BACKGROUND This study used in vivo three-dimensional to two-dimensional image registration techniques to compare the glenohumeral kinematics of shoulders with massive rotator cuff tears that were successfully treated conservatively and those of normal shoulders. METHODS Ten patients (age, 67.4 ± 3.63 years) with massive rotator cuff tears on one side and without contralateral tears were enrolled. We performed computed tomography and fluoroscopy on both shoulder joints and created three-dimensional bone models of the humerus and scapula using image registration techniques. We measured the humeral superoinferior translation, angle of humeral external rotation, scapular upward rotation, scapular anteroposterior tilt, and scapular external rotation of the torn shoulders with good range of motion after effective conservative treatment and compared these measurements to those of the contralateral normal shoulders. FINDINGS There was a significant difference in the initial position of the humeral head relative to the glenoid in the tear group; it was 2.0 mm higher than that in the normal group (p < .05). This difference disappeared in the range from 40° to full elevation. The scapular motion of the tear group was significantly more upwardly rotated than that of the normal group: by 9.9° at rest (p < .05) and by 11.6° at terminal elevation (p < .05). No significant differences were detected for humeral head external rotation, scapular anteroposterior tilt, and scapular external rotation between the two groups. INTERPRETATION Kinematics of shoulders with massive cuff tears could not be recovered completely even though the patients had no significant symptoms after successful conservative treatment.

中文翻译：

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正常肩部和肩部巨大肩袖撕裂的运动学的三维体内对比分析，并成功进行了保守治疗。

背景技术这项研究使用体内的三维到二维图像配准技术，比较了保守治疗成功的大肩袖撕裂和正常肩部肩关节的肩肱运动学。方法选取10例患者（年龄为67.4±3.63岁），一侧有巨大的肩袖撕裂且无对侧眼泪。我们对两个肩关节进行了计算机断层扫描和透视检查，并使用图像配准技术创建了肱骨和肩骨的三维骨模型。我们测量了肱骨上下平移，肱骨外旋转角度，肩cap骨向上旋转，肩cap骨前后倾斜，有效保守治疗后，撕裂的肩骨和肩external骨外部旋转具有良好的运动范围，并将这些测量结果与对侧正常肩those的测量结果进行比较。研究结果表明，在泪液组中，相对于关节盂，肱骨头的初始位置存在显着差异。比正常组高2.0 mm（p <.05）。这种差异在40°到全高范围内消失了。泪液组的肩cap骨运动比正常组明显向上旋转：静止时为9.9°（p <.05），末端抬高为11.6°（p <.05）。两组之间的肱骨头外旋，肩cap骨前后倾斜和肩cap骨外旋均无显着差异。