Do anatomic variants of the acromion shape in the frontal plane influence pain and function in calcifying tendinitis of the shoulder?

PURPOSE: To evaluate the relationship of a large acromion index and calcifying tendinitis of the supraspinatus tendon at the shoulder. MATERIALS AND METHODS: Between 2002 and 2008, 109 consecutive patients with isolated calcifying tendinitis of the supraspinatus tendon were prospectively analysed by clinical investigation and standardized radiographs. Deposit size and appearance were measured and classified according to Bosworth and Gartner. The acromion index (AI) was calculated based on measurements on true anteroposterior radiographs. Pain record on VAS scale, active and passive range of motion and the constant score (CS) were recorded. RESULTS: The mean age of the patients was 48.2 ± 8.0 (n = 46 male 48.6 ± 7.3; n = 63 female 47.9 ± 8.6; P > 0.05). Pain and function were not significantly correlated with deposit size or classification. The acromion index (mean 0.64 ± 0.08) was not significantly correlated with the affected or dominant side, gender, deposit size or classification or any functional parameter like pain and the CS or its subgroups. CONCLUSION: The theoretical concept of a high acromion index resulting in an increased resulting upward force against the subacromial space, which influences pain and function in calcifying tendinitis of the shoulder, was not supported.