The Lower Extremity and Pelvis 



largely brought about by the extent of development of the strong ridge on the lower and 

 front part of the neck, that acts as a bracket in strengthening the curve. The neck 

 should be looked on as the upper part of the shaft (Fig. 116) incurved, with the 

 muscular trochanters applied to it, but not interfering with the lines of the walls of the 

 shaft : intersecting arcades of cancellous lamellae spring from these walls and support 

 the articular surface. 



The front of the neck is ridged in its long axis and shows numerous vascular foramina. 

 These occur owing to the fibrous bands with small accompanying vessels that lie under 

 the synovial membrane : the membrane- covers 

 the whole of this face of the bone, extending to 

 the anterior intertrochanteric line. The fibrous 

 bands run from the capsular attachment here 

 towards the head : they are termed retinacula, 

 and there are three main collections of these 

 fibres below and behind, below and in front, and 

 above, internal to the front part of the great 

 trochanter. The last-mentioned is a broad band 

 that extends in towards the head for some distance 

 beyond the epiphysial line of the trochanter, which 

 (Fig. 117) encroaches here considerably on the 

 upper aspect of the neck. 



The posterior aspect is usually smooth, because 

 there are here no true transverse fibres in the 

 capsule to gain an insertion on the bone : a few 

 marginal fibres of the circular group are the only 

 ones that have any insertion into the femur, 

 and the synovial membrane is reflected from the 

 bone to the deep surface of the circular zone 

 directly. The line of reflection (Fig. 117) is about 

 half-way up the neck, continued up from the 

 turned-up lower end of the anterior intertro- 

 chanteric line. 



The Obturator externus is closely applied to 

 the lower and back part of the neck, passing to 

 the digital fossa, and the pressure of this muscle 

 moulds the shape of the bone slightly : an indefinite 

 suggestion of an oblique line (Fig. 118) directed 

 outwards and upwards shows the upper limit of 

 the surface affected by this muscle. Below this 

 line the capsule is in relation with the Obturator 

 externus, and above it is covered by the Obturator internus and Gemelli, so that the 

 Quadratus femoris has no direct relation with the capsule at all. 



The existence of a long neck is a necessity in a bone which, like the femur, has a 

 head received in a deep articular cavity for purpose of security : if such freedom of 

 movement as the femur enjoys is to be obtained, the body of the bone must be carried 

 at some distance from the embedded head. Necks are more vertical in long femora. 



The Great Trochanter (Fig. 118). 



The great trochanter is a traction epiphysis formed at the attachment of the 

 gluteal muscles, and pulled as a sort of hood over the base of the neck. The descriptive 



FIG. 1 1 6. i, Diagram of femur at 

 birth ; cartilage is dotted. 

 Upper end shows cartilage to a 

 lower level behind, because the 

 small trochanter is continuous 

 here with great. Observe the 

 short neck. 2, A later condition, 

 in which the shaft (thick lines) 

 has grown in length, carrying the 

 head away from the trochanters 

 and so lengthening the neck. The 

 lower part of the head is formed 

 at first by this shaft, but this is 

 afterwards hidden by epiphysial 

 growth. Trochanters remain as 

 masses applied to the wall of the 

 shaft. 3, A scheme of a section 

 through the small trochanter, 

 showing it applied to the shaft ; 

 the part of the wall which carries 

 it is thick and forms the calcar 

 femorale (see Fig. 125). 



