Manubriosternal joint: synchondrosis or symphysis? Analysis of morphology and aging in humans.

Abstract

The uncertainty about the morphological classification of the manubriosternal joint is historical in the field of Anatomy and is still under discussion. This makes it difficult to teach and diagnosing related matters, especially those that require radiological images. In fact, this subject lacks specific data. This study aims to describe the morphology of the manubriosternal joint and its age-related changes. Thirty specimens were divided in three groups: young adults up to 35years of age, middle-aged adults ranging from 36 to 55, and older adults over 56years. The subjects were labeled, and blind analysis were performed using the macroscopic and microscopic analysis. The large presence of isolated fibroblasts and chondrocytes and the lower degree of isogenic groups proved that the manubriosternal joint is a symphysis. Its age-related changes involve the reduction of thickness and hydrated characteristics, loss of uniformity and arrangement of the collagen fibers, hyalinization and the presence of focal lesions, that corroborate with the degenerative process. The manubriosternal joint is classified as symphysis and the main age-related changes is the relative thickness of the tissue.