178 THE SKELETON 



THE FEMUR 



The femur or thigh bone (figs. 215, 216) is the largest and longest bone in the 

 skeleton, and transmits the entire weight of the trunk from the hip to the tibia. 

 In the erect posture it inclines from above downward and medially, approaching 

 at the lower extremity its fellow of the opposite side, but separated from it above 

 by the width of the true pelvis. It presents for examination a superior extremity, 

 including the head, neck, and two trochanters, an inferior extremity, expanded 

 laterally into two condyles, and a shaft. 



The upper extremity is surmounted by a smooth, globular portion called the 

 head, forming more than half a sphere, directed upward and medially for articu- 

 lation with the acetabulum. With the exception of a small rough depression, the 

 fovea, for the ligamentum teres, a little below and behind the centre of the head, 

 its surface is covered with cartilage in the recent state. The head is connected 

 with the shaft by the neck, a stout rectangular column of bone which forms with 

 the shaft, in the adult, an angle of about 125*. Its anterior surface is in the same 

 plane with the front aspect of the shaft, but is marked off from it by a ridge to 

 which the capsule of the hip-joint is attached. The ridge, which commences at 

 the great trochanter in a small prominence, or tubercle, extends obliquely down- 

 ward, and winding to the back of the femur, passes by the lesser trochanter and 

 becomes continuous with the medial lip of the linea aspera, on the posterior aspect 

 of the shaft. This ridge forms the intertrochanteric line or spiral line of the femur. 

 The intertrochanteric line receives the bands of the ilio-femoral thickening of the 

 capsule of the hip-joint. The posterior surface of the neck is smooth and concave 

 and its medial two-thirds is enclosed in the capsule of the hip-joint. The superior 

 border of the neck, perforated by large nutrient foramina, is short and thick, and 

 runs downward to the great trochanter. The inferior border, longer and narrower 

 than the superior, curves downward to terminate at the lesser trochanter. 



The trochanters are the prominences which afford attachment to the rotator 

 muscles of the thigh; they are two in number — great and lesser. 



The great trochanter is a thick, quadrilateral process surmounting the junction 

 of the neck with the shaft, and presents for examination two surfaces and four 

 borders. The lateral surface is broad, rough, and continuous with the lateral 

 surface of the shaft. It is marked by a diagonal ridge running from the postero- 

 superior to the antero-inferior angle, which receives the insertion of the gluteus 

 medius. The ridge divides the surface into two triangular areas: an upper, cov- 

 ered by the gluteus medius, and occasionally separated from it by a bursa, and a 

 lower, covered by a bursa to permit the free gliding of the tendon of the gluteus 

 maximus. Of the medial surface the lower and anterior portion is joined with 

 the rest of the bone; the upper and posterior portion is free, concave, and presents 

 a deep depression, the trochanteric or digital fossa, which receives the tendon of 

 the obturator externus. The fore part of the surface is marked by an impression 

 for the insertion of the obturator internus and two gemelli. 



Of the four borders, the superior, thick and free, presents near the centre an oval mark for 

 the insertion of the piriformis; the anterior border, broad and irregular, receives the ghitevs 

 minimus; the posterior border, thick and rounded, is continuous with the intertrochanteric 

 crest, the prominent ridge uniting the two trochanters behind. Above the middle of this line is 

 an elevation, termed the tubercle of the quadratus, for the attachment of the upper part of the 

 quadralus femoris. The inferior border corresponds with the line of junction of the base of 

 the trochanter with the shaft; it is marked by a prominent ridge for the origin of the upper part 

 of the vastus lateralis. 



The lesser trochanter is a conical eminence projecting medially from the poste- 

 rior and medial asf)ect of the bone, where the neck is continuous with the shaft. 

 Its summit is rough and gives attacliment to the tendon of the ilio-psoas. The 

 fibres of the iliaais extend beyond the trochanter and are inserted into the surface 

 of the shaft inmiediately below. 



The body or shaft of the femur is almost cylindrical, but is slightly flattened in 

 front and strengthened behind by a projecting longitudinal ridge, the linea aspera, 

 for the origin and insertion of muscles. The linea aspera extends along the middle 

 third of the shaft and j^resents a medial lip and a lateral lip separated ])y a narrow 

 interval. When followed into the upper third of the shaft, the three parts diverge. 

 The lateral lip becomes continuous with the gluteal tuberosity and ends at the 

 base of the great trochanter. The ridge affords insertion to the gluteus maximus, 



