ABNORMAL CONDITIONS OF THE KNEE-JOINT. 
brane, instead of being white, is red and vil- 
lous, and much like mucous membrane in a 
high state of inflammation. We can frequently 
ascertain that this membrane has superadded 
to it layers of newly deposited lymph, which 
have become highly organized. Mr. Russell 
“says, that in his dissections of white swelling 
of the knee, he has found the inside of the 
synovial membrane covered with a layer of a soft 
_ substance, of a pale yellowish colour, and semi- 
transparent; that this substance was nearly 
one-eighth of an inch in thickness, softer in its 
‘inner concave surface, and firmer on the outer 
"convex part, where it adhered to the inside of 
the synovial capsule of the joint with a con- 
siderable degree of firmness. In many places 
observed on it avery beautiful plexus of 
_ vessels; and at the interstices between the sur- 
- face of the femur and tibia, he states that he 
generally found an appendage full of blood. 
vessels which had insinuated itself to the dis- 
tance of nearly half an inch. It very fre- 
quently happens that the cartilages and crucial 
ligaments are completely concealed from our 
view by a membrane, in some places of one- 
quarter or even one-half of an inch in thick- 
“hess, presenting a loose cellular structure, 
highly vascular, occupying the intervals be- 
tween the condyles, and hanging into the in- 
terior of the joint; and we have usually found 
this newly-formed structure to be superadded 
to the original synovial membrane, and to 
establish adhesions between the bones of the 
articulation, and we find bands of organized 
lymph stretching from the femur to the tibia. 
When this condition of the synovial membrane 
existed, we have usually found the cartilages 
remaining; but in other cases the synovial 
membrane itself has been found to be but little 
altered; and yet the cartilages have been re- 
‘moved partially or completely, the porous sub- 
Stance of the bone having been found exposed, 
; 4 covered by recent deposits of soft pultaceous 
lymph. 
Such are the organic changes which usu- 
ally produce white swellings. These changes 
present numerous varieties, but it is sufficient 
to notice the principal ones, and to observe 
‘that there are scarcely two patients in whom 
they are perfectly alike. 
__ Sir Benjamin Brodie, in his work on the 
joints, has remarked that when acute inflam- 
mation attacks the shaft of a cylindrical bone 
and the periosteum covering it, the disease is 
usually limited by the epiphysis, so that, not- 
withstanding the extensive abscesses and exfo- 
Tiations which frequently ensue, the neighbour- 
ing joints are not affected by it. Although we 
have seen numerous specimens proving the ge- 
neral truth of this observation, yet on the other 
hand we have witnessed exceptions to it: in- 
deed Sir Benjamin Brodie has further observed 
‘that a few instances occur in which acute in- 
flammation attacks the epiphysis itself, termi- 
nating also in exfoliations, &c. more or less ex- 
tensive. 
In very young subjects we occasionally see 
examples of diffuse inflammation which has 
engaged the periosteum of the femur or tibia, 
63 
and the epiphysis of one or both of these bones, 
the inflammation extending to the knee-joint. 
These cases are usually rapid in their course, 
and too frequently terminate fatally, the ordi- 
nary symptoms of diffuse inflammation being 
exhibited in their progress. In the post-mortem 
investigations of these cases we find that the 
periosteum is extensively separated from the 
bones by purulent matter; that the epiphyses, 
detached from the shafts of their respective 
bones, are loose in the interior of the joint; 
and that the synovial membrane is dis- 
tended by matter. In the serous and mu- 
cous membranes of the chest also we generally 
find evidences of acute inflammation having 
existed. The origin of these violent attacks is 
sometimes referred to a fall or other accidental 
injury, sometimes to a cold which commenced 
with a rigour. We have sometimes known 
this severe form of disease to succeed imme- 
diately to attacks of small-pox, and also of 
scarlatina. Dr. M‘Dowel, in the third and 
fourth volumes of the Dublin Journal, has de- 
scribed this disease under the heads Periostitis 
and Synovitis; and the museum of the Rich- 
mond hospital contains many specimens of 
these unhappy results of diffuse inflammation. 
Cases of diffuse inflammation are not the 
only ones in which we have seen matter, 
formed beneath the periosteum of the tibia, 
passing the epiphysis and getting into the 
cavity of the knee-joint; we have known in- 
stances of such occurrences in cases of acute 
necrosis of the tibia, in which the disease in its 
commencement had been exclusively confined 
to the one bone. Mr. Smyly, one of the sur- 
geons to the Meath Hospital, presented to the 
museum of the College of Surgeons in Dublin, 
a specimen, the result of an acute necrosis of 
the tibia. The following is the history of this 
case, which he kindly communicated to the 
writer. James Jarman, et. 9, was admitted 
into the Meath Hospital the 5th October, 1837. 
Sixteen days previously he had suffered a very 
severe contusion on the front of the left tibia 
by the accidental falling of an iron bar; there 
was, however, no breach of the skin, and the 
boy was able to walk about as usual for two 
days, when acute inflammation attacked the 
contused part, and daily increased for a fort- 
night. On the 4th of October he applied for 
relief at the dispensary. At this time a large 
and tense swelling extended from above the 
knee to the instep; a fluctuation was evident 
the whole way down the front of the leg. An 
incision was made into this swelling, which 
gave exit to a considerable quantity of thin 
discoloured pus, and the tibia was found quite 
denuded of periosteum. Great relief followed 
the opening of the abscess, but on the 10th of 
October there was much tumefaction observa- 
ble at each side of the patella, and redness, as 
if the joint were in a state of suppuration. 
The boy suffered much from irritative fever and 
occasional diarrhea: his pulse became very 
frequent, and his tongue red and dry. The ope- 
ration of amputation at the lower third of the 
thigh was now the only resource, and it was 
accordingly performed. 
