CARTILAGE. 



499 



Pathological conditions. Cartilages are not 

 subject to many diseases. Inflammation, ulce- 

 ration, and ossification are almost the only ones 

 to which they are liable ; and of these the first 

 is very indistinctly marked ; the last scarcely 

 deserves to be called disease. Cartilages are 

 supposed to owe this exemption from morbid 

 actions to their extremely low degree of vitality. 

 Destitute of red vessels, and supplied with no 

 more nervous influence than is barely sufficient 

 to constitute them a part of the living system, 

 they escape those changes to which highly 

 organized parts are exposed ; and, were it 

 not for their connexion with more delicate 

 and excitable tissues, their exemption would 

 be still more complete. Some eminent pa- 

 thologists have gone so far as to consider 

 them incapable of any morbid action; espe- 

 cially the diarthrodial cartilages. " Les carti- 

 lages diarthrodiaux ne jouissent point de la 

 vie," says Cruveilhier, who asserts that he 

 could not excite disease in them by any of his 

 experiments; and that he saw them perfectly 

 sound in the midst of every other diseased 

 structure. Mr. Key* also seems to allow them 

 very little vitality in health, and to consider 

 them very nearly passive in what are called 

 their diseases. 



Inflammation is rarely to be met with. Its 

 characters are so slightly marked in diarthro- 

 dial cartilage, that we infer its existence, not so 

 much from the signs which are present, as from 

 observing that ulceration is a common occur- 

 rence a state which we suppose to have been 

 preceded by inflammation. The only marks of 

 inflammation to be seen, even when most de- 

 veloped, are a softening of the cartilage, and in 

 two instances detailed by Sir B. Brodie, vessels 

 injected with red blood could be traced extend- 

 ing from the bones into the cartilages covering 

 them. Severe pain accompanies this disease; 

 but, as in all the cases on record, ulceration, or 

 some other disease was also present, it cannot 

 be determined how much of the pain belonged 

 exclusively to it. The costal cartilages are 

 subject to painful affections which usually 

 occur in patients who have had syphilis, or to 

 whom mercury has been administered inju- 

 diciously. These depend on inflammation of 

 the perichondrium. They may terminate in 

 ulceration or in osseous deposition, and have a 

 close resemblance to periostitis. 



Ulceration of cartilage is a very common 

 occurrence in joints, but is extremely rare in 

 other situations. It may be met with at any 

 period of life, or in any articulation, but it is in 

 the hip and knee we mo;t frequently find it, 

 and in persons who have passed the age of 

 puberty and are under thirty or thirty-five. 

 A striking peculiarity attends this affection, 

 namely, that the formation of pus is by no 

 means a constant accompaniment. The form 

 and situations of ulcers in diarthrodial cartilages 

 are very various. Sometimes they are small and 

 deep ; sometimes very superficial, like an abra- 

 sion at one time attacking the free, at another 

 the attached surface; and may commence in 



* Medico-Chimrgical Transactions., vol. xviii. 



the centre or at the circumference. These ulcers 

 may be divided into primary and secondary, the 

 former arising independently of any disease in 

 the adjoining tissues, the latter being preceded 

 by a morbid state of the bone or synovial 

 membrane. 



The primary ulcer commences towards the 

 centre of the cartilage, and always on its free 

 surface. It is accompanied with much pain, 

 but when exposed to view exhibits no sign of 

 inflammation. There is no vascularity To be 

 observed, no granulations, frequently no pus, 

 rior any unhealthy appearance of the synovial 

 membrane. Should the ulcer, however, have 

 extended itself quite through the cartilage to 

 the bone, the latter usually becomes carious, 

 pus is secreted abundantly, and the synovial 

 membrane sympathizes. The surface of the 

 ulcer differs very much in different cases ; in 

 some it appears smooth, and of the colour of 

 healthy cartilage, as if a portion were chiselled 

 out. In others, and more generally, it is a little 

 yellowish, dull looking, and slightly irregular. 

 The edges are often irregular, never elevated 

 nor undermined. The ulceration sometimes 

 spreads superficially over a large extent; at 

 other times it is small and deep, or it may 

 destroy all the cartilage and expose the bone, 

 which will also be found diseased. Most 

 generally the remaining cartilage, if any, retains 

 its healthy structure to the very edge of the ab- 

 sorbed portion. 



Another appearance is often observed; a part 

 of the cartilage is reduced to a fibrous state, the 

 fibres being attached at one extremity to the 

 bone, while at the other they are free, and have 

 no lateral connexion. This condition of carti- 

 lage is said, by Sir B. Brodie, to be frequently, 

 but not constantly, the first stage of ulceration ; 

 and he conceives it may often exist where no 

 ulceration is ever to follow. Mr. Key looks on 

 it as " a disease of a peculiar character." And 

 we have frequently found it in the dissecting 

 room, where there was not the slightest mark 

 externally or internally of any other morbid 

 action. The write/ has observed it oftener on the 

 patella than elsewhere ; and as this is so seldom 

 the part first involved in the ulcerative process, 

 it probably depends on an action of a different 

 nature. The writer has also seen it oftener in 

 joints long dead than in the more recent, and has 

 therefore thought it might possibly be caused, 

 in some cases at least, by the action of the 

 synovial fluid, or by decomposition. 



Secondary ulceration may commence in the 

 bone or in the synovial membrane, (a) When 

 the bone is previously diseased, that side of the 

 cartilage which was turned to it is first affected. 

 The adhesion of the two tissues is diminished ; 

 we find it more easy to separate them. After 

 some time a separation actually takes place, and 

 a vascular net-work, sometimes a layer of granu- 

 lations, occupies the interval. The surround- 

 ing cartilage is softened. The ulcer, with cha- 

 racters differing little from the primary form, 

 goes on more or less rapidly, until an opening 

 is made quite through into the cavity of the 

 joint. When this opening is effected, the mat- 

 ter, which in this form of ulcer is always pre- 



