骨性缺损对肩关节稳定性影响的研究

目的探讨肩关节骨性缺损对关节稳定性的影响,为临床提供理论依据。方法分别制作肩胛盂及肱骨头缺损模型并逐渐增加缺损程度;以盂肱关节旋转中立位、60°外展位为起始位置,逐渐增加外旋角度至盂肱关节脱位,测量脱位发生前肱骨头前移距离;保持盂肱关节外展60°,分别在旋转中立位及外旋60°位时增加轴向应力,直至盂肱关节脱位,测量脱位前肱骨头的应力强度变化。结果随着肩胛盂及肱骨头缺损程度增加,外旋角度增加,肩关节稳定性下降,肱骨头位移不断增大,各组间呈显著性差异(P<0.01);盂肱关节外展60°、旋转中立位时,肱骨头应力强度随着骨缺损增大而不断增大,正常应力强度从1.68 Mpa迅速增加至4.62 Mpa,各组间呈显著性差异(P<0.01);盂肱关节外展60°、外旋60°时,正常应力强度为1.94 Mpa,骨缺损时迅速增加至6.65 Mpa,各组间呈显著性差异(P<0.01);肩关节不同缺损时,其接触力学特性证实了对肩关节稳定性有较大的影响,肩关节不稳定现象十分突出。结论随着肩胛盂及肱骨头缺损范围的增大,肩关节稳定性不断下降,肱骨头位移和应力强度不断增加,以致发生提前脱位。

Research of bone defects associated with shoulder stability

Objective To examine the impact of bone defects on shoulder stability,provide a theoretical basis for clinical studies.Methods The bone defect models of glenoid and humeral head were made respectively,and the amount of defect was increased gradually.First,anterior translation of humeral head before the dislocation of glenohumeral joint was measured from 60° of abduction and neutral position to the dislocation by increasing external rotation angle.Then,maintaining 60° of abduction of the glenohumeral joint,the axial stress was increased at 60° of external rotation and neutral position respectively until the dislocation of glenohumeral joint,and then the stress intensity of humeral head was measured before the dislocation.Results With the increase of glenoid and humeral head defects and external rotation angle,the stability of shoulder joint decreased,the anterior translation of humeral head increased.There was a significant difference among each group(P<0.01).At 60° of abduction and neutral position of the glenohumeral joint,the stress intensity of humeral head increased with the amount of bone defect,increasing rapidly from 1.68 to 4.62 Mpa.There was a significant difference among each group(P<0.01).At 60° of abduction and 60° of external rotation of the glenohumeral joint,the normal stress intensity of humeral head was 1.94 Mpa,increasing rapidly to 6.65 Mpa with increased bone defects.There was a significant difference among each group(P<0.01).Contact pressure mechanical characteristics of shoulder joint showed that the amount of bone defect had tremendous influence on the stability of shoulder joint.Conclusion With the increase of glenoid and the humeral head defects,the stability of the shoulder joint decreased,and the anterior translocation and stress intensity of humeral head increased,resulting in the dislocation of glenohumeral joint in advance.