HSS Journal ®

, Volume 7, Issue 3, pp 218–222 | Cite as

Reliability of Determining and Measuring Acromial Enthesophytes

  • Keith M. Baumgarten
  • James L. Carey
  • Joseph A. Abboud
  • Grant L. Jones
  • John E. Kuhn
  • Brian R. Wolf
  • Robert H. Brophy
  • Charles L. Cox
  • Rick W. Wright
  • Armando F. Vidal
  • C. Benjamin Ma
  • Eric C. McCarty
  • G. Brian Holloway
  • Edwin E. SpencerJr
  • Warren R. Dunn
Original Article



Although the reliability of determining acromial morphology has been examined, to date, there has not been an analysis of interobserver and intraobserver reliability on determining the presence and measuring the size of an acromial enthesophyte.


The hypothesis of this study was that there will be poor intraobserver and interobserver reliability in the (1) determination of the presence of an acromial enthesophyte, (2) determination of the size of an acromial enthesophyte, and (3) determination of acromial morphology.

Patients and Methods

Fifteen fellowship-trained orthopedic shoulder surgeons reviewed the radiographs of 15 patients at two different intervals. Measurement of acromial enthesophytes was performed using two techniques: (1) enthesophyte length and (2) enthesophyte–humeral distance. Acromial morphology was also determined. Interobserver and intraobserver agreement was determined using intraclass correlation and kappa statistical methods.


The interobserver reliability was fair to moderate and the intraobserver reliability moderate for determining the presence of an acromial enthesophyte. The measurement of the enthesophyte length showed poor interobserver and intraobserver reliability. The measurement of the enthesophyte–humeral distance showed poor interobserver reliability and moderate intraobserver reliability. The interobserver and intraobserver reliability in determining acromial morphology was found to be moderate and good, respectively.


There is fair to moderate reliability among fellowship-trained shoulder surgeons in determining the presence of an acromial enthesophyte. However, there is poor reliability among observers in measuring the size of the enthesophyte. This study suggests that the enthesophyte–humeral distance may be more reliable than the enthesophyte length when measuring the size of the enthesophyte.


enthesophyte acromion reliability morphology 



This research was supported by Grant Number 5 K23 AR052392-04 from the National Institute of Arthritis and Musculoskeletal and Skin Diseases. This network has received research funding from Arthrex and NFL Charities.


  1. 1.
    Aoki M, Ishii S, Usui M. The morphology of the acromion and its relationship to rotator cuff impingement. Orthop Trans. 1986;10:228.Google Scholar
  2. 2.
    Banas MP, Miller RJ, Totterman S. Relationship between the lateral acromion angle and rotator cuff disease. J Shoulder Elbow Surg. 1995;4(6):454–461.CrossRefGoogle Scholar
  3. 3.
    Bigliani LU, Morrison DS, April EW. The morphology of the acromion and its relationship to rotator cuff tears. Orthop Trans. 1986;10:216.Google Scholar
  4. 4.
    Bright AS, Torpey B, Magid D, Codd T, McFarland EG. Reliability of radiographic evaluation for acromial morphology. Skeletal Radiol. 1997;26(12):718–721.CrossRefGoogle Scholar
  5. 5.
    Chambler AF, Bull AM, Reilly P, Amis AA, Emery RJ. Coracoacromial ligament tension in vivo. J Shoulder Elbow Surg. 2003;12(4):365–367.CrossRefGoogle Scholar
  6. 6.
    Chambler AF, Emery RJ. Acromial morphology: the enigma of terminology. Knee Surg Sports Traumatol Arthrosc. 1997;5(4):268–272.CrossRefGoogle Scholar
  7. 7.
    Chambler AF, Pitsillides AA, Emery RJ. Acromial spur formation in patients with rotator cuff tears. J Shoulder Elbow Surg. 2003;12(4):314–321.CrossRefGoogle Scholar
  8. 8.
    Edelson JG. The ‘hooked’ acromion revisited. J Bone Joint Surg Br. 1995;77(2):284–287.CrossRefGoogle Scholar
  9. 9.
    Edelson JG, Taitz C. Anatomy of the coraco-acromial arch. Relation to degeneration of the acromion. J Bone Joint Surg Br. 1992;74(4):589–594.CrossRefGoogle Scholar
  10. 10.
    Epstein RE, Schweitzer ME, Frieman BG, Fenlin JM, Jr., Mitchell DG. Hooked acromion: prevalence on MR images of painful shoulders. Radiology. 1993;187(2):479–481.CrossRefGoogle Scholar
  11. 11.
    Farley TE, Neumann CH, Steinbach LS, Petersen SA. The coracoacromial arch: MR evaluation and correlation with rotator cuff pathology. Skeletal Radiol. 1994;23(8):641–645.CrossRefGoogle Scholar
  12. 12.
    Fealy S, April EW, Khazzam M, Armengol-Barallat J, Bigliani LU. The coracoacromial ligament: morphology and study of acromial enthesopathy. J Shoulder Elbow Surg. 2005;14(5):542–548.CrossRefGoogle Scholar
  13. 13.
    Fleiss J. Statistical methods for rates and proportions, 2nd edition. New York: Wiley; 1981.Google Scholar
  14. 14.
    Getz JD, Recht MP, Piraino DW, Schils JP, Latimer BM, Jellema LM, et al. Acromial morphology: relation to sex, age, symmetry, and subacromial enthesophytes. Radiology. 1996;199(3):737–742.CrossRefGoogle Scholar
  15. 15.
    Gill TJ, McIrvin E, Kocher MS, Homa K, Mair SD, Hawkins RJ. The relative importance of acromial morphology and age with respect to rotator cuff pathology. J Shoulder Elbow Surg. 2002;11(4):327–330.CrossRefGoogle Scholar
  16. 16.
    Graves WW. Observation on ages changes in the scapula. Am j Phys Anthrop. 1922;5:21–34.CrossRefGoogle Scholar
  17. 17.
    Haygood TM, Langlotz CP, Kneeland JB, Iannotti JP, Williams GR, Jr., Dalinka MK. Categorization of acromial shape: interobserver variability with MR imaging and conventional radiography. AJR Am J Roentgenol. 1994;162(6):1377–1382.CrossRefGoogle Scholar
  18. 18.
    Hirano M, Ide J, Takagi K. Acromial shapes and extension of rotator cuff tears: magnetic resonance imaging evaluation. J Shoulder Elbow Surg. 2002;11(6):576–578.CrossRefGoogle Scholar
  19. 19.
    Jacobson SR, Speer KP, Moor JT, Janda DH, Saddemi SR, MacDonald PB, et al. Reliability of radiographic assessment of acromial morphology. J Shoulder Elbow Surg. 1995;4(6):449–453.CrossRefGoogle Scholar
  20. 20.
    Karanicolas PJ, Bhandari M, Kreder H, Moroni A, Richardson M, Walter SD, et al. Evaluating agreement: conducting a reliability study. J Bone Joint Surg Am. 2009;91 Suppl 3:99–106.CrossRefGoogle Scholar
  21. 21.
    Kitay GS, Iannotti JP, Williams GR, Haygood T, Kneeland BJ, Berlin J. Roentgenographic assessment of acromial morphologic condition in rotator cuff impingement syndrome. J Shoulder Elbow Surg. 1995;4(6):441–448.CrossRefGoogle Scholar
  22. 22.
    Kramer M. Undersurface acromial osteophyte or deltoid tendon attachment to the acromion? AJR Am J Roentgenol. 2008;190(6):W376-377; author reply W378.CrossRefGoogle Scholar
  23. 23.
    Landis JR, Koch GG. The measurement of observer agreement for categorical data. Biometrics. 1977;33(1):159–174.CrossRefGoogle Scholar
  24. 24.
    MacGillivray JD, Fealy S, Potter HG, O’Brien SJ. Multiplanar analysis of acromion morphology. Am J Sports Med. 1998;26(6):836–840.CrossRefGoogle Scholar
  25. 25.
    Mahakkanukrauh P, Surin P. Prevalence of osteophytes associated with the acromion and acromioclavicular joint. Clin Anat. 2003;16(6):506–510.CrossRefGoogle Scholar
  26. 26.
    Mayerhoefer ME, Breitenseher MJ, Roposch A, Treitl C, Wurnig C. Comparison of MRI and conventional radiography for assessment of acromial shape. AJR Am J Roentgenol. 2005;184(2):671–675.CrossRefGoogle Scholar
  27. 27.
    Milz S, Jakob J, Buttner A, Tischer T, Putz R, Benjamin M. The structure of the coracoacromial ligament: fibrocartilage differentiation does not necessarily mean pathology. Scand J Med Sci Sports. 2008;18:16–22.CrossRefGoogle Scholar
  28. 28.
    Morrison DS, Frogameni AD, Woodworth P. Non-operative treatment of subacromial impingement syndrome. J Bone Joint Surg Am. 1997;79(5):732–737.CrossRefGoogle Scholar
  29. 29.
    Natsis K, Tsikaras P, Totlis T, Gigis I, Skandalakis P, Appell HJ, et al. Correlation between the four types of acromion and the existence of enthesophytes: a study on 423 dried scapulas and review of the literature. Clin Anat. 2007;20(3):267–272.CrossRefGoogle Scholar
  30. 30.
    Neer CS, 2nd. Anterior acromioplasty for the chronic impingement syndrome in the shoulder: a preliminary report. J Bone Joint Surg Am. 1972;54(1):41–50.CrossRefGoogle Scholar
  31. 31.
    Nicholson GP, Goodman DA, Flatow EL, Bigliani LU. The acromion: morphologic condition and age-related changes. A study of 420 scapulas. J Shoulder Elbow Surg. 1996;5(1):1–11.CrossRefGoogle Scholar
  32. 32.
    Ogata S, Uhthoff HK. Acromial enthesopathy and rotator cuff tear. A radiologic and histologic postmortem investigation of the coracoacromial arch. Clin Orthop Relat Res. 1990(254):39–48.Google Scholar
  33. 33.
    Ogawa K, Yoshida A, Inokuchi W, Naniwa T. Acromial spur: relationship to aging and morphologic changes in the rotator cuff. J Shoulder Elbow Surg. 2005;14(6):591–598.CrossRefGoogle Scholar
  34. 34.
    Panni AS, Milano G, Lucania L, Fabbriciani C, Logroscino CA. Histological analysis of the coracoacromial arch: correlation between age-related changes and rotator cuff tears. Arthroscopy. 1996;12(5):531–540.CrossRefGoogle Scholar
  35. 35.
    Paraskevas G, Tzaveas A, Papaziogas B, Kitsoulis P, Natsis K, Spanidou S. Morphological parameters of the acromion. Folia Morphol (Warsz). 2008;67(4):255–260.PubMedGoogle Scholar
  36. 36.
    Park TS, Park DW, Kim SI, Kweon TH. Roentgenographic assessment of acromial morphology using supraspinatus outlet radiographs. Arthroscopy. 2001;17(5):496–501.CrossRefGoogle Scholar
  37. 37.
    Pearsall AWt, Bonsell S, Heitman RJ, Helms CA, Osbahr D, Speer KP. Radiographic findings associated with symptomatic rotator cuff tears. J Shoulder Elbow Surg. 2003;12(2):122–127.CrossRefGoogle Scholar
  38. 38.
    Portney L, Watkins M. Foundations of Clinical Research: Applications to Practice. New Jersey Prentice Hall Health; 2000.Google Scholar
  39. 39.
    Sangiampong A, Chompoopong S, Sangvichien S, Thongtong P, Wongjittraporn S. The acromial morphology of Thais in relation to gender and age: study in scapular dried bone. J Med Assoc Thai. 2007;90(3):502–507.PubMedGoogle Scholar
  40. 40.
    Taheriazam A, Sadatsafavi M, Moayyeri A. Outcome predictors in nonoperative management of newly diagnosed subacromial impingement syndrome: a longitudinal study. MedGenMed. 2005;7(1):63.PubMedPubMedCentralGoogle Scholar
  41. 41.
    Toivonen DA, Tuite MJ, Orwin JF. Acromial structure and tears of the rotator cuff. J Shoulder Elbow Surg. 1995;4(5):376–383.CrossRefGoogle Scholar
  42. 42.
    Wang JC, Horner G, Brown ED, Shapiro MS. The relationship between acromial morphology and conservative treatment of patients with impingement syndrome. Orthopedics. 2000;23(6):557–559.PubMedGoogle Scholar
  43. 43.
    Wang JC, Shapiro MS. Changes in acromial morphology with age. J Shoulder Elbow Surg. 1997;6(1):55–59.CrossRefGoogle Scholar
  44. 44.
    Zuckerman JD, Kummer FJ, Cuomo F, Greller M. Interobserver reliability of acromial morphology classification: an anatomic study. J Shoulder Elbow Surg. 1997;6(3):286–287.CrossRefGoogle Scholar

Copyright information

© Hospital for Special Surgery 2011

Authors and Affiliations

  • Keith M. Baumgarten
    • 1
  • James L. Carey
    • 2
  • Joseph A. Abboud
    • 3
  • Grant L. Jones
    • 4
  • John E. Kuhn
    • 2
  • Brian R. Wolf
    • 6
  • Robert H. Brophy
    • 7
  • Charles L. Cox
    • 2
  • Rick W. Wright
    • 7
  • Armando F. Vidal
    • 8
  • C. Benjamin Ma
    • 9
  • Eric C. McCarty
    • 10
  • G. Brian Holloway
    • 11
  • Edwin E. SpencerJr
    • 11
  • Warren R. Dunn
    • 5
  1. 1.Sports Medicine and Shoulder Surgery SectionOrthopedic InstituteSioux FallsUSA
  2. 2.Department of Orthopaedics and RehabilitationVanderbilt University Medical CenterNashvilleUSA
  3. 3.Shoulder and Elbow Service, Department of Orthopaedic SurgeryUniversity of Pennsylvania Health SystemPhiladelphiaUSA
  4. 4.Department of Orthopaedic SurgeryThe Ohio State UniversityColumbusUSA
  5. 5.Department of Orthopaedics & Rehabilitation, Health Sciences Research CenterVanderbilt University Medical CenterNashvilleUSA
  6. 6.Department of Orthopaedic SurgeryUniversity of Iowa Hospitals and ClinicsIowa CityUSA
  7. 7.Department of Orthopaedic SurgeryWashington University School of MedicineSt. LouisUSA
  8. 8.Sports Medicine and Shoulder Service, Department of Orthopaedic SurgeryUniversity of Colorado School of MedicineDenverUSA
  9. 9.Department of Orthopaedic SurgeryUniversity of California, San FranciscoSan FranciscoUSA
  10. 10.Department of Orthopaedic SurgeryUniversity of Colorado School of MedicineDenverUSA
  11. 11.Shoulder and Elbow InstituteKnoxville Orthopaedic ClinicKnoxvilleUSA

Personalised recommendations