The relationship between acromion thickness and body habitus: practical implications in subacromial decompression procedures.

To define the bone's amount that should be removed during an acromioplasty has always been a challenge. We aimed to verify the correlations between scapular dimensions and acromial thickness, assess the differences between the two genders, investigate the relationship between acromial type and thickness. We examined 500 dried scapulae, measuring the major axis of the scapular body and the acromial thickness; these were also catalogued according to gender. Acromial shape was classified according to Bigliani's method. Frequencies: Type I 38.9 %, Type II 39.4 %, Type III 21.7 %. The mean acromial thickness was 0.85 cm, and it resulted wider in men. There was a direct linear relationship between scapular dimensions and acromial thickness. The range of thickness of Type III acromion was significantly different from the others. We should be aware that gender, scapular dimensions and acromial shape should be evaluated preoperatively since they influence the acromial thickness.