ABNORMAL CONDITIONS OF THE KNEE-JOINT. 
cartilage, and the convexity of the villous mem- 
brane seems sunk into fovee 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 
os eed to the Pathological Society of Dub- 
in 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 
cute 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 
peeen 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 
_ tesolved and spread out into thin membranes 
_ or fasciz, 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 
_ crureeus 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 
| 
55 
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- 
osed of equal parts of pus and synovial fluid. 
his 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. -This pain is not. 
sufficient to prevent him from following his 
