35C 



SURGICAL ANATOMY. 



care is requisite in keeping the pointed extremity of the upper fragment in proper apposition ; 

 otherwise, after union of the fracture, extension of the limb is partially destroyed from the Kec- 

 tus muscle being held down by the fractured end of the bone, and from the patella, when elevated, 

 being drawn upwards against it. 



Fig. 201. Fracture of the Femur above the Condyles. 



Fig. 202. Fracture of the Patella. 



Fig. 203. Oblique Fracture of the Shaft 

 of the Tibia. 



Fracture of the patella (fig. 202) may be produced by muscular action, or by direct violence. 

 When produced by muscular action, it occurs thus : a person in danger of falling forwards, 

 attempts to recover himself by throwing the body backwards, and the violent action of the 



Quadriceps extensor upon the patella snaps 

 that bone transversely across. The upper frag- 

 ment is drawn up the thigh by the Quadriceps 

 extensor, the lower fragment being retained in 

 its position by the ligamentum patella? ; the 

 extent of separation of the two fragments de- 

 pending upon the degree of laceration of the 

 ligamentous structures around the bone. The 

 patient is totally unable to straighten the 

 limb, the prominence of the patella is lost, 

 and a marked but varying interval can be felt 

 between the fragments. The treatment consists 

 in relaxing the opposing muscles, which maybe 

 effected by raising the trunk, and slightly elevat- 

 ing the limb, which should be kept in a straight 

 position. Union is usually ligamentous. In 

 fracture from direct violence, the bone is gene- 

 rally comminuted, or fractured obliquely or per- 

 pendicularly. 



Oblique fracture of the shaft of the tibia 

 (fig. 203) usually occurs at the lower fourth of 

 the bone, this being the narrowest and weakest 

 part, and is usually accompanied with fracture 

 of the fibula. If the fracture has taken place 

 obliquely from above, downwards and forwards. 

 the fragments ride over one another, the lower 

 fragment being drawn backwards and upwards 

 by the powerful action of the muscles of the calf; 

 the pointed extremity of the upper fragment 

 projects forwards immediately beneath the in- 

 tegument, often protruding through it, and ren- 

 dering the fracture a compound one. If the 

 direction of the fracture is the reverse of that 

 shown in the figure, the pointed extremity of the 

 lower fragment projects forwards, riding upon 

 the lower end of the upper one. By bending the 

 knee, which relaxes the opposing muscles, and 



