Elastic-related fibers in the annular ligament of the stapes-oval window articulation. An electron microscopic and histochemical study in the rat and the rabbit.

The annular ligament that attaches the circumference of the base of the stapes to the margin of the oval window (fenestra vestibuli) was stained with selective methods for elastic system fibers and was also studied at the ultrastructural level after tannic acid-glutaraldehyde fixation. Although the annular ligament is devoid of elastic fibers, it is rich in elastic-related fibers (i.e. = oxytalan and elaunin fibers). Elaunin fibers predominate in the annular ligament itself and they are continuous with the oxytalan fibers which are embedded in the matrix of the articular cartilage.