290 



THE SKELETON. 



Appears at 4th 

 year; joins shaft >$ 

 about 18th year. ^ 



Appears at end 

 > <?* of 1st year ; 

 joins shaft about 

 18th year. 



are to be seen, so that the spongy tissue in this situation presents an appearance of 

 being mapped out into a series of rectangular areas. 



Articulations. With three bones : the os innominatum, tibia, and patella. 



Development (Fig. 217). The femur is developed by five centres : one for the 



shaft, one for each extremity, and one for each trochanter. Of all the long bones, 



except the clavicle, it is the first to show traces of ossification : this commences in 



the shaft, at about the fifth week of foetal life, the centres of ossification in the 



epiphyses appearing in the following 

 order: First, in the lower end of 

 the bone, at the ninth month of foetal 

 life 1 (from this the condyles and 

 tuberosities are formed) ; in the head 

 at the end of the first year after 

 Appears isth-uthyear; birttl . in tte great trochanter, during 



joins shaft about 18th , ' , & 



year. the fourth year ; and in the lesser 



trochanter, between the thirteenth 

 and fourteenth. The order in which 

 the epiphyses are joined to the shaft 

 is the reverse of that of their appear- 

 ance: their junction does not com- 

 mence until after puberty, the lesser 

 trochanter being first joined, then 

 the great, then the head, and, lastly, 

 the inferior extremity (the first in 

 which ossification commenced), which 

 is not united until the twentieth 

 year. 



Attachment of Muscles. To 

 twenty-three. To the great tro- 

 chanter : the Gluteus medius, Gluteus 

 minimus, Pyriformis, Obturator inter- 

 nus, Obturator externus, Gemellus 

 superior, Gemellus inferior, and 

 Quadratus femoris. To the lesser 

 trochanter : the Psoas magnus and 

 the Iliacus below it. To the shaft : 



the Vastus externus, Gluteus maximus, short head of the Biceps, Vastus internus, 

 Adductor magnus, Pectineus, Adductor brevis, Adductor longus, Crureus, and 

 Subcrureus. To the condyles : the Gastrocnemius, Plantaris, and Popliteus. 



Surface Form. The femur is covered with muscles, so that in fairly muscular subjects the 

 shaft is not to be detected through its fleshy covering, and the only parts accessible to the touch 

 are the outer surface of the great trochanter and the lower expanded end of the bone. The 

 external surface of the great trochanter is to be felt, especially in certain positions of the limb. Its 

 position is generally indicated by a depression, owing to the thickness of the Gluteus medius and 

 minimus, which project above it. When, however, the thigh is flexed, and especially if 

 crossed over the opposite one, the trochanter produces a blunt eminence on the surface. The 

 upper border is about on a line with the spine of the os pubis, and its exact level is indicated by 

 a line drawn from the anterior superior spinous process of the ilium, over the outer side of the 

 hip, to the most prominent point of the tuberosity of the ischium. This is known as Nekton's 

 line. The outer and inner condyles of the lower extremity are easily to be felt. The outer one 

 is more subcutaneous than the inner one, and readily felt. The tuberosity on it is comparatively 

 little developed, but can be more or less easily recognized. The inner condyle is more thickly 

 covered, and this gives a general convex outline to this part, especially when the knee is 

 flexed. The tuberosity on it is easily felt, and at the upper part of the condyle the sharp 

 tubercle for the insertion of the tendon of the Adductor magnus can be recognized without 

 difficulty. When the knee is flexed, and the patella situated in the interval between the con- 

 dyles and the upper end of the tibia, a part of the trochlear surface of the femur can be made 

 out above the patella. 



Surgical Anatomy. There are one or two points about the ossification of the femur 



1 This is the only epiphysis in which ossification begins before birth. 



Appears at 

 9th month 

 (foetal). 



Joins shaft at 20th 

 year. 



Lower extremity. 



FIG. 217. Plan of the development of the femur, 

 five centres. 



By 



