ABNORMAL CONDITIONS OF THE KNEE-JOINT. 



55 



cartilage, and the convexity of the villous mem- 

 brane seems sunk into foveas formed in the 

 cartilage, so as to leave no doubt of the vital 

 mechanism, if we can so say, of the process, 

 which seems quite analogous to the absorption 

 of the sequestrum of a cylindrical bone, or the 

 exfoliating piece of a flat bone. The writer 

 presented to the Pathological Society of Dub- 

 lin a recent specimen and a drawing of the 

 knee-joint of a man aged seventy, William 

 Walsh, who died the day previously (13th Dec. 

 1839) in the House of Industry, of an attack of 

 acute arthritis genu which had supervened on a 

 chronic disease of the joint of long standing. 

 The synovial sac of the joint had been much 

 distended and was more capacious than usual. 

 It was greatly thickened, and presented on its 

 internal surface an intense scarlet colour. Ex- 

 tensive deposits of a yellowish green lymph 

 were noticed over the entire of the synovial 

 sac : the strong contrast in colour between the 

 green lymph and the red villous synovial mem- 

 brane is well seen in the preparation. The cru- 

 cial ligaments were partially removed, and it 

 was found on dissection that the internal and 

 external lateral ligaments had lost all their dis- 

 tinctness as fibrous bands ; both seemed to be 

 resolved and spread out into thin membranes 

 or fasciae, which but little restrained the move- 

 ments of the knee, and allowed of a motion of 

 rotation being communicated to the joint. The 

 articular and semilunar cartilages were removed, 

 and the denuded porous surfaces of the bones 

 of the tibia, femur, and patella presented nu- 

 merous small red spots, as if they had been 

 sprinkled with red sand. An abscess contain- 

 ing about two ounces of yellowish green pus, 

 of a laudable consistence, was found under the 

 crurceus muscle, just above the synovial sac of 

 the joint: this abscess was isolated, and had no 

 communication whatever with the interior of 

 the sac of the joint. The fluid in the interior 

 of the articulation was more of a thin sanies 

 than pus, but was abundant in quantity, and 

 had made its way externally by a large sloughy- 

 looking opening in front of the leg, about two 

 inches below the knee. 



Michael Smith, 58 years of age, was admitted 

 into the Richmond Hospital in 1838, labouring 

 under erysipelas of the head. During the 

 course of the disease, one of his knee-joints 

 became hot and swollen, the patella seemed to 

 float, and on each side of it a fluctuation be- 

 came evident. He was more or less insensible 

 from the erysipelas of the head, but when the 

 knee-joint was moved, he exhibited signs of 

 suffering. On the eighth day after the knee- 

 joint was first affected, he died of the erysipelas 

 of the head. The knee-joint was carefully 

 inspected, fine red injection having been previ- 

 ously thrown into the femoral artery. The 

 synovial sac of the articulation was distended 

 by a turbid yellowish-green fluid, apparently 

 composed of a mixture of pus and synovia. 

 When this was washed away, the synovial 

 membrane was found not so much thickened as 

 in the former case, nor had it so much of the 

 vivid scarlet colour as the last specimen alluded 

 to ; and reminded those who examined it of the 



appearance which the conjunctiva presents in 

 subacute conjunctivitis. This membrane ap- 

 peared to be thickened and pulpy where it had 

 already advanced somewhat over the external 

 condyle of the femur. The subsynovial tissues 

 were more or less infiltrated. The cartilages 

 had lost their normal whiteness and brilliancy, 

 and were of a murky yellowish hue ; they were 

 somewhat softened in their substance, and the 

 cartilaginous covering of the patella was slightly 

 elevated, in patches, and one spot of ulceration 

 was seen at the circumference of its external 

 edge. The cartilage covering this bone was so 

 soft that the blunt probe easily penetrated into 

 its structure. Many would call this a case of 

 simple synovitis genu, but it is manifest that, 

 although the acute disease in the knee originated 

 in the synovial membrane, the other structures 

 of the joint very soon became implicated, and 

 that, at the period of the patient's death, which 

 was only a few days after the first attack of the 

 joint, the term of synovitis of the knee-joint 

 was not sufficiently comprehensive. We have 

 had many opportunities of examining the knee- 

 joints of those who have died of diffuse inflam- 

 mation, which has occurred in females some 

 short time after parturition, and in those cases 

 denominated puerperal rheumatism, and in 

 cases where the arthritis of the knee or other 

 joints was concurrent with phlebitis ; and in 

 such cases we have found the most remarkable 

 phenomena to be, great effusion into the knee- 

 joint of a fluid which would seem to be com- 

 posed of equal parts of pus and synovial fluid. 

 This was viscid, of a sea-green colour, and of 

 the consistence of honey. In cutting down to 

 the joint in these cases we frequently met with 

 ill-digested matter in and amongst the muscles 

 surrounding the affected articulation. The 

 synovial membrane was of a pink colour. The 

 articular cartilages presented an appearance 

 which was rather peculiar. We have found 

 them generally to preserve their normal adhesion 

 to bone, to be smooth on their surface, but to 

 be evidently thinned, and so reduced as to 

 form a stratum covering the condyles of the 

 femur scarcely half a line in thickness. The 

 inter-articular cartilages externally preserve their 

 normal appearance, but we can occasionally 

 discover that after an attack of acute arthritis of 

 the description now under consideration, these 

 structures shew that they are permeated inter- 

 nally by capillary vessels containing red blood. 

 We have had many, too many examples lately 

 verifying the above description of the anatomical 

 appearances presented on the examination of 

 the knee-joints of those who have died of dif- 

 fuse inflammation. 



Simple chronic arthritis of the knee. The 

 symptoms which denote the existence of simple 

 chronic inflammation of the knee-joint are very 

 similar to those belonging to the acute affection 

 of this articulation, being only slower in the 

 different stages of their developement and 

 milder in their character. 



The simple chronic arthritis genu commences 

 with a pain which the patient usually refers to 

 the inner side of the joint. Tin's pain is not 

 sufficient to prevent him from following his 



