肩关节MRI对肩峰小骨与冈上肌和冈下肌损伤的相关性评估

Shoulder MRI evaluation of the association of os acromiale with supraspinatus and infraspinatus injury

目的:探讨肩峰小骨的MRI表现,并分析肩峰小骨与冈上肌和冈下肌损伤之间的相关性。方法:回顾性分析2010年1月至2020年8月诊断为肩峰小骨患者21例(有肩峰小骨组)的MRI资料,并匹配同期检查的21例无肩峰小骨者作为无肩峰小骨组。有肩峰小骨组男14例,女7例;年龄29~77(55.5±11.5)岁。无肩峰小骨组男10例,女11例;年龄31~70(51.1±10.0)岁。根据肩峰小骨周围骨髓有无骨髓水肿分为水肿型肩峰小骨与无水肿型肩峰小骨;根据肩峰小骨有无错位分为错位型肩峰小骨与无错位型肩峰小骨。分析肩峰小骨的MRI表现,分别比较有肩峰小骨组与无肩峰小骨组中肩袖撕裂和冈上肌、冈下肌损伤的差异,水肿型肩峰小骨与无水肿型肩峰小骨中冈上肌和冈下肌撕裂的差异,错位型肩峰小骨与无错位型肩峰小骨中冈上肌和冈下肌撕裂的差异,错位型肩峰小骨与无肩峰小骨组中冈上肌和冈下肌撕裂的差异。结果:21例肩峰小骨在MRI上均表现为肩峰前部三角形或不规则形骨块,与肩峰形成假关节;11例为水肿型肩峰小骨,11例为错位型肩峰小骨。有肩峰小骨组17例合并冈上肌撕裂,1例合并冈上肌腱炎,11例合并冈下肌撕裂,4例合并冈下肌腱炎;无肩峰小骨组11例合并冈上肌撕裂,2例合并冈上肌腱炎,5例合并冈下肌撕裂,1例合并冈下肌腱炎。有肩峰小骨组与无肩峰小骨组在肩袖撕裂、冈上肌和冈下肌损伤方面比较差异无统计学意义(P>0.05)。11例水肿型肩峰小骨中,10例合并冈上肌撕裂,7例合并冈下肌撕裂;10例无水肿型肩峰小骨组中,7例合并冈上肌撕裂,4例合并冈下肌撕裂。冈上肌和冈下肌撕裂在水肿型肩峰小骨与无水肿型肩峰小骨之间比较,差异无统计学意义(P>0.05)。11例错位型肩峰小骨中,11例合并冈上肌撕裂,9例合并冈下肌撕裂;10例无错位型肩峰小骨中,6例合并冈上肌撕裂,2例合并冈下肌撕裂。冈上肌和冈下肌撕裂在错位型肩峰小骨与无错位型肩峰小骨之间比较,差异有统计学意义(P<0.05),冈上肌和冈下肌撕裂在错位型肩峰小骨与无肩峰小骨组之间比较,差异有统计学意义(P<0.05)。结论:肩关节MRI能够很好地评估肩峰小骨及并发的骨髓水肿、错位和肩袖损伤的情况,并可用于评估肩峰小骨的稳定性。肩峰小骨的存在可能不会增加冈上肌和冈下肌损伤的风险,但错位型肩峰小骨的存在可能会增加冈上肌和冈下肌撕裂的风险。

Objective:To explore the MRI findings of os acromiale and to analyze the relationship between os acromiale and the supraspinatus and infraspinatus injury.Methods:From January 2010 to August 2020,21 patients with os acromiale(os arcomiale group)were compared with 21 subjects with no evidence of os acromiale(no os arcomiale group).There were 14 males and 7 females in the os arcomiate group,aged from 29 to 77 years old,mean aged(55.5±11.5)years old.While in the control group,there were 10 males and 11 females in no os arcomiale group,aged from 31 to 70 years old,mean aged(51.1±10.0)years old.The os acromiales were classified as edematous os acromiale or non-edematous os acromiale based on whether the presence of marrow edema,and as displaced os acromiale or non-displaced os acromiale based on whether the presence of displacement of the os acromiale.The MRI features of os acromiale were analyzed.Statistical analyses were performed to identify the differences between the os arcomiale group and no os arcomiale group regarding rotator cuff tear,supraspinatus and infraspinatus injury.Differences in the supraspinatus and infraspinatus tear between the edematous and non-edematous os acro miale group,the displaced and non-displaced os acromiale group,the displaced os acromiale and no os arcomiale group were also assessed.Results:On MRI,all the 21 os acromiales appeared as a triangular or irregular bone fragment of the distal acromion,and forms a pseudo-acromioclavicular joint with the acromion.Eleven cases were edematous os acromiale,11 cases were displaced os acromiale.In the os arcomiale group,17 had supraspinatus tear,1 had supraspinatus tendinitis,11 had infraspinatus tear,and 4 had infraspinatus tendinitis.In the no os arcomiale group,11 had supraspinatus tear,2 had supraspinatus tendinitis,5 had infraspinatus tear,and 1 had infraspinatus tendinitis.No statistically significant difference between the os arcomiale group and no os arcomiale group regarding the rotator cuff tear,supraspinatus and infraspinatus injury(P>0.05).In the 11 cases of edematous os arcomiale,10 had supraspinatus tear and 7 had infraspinatus tear.In the 10 cases of non-edematous os acromiale,7 had supraspinatus tear and 4 had infraspinatus tear.No statistically significant difference was noted between the edematous os acromiale and non-edematous os acromiale in terms of supraspinatus and infraspinatus tear(P>0.05).In the 11 cases of displaced os acromiale,11 had supraspinatus tear and 9 had infraspinatus tear.In the 10 cases of non-displaced os acromiale,6 had supraspinatus tear and 2 had infraspinatus tear.In the no os arcomiale group,11 had supraspinatus tear and 5 had infraspinatus tear.There was a statistically significant increases in the prevalence of supraspinatus and infraspinatus tear in the displaced os acromiale group compared with non-displaced os acromiale group,the displaced os acromiale group and no os arcomiale group(P<0.05).Conclusion:Shoulder MRI can very well depict os acromiale and can reveal associated abnormalities such as adjacent bone marrow edema,displaced deformity,and rotator cuff tear,and it can be used to assess the stability of the os acromiale.The presence of os acromiale may not increase the risk of supraspinatus and infraspinatus tear significantly.However,the presence of displaced os acromiale is at greater risk of supraspinatus and infraspinatus tear.