250 THE SKELETON 



Fractiures. — When too great pressure is applied to a bone it 

 can bend no farther, and the result is a break. Such a break 

 tears the periosteum and injures the surrounding tissue cells, 

 nerves and blood vessels. The result is a painful and serious 

 injury. Such a break is called a fracture. The surgeon remedies 

 such fractures by placing the two ends of the bones together and 

 binding them firmly in place with splints or a plaster cast. When 

 kept in this position for a sufficient length of time, the bone cells 

 produce new bone material and the two ends are soon as firmly 

 united as before the break. In young people this union takes 

 place very quickly, as their bone cells are in a naturally active 

 condition. In older persons this power of growth has become 

 weakened, and a long time is required for the knitting together 

 of the ends. Owing to the large proportion of lime in the bones 

 of old people, their bones are much more brittle than those of 

 children and much more easily fractured. 



If a bone is broken in two without splintering, it is called a 

 simple fracture. When the break is not a clean break but splin- 

 ters are formed, it is called a splintered fracture. If the broken 

 end of the bone or bones work their way out through the flesh 

 and are exposed, the fracture is called a compound fracture. 



Sprains. — When joints are bent more than is natural the 

 ligaments and surrounding muscles are stretched and torn. The 

 result is the production of inflammation with swelling and pain. 

 Such an injury is called a sprain. The remedy requires the reduc- 

 tion of the swelling and inflammation, and hot or cold applica- 

 tions will usually produce the desired result. 



Dislocations. — ■ When the bending of a joint is so great as to 

 force the ends of the bones apart, the result is called a dislocation. 

 Accompanying such dislocations is the tearing and stretching of 

 ligaments and muscles and all the results of a sprain. The first 

 step in the repair of such an injury is to replace the dislocated 

 bones in their original position. This may often be done by 

 simply pulling on the bone until it settles back into its place. 

 This result is usually indicated by a snap as the ends come to- 

 gether. After the dislocation is repaired the swelling and inflam- 

 mation may be reduced by methods similar to those employed in 

 treatment of sprains. 



