Process of neovascularization compared with pain intensity in tendinopathy of the long head of the biceps brachii tendon associated with concomitant shoulder disorders, after arthroscopic treatment

Background: Tendinopathy of the long head of the biceps brachii tendon is one of the most common, painful conditions of the anterior part of the shoulder and often coexists with rotator cuff tears. Multifactorial etiopathology of tendinopathy is poorly understood, however, several studies indicated that it is seen predominantly in areas with decreased vascularity of the tissue; the pathology is also characterized by expansive and abundant neovascular in–growth. The aim of the study was to investigate the relationship between the neovascularization of proximal part of the long head of the biceps brachii tendon and pain along the bicipital groove. Material and methods: Tissue material was obtained from 28 patients who underwent a shoulder arthroscopy and VAS score. CD31 and CD34 molecules were visualized by immunohistochemical method to assess biceps tendon neovascularization and quantify it based on a Bonar scoring system. Results: Although all patients reported pain prior to arthroscopy (mean VAS score was 7.5), microscopic examination did not reveal neovascularization in all cases. Immunohistochemical staining for CD31 and CD34 allowed for very precise visualization and quantification of neovascularization, however there was also no correlation between vessels in-growth scores and pain. Conclusions: The obtained data suggest that neovascularization process in tendinopathy is not directly related to pain, however, further studies are needed to explain its significance in the long head of the biceps brachii tendon tendinopathy.