surg Traumatol 18:415–424CrossRefGoogle Scholar
  7. 7.
    Sallay PI, Pedowitz RA, Mallon WJ, Vandemark RM, Dalton JD, Speer KP (1997) Reliability and reproducibility of radiographic interpretation of proximal humeral fracture pathoanatomy. J Shoulder Elbow Surg 6:60–69PubMedCrossRefGoogle Scholar
  8. 8.
    Shrader MW, Sanchez-Sotelo J, Sperling JW, Rowland CM, Cofield RH (2005) Understanding proximal humerus fractures: image analysis, classification, and treatment. J Shoulder Elbow Surg 14:497–505PubMedCrossRefGoogle Scholar
  9. 9.
    Siebenrock KA, Gerber C (1993) The reproducibility of classification of fractures of the proximal end of the humerus. J Bone Joint Surg Am 75:1751–1755PubMedGoogle Scholar
  10. 10.
    Sjödén GO, Movin T, Aspelin P, Güntner P, Shalabi A (1999) 3D-radiographic analysis does not improve the Neer and AO classifications of proximal humeral fractures. Acta Orthop Scand 70:325–328PubMedCrossRefGoogle Scholar
  11. 11.
    Tamai K, Hamada J, Ohno W, Saotome K (2002) Surgical anatomy of multipart fractures of the proximal humerus. J Shoulder Elbow Surg 11:421–427PubMedCrossRefGoogle Scholar
  12. 12.
    Neer CS (1970) Displaced proximal humeral fractures. I. Classification and evaluation. J Bone Joint Surg Am 52:1077–1089PubMedGoogle Scholar
  13. 13.
    Neer CS. Four Segment Classification (2008) In shoulder reconstruction. W.B. Saunders, Philadelphie, pp. 366–370Google Scholar
  14. 14.
    Jakob RP, Kristiansen T, Mayo K, Ganz R, Müller ME (1984) Classification and aspects of treatment of fractures of the proximal humerus. Bateman and WelshGoogle Scholar
  15. 15.
    Jakob RP, Miniaci A, Anson PS, Jaberg H, Osterwalder A, Ganz R (1991) Four-part valgus impacted fractures of the proximal humerus. J Bone Joint Surg Br 73:295–298PubMedGoogle Scholar
  16. 16.
    Duparc J, Largier A (1976) Fracture-dislocations of the upper end of the humerus. Rev Chir Orthop Reparatrice Appar Mot 62:91–110PubMedGoogle Scholar
  17. 17.
    Boehler J (1935) Boehler (The treatment of fractures), 4th edn. Williams Wood, BaltimoreGoogle Scholar
  18. 18.
    Court-Brown CM, Cattermole H, McQueen MM, Impacted valgus fractures (B1.1) of the proximal humerus (2002) The results of non-operative treatment. J Bone Joint Surg Br 84:504–508PubMedCrossRefGoogle Scholar
  19. 19.
    Lee CK, Hansen HR (1981) Post-traumatic avascular necrosis of the humeral head in displaced proximal humeral fractures. J Trauma 21:788–791PubMedCrossRefGoogle Scholar
  20. 20.
    Fleiss JL (1971) Measuring nominal scale agreement among many raters. Psychol Bull 76:378–382CrossRefGoogle Scholar
  21. 21.
    Landis JR, Koch GG (1977) The measurement of observer agreement for categorical data. Biometrics 33:159–174PubMedCrossRefGoogle Scholar
  22. 22.
    Duparc F, Huten D (1998) Conservative treatment of fractures of the upper end of the humerus. Rev Chir Orthop Reparatrice Appar Mot 84(Suppl 1):121–189PubMedGoogle Scholar
  23. 23.
    Sjödén GO, Movin T, Güntner P, Aspelin P, Ahrengart L, Ersmark H et al (1997) Poor reproducibility of classification of proximal humeral fractures. Additional CT of minor value. Acta Orthop Scand 68:239–242PubMedCrossRefGoogle Scholar
  24. 24.
    Kristiansen B, Andersen UL, Olsen CA, Varmarken JE (1988) The Neer classification of fractures of the proximal humerus. An assessment of interobserver variation. Skeletal Radiol 17:420–422PubMedCrossRefGoogle Scholar
  25. 25.
    Sidor ML, Zuckerman JD, Lyon T, Koval K, Cuomo F, Schoenberg N (1993) The Neer classification system for proximal humeral fractures. An assessment of interobserver reliability and intraobserver reproducibility. J Bone Joint Surg Am 75:1745–1750PubMedGoogle Scholar

Copyright information

© Springer-Verlag 2011

Authors and Affiliations

  • Christian Cuny
    • 1
    Email author
  • Cedric Baumann
    • 2
  • Julien Mayer
    • 1
  • Didier Guignand
    • 1
  • M’barek Irrazi
    • 1
  • Aboubekr Berrichi
    • 1
  • Nicolas Ionescu
    • 1
  • Francis Guillemin
    • 2
  1. 1.Department of Orthopaedics and TraumatologyCHR Metz Bon-SecoursMetz CedexFrance
  2. 2.Department of Clinical Epidemiology, CHU NancyVandoeuvre-lès-NancyFrance

Personalised recommendations