Variability
An X-ray study of 100 shoulders in US soldiers found considerable variation in the size and shape of the joint. The articular surfaces were notably different in size and form. On some they are separated by a meniscus attached to the superior acromioclavicular ligament. This meniscus may be a blade of fibrocartilage that extends nearly halfway into the joint or it may form a complete disc that divides the joint into two parts. In other joints no synovial joint is present with the joint being made by a pad of fibrous tissue attached to the outer end of the clavicle, and no articular cavity.
Read more about this topic: Acromioclavicular Joint
Famous quotes containing the word variability:
“The grand points in human nature are the same to-day they were a thousand years ago. The only variability in them is in expression, not in feature.”
—Herman Melville (1819–1891)