CHAPTER V 

 COMPLETION, REPAIR AND FUNCTIONS OF BONES 



NOTES CONCERNING THE COMPLETION OF LONG BONES 



In the humerus, radius, and ulna, the nutrient canals lead toward the elbow 

 and the bones are completed here at an earlier date than at the wrist or 

 shoulder. In the femur, tibia, and fibula, the nutrient canals lead away 

 from the knee; and the bones are completed first at the hip and the ankle. 



Surgical notes. The time of union of -the extremities and shafts of long 

 bones is important from a surgical viewpoint. Thus, in the ends of bones 

 at the elbow-joint the extremities join the shafts at about the seventeenth or 

 eighteenth year; therefore, injuries near the elbow-joint before this age may 

 cause a separation of the parts, called an epiphyseal fracture. The upper 

 end of the humerus and lower ends of the radius and ulna unite with their 

 shafts at about the twentieth year; therefore, in the case of an injury of the 

 shoulder or wrist before this age the same possibility is borne in mind. 



In the lower extremity certain differences are noted, since the nutrient 

 arteries run differently. The bones are completed first at the upper end of the 

 thigh, at about nineteen, and at the lower end of the leg at about eighteen or 

 twenty years, while the knee is completed last, at between twenty and 

 twenty-five. 



It is important for the nurse to understand something of the 

 nature of the baby's skeleton. The general condition at certain 

 periods of life is also of interest. 



BRIEF SURVEY OF THE SKELETON AT DIFFERENT AGES 



At birth: 



Head Skull-bones have unossified borders and angles, there- 

 fore, the membrane is soft at the fontanelles; the base 

 of the skull is largely in cartilage, and the bones are 

 slightly movable. 



Face-bones small and very incomplete. 



Spinal column Bodies of vertebrae partially ossified, with much carti- 

 lage between them. 

 Arches, each in two separate pieces or halves. 



Pelvic-girdle Hip-bones (ossa coxae) in three pieces, well separated 



by cartilage. 



Sacrum partially ossified. 

 Coccyx not at all ossified. 

 Ribs Shafts only are bony. 



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