Book One -- The things that sustain and support the entire body, and what braces and attaches them all. [the bones and the ligaments that interconnect them] | Chapter 2 The Nature, Use, and Varieties of Cartilage

A third cartilage in certain joints

Indeed, the wise Maker of things recognized that there would be an outstanding use of cartilage in the joints, so he not only equipped the bones in the way we have described with a smooth and slippery casing of cartilage [cartilago articularis] at the point of mutual contact, but in several joints he also applied a third substance besides these cartilages, 8 which is attached to the cartilage of neither bone, but only to the membranous ligaments [capsulae articulares] of the joint [juncturae synoviales]; it is circular, and creates as it were an intervening space [cavitas articularis] between the cartilages covering the bones. This [discus articularis] is smooth on both sides where it lies between the other cartilages, and is slippery because of a viscous liquid [synovia] with which it is coated, and much softer than the cartilages that grow on the bones. You will learn in the appropriate place that cartilage of this kind [c. fibrosa] separates the joints of the lower maxilla to the upper [articulatio temporomandibularis]. Others separate the joint of the sternum with the clavicle [articulatio sternoclavicularis], the clavicle with the upper humerus [articulatio acromioclavicularis], the ulna with the carpus [articulatio radio-ulnaris distalis], and the tibia with the femur [articulatio femoro-tibialis]: in this joint, by the great providence of Nature, cartilages of this kind specially enhance the depressions in which the heads of the femur are received. In fact, cartilages of this kind do not seem to have been noticed by Galen, save only those [meniscus lateralis, meniscus medialis] which we have said belong to the knee: he mentions them once 9 as ligaments, and only in passing. That they were better known to the Arabs 10 can be inferred because in explaining the structure of the bones they wrote that all bones are connected, the only exception being those in which the Laguahic (or more properly Luhach) intercede and separate the bones somewhat from each other, understanding by the term a cartilage of this kind that in its softness differs little from a ligament. But where these cartilages are located, I have so far found none of the Arabs to explain. 11 This is the role that cartilage plays in the joints.



Book One -- The things that sustain and support the entire body, and what braces and attaches them all. [the bones and the ligaments that interconnect them] | Chapter 2 The Nature, Use, and Varieties of Cartilage