ABNORMAL CONDITIONS OF THE KNEE-JOINT. 



61 



Patients under an incipient attack of white 

 swelling first experience inconvenience in walk- 

 ing from weakness of the joint, a symptom 

 which is more especially troublesome after 

 exercise. But as soon as the pain becomes 

 constant, the patient is no longer able to rest 

 the weight of his body upon the affected limb 

 without a great increase of uneasiness. On 

 this account he is willing to save the limb as 

 much as possible ; he touches the ground, 

 therefore, merely with his toes, trusting the 

 support of his body chiefly to the other limb. 

 In walking in this way the knee necessarily 

 becomes bent, and what is thus begun becomes 

 permanent from other causes ; so that after a 

 certain period the joint continues permanently 

 in a state of flexion. 



Although we occasionally see cases in which 

 the leg remains extended on the thigh, they 

 must be considered rare, for in general the leg 

 is in a more or less forced state of flexion on 

 the thigh, and such is the patient's apprehen- 

 sion of pain he will not on any account extend 

 the leg voluntarily, nor allow it to be extended 

 by others. 



The earlier period of the disease is succeeded 

 by a second stage,* in which the patient usually 

 submits to the adoption of active and energetic 

 treatment. The pain now not unfrequently 

 diminishes, but the swelling continues in- 

 creasing, the ham becomes fully occupied by 

 it, the extremities of the bones appear to 

 enlarge, and become more prominent as the 

 flexion increases. Attacks of inflammation 

 ensue, accompanied by pain starting up and 

 down the limb, by which sleep is interrupted. 

 These attacks are usually succeeded by effusion 

 of fluid into the synovial sac of the joint and 

 cellular interstices around : abscesses form, and 

 some fluctuation may now be discovered in 

 different parts of the swelling. If at this 

 period, which may be called the third or sup- 

 purative stage of the disease, the bones be 

 moved laterally, it will be perceived that the 

 ligaments permit an unnatural degree of motion 

 between them, and now, as in other articula- 

 tions, partial or complete luxation may occur. 

 Such, however, is the breadth of the surfaces of 

 contact of the bones of the knee-joint, that 

 complete luxation seldom happens. The limb 

 at this period is usually found lying powerless 

 on its outer side and in the semiflexed position ; 

 and after some time a partial displacement of 

 the leg outwards on the femur occurs : under 

 other circumstances a partial or complete luxa- 

 tion backwards happens. Although the disease, 

 arrived at this stage, seldom terminates favour- 

 ably, still instances do occur of unexpected 

 improvement of the general health, of the 

 resolution of the swelling, of the absorption of 

 matter, and of one of the forms of anchylosis 

 taking place. But usually the matter formed 

 in and around the joint goes on accumulating, 



* Mr. Lloyd divides scrofulous white swellings 

 into three stages ; the first being that in which the 

 affection is confined to the bone ; the second that 

 in which the external parts become thickened and 

 swelled ; and the third what he denominates the 

 sub-acute stage. Lloyd on scrofula. 



the tension of the knee-joint increases, and 

 now in most cases an accompanying oedema of 

 the foot is observed, a symptom than which 

 there can be none more unfavourable. The 

 nocturnal starlings of the limb, disturbing the 

 patient's rest, become more painful and urgent, 

 and abscesses communicating with the interior 

 of the articulation open externally by one or 

 more orifices, and give exit to a quantity of 

 matter, which rarely has the quality of laud- 

 able pus; on the contrary, it is for the most 

 part a sero-purulent liquid, of a yellowish 

 green colour, like whey, in which curdy mat- 

 ters are found floating. It is remarkable that 

 little diminution in the size of the swelling 

 follows the escape of this matter. 



We have stated that the pus is seldom lau- 

 dable. On some few occasions, however, its 

 consistence may be that of good pus ; but even 

 then it soon degenerates into a thin foetid sa- 

 nies of bad quality. The openings giving exit 

 to the discharge sometimes close very speedily, 

 and new collections form in different parts of 

 the tumour. This, however, is unfortunately 

 rare, for generally the openings degenerate into 

 fistulae. A probe introduced into one of these 

 penetrates, if the route be not long and cir- 

 cuitous, into the interior of the joint, and dis- 

 covers the internal parts to be carious and dis- 

 organised ; and if the bones of the articulation 

 be now pressed together, a crepitation, arising 

 from the friction of the carious and ulcerated 

 surfaces, is perceived, furnishing unequivocal 

 evidence of the last stage of disorganization of 

 all the structures of the articulation. This is 

 the most common course of the disease, but in 

 some cases there are varieties to be observed. 

 For example, the suppuration of the soft parts 

 and of the cartilages, and even caries of the 

 bones, may occasionally precede the displace- 

 ment of the bones ; and all the parts of the 

 articulation may be destroyed without the oc- 

 currence of any displacement; but if, in this 

 case, we move the bones of the articulation in 

 opposite directions, we easily ascertain the re- 

 laxation of the uniting ligaments, and that 

 many of the conditions necessary to the dis- 

 placement exist, although, from some cause not 

 easily explained, it has not occurred. 



As to our prognosis we should remember 

 that the age and constitution of the patient 

 have considerable influence on the ulterior pro- 

 gress of the disease, and our knowledge of this 

 must control our anticipations as to the result 

 to be expected, cateris paribus. The disease 

 in the truly strumous subject is very rebellious, 

 and has a disposition to terminate in suppu- 

 ration which it is difficult to baffle. In young- 

 subjects it is in general more acute, or the suc- 

 cession of the different orders of symptoms is 

 more rapid ; but in young persons there is 

 much more hope of cure than in the old and 

 exhausted. We agree with Mr. Russell in 

 opinion that it is in the cases of infants that 

 the formation of anchylosis may be expected as 

 the termination of a case of white swelling, 

 though even with these true bony anchylosis 

 must be considered as a very rare occurrence. 



In the beginning the disease has but little 



