• BACKGROUND AND PURPOSE
    • Indications for acromioplasty are based on clinical symptoms and are generally supported by typical changes in acromial morphology on standard radiographs. We evaluated 5 commonly used radiographic parameters of acromial morphology and assessed the association between different radiographic characteristics on the one hand and subacromial impingement or rotator cuff tears on the other.
  • PATIENTS AND METHODS
    • We measured acromial type (Bigliani), acromial slope (AS), acromial tilt (AT), lateral acromial angle (LAA), and acromion index (AI) on standard radiographs from 50 patients with full-thickness supraspinatus tendon tears, 50 patients with subacromial impingement, and 50 controls without subacromial pathology.
  • RESULTS
    • The acromial type according to Bigliani was not associated with any particular cuff lesion. A statistically significant difference between controls and impingement patients was found for AS. AT of controls was significantly smaller than that of impingement patients and cuff-tear patients. LAA of cuff-tear patients differed significantly from that of controls and impingement patients, but LAA of controls was not significantly different from that of impingement patients. Differences between impingement patients and cuff-tear patients were also significant. AI of controls was significantly lower than of impingement patients and of cuff-tear patients. A good correlation was found between acromial type and AS.
  • INTERPRETATION
    • A low lateral acromial angle and a large lateral extension of the acromion were associated with a higher prevalence of impingement and rotator cuff tears. An extremely hooked anterior acromion with a slope of more than 43° and an LAA of less than 70° only occurred in patients with rotator cuff tears.