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 30 On the Femur

The two lower heads of the femur and their depression

At its lower end the femur is quite thick, and is separated into two heads 11 [condylus lateralis et medialis] (E, F in figs. 1, 2), the largest of all the heads of bones in the entire body; these extend much farther to the posterior side of the femur than to the anterior, 12 as in fact had been useful for their joint with the tibia. They are articulated (join E, F, I in figs. 1, 2 with G, F, I in fig. 7 ch. 31) with the tibia by mutual entry in such a way that the tibia can only be flexed and extended, but not at all moved to the side, even the slightest bit — no matter how Galen thought it, who in listing the motions of the tibia was deceived by the motion of the femur on the hipbone. 13 The heads of the femur are also extended posteriorly because it was better that the tibia be bent at an angle 14 and not extended beyond a straight line 15 or raised in a forward direction; so because of that motion the heads of the femur do not project at all in the anterior side of the femur. Although in their anterior side these heads show a depression [facies patellaris] (H in fig. 2) common to both, quite wide and coated with cartilage, it was not made to receive any projection of the tibia. You will hear that the orbicular bone [patella] which is not unlike a small shield fits into that depression with an appropriately shaped projection [facies posterior] (A, B, C, D in fig. 2, ch. 32) when the account of that bone is undertaken in the second chapter after this. On the posterior side of the femur these heads [condylus medialis, c. lateralis] are separated from each other by a wide interval (I in fig. 1), and between them they make a wide, deep depression [fossa intercondylaris] that is quite rough and not at all covered with cartilage. It receives the rough and uneven projection [eminentia intercondylaris] (I in fig. 7, ch. 31) of the tibia which we shall write projects between the depressions [facies articularis superior] of the tibia and puts forth a ligament [lig. cruciatum anterius] (X in the figure for ch. 1, Bk. 2) which is very strongly inserted in that depression together with another quite robust ligament [lig. cruciatum posterius] originating from the posterior side of the tibia. This depression assists in bringing down the largest nerve [n. ischiadicus] 16 of the entire body (z, h, q in the 10th table of muscles) together with the vein [vv. tibiales anteriores et posteriores] and the artery [a. tibialis anterior] (r, u in the last figure of Bk. 3) to the tibia. Though the lower heads [condyles] of the femur are brought so far to the rear for the motions of the tibia, they also function to let the nerve and the vessels descend between them with the greatest safety. As processes do, they also provide origins for a number of muscles that move the foot; for 17 the first [m. gastrocnemius, caput mediale] (F in the 12th table of muscles) of the muscles that move the foot originates from the upper side (K in fig. 1) of the inner head [condylus medialis], 18 and from the upper side (L in fig. 1) of the outer head [condylus lateralis] the second [m. gastrocnemius, caput laterale] (Y in the 12th table of muscles) and third [m. plantaris] (F in the 13th) of the muscles responsible for motions of the foot originate. 19 Also, if the muscle [m. popliteus] (G in the 14th table) concealed behind the knee takes some part of its origin from a bone, it surely does so from this outer head [condylus lateralis] of the femur, although its principal origin will be shown to come from the ligament [lig. collaterale fibulare] (T in the figure for ch. 1, Bk. 2) that more than any other secures this head of the femur to the tibia. A tendon (C, then h, z in the 12th table of muscles) is inserted into the upper region (M in fig. 1) of the inner head somewhat toward its inner side; this belongs to the fifth of the muscles [m. adductor magnus] that move the femur; because of this insertion, this head of the femur shows its side compressed there, suited for receiving a tendon [lig. collaterale tibiale]. Dogs show a small ossicle here, like those which we compare to a sesame seed [ossa sesamoidea] (y, w in fig. 2, ch, 33). 20 That is how the anterior, inferior, and posterior sides of these heads are arranged; their sides 21 are filled with many small, blind foramina, so that the very powerful ligaments containing the knee joint may fitly originate from here. The outer side of the outer head [condylus lateralis] puts out a separate depression (N in figs. 1, 2) incised obliquely to it near the posterior region of the side, made for the tendon of the fourth [m. biceps femoris] (Y in the 10th table of muscles) of the muscles that move the tibia. Lest the tendon leave its course when flexed obliquely from here, Nature prepared this depression 22 . The inner side of the inner head [condylus medialis], though several tendons (of muscles L, D, R, V, V in the 16th table of muscles or q, g, b, d, d in the 2nd) 23 are bent upon it, has no such depression. But when the bone has just been cleaned, a compression (O in fig. 1) appears near the posterior area of the side [condylus medialis] by which the tendons can safely be brought down; they do not slip out of place because of a wide convexity that arises (P in fig. 1) in the middle of the side just mentioned and allows the tendons to be brought down opportunely along its posterior surface. The tendons brought down this way will be counted as belonging to the first three and the fifth of the muscles that move the tibia.



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 30 On the Femur