THE FEMUR, OR THIGH-BONE. 183 



touch is the tuberosity of the ischium, situated beneath the gluteal fold, and, when the hip is 

 flexed, easily to be felt, as it is then to a great extent uncovered by muscle. Finally, the spine 

 of the os pubis can always be readily felt, and constitutes an important surgical guide, especially 

 in connection with the subject of hernia. It is nearly in the same horizontal line with the upper 

 edge of the great trochanter. In thin subjects it is very apparent, but in the obese it is obscured 

 by the pubic fat. It can, however, be detected by following up the tendon of origin of the 

 Adductor longus muscle. 



Surgical Anatomy. There is arrest of development in the bones of the pelvis in cases 

 of extroversion of the bladder ; the anterior part of the pelvic girdle being deficient, the bodies 

 of the pubic bones imperfectly developed, and the symphysis absent, The pubic bones are 

 separated to the extent of from two to four inches, the superior rami shortened and directed 

 forward, and the obturator foramen diminished in size, narrowed, and turned outward. The 

 iliac bones are straightened out more than normal. The sacrum is very peculiar. The lateral 

 curve, instead of being concave, is flattened out or even convex, with the ilio-sacral facets 

 turned more outward than normal, while the vertical curve is straightened. 1 



Fractures of the pelvis are divided into fractures of the false pelvis and of the true pelvis. 

 Fractures of the false pelvis vary in extent : a small portion of the crest may be broken or one 

 of the spinous processes may be torn off', and this may be the result of muscular action ; or the 

 bone may be extensively comminuted. This latter accident is the result of some crushing vio- 

 lence, and may be complicated with fracture of the true pelvis. These cases may be accom- 

 panied by injury to the intestine as it lies in the hollow of the bone, or to the iliac vessels as 

 they course along the margin of the true pelvis. Fractures of the true pelvis generally occur 

 through the ascending ramus of the os pubis and the ramus of the ischium, as this is the 

 weakest part of the bony ring, and maybe caused either by crushing violence applied in an 

 antero-posterior direction, when the fracture occurs from direct force, or by compression later- 

 ally, when the acetabula are pressed together, and the bone gives way in the same place from 

 indirect violence. Occasionally the fracture may be double, occurring on both sides of the body. 

 It is in these cases that injury to the contained viscera is liable to take place : the urethra, the 

 bladder, the rectum, the vagina in the female, the small intestines, and even the uterus, have 

 all been lacerated by a displaced fragment, Fractures of the acetabulum are occasionally met 

 with : either a portion of the rim may be broken off, or a fracture may take place through the 

 bottom of the cavity, and the head of the femur driven inward and project into the pelvic 

 cavity. Separation of the Y-shaped cartilage at the bottom of the acetabulum may also occur 

 in the young subject, separating the bone into its three anatomical portions. 



The sacrum is occasionally, but rarely, broken by direct violence i. e., blows, kicks, or 

 falls on the part. The lesion may be complicated with injury to the nerves of the sacral 

 plexus, leading to paralysis and loss of sensation in the lower extremity, or to incontinence 

 of faeces from paralysis of the sphincter ani. 



The pelvic bones often undergo important deformity in rickets, the effect of which in the 

 adult woman may interfere seriously with childbearing. The deformity is due mainly to the 

 weight of the spine and trunk, which presses on the sacro-vertebral angle and greatly increases 

 it, so that the antero-posterior diameter of the pelvis is diminished. But, in addition to this, 

 the weight of the viscera on the venter ilii causes them to expand and the tuberosities of the 

 ischia to be incurved. In osteomalacia also great deformity may occur. The weight of the 

 trunk causes an increase in the sacro-vertebral angle and a lessening of the antero-posterior 

 diameter of the inlet, and at the same time the pressure of the acetabula on the heads of the 

 thigh-bones causes these cavities, with the adjacent bone, to be pushed upward and backward, 

 so that the oblique diameters of the pelvis are also diminished, and the cavity of the pelvis 

 assumes a triradiate shape, with the symphysis pubis pushed forward. 



THE THIGH. 



The Thigh is that portion of the lower extremity which is situated between the 

 pelvis and the knee. It consists in the skeleton of a single bone, the femur. 



The Femur, or Thigh-Bone. 



The Femur (femur, the thigh) is the longest, 2 largest, and strongest bone in 

 the skeleton, and almost perfectly cylindrical in the greater part of its extent. In 

 the erect posture it is not vertical, being separated from its fellow above by a 

 considerable interval, which corresponds to the entire breadth of the pelvis, but 

 inclining gradually downward and inward, so as to approach its fellow toward 

 its lower part, for the purpose of bringing the knee-joint near the line of gravity 

 of the body. The degree of this inclination varies in different persons, and is 

 greater in the female than the male, on account of the greater breadth of the 

 pelvis. The femur, like other long bones, is divisible into a shaft and 

 extremities. 



1 Wood. Heath's Dictionary of Practical Surgery, i., 426. 



* In a man six feet high it measures eighteen inches one-fourth of the whole body. 



