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

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.