Three varieties of wounds are described: incised, punctured, and contused and lacerated.

Incised Wounds.—Typical examples of incised wounds are those made by the surgeon in the course of an operation, wounds accidentally inflicted by cutting instruments, and suicidal cut-throat wounds. It should be borne in mind in connection with medico-legal inquiries, that wounds of soft parts that closely overlie a bone, such as the skull, the tibia, or the patella, although, inflicted by a blunt instrument, may have all the appearances of incised wounds.

Clinical Features.—One of the characteristic features of an incised wound is its tendency to gape. This is evident in long skin wounds, and especially when the cut runs across the part, or when it extends deeply enough to divide muscular fibres at right angles to their long axis. The gaping of a wound, further, is more marked when the underlying tissues are in a state of tension—as, for example, in inflamed parts. Incised wounds in the palm of the hand, the sole of the foot, or the scalp, however, have little tendency to gape, because of the close attachment of the skin to the underlying fascia.

Incised wounds, especially in inflamed tissues, tend to bleed profusely; and when a vessel is only partly divided and is therefore unable to contract, it continues to bleed longer than when completely cut across.

The special risks of incised wounds are: (1) division of large blood vessels, leading to profuse hæmorrhage; (2) division of nerve-trunks, resulting in motor and sensory disturbances; and (3) division of tendons or muscles, interfering with movement.

Treatment.—If hæmorrhage is still going on, it must be arrested by pressure, torsion, or ligature, as the accumulation of blood in a wound interferes with union. If necessary, the wound should be purified by washing with saline solution or eusol, and the surrounding skin painted with iodine, after which the edges are approximated by sutures. The raw surfaces must be brought into accurate apposition, care being taken that no inversion of the cutaneous surface takes place. In extensive and deep wounds, to ensure more complete closure and to prevent subsequent stretching of the scar, it is advisable to unite the different structures—muscles, fasciæ, and subcutaneous tissue—by separate series of buried sutures of catgut or other absorbable material. For the approximation of the skin edges, stitches of horse-hair, fishing-gut, or fine silk are the most appropriate. These stitches of coaptation may be interrupted or continuous. In small superficial wounds on exposed parts, stitch marks may be avoided by approximating the edges with strips of gauze fixed in position by collodion, or by subcutaneous sutures of fine catgut. Where the skin is loose, as, for example, in the neck, on the limbs, or in the scrotum, the use of Michel's clips is advantageous in so far as these bring the deep surfaces of the skin into accurate apposition, are introduced with comparatively little pain, and leave only a slight mark if removed within forty-eight hours.

When there is any difficulty in bringing the edges of the wound into apposition, a few interrupted relaxation stitches may be introduced wide of the margins, to take the strain off the coaptation stitches. Stout silk, fishing-gut, or silver wire may be employed for this purpose. When the tension is extreme, Lister's button suture may be employed. The tension is relieved and death of skin prevented by scoring it freely with a sharp knife. Relaxation stitches should be removed in four or five days, and stitches of coaptation in from seven to ten days. On the face and neck, wounds heal rapidly, and stitches may be removed in two or three days, thus diminishing the marks they leave.

Drainage.—In wounds in which no cavity has been left, and in which there is no reason to suspect infection, drainage is unnecessary. When, however, the deeper parts of an extensive wound cannot be brought into accurate apposition, and especially when there is any prospect of oozing of blood or serum—as in amputation stumps or after excision of the breast—drainage is indicated. It is a wise precaution also to insert drainage tubes into wounds in fat patients when there is the slightest reason to suspect the presence of infection. Glass or rubber tubes are the best drains; but where it is desirable to leave little mark, a few strands of horse-hair, or a small roll of rubber, form a satisfactory substitute. Except when infection occurs, the drain is removed in from one to four days and the opening closed with a Michel's clip or a suture.

Punctured Wounds.—Punctured wounds are produced by narrow, pointed instruments, and the sharper and smoother the instrument the more does the resulting injury resemble an incised wound; while from more rounded and rougher instruments the edges of the wound are more or less contused or lacerated. The depth of punctured wounds greatly exceeds their width, and the damage to subcutaneous parts is usually greater than that to the skin. When the instrument transfixes a part, the edges of the wound of entrance may be inverted, and those of the exit wound everted. If the instrument is a rough one, these conditions may be reversed by its sudden withdrawal.

Punctured wounds neither gape nor bleed much. Even when a large vessel is implicated, the bleeding usually takes place into the tissues rather than externally.