466 THE INFERIOR EXTREMITY 



brittle. After this age, therefore, subcutaneous fracture or 

 cuneiform osteotomy (p. 438) is necessary to overcome the 

 deformity. 



Injuries in the Region of the Knee. Supra-condylar 

 Fracture of the Femur (p. 440) is sometimes converted into a 

 T-shaped fracture involving the knee-joint, by a vertical splitting 

 of the distal fragment through the intercondylar fossa. The 

 nature of the injury may be determined by the widening of the 

 distal extremity of the femur and the independent movements 

 of each condyle, and of the femoral shaft. There is usually 

 considerable effusion into the joint, and this, together with the 

 swelling of the surrounding parts, may mask the condition to 

 some extent. Manipulations to restore the correct alignment 

 are carried out with the knee flexed in order to relax the 

 gastrocnemius, and for the same reason the limb is then placed 

 on a double-inclined plane. 



Separation of the Distal Epiphysis of the Femur usually 

 occurs between the ages of ten and fourteen, and is due to violent 

 hyperextension of the knee. This movement throws a severe 

 strain on the posterior part of the capsule, which is of great 

 strength and consequently does not give way. The strain is 

 therefore transmitted to the femoral epiphysis and a diastasis 

 occurs. The causative force is usually applied to the leg from 

 behind, and on this account the epiphysis is usually displaced 

 forwards, overriding the distal extremity of the diaphysis. 



Though this injury is by no means common, it is of great 

 importance, because it is usually complicated by injury of the 

 popliteal vessels. The laceration is frequently so extensive 

 that amputation may ultimately be necessary owing to the 

 occurrence of gangrene. 



Reduction is obtained by traction on the leg and downward 

 pressure on the displaced epiphysis, the knee being flexed, and 

 the limb is then slowly extended. If, despite these manipulations, 

 the deformity recurs, the limb must be put up with the leg 

 flexed. 



Fracture of Either Condyle alone may be caused by 

 violent movements of abduction or adduction. When the limb 

 is straightened there is little displacement, but a double-inclined 

 plane should be used in order to keep the gastrocnemius relaxed. 

 Less severe strains of a similar nature may result in avulsion 

 of the femoral attachment of a collateral ligament. 



Fracture of the Patella may be due either to direct or to 



