BONE, PATHOLOGICAL CONDITIONS OF. 



4.53 



that her sufferings were not of long duration, 

 and an opportunity was speedily afforded for 

 examining the pathological condition of the 

 back. It appeared that three of the vertebrae 

 had been engaged, the spongy portion of one 

 of which had been completely removed. There 

 was nothing like a reproduction of osseous 

 material, although the caries had long ceased, 

 and the spine was sufficiently strong for every 

 ordinary purpose of support ; but the space 

 that had been left by the absorption of the 

 bone was filled up by a ligamento-cartilaginous 

 substance, which, attached like a new and 

 adventitious ligament to the vertebrae above 

 and below, held them with a sufficient tight- 

 ness to prevent the smallest motion, and gave 

 to the entire column a tolerable degree of firm- 

 ness. We have also seen examples of true 

 bony anchylosis in patients apparently scrofu- 

 lous, but it seems to occur generally in males 

 rather than in females, and more particularly 

 in patients about or approaching to the age of 

 puberty, a period at which it is generally sup- 

 posed some important change takes place in 

 the constitution of scrofulous subjects. Where 

 there is no such taint, or where, as Sir B. 

 Brodie expresses it, the bones retain their na- 

 tural texture and hardness, it may be easily 

 conceived that a cure is effected in less time 

 and with less difficulty. 



There is another specimen of caries or ulce- 

 ration of bone without the formation of matter, 

 occasionally observed in the neck of the thigh- 

 bone of very old persons, the symptoms of 

 which have particular relation to the hip-joint; 

 we shall therefore postpone our remarks on it 

 until we come to discuss the pathology of 

 joints. 



Necrosis. There are few subjects more in- 

 teresting either to the pathological inquirer or 

 to the practical surgeon than the death of a 

 portion of the osseous system, and the circum- 

 stances connected with this event. Neither is 

 there any one with respect to which the ideas 

 of medical men generally are less definitively 

 settled. Thus also some confusion has crept 

 into our nomenclature, and necrosis and ex- 

 J'oliation have been often indifferently used, as 

 if they applied to one and the same diseased 

 action ; or, perhaps, to speak more correctly, 

 the term necrosis has been made to extend to 

 every case in which a bone or a portion of a 

 bone is deprived of vitality, no matter how 

 the dead material is to be removed or replaced. 

 According to the etymology of the term such 

 is in fact its true meaning ; nevertheless, we 

 are hardy enough to dissent from this applica- 

 tion of the word, and to confine its use to one 

 form of the death of a bone, exfoliation more 

 properly belonging to another. And we do so 

 the more readily because not only do these two 

 affections present different pathological pheno- 

 mena, but there are such practical discrepancies 

 between them that it is essential to every sur- 

 geon to have a distinct and separate notion of 

 each . 



Exfoliation, then, expresses the death of a 

 portion of bone which is either never replaced, 

 or replaced by a process which is set up after 



its death, and is analogous to mortification in 

 the soft parts, where the slough is thrown off, 

 and the consequent ulcer subsequently heals by 

 granulation and cicatrization. 



Necrosis is the death of a bone or part of a 

 bone accompanied by a process of regeneration 

 established at a time coeval or nearly coeval 

 with the inflammation or accident that deprives 

 it of vitality. In this point of view the disease 

 is singular, there being nothing like or ana- 

 logous to it in any affection of the soft parts. 



Necrosis is rarely a disease of early and 

 never of advanced life, being, except in cases 

 where it attacks the lower jaw, almost exclu- 

 sively confined to the period between the ages 

 of ten and twenty-two : exfoliation may occur 

 at any time, but is more likely to appear in the 

 adult or the aged. 



Necrosis, although it may succeed to acci- 

 dent, as in this manner compound fractures and 

 other injuries are not infrequently repaired, yet 

 is it more generally an idiopathic disease, or 

 may be the sequela of continued fever; whilst 

 exfoliation in the great majority of instances is 

 the consequence of injury. 



According to the acceptation in which we 

 employ the term, it is extremely questionable 

 whether necrosis is ever a disease of the flat 

 bones; at least, except in the instance of the 

 lower jaw, we have never met with an example 

 of the death of one of these structures accom- 

 panied or even followed by a regenerative pro- 

 cess. 



As necrosis, then, presents a solitary exam- 

 ple of the efforts of nature in counteracting, or 

 rather in providing against the rava-es of dis- 

 ease, the process by which it is accomplished 

 becomes an exceedingly interesting subject of 

 inquiry. Different opinions are entertained 

 upon this subject. It seems to be agreed 

 upon all sides that the commencement of the 

 disease is marked by inflammation of the bone: 

 at this period it is red, vascular, and receives 

 the tinge of coloured injections. How this in- 

 flammation may be caused or why it is followed 

 by the formation of new bone, are points not so 

 easily determined. Troja introduced a sharp 

 instrument through a bone, by which he con- 

 trived to destroy the internal periosteum and 

 marrow, and thus produced a number of cases 

 of necrosis, which presented the same sym- 

 ptoms and ran the same course as if they had 

 been examples of idiopathic disease. Hence it 

 came to be believed that the death of the inter- 

 nal periosteum was a necessary prelude to 

 necrosis, until it was observed that the parts 

 surrounding a bone had assumed those actions 

 which end in the formation of a new one before 

 the absolute destruction of any part of the old 

 one whatsoever ; and therefore that, although 

 the injury inflicted on the internal periosteum 

 might cause necrosis, yet it was only one cause, 

 and acted by creating inflammation within the 

 substance of the bone. Thus we are obliged to 

 return to the point from which we set out : we 

 know that inflammation is established within 

 the bone, and, coeval with this or nearly so, 

 that nature commences the process of repro- 

 duction; but why this latter is confined to a 



