Shoulder
Relationship of radiographic acromial characteristics and rotator cuff disease: a prospective investigation of clinical, radiographic, and sonographic findings

https://doi.org/10.1016/j.jse.2011.09.028Get rights and content

Background

Many studies have attempted to correlate radiographic acromial characteristics with rotator cuff tears, but the results have not been conclusive. Therefore, the purpose of this study was to determine the relationship between rotator cuff disease and the development of symptoms with different radiographic acromial characteristics, including shape, index, and presence of a spur.

Materials and methods

The records of 216 patients enrolled in an ongoing prospective, longitudinal study investigating asymptomatic rotator cuff tears were reviewed. All patients underwent standardized radiographic evaluation, clinical evaluation, and shoulder ultrasonography at regularly scheduled surveillance visits. Three blinded observers reviewed all radiographs to determine the acromial morphology, presence, and size of an acromial spur, as well as the acromial index. These findings were analyzed to determine an association with the presence of a full-thickness rotator cuff tear.

Results

The 3 observers demonstrated poor agreement for acromial morphology (κ = 0.41), substantial agreement for the presence of an acromial spur (κ = 0.65), and excellent agreement for the acromial index (κ = 0.86). The presence of an acromial spur was highly associated with the presence of a full-thickness rotator cuff tear (P = .003), even after adjusting for age. No association was found between the acromial index and rotator cuff disease (P = .92).

Conclusion

The presence of an acromial spur is highly associated with the presence of a full-thickness rotator cuff tear in symptomatic and asymptomatic patients. The acromial morphology classification system is an unreliable method to assess the acromion. The acromial index shows no association with the presence of rotator cuff disease.

Section snippets

Study subjects

Data for this investigation were obtained as a separate, specific aim of an ongoing prospective, longitudinal study of asymptomatic rotator cuff tears. To be included into this prospective study, patients had to have (1) presented for bilateral shoulder ultrasonography at our institution for investigation of unilateral shoulder pain secondary to rotator cuff disease, (2) been discovered to have a partial or full-thickness rotator cuff tear in the asymptomatic shoulder, (3) no history of trauma

Study subjects and tear characteristics

The analysis consisted of 216 subjects who were an average age of 64.8 ± 10 years (range, 37.1-90.2 years); of these, 123 had full-thickness rotator cuff tears, 46 had partial-thickness tears, and 47 had no rotator cuff tear (control) at the most recent surveillance visit. The average age was 62.8 ± 10 years for the patients with an intact rotator cuff or partial-thickness tear, and 66.2 ± 10 years for patients with a full-thickness tear (P = .01). Of the 216 study subjects, 88 (41%) were

Discussion

The acromion has been implicated in the pathogenesis of rotator cuff disease for many years. Neer24 investigated the mechanism of impingement and described a focal, critical area of contact between the supraspinatus tendon and the undersurface of the anterolateral acromion. Further cadaveric investigations showed a close relationship between acromial shape and rotator cuff disease.4, 23 These findings led to the widespread use of partial anterior acromioplasty to treat rotator cuff disease, and

Conclusions

The presence of an acromial spur at the acromial insertion of the coracoacromial ligament is highly associated with the presence of a full-thickness rotator cuff tear in both symptomatic and asymptomatic subjects, even after controlling for confounding variables such as age and sex. Spurs measuring greater than 5 mm are associated with larger rotator cuff tears. Acromial morphology is an unreliable classification system with poor interobserver reliability. The acromial index is associated with

Acknowledgments

The authors thank Tomoyuki Mochizuki, MD, and Chanteak Lim, MD, for their invaluable contributions to this study.

Disclaimer

The funding source for this study was an R01 grant (AR051026-01A1) from the National Institutes of Health.

Dr Yamaguchi receives royalties from Tornier, which is unrelated to the subject of this article. The authors, their immediate families, and any research foundations with which they are affiliated have not received any financial payments or other benefits from any commercial entity related to the subject of this article.

References (41)

  • C. Torrens et al.

    The influence of the acromial coverage index in rotator cuff tears

    J Shoulder Elbow Surg

    (2007)
  • J.D. Zuckerman et al.

    Interobserver reliability of acromial morphology classification: an anatomic study

    J Shoulder Elbow Surg

    (1997)
  • M. Aoki et al.

    Clinical application for measuring the slope of the acromion

  • P. Biberthaler et al.

    Microcirculation associated with degenerative rotator cuff lesions: in vivo assessment with orthogonal polarization spectral imaging during arthroscopy of the shoulder

    J Bone Joint Surg Am

    (2003)
  • L.U. Bigliani et al.

    Anterior acromioplasty for subacromial impingement in patients younger than 40 years of age

    Clin Orthop Relat Res

    (1989 Sep)
  • L.U. Bigliani et al.

    The morphology of the acromion and its relationship to rotator cuff tears

    Orthop Trans

    (1986)
  • A.S. Bright et al.

    Reliability of radiographic evaluation for acromial morphology

    Skeletal Radiol

    (1997)
  • E.A. Codman

    Rare lesions of the shoulder

  • R.E. Epstein et al.

    Hooked acromion: prevalence on MR images of painful shoulders

    Radiology

    (1993)
  • H. Fukuda et al.

    Pathology and pathogenesis of bursal-side rotator cuff tears viewed from en block histologic sections

    Clin Orthop Relat Res

    (1990)
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    This study was approved by the Washington University Human Research Protection Office (Investigational Review Board #201103230).

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