Magnetic resonance imaging parameters of the greater tuberosity morphology in different types of chronic rotator cuff tears

Abstract

Background: The purpose of this study was to explore the distinction and relation among different types of chronic rotator cuff tears, in terms of some magnetic resonance imaging (MRI) parameters that reflected the greater tuberosity morphology.Methods: This study retrospectively assessed 160 patients diagnosedwith chronic rotator cuff tears (including bursal-side, articular-side and full-thickness rotator cuff tears) and 48 controls diagnosed without rotator cuff tears by MRI. The types of rotator cuff tear were confirmed by shoulder MRI and arthroscopy. Oblique coronal sections of MRI were used to measure the parameters including greater tuberosity abduction angle(GTAA), greater tuberosity width index (GTWI), and greater tuberosity height index(GTHI).Results: GTAA in patients with articular-side and full-thicknessrotator cuff tearswere smaller than those in patients with bursal-side rotator cuff tears and in controls.GTWI and GTHI were present in greater proportions in patients with articular-side and full-thickness rotator cuff tearsthan in patients with bursal-side rotator cuff tears and in controls.There was no significant difference between the articular-side and full-thickness cuff tears regarding GTAA, GTWI, or GTHI. The same was true between bursal-side rotator cuff tears and the controls.Conclusions: The greater tuberosity abduction angles are smaller, and greater tuberosity are more convex outward and upwardin patients with articular-side or full-thickness rotator cuff tears, than those in patients with bursal-side rotator cuff tears or in controls.