266 Diseases of Bone. 



The sequestrum shows the usual characteristics. The new- 

 tibia is curved forward, and is thickened, especially on its 

 inner surface and behind. There is a well-marked medullary 

 cavity, partially occupied by cancellated tissue, and with 

 compact walls, which are thick and dense, especially about 

 the middle. The thick part is the seat also of the bend, and 

 this was doubtless the place from which the sequestrum came. 

 Probably the bone yielded by being used before it was solid. 

 The thickening may have followed afterwards from strain. 

 Compare the rickety tibia, K"o. 6. 38. G. C. 1143. 



Presented hy Professor James Russell. 



6. 157. Reparation of Tibia after Removal of a Seques- 

 trum. — Sequestrum and left tibia in section — macerated, illus- 

 trating the above. 



The specimen was obtained eighteen years after the removal of the 

 sequestrum. 



The sequestrum, which has consisted of the entire thickness 

 of the shaft, over the greater part of its extent shows the usual 

 characteristics. The new tibia is somewhat bent, but in addition 

 is very irregular. New bone has been thrown out on all 

 sides, but especially over the shin, where there is also a shelf- 

 like projection towards the outer side. The medullary canal 

 has been filled in, if a new one was ever formed. Ai each end 

 there is a cavity in the cancellous tissue, but these may have 

 been made in preparing the specimen. 



A large ulcer has probably remained after the sequestrum 

 was removed, and having become chronic, has produced 

 secondary changes upon the newly formed tibia. G. C. 1142. 

 Presented by Professor James Russell. 



B. Where the Organisms have reached the Bone through "Wounds 

 in the adjacent Soft Parts. 



a. Disease in bone secondary to ulcers. 



6, 158. Ulcer of the Leg" extending down to the Bone.— 



