The incipient stage of such disease may exist without the synovial membrane being much, if at all, affected; but when the ulceration has made farther progress, all the articulating apparatus is more or less diseased. It may be here remarked, that the synovial membrane may be affected for a long period, thickened portions may extend over the cartilages, and these may have lymph upon them and yet remain intact. [Illustration] The cure, resorted to by nature, and in which she may be much assisted by the surgeon, is Anchylosis, ligamentous or osseous. New bone is deposited in the neighbourhood of the disease, and the ulcers become, as it were, cicatrised; the articulating extremities of the bones are joined to each other by a firm osseous matter, either universally disposed or consisting of processes extended between the bones at various points: or again, in consequence of the effusion of lymph into the cellular tissue, and the consequent thickening and induration of that and of the fibrous tissue exterior to the joint, this connecting medium is so strengthened and concentrated as to retain the articulating surfaces in exact apposition; from one, and usually from both, of these changes, the joint is securely fixed and rendered immovable, or nearly so. In complete anchylosis, the cancellous texture of the two bones, after some time, becomes perfectly continuous, so that they in fact constitute but one bone, as seen in cut, p. 84. A very perfect specimen of anchylosed knee joint is also delineated in the cut above. But even after this happens, the disease is still apt to recur from slight causes, the bony or ligamentous union being disturbed or destroyed, and the original disease attacking the parts with fresh activity; abscesses form,—may be extensive both in size and number,—and thereby the health is again undermined. So that the patient, after undergoing much suffering and risk, preserves, perhaps only for a few years, a limb which is almost useless to him, and which must be removed at last. In other cases, the union is permanent, the disease does not return; by care and time the limb is brought into the most convenient position, and proves of considerable service. [Illustration]