Pathology of rotator cuff tendon tear:Inflammation and potential for repair reduces as tear size increases

Authors: T.J.W. Matthews, G.C.R. Hand, J.L. Rees, N.A. Athanasou, A.J. Carr

References: SECEC 2005

Abstract
AIMS: The aim of this study was to observe cellular and vascular changes in different stages of full thickness rotator cuff tear.

MATERIAL: Biopsies of the supraspinatus tendon in 40 patients with chronic rotator cuff tears undergoing surgery were analysed using histological and contemporary immunocytochemical techniques. Sections were stained with primary antibodies against PCNA (Proliferating cell nuclear antigen), CD34 (QBEnd 10), CD45 (Leucocyte Common Antigen), CD68, D2-40 (lymphatic Endothelia Marker) and Mast Cell Tryptase. A histological analysis was performed with Mayer’s Haemotoxylin and Eosin, Congo Red and Toluidine Blue.

RESULTS: The reparative response and inflammatory component of the tissue was seen to diminish as the rotator cuff tear size increased. This was evidenced by increasing degeneration and oedema, reducing fibroblast proliferation, reduced thickening of the synovial membrane and reducing vascularity. Macrophage, other lecocyte and mast cell numbers also reduced as tear size increased. Large and massive tears revealed a higher degree of chondroid metaplasia and amyloid deposition when compared to smaller sized tears. There was no association with the patient’s age or duration of symptoms.

CONCLUSION: Small sized rotator cuff tears retain the greatest potential to heal and have a significant inflammatory component. Tissue from large and massive tears is of such a degenerate nature that it may never heal and this is probably a significant cause of re-rupture after surgical repair in this group. Selection of patients for reconstructive surgery should take into account the composition and healing potential of tendon tissue and its relationship to tear size in chronic tears of the rotator cuff.