Surgical and Radiologic Anatomy

, Volume 38, Issue 1, pp 135–146 | Cite as

Distribution of bone and tissue morphological properties related to subacromial space geometry in a young, healthy male population

  • Jaclyn N. Chopp-Hurley
  • John M. O’Neill
  • Clark R. DickersonEmail author
Original Article



Particular bone and tissue morphological features of the scapula and humerus often exist disproportionately in persons with subacromial impingement syndrome (SAIS) and/or rotator cuff pathology. However, the origins of morphological variation, genetic or mechanistic, remain unclear. This research evaluated the distribution of and correlation between several bone and tissue characteristics associated with these pathologies amongst a baseline cohort population consisting of young, healthy, males. As well, the predisposition to SAIS was estimated by calculating the ratio (occupation ratio) of subacromial tissue thickness to minimum subacromial space width (SAS).


Anterior-posterior and trans-scapular radiographs and musculoskeletal ultrasound were used to measure morphological characteristics related to the subacromial space. Each bone morphological characteristic was classified as healthy or unhealthy based on previous definitions. Supraspinatus tendon and subacromial bursa thicknesses were used to calculate the occupation ratio from both radiographic and ultrasonic measures of the SAS.


Each characteristic demonstrated considerable variability, with some participants having ‘unhealthy’ variants for each bone characteristic examined. The percentage of the population with bone characteristics classified as “unhealthy” ranged from 15 to 55 % across characteristics evaluated. The strongest correlation existed between the acromion index and the minimum subacromial space width (−0.59) suggesting that a larger lateral extension of the acromion may predispose an individual to SAIS. The average occupation ratio was 65.3 % with a 1–99 % confidence interval ranging from 21.6 to 108.9 %.


The distributions of both morphological characteristics and occupation ratios indicate that individuals within this healthy, baseline population have a highly differential predisposition for subacromial tissue compression solely based on inherent morphological variation. This suggests that while mechanistic and/or age-related degenerative changes may contribute to SAIS and eventual rotator cuff pathology, intrinsic predisposing geometry should not be discounted.


Acromion Glenoid Morphology Subacromial impingement Rotator cuff Shoulder 



Partial project support came from a CIHR Research Incentive Fund Grant from the University of Waterloo on which Dr. Clark Dickerson was the principle investigator. Jaclyn Chopp-Hurley was supported through an NSERC PGS-D award. Many thanks to Alison McDonald, Jacquelyn Maciukiewicz and the team of ultrasound and radiographic technologists and research coordination staff at St. Joseph’s Healthcare Hamilton for all of their assistance during data collection.

Compliance with ethical standards

This research complies with the current ethical laws of the country in which it was performed.

Conflict of interest

The authors declare that they have no conflict of interest.


  1. 1.
    Aoki M, Ishii S, Usui M (1986) The slope of the acromion and rotator cuff impingement. Orthop Trans 10:228Google Scholar
  2. 2.
    Balke M, Schmidt C, Dedy N, Banerjee M, Bouillon B, Liem D (2013) Correlation of acromial morphology with impingement syndrome and rotator cuff tears. Acta Orthop 84(2):178–183. doi: 10.3109/17453674.2013.773413 PubMedCentralCrossRefPubMedGoogle Scholar
  3. 3.
    Banas MP, Miller RJ, Totterman S (1995) Relationship between the lateral acromion angle and rotator cuff disease. J Shoulder Elbow Surg 4(6):454–461. doi: 10.1016/S1058-2746(05)80038-2 CrossRefPubMedGoogle Scholar
  4. 4.
    Bey MJ, Brock SK, Beierwaltes WN, Zauel R, Kolowich PA, Lock TR (2007) In vivo measurement of subacromial space width during shoulder elevation: technique and preliminary results in patients following unilateral rotator cuff repair. Clin Biomech 22:767–773. doi: 10.1016/j.clinbiomech.2007.04.006 CrossRefGoogle Scholar
  5. 5.
    Bigliani LU (1986) The morphology of the acromion and its relationship to rotator cuff tears. Orthop Trans 10:228Google Scholar
  6. 6.
    Bland JM, Altman DG (2010) Statistical methods for assessing agreement between two methods of clinical measurement. Int J Nurs Stud 47(8):931–936. doi: 10.1016/S0140-6736(86)90837-8 CrossRefGoogle Scholar
  7. 7.
    Cohen J (1992) Statistical power analysis. Curr Dir Psychol Sci 1(3):98–101CrossRefGoogle Scholar
  8. 8.
    Cotton RE, Rideout DF (1964) Tears of the humeral rotator cuff. J Bone Joint Surg Br 46:314–328PubMedGoogle Scholar
  9. 9.
    Edelson JG (1995) The ‘hooked’ acromion revisited. J Bone Jt Surg Br 77B(2):284–287Google Scholar
  10. 10.
    Faul F, Erdfelder E, Lang A-G, Buchner A (2007) G*Power 3: a flexible statistical power analysis program for the social, behavioural, and biomedical sciences. Behav Res Methods 39(2):175–191. doi: 10.3758/BF03193146 CrossRefPubMedGoogle Scholar
  11. 11.
    Flieg NG, Gatti CJ, Case Doro L, Langenderfer JE, Carpenter JE, Hughes RE (2008) A stochastic analysis of glenoid inclination angle and superior migration of the humeral head. Clin Biomech 23(5):554–561. doi: 10.1016/j.clinbiomech.2008.01.001 CrossRefGoogle Scholar
  12. 12.
    Gill TJ, McIrvin E, Kocher MS, Homa K, Mair SD, Hawkins RJ (2002) The relative importance of acromial morphology and age with respect to rotator cuff pathology. J Shoulder Elb Surg 11(4):327–330. doi: 10.1067/mse.2002.124425 CrossRefGoogle Scholar
  13. 13.
    Golding FC (1962) The shoulder—the forgotten joint. Br J Radiol 35:149–158. doi: 10.1259/0007-1285-35-411-149 CrossRefPubMedGoogle Scholar
  14. 14.
    Graichen H, Bonel H, Stammberger T, Englmeier KH, Reiser M, Eckstein F (1999) Subacromial space width changes during abduction and rotation—a 3-D MR imaging study. Surg Radiol Anat 21(1):59–64. doi: 10.1016/S0021-9290(99)00209-2 CrossRefPubMedGoogle Scholar
  15. 15.
    Gruber G, Bernhardt GA, Clar H, Zacherl M, Glehr M, Wurnig C (2010) Measurement of the acromiohumeral interval on standardized anteroposterior radiographs: a prospective study of observer variability. J Shoulder Elb Surg 19(1):10–13. doi: 10.1016/j.jse.2009.04.010 CrossRefGoogle Scholar
  16. 16.
    Haldar A, Mahadevan S (2000) Probability, reliability, and statistical methods in engineering design. John Wiley, New YorkGoogle Scholar
  17. 17.
    Hughes RE, Bryant CR, Hall JM, Wening J, Huston LJ, Kuhn JE, Carpenter JE, Blasier RB (2003) Glenoid inclination is associated with full-thickness rotator cuff tears. Clin Orthop Relat Res 407:86–91. doi: 10.1097/01.blo.0000043055.62337.a8 CrossRefPubMedGoogle Scholar
  18. 18.
    Kitay GS, Iannotti JP, Williams GR, Haygood T, Kneeland BJ, Berlin J (1995) Roentgenographic assessment of acromial morphologic condition in rotator cuff impingement syndrome. J Shoulder Elb Surg 4(6):441–448. doi: 10.1016/S1058-2746(05)80036-9 CrossRefGoogle Scholar
  19. 19.
    Konrad GG, Markmiller M, Jolly JT, Ruter AE, Sudkamp NP, McMahon PJ, Debski RE (2006) Decreasing glenoid inclination improves function in shoulders with simulated massive rotator cuff tears. Clin Biomech 21(9):942–949. doi: 10.1016/j.clinbiomech.2006.04.013 CrossRefGoogle Scholar
  20. 20.
    Lehtinen JT, Belt EA, Lyback CO, Kauppi MJ, Kaarela K, Kautiainen HJ, Lehto MUK (2000) Subacromial space in the rheumatoid shoulder: a radiographic 15-year follow-up study. J Shoulder Elb Surg 9(3):183–187. doi: 10.1067/mse.2000.105446 CrossRefGoogle Scholar
  21. 21.
    MacGillivray JD, Fealy S, Potter HG, O’Brien SJ (1998) Multiplanar analysis of acromion morphology. Am J Sports Med 26(6):836–840PubMedGoogle Scholar
  22. 22.
    Maurer A, Fucentese SF, Pfirrmann CWA, Wirth SH, Djahangiri A, Jost B, Gerber C (2012) Assessment of glenoid inclination on routine clinical radiographs and computed tomography examinations of the shoulder. J Shoulder Elb Surg 21(8):1096–1103. doi: 10.1016/j.jse.2011.07.010 CrossRefGoogle Scholar
  23. 23.
    Michener LA, Subasi Yesilyaprak SS, Seitz AL, Timmons MK, Walsworth MK (2015) Supraspinatus tendon and subacromial space parameters measured on ultrasonographic imaging in subacromial impingement syndrome. Knee Surg Sports Traumatol Arthrosc 23(2):363–369. doi: 10.1007/s00167-013-2542-8 CrossRefPubMedGoogle Scholar
  24. 24.
    Nicholson GP, Goodman DA, Flatow EL, Bigliani LU (1996) The acromion: morphological condition and age-related changes. A study of 420 scapulas. J Shoulder Elb Surg 5(1):1–11. doi: 10.1016/S1058-2746(96)80024-3 CrossRefGoogle Scholar
  25. 25.
    Nyffeler RW, Werner CML, Sukthankar A, Schmid MR, Gerber C (2006) Association of a large lateral extension of the acromion with rotator cuff tears. J Bone Jt Surg Am 88A(4):800–805. doi: 10.2106/JBJS.D.03042 CrossRefGoogle Scholar
  26. 26.
    Petersson CJ, Redlund-Johnell I (1984) The subacromial space in normal shoulder radiographs. Acta Orthop Scand 55(1):57–58. doi: 10.3109/17453678408992312 CrossRefPubMedGoogle Scholar
  27. 27.
    Shah NN, Bayliss NC, Malcolm A (2001) Shape of the acromion: congenital or acquired—a macroscopic, radiographic, and microscopic study of acromion. J Shoulder Elb Surg 10(4):309–316. doi: 10.1067/mse.2001.114681 CrossRefGoogle Scholar
  28. 28.
    Stehle J, Moore SM, Alaseirlis DA, Debski RE, McMahon PJ (2007) Acromial morphology: effects of suboptimal radiographs. J Shoulder Elb Surg 16(2):135–142. doi: 10.1016/j.jse.2006.05.004 CrossRefGoogle Scholar
  29. 29.
    Tetreault P, Krueger A, Zurakowski D, Gerber C (2004) Glenoid version and rotator cuff tears. J Orthop Res 22(1):202–207. doi: 10.1016/S0736-0266(03)00116-5 CrossRefPubMedGoogle Scholar
  30. 30.
    Thompson MD, Landin D, Page PA (2011) Dynamic acromiohumeral interval changes in baseball players during scaption exercises. J Shoulder Elb Surg 20(2):251–258. doi: 10.1016/j.jse.2010.07.012 CrossRefGoogle Scholar
  31. 31.
    Toivonen DA, Tuite MJ, Orwin JF (1995) Acromial structure and tears of the rotator cuff. J Shoulder Elb Surg 4(5):376–383. doi: 10.1016/S1058-2746(95)80022-0 CrossRefGoogle Scholar
  32. 32.
    Torrens C, Lopez J-M, Puente I, Caceres E (2007) The influence of the acromial coverage index in rotator cuff tears. J Shoulder Elb Surg 16(3):347–351. doi: 10.1016/j.jse.2006.07.006 CrossRefGoogle Scholar
  33. 33.
    Tuite MJ, Toivonen DA, Orwin JF, Wright DH (1995) Acromial angle on radiographs of the shoulder: correlation with the impingement syndrome and rotator cuff tears. Am J Roentgenol 165(3):609–613CrossRefGoogle Scholar
  34. 34.
    Vahakari M, Leppilahti J, Hyvonen P, Ristiniemi J, Paivansalo M, Jalovaara P (2010) Acromial shape in asymptomatic subjects: a study of 305 shoulders in different age groups. Acta Radiol 51(2):202–206. doi: 10.3109/02841850903476556 CrossRefPubMedGoogle Scholar
  35. 35.
    Wang JC, Shapiro MS (1997) Changes in acromial morphology with age. J Shoulder Elb Surg 6(1):55–59. doi: 10.1016/S1058-2746(97)90071-9 CrossRefGoogle Scholar
  36. 36.
    Weiner DS, MacNab I (1970) Superior migration of the humeral head. J Bone Jt Surg Br 52B(3):524–527Google Scholar
  37. 37.
    Wong AS, Gallo L, Kuhn JE, Carpenter JE, Hughes RE (2003) The effect of glenoid inclination on superior humeral head migration. J Shoulder Elb Surg 12(4):360–364. doi: 10.1016/S1058-2746(03)00026-0 CrossRefGoogle Scholar
  38. 38.
    Zuckerman JD, Kummer FJ, Cuomo F, Simon J, Rosenblum S, Katz N (1992) The influence of coracoacromial arch anatomy on rotator cuff tears. J Shoulder Elb Surg 1(1):4–14. doi: 10.1016/S1058-2746(09)80010-4 CrossRefGoogle Scholar

Copyright information

© Springer-Verlag France 2015

Authors and Affiliations

  • Jaclyn N. Chopp-Hurley
    • 1
  • John M. O’Neill
    • 2
  • Clark R. Dickerson
    • 1
    Email author
  1. 1.Department of KinesiologyUniversity of WaterlooWaterlooCanada
  2. 2.St. Joseph’s HealthcareHamiltonCanada

Personalised recommendations