INFLAMMATION. 389 



tissue. The newly formed trabeculae of bone are in every respect 

 identical to those observed after plastic periostitis, and in this sit- 

 uation termed "exostoses" and " osteophytes." (See Fig. 164.) 



The connection between the old and the new bone is estab- 

 lished at the fractured surfaces by direct inosculation. At the 

 surface of the compact bone, however, bay-like excavations are 

 often wanting, and the newly formed bone may be attached to 

 the old bone without the latter exhibiting any marked inflamma- 

 tory changes. This occurrence has misled some authors into 

 the belief that the newly formed bone is simply in apposition to 

 the compact structure of the old bone, without being directly 

 connected with it. Such views must be the result of the study 

 of dry specimens, for in all other preparations there is no diffi- 

 culty in ascertaining a direct union of the newly formed bone- 

 corpuscles with the old ones by means of anastomosing offshoots. 



The originally irregular and bulky new formation of bone, 

 gradually viz. : after several months is transformed into a 

 more regular osseous structure. This can be explained by the 

 supposition of repeated dissolution and new formation of bone- 

 tissue only. After the lapse of several years the bony cicatrix 

 becomes so perfect, and even supplied with a central marrow- 

 space, in continuity with the old one, that, were it not for the 

 deviation of the fractured ends, no trace of the former accident 

 could be discovered. 



My researches may be summed up in the following state- 

 ments : 



(1) The injury done to the bone and the adjacent soft tissues 

 by the fracture leads to an inflammation, which is most intense 

 in the most vascularized tissue viz., in the periosteum j 



(2) The inflammatory new formation results in the produc- 

 tion of a medullary or inflammatory tissue, from which arises 

 cartilage tissue, representing the formation termed a provisional 

 callus " ; 



(3) The cartilage tissue at certain regular intervals, which 

 depend upon the new formation of blood-vessels, is broken down 

 into- a freely vascularized medullary tissue ; 



(4) The medullary tissue, which has sprung from the former 

 cartilage, produces bone, first in the form of irregular trabeculae, 

 constituting the formation termed " definitive callus ; 



(5) The formation of the definitive callus is in all essentials 

 like the formation of bone in the process of normal ossification 

 from cartilage and periosteum. 



