目的　探讨应力刺激对肩袖腱-骨修复的促进作用。  方法　选取26只成年雄性新西兰白兔，术前随机选取2只白兔行MRI检查，检查后处死，以熟悉解剖结构及正常对照用，余24只白兔建造兔肩袖腱-骨急性断裂止点重建术后动物模型。随机分为2组：应力负荷组与非应力负荷组。非应力负荷组正常笼养，应力负荷组术后2周进行双侧肩关节被动活动训练。分别于术后第2、4、6、8周训练结束后随机选取各组中3只白兔行肩关节MRI检查。  结果　术后2周，T2WI相可见所有兔冈上肌腱止点重建处呈现高信号。术后4周，T2WI相应力负荷组止点重建处低信号显示面积较非应力负荷组稍大。术后6周，T2WI相应力负荷组肌腱止点处腱样组织信号区域稍显宽大，组间比较，无明显差异。术后8周，T2WI相显示腱-骨断裂高信号，但高信号较前明显减少。组间比较，应力负荷组愈合肌腱中低信号面积稍显宽大，滑囊液性信号已无明星差别。  结论　MRI对肩袖断裂诊断及其修复过程中的监测敏感性相对较高，且一定的应力刺激在兔肩袖急性断裂术后腱-骨修复过程中起到积极促进作用。

Objective　To explore the roles of stress on the postoperative recovery after acute rotator cuff injury.　Methods　26 adult male New Zealand white rabbits were used in this study. Taking as the control, 2 rabbits were randomly selected to conduct MRI scan preoperatively. The acute rotator cuff tear was performed in other 24 animals, followed by the randomly group division: stress loading group with the passive activities on bilateral shoulder joints 2 weeks postoperatively, and non-stress loading group without any postoperative movement behavior. MRI survey was performed on 3 rabbits randomly selected in each group at the week of 2, 4, 6 and 8 after operation, respectively.　Results　2 weeks postoperatively, T2WI showed high signal on the insertion of the tendon of supraspinatus muscle, at 4 weeks, the areas of the low signals of the tissues connected tendon and bone were slightly larger than that in non-stress group, at 6 weeks, the signals were larger than that in non-stress group, however, which was not significant between two groups. At 8 weeks, the high signals of the crack still preserved, although the intensity decreased compared to that of other time points. The lower signal area of the healed tendinous structure was slightly larger in stress loading group, but the signals of synovial fluid were not significant compared to that of the unloading groups.　Conclusions　MRI is valuable for monitoring the repairing process of postreconstructive acute rotator cuff tear, while, stress stimulation plays an active role for the repairing of reconstructed rotator cuff tear.