Os acromiale is non-union of one or more ossification centers of the acromion to the rest of the scapula. Among 70 cases with rotater cuff tear who we operated on, two were found to have a rotator cuff tear with os acromiale. We report these 2 cases and discuss the relationship between the occurrence of rotator cuff tear and os acromiale.
The two patients were aged 56 and 70-years-old respectively. They consulted our hospital due to shoulder joint pain and limitation in range of movement without any episode of injury. Roentgenograms showed the existence of the os acromiale and osteophyte formation on the undersurface of the acromion and an arthrogram confirmed rotator cuff tear. As abnormal movement of os acromiale was recognised during surgery, it was removed and the torn rotator cuff repaired.
As abnormal mobility of os acromiale and ostephyte formation are consistent with the site of rotator cuff tears, these two factors may possibly contribute to the occurrence of rotator cuff tear injury.
