422 SURGICAL APPLJED ANATOMY. [Chap. xx. 



greatly upon the obliquity of the fracture. As a rule 

 the lower fragment is drawn up behind the upper 

 one by the hamstrings, aided by the rectus, gra- 

 cilis, sartorius, tensor vaginae, and adductors, and is 

 carried a little to its inner side under the influence 

 of the last-named muscles. The lower end of the 

 upper fragment usually projects forwards and a little 

 outwards. This is produced by the agency of the 

 lower fragment, which tilts the upper piece of bone in 

 the direction named. In the fracture of the upper 

 third of the shaft the projection forwards of the upper 

 fragment is aided by the ilio-psoas muscle. Thus the 

 deformity produced in fractures of the femoral shaft 

 is usually angular in character. The e version of the 

 foot noted in fractures of the femur is due to the 

 weight of the limb, which causes the helpless member 

 to roll out, aided probably by the action of the 

 external rotator muscles. 



Certain spiral fractures (helicoidal fractures of 

 Leriche) may be produced in the lower part of the 

 shaft as the result of torsion. M. Fere finds by 

 experiment that if the limb be carried forwards in 

 front of the opposite knee, and the foot rotated 

 outwards, a spiral fracture can be produced at the 

 junction of the lower and middle thirds of the femur. 

 A like fracture at the same level, but with the 

 direction of the spiral reversed, can be produced by 

 carrying the limb outwards and then rotating it 

 inwards. 



Shortening of the limb after fracture. 

 It is doubtful if a fracture of the shaft of the femur 

 can, after any treatment, become united without some 

 shortening resulting, except in a few exceptional cases. 

 It is important, in connection with this subject, to 

 remember that the lower limbs may be normally of 

 unequal length. Dr. Wight, of Brooklyn, has fully 

 investigated this matter, and has arrived at the 



