DISEASES OP BONES 157 



, 3. ALnormal mobility, usually in all directions. By it is 

 Tinderstood an independent mobility of a part of a bone wliich. 

 normally is an unbroken structure. This is detected by 

 inspection and palpation. While as a rule quite readily ob- 

 served in complete fractures, it nevertheless is at times ap- 

 parently wanting, as in fracture of the vertebrae or in those 

 fractures where the fragments are driven into each other 

 {impaction fracture) and in incomplete fractures, 



4. Crepitation. By it is understood the peculiar grating 

 sensation heard or felt due to the rubbing together of the 

 "broken surfaces. This symptom is pathognomic of a fracture 

 Isest detected by palpation and passive movements of the ends 

 of the bone supposed to be fractured. It is wanting when the 

 iDroken fragments are very much displaced, in vertebral 

 fractures and incomplete fractures. 



5. Swelling. While quite often wanting in incomplete 

 fractures, it soon follows other fractures, consisting of a 

 swelling of the adjacent soft tissues, either due to the lacera- 

 tion of the tissues at the time the accident occurred, subse- 

 quent injury by the bony fragments, or septic inflammation. 

 Swelling often greatly handicaps the diagnosis of a fracture, 

 obscuring such symptoms as abnormal mobility and crepi- 

 tation. 



6. Injury of the skin may or may not be present, while in 

 older fractures abscess formation fistulous tracts are seen. 



7. Constitutional disturbance. Rise of temperature may 

 le due to the absorption of ferment-like materials coming 

 from the disintegration of the blood corpuscles at the point of 

 fracture, being an aseptic fever and slight. In complicated 

 fractures, as the result of the invasion of pus-producing 

 bacteria and the consequent absorption of the septic material, 

 a septic fever of variable intensity and seriousness results. 



