In 1986, Bigliani studied the relationship between the shape of the acromion and rotator cufftears. He reported that a higher incidence of rotator cuff tears results in a hooked type acromion. The aim of this study is to investigate the relationship between the morphology of the acromion obtained at surgery with that of the pre-operative MR image and Scapular Y view.
56 patients with an average age of 56 years were operated on, pre-operating MR imaging was carried out in 47 cases and Scapular Y view was in 43 cases. The acromion was obtained at surgery by lateral acromioplasty. The acromion was sliced into a thickness of 100μ and it was classified as flat (type 1), smoothly curved (type 2), or hooked (type 3) according to Bigliani's classification. Scapular Y view was taken with a X-ray fluoroscopy so that the undersurface of the acromion could be observed and classified into three groups. The acrominal shape of MRI imaging was classified from the sagital oblique gradient echo images, and Scapular Y view were obtained and classified into the same classification.
Specimens type 1, type 2 and type 3 were 19.6%, 48.2% and 32.1% respectively. The accurancy of MRI image and Scapular Y view were 51.1% and 37.2%. In this study, no higher incidence of rotator cufftears was found in hooked type acromion, but there was a difference between the acrominal type in MRI imaging, Scapular Y view and that of specimens.
