健康人及肩峰撞击症患者肩峰下空间宽度的三维测定

Three dimensional measurement of the width of the subacromial space in healthy subjects and patients with impingement syndrome

目的 对健康人及肩峰撞击症患者的上臂主动和被动外展过程中的肩峰下空间宽度进行三维测定,分析肩峰撞击症患者潜在的冈上肌功能缺陷。方法 用开放MRI对 10例健康受试者和 10例肩峰撞击症患者在臂外展过程中,有或无肩部肌肉参与下进行肩部成像。在成像过程中,在肱骨远端施加一个 10N的外展力,三维图像重建后,测出最小的肩峰-肱骨距离。结果 在健康志愿者中, 外展 60°时,肌肉的参与会导致肩峰-肱骨距离减少( -32%,P<0 05),而在外展 120°时,此距离则增加 ( +44%,P<0. 05)。外展 90°时,肌肉的参与未造成肩峰-肱骨距离变化。然而在 10例肩峰撞击症患者中,肌肉的活动导致肩峰下空间宽度较正常的对侧肩减小。结论 肌肉收缩和上臂的外展位置可以造成肩峰下空间宽度的改变。然而,对于早期的肩峰撞击症患者来说,在肌肉放松时外展肌的功能不全表现得并不明显。

Objective To practice a three dimensional measurement of the width of subacromial space during passive and active arm abduction in healthy volunteers and patients with impingement syndrome, and to analyze potential functional deficits of the supraspinous muscle in patients with impingement syndrome. Methods During abduction, used an open MRI system to image the shoulders of 10 healthy volunteers and 10 patients with impingement syndrome, with and without activation of the shoulder muscles. During image acquisition, added an abduction force of 10 N to distal humerus. After three-dimensional reconstruction, the minimal acromiohumeral distance was measured. Results In the 10 healthy volunteers, muscle activity led to a decrease (-32%,P<0.05) of the acromiohumeral distance at 60°of abduction,whereas at 120°of abduction the distance was increased (+44%, P<0.05).In these volunteers, muscle activation cause no change at 90° of abduction. However, in the 10 patients with impingement syndrome, muscle activity led to a decrease in the width of the subacromial space compared with that of the healthy contralateral side. Conclusions Muscle activity and arm position were found to cause systematic change in the width of subacromial space. Functional deficits of the supraspinous muscle in patients with early-stage impingement syndrome were not apparent during muscle relaxation.