Abstract

Objective: To examine the relative prevalence of histological changes which have been associated with the process of tendinopathy in lesions of the tendon of the long head of the biceps brachii. To evaluate the reliability of histopathologic evaluation of tendon tissue in lesions of the tendon of the long head of the biceps. Design: Tendon samples were harvested from 51 patients (31 men, 20 women; mean age, 63.2 years) who underwent arthroscopic release of the LHBT because of refractory biceps tendinopathy, and from 5 male patients who died of cardiovascular events (mean age, 69.6 years). Histologic examination was performed using Haematoxylin and Eosin stained slides that were interpreted using a semiquantitative grading scale assessing fiber structure and arrangement, rounding of the nuclei, regional variations in cellularity, increased vascularity, decreased collagen stainability and hyalinization. Results: The mean pathologic sum-score of ruptured tendons was greater than the mean pathologic score of control tendons (15.76 + 3.11 versus 3.4 + 1.9, P 0.001). Within each specific category of tendon abnormalities, the chi square test showed association between the control and ruptured tendons; all the variables were significantly different (Mann-Whitney U-test 0.05, P 0.001). Using the kappa statistics, the agreement between the two readings ranged from 0.53 to 0.85 Conclusions: Unruptured tendons of the long head of the biceps, even at an advanced age, and ruptured tendons of the long head of the biceps are clearly part of two distinct populations.