Histopathological Examinations of the Inferior Acromial Surface in Patients with Shoulder Impingement Symptoms.

Abstract

[Purpose] We performed anterior acromioplasty on patients with shoulder impingement symptoms and examined how much demage to the rotator cuff influenced on the inferior acromial surface.
[Methods] There were 28 patients (7 females and 21 males), including 6 patients without any rotator cuff demage,4 with partial thickness cuff tears and 18 with full thickness cuff tears. They were aged from 22 to 80 years (mean ; 58.2 years) at time of surgery.
[Results] None of the patients were observed with a clear 4-layer structure. The patients without any cuff demage showed a partial disappearance of the synovial layer and fibrous tissue, and such degeneration tended to correlate with age. In patients with cuff tears, the degeneration was correlated with the severity and extent of the tears. Age rather than the presence and range of cuff tears influenced the changes of the coracoacromial ligament (C-A lig), in which the interstitial substance between the collagen fibers tended to decrease and these fibers tended to become coarser with aging.
[Conclusion] Cuff tears caused pathological changes of the inferior acromial surface by mechanical loading, while it had almost no effect on the C-A ligament.