1881.] Observations concerning Transplantation of Bone. 237 



in immediate contact with the bone, and which sends prolongations 

 into the Haversian canals. Now, if one attempts to elevate periosteum 

 from healthy bone, portions of the osteogenic layer are apt to be left 

 adhering to the osseous surface, the capabilities for bone formation of 

 the periosteal graft being thereby deteriorated or destroyed. 



The whole of the Osseous Elements ought to he included in Transplants 

 of Bone. — In taking the calcareous matter along with the periosteum, 

 the whole periosteal osteogenic layer is preserved, the calcareous matter 

 at the same time forming a support to and mould for the new bone. 

 Besides, the prolongations of periosteum contained in the Haversian 

 canals will proliferate if they have a free surface to expand into, and 

 therefore the soft parts inclosed in the calcareous matter are important 

 elements in the graft. The medulla is also under certain circumstances 

 capable of producing bone ; and, through its intermediary, the vascu- 

 larity of the graft might the more easily be effected. It was, there- 

 fore, determined that a graft should be composed of the whole of the 

 osseous elements, periosteum, calcareous matter, and medulla. 



Failure of Osseous Transplants due to want of Nutrition. — In trans- 

 planting bone the paucity of its vascular elements made the re- 

 establishment of its blood supply the first point to be considered. 

 Failure has attended attempts at grafting cylindrical portions of the 

 long bones, owing to the length of time necessary to establish the 

 blood supply through the periosteum to the more distant and dense 

 portions of bone. 



How to Maintain Nutrition after Transplantation. — In order to place 

 transplanted bone in the most favourable conditions for living, it ought 

 to be divided into small pieces, so that the blood effused from the 

 intermuscular space into which the bone would be implanted, may 

 permeate between the individual fragments, and thereby afford a 

 medium for the establishment of vascular connexions, and the supply 

 of nutriment to the individual pieces of bone. Though the transplant 

 consisted of dense osseous tissue, in its divided form it would some- 

 what resemble cancellated tissue. The re-establishment of the blood 

 supply to the grafts would thus be hastened and facilitated, and any 

 portion of the graft which was not suitable could be easily thrown off 

 without involving the whole. 



Other reasons for Dividing Bone into Small Pieces. — On other grounds 

 the division of the osseous transplant into small portions is advan- 

 tageous. Whether the leucocytes in the effused blood clot may or 

 may not be transformed into bony tissue, the blood clot itself when 

 small in quantity forms an excellent matrix for the proliferation of 

 the osteogenic elements. Again, the division of the bone into small 

 pieces not only makes the individual vitality more certain, but it also 

 supplies a greater number of proliferating osseous centres. In the 

 case of the calcareous tissue there is this further potent reason, 



