Histological studies of the glenoid labrum from fetal life to old age.

To help to resolve the controversy regarding the composition of the glenoid labrum, thirty-eight shoulders from cadavera were examined grossly and histologically. We used specimens for individuals of different ages so that we could determine what changes occur as a result of aging. In children and adults, the labrum appeared to be fibrocartilaginous tissue. The labrum was a separate anatomical structure that could be distinguished from the fibrous capsule of the shoulder. Neonatal labra were composed of primitive mesenchymal tissue containing only few chondrocytes that modulated into fibrocartilage in the first few years of life. Neonatal labra contained no elastin, whereas specimens from adults had rare elastin fibers. The labrum was sparsely vascularized throughout its substance, with no particular pattern of distribution. Vascularity decreased with increasing age of the individual.