反復性肩関節前方脱臼症例における肩甲下筋の走行形態

MR関節造影による検討

抄録

Purpose: As one of the anterior stabilizing mechanisms of the shoulder, the importance of thesubscapularis has been an object of attention in several literatures. The purpose of this study was toclarify the manner of the subscapularis extension in recurrent anterior dislocation of the shoulder.
Materials and Methods: Both shoulders of 44 patients with a recurrent anterior dislocation underwentMR arthrography after an intraarticular injection of 20 ml of Gd-DTPA solution (diluted 1:400). Tlweightedimages were obtained using SE sequences. The average age was 26.6 years. To evaluate theform of the subscapularis extension, we established three parameters in transverse and oblique sagittalplanes: M value: the ratio between the length from the anterior labrum to a contact point of the musclebelly on the anterior aspect of the scapula and the diameter of the glenoid articular surface, A value:the ratio between the length from the anterior labrum to the subscapularis tendon and the diameter ofthe glenoid, and S value: the angle determined by intersection of a line drawn from the center to the 0 o'clock position of the glenoid and a second line drawn from the clossing point of the outline of theglenoid and a horizontal line passing the superior border of the subscapularis tendon to the center ofthe glenoid. These values were compared between the involved sides and the healthy sides using t-tests.
Results: The averages of each value were higher in the involved sides. There were statisticaly significant differences in each value(M:p=0.007, A: p=0.001, S:p<0.001).
Conclusion: The subscapularis extension had tendencies of separating from the scapular neck, shiftinganterior, and displacing downward in recurrent anterior dislocation of the shoulder.