THE FEMUR, OR THIGH BONE 229 



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 bv 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 ischinm. This is known as Nelaton's line. 

 The outer and inner condyles of the lower extremity may easily 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. Occa- 

 sionally, exostoses develop in the tendon of insertion of the Adductor magnus; these are the 

 " rider's bones " of cavalry soldiers and horsemen. When the knee is flexed, and the patella 

 situated in the interval between the condyles and the upper end of the tibia, a part of the 

 trochlear surface of the femur can be made out above the patella. 



Applied Anatomy. There are one or two points about the ossification of the femur bear- 

 ing on practice to which allusion must be made. It has been stated above that the lower end 

 of the femur is the only epiphysis in which ossification has commenced at the rime of birth. 

 The presence of the ossific centre in npwly bnrn nhilHrpn fnnnrl rJpad i\ tViorpfru-^ Q prr.f that 

 the child has arrived at the full period of uterogestation. and is always relied upon in rnedicn- 

 leora.1 investigations. The position of the epiphyseal line should be carefully noted. It is on a 

 level with the adductor tubercle, and the epiphysis does not, therefore, form the whole of the 

 cartilage-clad portion of the lower end of the bone. It is essential to bear this point in mind 

 in performing excision of the knee, since growth in length of the femur takes place chiefly from 

 the lower epiphysis, and any interference with the epiphyseal cartilage in a young child would 

 involve such ultimate shortening of the limb, from want of growth, as to render it almost useless. 

 Separation of the lower epiphysis may take place up to the age of twenty, at which time it be- 

 comes completely joined to the shaft of the bone; but, as a matter of fact, few -cases occur after 

 the age of sixteen or seventeen. The epiphysis of the head of the femur is of interest princi- 

 pally on account of its being the seat of origin of a large number of cases of tuberculous disease 

 of the hip-joint. The disease commences in the majority of cases in the highly vascular and 

 growing tissue in the neighborhood of the epiphysis, and from here extends into the joint. In 

 the condition known as coxa vara the head of the femur falls to a lower level than normal. The 

 angle between the neck and shaft is greatly diminished and may become a right angle or the 

 head may actually descend to a lower level than that of the trochanter. The neck is also bent 

 with a convexity forward; coxa vara is due to rhachitis. 



Fractures of the femur are divided, like those of the other long bones, into fractures of the 

 upper end, of the shaft, and of the lower end. The fractures of the upper end may be classi- 

 fied into (1) fracture of the neck; (2) fracture at the junction of the neck with the great trochanter; 

 (3) fracture of the great trochanter; and (4) separation of the epiphysis, either of the head or 

 the great trochanter. The first of these, fracture of the neck, is usually termed intracapsular 

 fracture, but this is scarcely a correct designation, as, owing to the attachment of the capsular 

 ligament, the fracture may be partly within and partly without the capsule, when the fracture 

 occurs at the lower part of the neck. It generally occurs in old people, principally women, and 

 usually from a very slight degree of indirect violence. Probably the main cause of the fracture 

 taking place in old people is in consequence of the degenerative changes which the bone has 

 undergone. Merkel believes that it is mainly due to the absorption of the calcar femorale. 

 These fractures are occasionally impacted. As a rule, they unite by fibrous tissue, and frequently 

 no union takes place, and the surfaces of the fracture become smooth and eburnated. The 

 lack of reparative power in intracapsular fracture is due to lack of apposition of the fragments and 

 diminution in the amount of blood sent to the smaller fragment. The head of the bone receives 

 blood from the neck through the reflected portions of the capsule and through the ligamentum 

 teres. A fracture cuts off the supply by the neck and by the reflected portions of the capsule. 



Fractures at the junction of the neck with the great trochanter are usually termed extracap- 

 xular, but this designation is also incorrect, as the fracture is partly within the capsule, owing 

 to its attachment in front to the anterior intertrochanteric line, which is situated below the line 

 of fracture. These fractures are produced by direct violence to the great trochanter, as from a 

 blow or fall laterally on the hip. From the manner in which the accident is caused, the neck of 

 the bone is driven into the trochanter, where it may remain impacted or the trochanter may 

 split up into two or more fragments, and thus no fixation takes place. 



Fractures of the great trochanter may be either "oblique fracture through the trochanter 

 major, without implicating the neck of the bone" (Astley Cooper), or separation of the great 

 trochanter. Most of the recorded cases of this latter injury occurred in young persons, and 

 were probably cases of separation of the epiphysis of the great trochanter. Separation of the 

 epiphysis of the head of the femur has been said to occur, but has probably never been verified 

 by postmortem examination. 



