有限元分析不同程度冈上肌断裂对肩关节应力的影响

Finite element analysis of impact of varying degrees of supraspinatus muscle rupture on shoulder joint stress

背景:目前研究冈上肌的精细解剖及各亚区域的生物力学表现的实验较多,但是对冈上肌不同区域的损伤所带来的肩关节应力的影响鲜有耳闻。很有必要了解不同区域的冈上肌损伤对关节软骨及关节盂的应力大小及分布的影响,从而给临床诊治提供一些理论支持。目的:探究在三维有限元软件中模拟不同程度的冈上肌断裂对肱骨软骨面、关节盂唇及关节盂软骨关节面的最大应力值。方法:获取正常健康的肩关节CT或MRI导入Mimics、Geomagic进行提取模型,再通过Soildworks对模型构建,再对各个模型的冈上肌进行不同程度的损伤,模拟出不同区域的断裂。最后导入机械软件Ansys,进行三维有限元生物力学分析,计算肱骨软骨面、关节盂唇及关节盂软骨关节面的应力数值。结果与结论:①随着冈上肌损伤程度的加重肩关节软骨面及盂唇的应力也会增加;②冈上肌前部在各区域中最为重要;③不同程度的冈上肌断裂对肩关节盂唇面的软骨应力大小有影响,而应力的分布区域无明显改变;④提示肩关节水平外展起始时,前部发挥着重要的作用,其次为后部深区;当冈上肌前部损伤时肩关节软组织应力增加明显,还容易引起关节盂唇顶部及关节盂软骨前下方的损伤。

BACKGROUND:Currently,numerous experiments delve into the intricate anatomy and biomechanical behavior of distinct segments of the supraspinatus muscle.However,the impact of shoulder joint stress resulting from damage to various regions of this muscle remains a scarcely explored domain.Understanding the repercussions of supraspinatus muscle injuries across different regions on the stress distribution and magnitude of articular cartilage and the glenoid is crucial for providing some theoretical support for clinical diagnosis and treatment.OBJECTIVE:To ascertain the maximum stress values by simulating different degrees of supraspinatus muscle rupture on the humeral cartilage surface,glenoid lip,and glenoid cartilage joint surface using three-dimensional finite element software.METHODS:Normal and healthy shoulder joint CT or MRI scans were processed through Mimics and Geomagic to extract molds.Subsequently,models were constructed via Solidworks.Varying degrees of supraspinatus muscle damage were simulated for each model to mimic fractures in different regions.Finally,Ansys,mechanical software,was employed for three-dimensional finite element biomechanical analysis,calculating stress values for the humeral cartilage surface,glenoid lip,and glenoid cartilage joint surface.RESULTS AND CONCLUSION:(1)With worsening degrees of supraspinatus muscle injury,the stress on the shoulder joint cartilage surface and glenoid lip escalated.(2)Among various regions,the anterior part of the supraspinatus muscle exhibited paramount significance.(3)While supraspinatus muscle fractures of differing degrees impacted the magnitude of cartilage stress on the glenoid labial surface,the stress distribution remained constant.(4)It is indicated that during the initial stages of horizontal abduction of the shoulder joint,the anterior region assumes a pivotal role,followed by the posterior deep region.Injury to the anterior part of the supraspinatus muscle leads to a significant surge in stress within the shoulder joint’s soft tissue,potentially causing damage to the top of the glenoid lip and the anterior part of the glenoid cartilage.