Objective: To investigate the histopathological changes in cricoarytenoid joints in 32 animal models. The characteristic histopathological changes of arytenoid cartilages after recurrent nerve paralysis were evaluated.
Methods: Sixteen dogs (32 vocal folds, 8 as normal control) were divided into different animal models of recurrent nerve paralysis as transection, half-section, ligation, or crush. The histopathological finds of arytenoid cartilages were analysed.
Results: Arytenoid cartilages showed fibrin (12/24), disruption of the fibrous membrane (9/24), fibrillation (7/24) and degenerative changes in their joint surface structure (3/24) at various levels of intensity. The fibrin and disruption of the fibrous membrane were found 1 month after injury, and all changes appeared in 6 months. The fibrillation and arytenoid cartilages degenerative changes revealed in transaction group and ligation group, and became stronger in time of 6 months. The correlation among the fibrillation ratio and the normal control was positive (t were 6.23 and 3.65, P < 0.01). The correlation among the number of cellular of arytenoid cartilages and the normal control was positive (t = 2.78, P < 0.05). The fibrillation (7) and arytenoid cartilages degenerative changes (3) revealed in vocal fold fixation to influence the recovery of laryngeal function.
Conclusions: The histopathological change of cricoarytenoid joint after recurrent nerve paralysis was related to the severity of neural injury. Influence the recovery of laryngeal function more often from 6 months.