The Healing Condition.—­The process of healing in an ulcer has already been studied, and we have learned that it takes place by the formation of granulation tissue, which becomes converted into connective tissue, and is covered over by epithelium growing in from the edges.

Those ulcers which are stationary—­that is, neither healing nor spreading—­may be in one of several conditions.

The Weak Condition.—­Any ulcer may get into a weak state from receiving a blood supply which is defective either in quantity or in quality.  The granulations are small and smooth, and of a pale yellow or grey colour, the discharge is small in amount, and consists of thin serum and a few pus cells, and as this dries on the edges it forms scabs which interfere with the growth of epithelium.

Should the part become oedematous, either from general causes, such as heart or kidney disease, or from local causes, such as varicose veins, the granulations share in the oedema, and there is an abundant serous discharge.

The excessive use of moist dressings leads to a third variety of weak ulcer—­namely, one in which the granulations become large, soft, pale, and flabby, projecting beyond the level of the skin and overlapping the edges, which become pale and sodden.  The term “proud flesh” is popularly applied to such redundant granulations.

[Illustration:  FIG. 18.—­Callous Ulcer, showing thickened edges and indurated swelling of surrounding parts.]

The Callous Condition.—­This condition is usually met with in ulcers on the lower third of the leg, and is often associated with the presence of varicose veins.  It is chiefly met with in hospital practice.  The want of healing is mainly due to impeded venous return and to oedema and induration of the surrounding skin and cellular tissues (Fig. 18).  The induration results from coagulation and partial organisation of the inflammatory effusion, and prevents the necessary contraction of the sore.  The base of a callous ulcer lies at some distance below the level of the swollen, thickened, and white edges, and presents a glazed appearance, such granulations as are present being unhealthy and irregular.  The discharge is usually watery, and cakes in the dressing.  When from neglect and want of cleanliness the ulcer becomes inflamed, there is considerable pain, and the discharge is purulent and often offensive.

The prolonged hyperaemia of the tissues in relation to a callous ulcer of the leg often leads to changes in the underlying bones.  The periosteum is abnormally thick and vascular, the superficial layers of the bone become injected and porous, and the bones, as a whole, are thickened.  In the macerated bone “the surface is covered with irregular, stalactite-like processes or foliaceous masses, which, to a certain extent, follow the line of attachment of the interosseous membrane and of the intermuscular septa” (Cathcart) (Fig. 19).  When the whole thickness of the soft tissues is destroyed by the ulcerative process, the area of bone that comes to form the base of the ulcer projects as a flat, porous node, which in its turn may be eroded.  These changes as seen in the macerated specimen are often mistaken for disease originating in the bone.