目的: 评估肩袖组织损伤程度与肱骨头上移距离之间的关系。方法: 选取2015年9月至2016年5月北京大学人民医院创伤骨科收治的肩袖损伤患者30例,均已行患侧肩关节磁共振及X线检查。将患者根据X线正位片测量所得的肱骨头上移系数(upward migration index,UMI),即肱骨头中心至肩峰距离与肱骨头半径的比值分为3个小组,每组10人,组1:1.2≥UMI >1,组2:1.4≥UMI >1.2,组3:UMI >1.4,进行Spearman等级相关分析,判定不同的UMI值与肩袖组织脂肪变程度、肩袖撕裂范围、撕裂处冈上肌厚度之间的关系。结果: 在X线正位片上,平均UMI值为1.33(范围1.02~1.51,标准差为±0.22),UMI值与肩袖组织撕裂的大小呈负相关(R=-0.584,P<0.01),与冈上肌脂肪变程度呈负相关(R=-0.312,P=0.033),而与磁共振上撕裂处冈上肌厚度并无相关性(R=0.127,P=0.071)。结论: UMI与肩袖撕裂及肩袖脂肪变程度存在相关性,UMI值与肩袖组织撕裂大小和冈上肌脂肪化程度呈负相关,其数值减小是肩袖撕裂及脂肪化退变的可靠标志。当患者因急性肩痛就诊时,门诊医师可结合临床表现、体格检查及X线影像学检查结果作出初步判断,对初步筛查肩袖损伤及指导进一步治疗具有重要意义。

Objective: To evaluate the association between rotator cuff tear and the proximal migration of humeral head.Methods: In this research, we retrospectively selected 30 patients with unilateral rotator cuff tear in Peking University People’s Hospital from September 2015 to May 2016, who received magnetic resonance imaging (MRI) and X-ray of the painful shoulder before enrollment in this study, the duration between the two examinations was no longer than 1 week, and also there was no past history of surgery in the selected shoulders. There was no other exclusion criteria. Upward migration index (UMI) was the ratio between the distance of humeral head center to the lower surface of acromion, and the radius of humeral head circle, which could help to minimize the effect of anatomy difference and imaging magnification, compared with the traditional acromiohumeral distance (AHD). Then we introduced this index to stratify the selected 30 patients into 3 groups , and each group contained 10 patients, UMI of group 1 was >1 and ≤1.2, UMI of group 2 was >1.2 and ≤1.4, UMI of group 3 was >1.4. As the supraspinatus was most commonly affected by pathological change among the four rotator cuff tendons, we took it as the research object. Then we used the Spearman correlation analysis to evaluate the relationship between UMI and fatty degeneration, rotator cuff tear size and the thickness of ruptured supraspinatus tendon from X-ray and MRI.Results: In the A-P view, the average UMI was 1.33 (1.02-1.51, SD: ±0.22). UMI and the tear size had a significant negative correlation (R=-0.584, P<0.01), and also there was a negative correlation between the fatty degeneration of the supraspinatus (R=-0.312, P=0.033). However, there was no correlation between UMI and the thickness of ruptured supraspinatus (R=0.127, P=0.071).Conclusion: UMI is related with the fatty degeneration of supraspinatus and the tear size. The reduction of UMI is a predictable and reliable mark of rotator cuff tear and degeneration in clinic. Physicians can use physical examination and X-ray first when facing the patients with shoulder pain, which is convenient and helpful for evaluating rotator cuff tears.