ration exterior to the synovial membrane, the granulations by which the cavity of the abscess is obliterated constitute afterwards tough bands, approaching in density to fibrous tissue. These gradually contract in a manner similar to the contraction that takes place in cutaneous cicatrices, and constitute an additional obstacle to the restoration of the motions of the joint. The amount of resistance these bands may offer will greatly depend on their direction. Should the suppuration have been accompanied with loss of substance, sloughing of the cellular tissue, fascia, or tendons, the tendency to contraction and ankylosis will be proportionably stronger. But if the intensity of the inflammation have been spent upon the synovial membrane and the ligaments immediately around it, and either cellular adhesions within the joint, or thickening and induration of the ligaments, have resulted, combined with adventitious bands in the track of abscesses, the probability of ankylosis is still greater. This is further increased if the suppuration within the articulation have communicated with the exterior. The case may be complicated with absorption of cartilage, adhesion by granulation between the denuded articular surfaces, fibro-cartilaginous transformation of these adhesions, or osseous deposit, constituting true ankylosis. Such are the modes in which ankylosis is produced by common inflammation. I have now briefly to consider the influence of scrofulous and rheumatic inflammation. The strumous forms of disease usually differ in the slowness of their course from common inflammation,—the contraction is very gradual; but as the disease affects young subjects, the muscular retraction becomes ultimately, from the causes I have mentioned, as inextensible as in ankylosis from ordinary inflammation. The limb is rarely so acutely flexed, but contraction occurs in the larger proportion of cases. Although suppuration sometimes extends outwardly, accompanied with caries of the bones, it is usually circumscribed, and does not induce the formation of the extensive bands of dense adventitious tissue succeeding to the suppuration of acute inflamma tion. The disorganisation of the ligamentous structures being the common result of this disease, the ankylosis is rarely simple. Partial luxation of the articular surfaces often occurs, constituting compound ankylosis. Thus, in the knee-joint, the head of the tibia is drawn outwards and backwards, being applied to the posterior part of both condyles, or it may gradually abandon the internal condyle, and articulate almost exclusively with the posterior part of the external condyle; and sometimes the luxation is so complete, that it articulates only with its external and posterior surface. The tibia undergoes, at the same time, rotation outwards (see Ankylosis of the Knee). Arthritic inflammation, under which head I include rheumatism and gout, more frequently induces complete immobility of the joint than any other disease. Greater induration and rigidity of the articular tissues appear to follow this than other inflammations, and considerable proneness to calcareous or ossific deposit around and between the articulating surfaces exists. Ankylosis may occur as an immediate result of acute arthritis, or be a sequel of the chronic form of the disease, years elapsing before the calcareous deposit acquires a sufficient amount to render the joint quite immovable. It is worthy of recollection, that the simple induration of the tissues from rheumatism may suffice to produce complete immobility, without the existence of any ossific union, and occasion an erroneous belief in the presence of true ankylosis. The ginglymoid articulations, and those by plane surfaces, are more susceptible of ankylosis, whether true or false, than the ball-and-socket joints. The adhesion of the articular surfaces of the ginglymus is probably facilitated by their being naturally more largely in apposition, and by the smaller amount of mobility proper to this form of articulation. Thus ankylosis occurs more frequently in the knee, elbow, and wrist, than in the hip or shoulder. The comparatively greater frequency of ankylosis in the knee, elbow, and wrist, likewise depend, in some degree, on the greater liability of these joints to disease; and possibly that disease of the may hip often destroys the patient before time is afforded for the production of ankylosis. Several joints having been simultaneously or successively diseased, the individual may present ankylosis in several parts of the body. This is frequently observed in rheumatic and scrofulous subjects. Extraordinary cases of universal ankylosis, the entire skeleton constituting one bone, have been occasionally witnessed. The following table contains an enumeration of the causes of the various forms of ankylosis of the knee, in the order of their severity. It may be incomplete: it includes, however, the causes of every variety that has fallen under my observation, and will serve to illustrate the causes of ankylosis in other articulations.* I have rejected the simple state of rest or disuse of an articulation as a cause of true ankylosis; for, in the absence of conclusive evidence, we cannot conceive the production of such disorganisation of the synovial membrane and cartilages as is implied by the occurrence of ossific union between the articular surfaces, without that previous alteration in the functions of the capillaries which is designated inflammation. Cloquet (Dictionnaire de Médecine et Chirurgie—article, Ankylose) mentions the occurrence of ossific union between the articular surfaces of the joints of persons whose limbs had been condemned to constant repose by paralysis. This celebrated anatomist does not state whether he had the opportunity of examining the subjects during life-time, so as to be able distinctly to certify that the cause was paralysis, or whether les pièces anatomiques came under his observation only after death: the latter is the more probable conjecture. In our vernacular, persons are often stated to have "lost the use of their limbs ;" and the physician cannot from this information determine whether the disease be paralysis or rheumatism. The wasted, powerless muscles of the lower extremities of an individual, with every articulation contracted, and one or more perhaps ankylosed, from rheumatism, present considerable resemblance to those affected with paralysis. In complete paralysis of long standing, the utter abolition of voluntary power, and the annihilation of the organic contractility of the muscles which subsequently ensues, occasion the well-known laxity of the paralytic articulation, the articular surfaces being held together as it were by the flaccid skin and ligaments only. This does not constitute a state of things favourable to a complete state of rest of the articulation. Every movement of the patient's frame effected by external aid jolts the articulations, and would interfere with the ossifying process, if it were disposed to occur. The only cases in which I can conceive the occurrence of true ankylosis from paralysis possible, are those in which the paralysis of one set of muscles is Ankylosis, false and true, each subdivided into angular and straight. (a) Angular: FALSE ANKYLOSIS. 1. From strumous synovitis, from inflammation produced by mechanical injury, and erysipelas succeeded by phlegmon, terminating in thick ening of structures in and about the articulation and muscular contraction. 2. From abscess exterior to the synovial membrane, followed by reunion of · parts, unnatural adhesions, contraction of muscles. 3. From rheumatic and gouty inflammation, producing induration and adhesion of tissues, from effusion of lymph, with or without incipient calcareous deposit, muscular contraction. 4. From strumous synovitis, or white swelling, ending in disorganisation of ligaments, muscular contraction, partial luxation of articular extremities, caries. 5. Inflammation and suppuration within the synovial membrane communicating with the exterior, destruction of ligaments, membranous adhesions within and without the articulations, muscular contraction, partial luxation, attrition of cartilage and bones. False compound ankylosis. succeeded by permanent contraction of their antagonists, and immobility of the joint-contracture. But ankylosis from this source has never fallen under my observation. (See Morbid Anatomy of Contracture.) True ankylosis is often observed in the bodies of aged individuals, in the bones of the carpus, tarsus, vertebral column, and elsewhere; and is usually, but improperly, considered to be the direct effect of a state of rest of the articulations. It arises, in my opinion, from the slow operation of chronic rheumatism, favoured by the well-known senile tendency to induration and ossification of tissues. Strong corroborative evidence that disuse of an articulation is not necessarily followed by ankylosis is afforded by the circumstance, that in the highest grade of congenital club-foot of thirty and forty years' duration, the articular facets of the tarsal bones, some of which, it may be safely affirmed, have been many years in a perfect state of rest from disuse, retain their normal anatomical characters, and by the restoration of the position of the foot are enabled to perform those functions which, owing to the congenital nature of the deformity, had never been exercised. The effects of friction, abrasion of cartilage and bone, may occasionally be observed in such cases of club-foot; and should inflammation of the integuments and fibrous tissues investing the articulation of the os calcis with the os cuboides, or this bone with the fifth metatarsal bone, be excited by undue pressure in walking, and spread to the subjacent articulations, the ordinary effects of inflammation, membranous and osseous adhesion between the articular surfaces-ankylosis, may unquestionably occur. (b) Straight: 1. From abscess resulting from inflammation, preceded by mechanical 1. From chronic strumous disease, inducing ulceration of cartilage and 2. From acute inflammation, traumatic, phlegmonous, erysipelatous, 3. From gouty inflammation, without external suppuration, calca- 4. From fracture. (b) Straight 1. From fracture. 2. From rheumatic inflammation. May be combined with luxation, and constitute true compound ankylosis. MORBID ANATOMY OF ANKYLOSIS. This subject has been so ably treated by numerous pathological writers, that I am relieved from the necessity of minutely describing all the varieties of morbid processes in the articulations which precede ankylosis. However interesting, in a pathological point of view, is the study of many of the phenomena resulting from the ravages of inflammation in articular tissues, I shall, as the object of this treatise is mainly practical, pass over many of those facts and opinions which do not illustrate the diagnosis of stiff joints, and the treatment to be recommended. The morbid anatomy of ankylosis is really that of diseased joints in general; and as an apology for the omission of much that it may be sup |