Chronic rheumatic arthritis of the knee.— In the articles HAND, HIP, ELBOW, &c. in this work we have treated of a chronic disease affecting other articulations, which we have denominated chronic rheumatic arthritis; we shall now give an account of the symptoms and anatomical characters of this disease as we have found it in the knee-joint. - IN hen this articulation is affected with it, other joints in the same individual will also be found more or less implicated. The commencement of this disease of the knee is marked by evidences of subacute inflammation, such as pain, heat, con siderable swelling. This is followed by a second period, in which the heat and swelling diminish, but the pain continues. This pain is usually referred to the inner condyle of the femur and tibia. The patient may for a long period be able to walk, but every movement produces considerable pain, and at length he becomes incapable of walking or even of stand ing. The limbs diminish in size, but become remarkably firm to the feel. The patient having at last lost the power of flexing or extending the limb, the hamstring muscles gradually become more tense. The knee-joints from the com mencement incline slightly inwards, and the tibia outwards, and this bone is at the same time rotated in this last direction, so that the foot is everted ; if the limb then be kept in the semi-flexed position, and the tibia be thus rotated outward, carrying with it the ligamentum patella, it is easy to account for the circumstance which we have in some examples witnessed in the disease,—viz. that the patella leans towards the outer condyle, and further, that it is then sometimes thrown completely over it, so as to represent the external dislocation of this bone.
When the distension of the synovial sac of the articulation is at its maximum, we usually notice in this disease a prominent tumour about the size of a small hen's egg projecting into the popliteal space (fig. 3). This tumour leans towards the inner head of the gastro cnemius ; it disappears when the knee is flexed, and becomes more tense and hard when the limb is in the extended posture, as when the patient stands erect. We have known several cases of this disease of the knee-joint, where the synovial sacs of the knees have been much distended, and have on these occasions almost uniformly observed this popliteal tumour formed. From its situation, and from negative evidence, we can readily infer that the swelling consists of synovial fluid contained in a bursa, which has a communication with the interior of the knee-joint.
We have witnessed very many cases of this chronic rheumatic arthritis of the knee, in which this dropsical condition of the popliteal bursa existed, and some of these having had this chronic disease in both knee-joints, the bursa: were seen in both popliteal spaces,—presenting in these cases on a superficial inspection the resemblance to a case of double popliteal aneurism.
We have also enjoyed an opportunity of ascertaining by anatomical examination the real condition of this synovial sac in this disease, and its relation to the synovial membrane of the joint itself, to which we shall have occasion just now to revert.
When the palm of the hand is applied over the patella in the early stages of the affection, a sensation of a preternatural degree of heat is felt; and when pressure is made on the patella, and a lateral movement across the condyles is communicated to it, a very evident roughness is perceived, either on the articular surface of the patella itself, or the corresponding surface of the trochlea of the femur ; and when the knee-joint is fully flexed, a characteristic arti cular crepitus becomes manifest. In the later stages of the disease, the subacute inflamma tion, with the phenomena which it presents, subsides, the synovial fluid becomes absorbed, and the patella falls down on the trochlea of the femur; the popliteal bursa also disappears, and the grating produced by rubbing surfaces is perceived by the patient himself in all his movements, and can even be heard by the by standers. If the joint be now examined care fully by the surgeon, he feels satisfied that the smooth cartilage has been removed, either par tially or completely, from the articular surfaces. Crests of ossific deposit may even be per ceived, and, almost invariably, foreign bodies may be felt in the interior of the joint. Some of these are superficial, small, and moveable ; others are evidently situated more deeply in the interior of the joint. Some are small, some large, and we have known one case, which we learned to be of forty years standing, in which numerous bodies' of this description could be felt, some literally as large as the patella, floating about in the interior of the knee-joint, and which, we doubt not, were exactly of the same nature as those we have described in the elbow-joint.
The prognosis in this disease must be un favourable, as it seldom yields to medicine, but it does not appear to us to shorten life. We have seen an example in which the knee-joints had been affected with this disease, as the patient herself reported, for forty years. We are not prepared to say, however, that medicine and proper treatment may not occasionally cut short the disease, and we are sure the sufferings of the patient may be palliated at least by appropriate treatment. The following case is a good example of this disease.
Case of chronic rheumatic arthritis.—Patrick Donohoe, aged 38, a carter, admitted into the Richmond Hospital, (Dublin,) Nov. 24, 1836, complained of chronic pains in all his joints, but the principal source of his uneasiness was the diseased condition of his knee-joints, which prevented his earning his livelihood. Both knee-joints were greatly swollen ; he com plained of stiffness of them, and of some pain at the inner condyle of the tibia, which in creased when he stood up ; yet he was able to walk a considerable distance. The limbs could be fully extended, and when in bed he kept them pretty constantly in this position. Ile could not fully flex them backwards. The swelling of the knees differs from that of an ordinary white swelling, although it might cor respond much to the characters which a case of chronic synovitis of the knee might present, or to a case which the older writers denominated hydrops articuli. The swelling viewed in front is of an irregular globular form, involving the patella, its ligament, and the hamstring ten dons in one uniform tumour ; on the contrary the ligamentum patella: can be felt, with its edges as yet sharp and well defined, when the patient is desired to exert the extensor muscles of the leg. The tibia at the side of the liga ment, as far as the insertion of the internal lateral ligament, can be plainly felt through the skin to be rough and scabrous, and it can be perceived that this part of the bone is beset with bony vegetations. The breadth of the head of the tibia is increased ; the synovial membrane contains a redundant secretion, which elevates the vastus internus and forms a swelling here which measures about seven inches in its vertical diameter, and which seems to be some what constricted transversely in its centre (/ig.2). The swellingof the knee on the outside is evident enough, but is not so well marked as that on the inner side. It presents no transverse band, subdividing it into two tumours. The out line of the hamstring tendons is seen, when the joint is viewed in profile, either from without or within, and a very well defined ovoid projection from the popliteal space is observed (fig. 3). Its centre is on a level with the up per and projecting margin of the inner condyle of the tibia : it leans to the inner hamstring muscle. The rest of the popliteal space pre sents a normal appearance. When the limb is fully extended, and the muscles are allowed to remain in a passive state, the patella may be moved from side to side with much freedom. It appears to float as it were on the surface of an accumulated quantity of synovial fluid. When pressed against the trochlea of the femur, this fluid is moved laterally, and the patella strikes against the femur, and if a lateral movement be now communicated to this bone, a grating of rough surfaces may be perceived. If we grasp the leg and flex it on the thigh, we find we can elicit a peculiar articular crepitus. In this case it is quite audible, and resembles much the noises which electric sparks make when dis charged in quick succession from an electrical apparatus. When the limb is much flexed, the swelling of course feels remarkably hard and solid, but when the limb is again brought back to its ordinary state of extension, fluctua tion may be felt very evidently in it over its whole surface. The popliteal bursa, however, is felt very tense in the extended position of the joint, as when the patient stands and throws his weight on the limb. if we feel this bursa, and then cause the patient's limb to be flexed, we can follow the fluid, as it were, with our fingers into the articulation. As the patient lies in bed, the limb left in the extended posi tion, and the synovialsac as flaccid as possible, moveable bodies may be detected in its interior. Some appear to be adherent, and situated more particularly in the upper portion of the sub crural bursa. When we elevate the leg, and preserve it still in the fully extended position, the patient, without any apprehension of pain, will permit us to press it firmly against the femur, and does not experience the least suf fering even if we strike the heel forcibly. (See