Introduction
Adhesive capsulitis of the shoulder is a progressive loss of active and passive range of motion of insidious onset, and pain. Histologically is defined as a pancapsular fibroplasia with a possible origin in the rotator interval.
Objective
to evaluate the histologic appearance of the capsule and rotator interval and compare them.
Materials And Methods
Between January 2010 and May 2014, 20 arthroscopic capsulotomies where performed, 15 for idiopathic capsulitis and 5 for secondary capsulitis., with insulin requiring diabetes or rheumatologic diseases. Multiple biopsies were performed on the capsule of the rotator interval, anteroinferior capsule, and posterior capsule. Lymphocyte infiltration, vascular proliferation, fibroblastic proliferation, chondroid metaplasia and vimentin expression were quantitatively evaluated.
Results
The rotator interval showed significant increase of synovial hyperplasia, lymphocyte infiltration, fibroblast proliferation, fibrosis and vimentin expression on the stroma when compared with the specimens of the rest of the capsule (p<0,0001). The samples of secondary capsulitis showed in the rotator interval, chondroid metaplasia not present in the rest of the samples.
Conclusion
The histologic study of the capsule shows that the fibrous dysplasia is pancapsular in the idiopathic adhesive capsulitis with a contracture of the rotator interval with vimentin expressed markedly in the rotator interval, making its release the key. The presence of chondroid metaplasia in the rotator interval could be the cause of the poor results of the treatment of this group of patients.