A wound is a solution in the continuity of the skin or mucous membrane and of the underlying tissues, caused by violence.
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.
The risks incident to this class of wounds are: (1) the extreme difficulty, especially when a dense fascia has been perforated, of rendering them aseptic, on account of the uncertainty as to their depth, and of the way in which the surface wound closes on the withdrawal of the instrument; (2) different forms of aneurysm may result from the puncture of a large vessel; (3) perforation of a joint, or of a serous cavity, such as the abdomen, thorax, or skull, materially adds to the danger.
Treatment.—The first indication is to purify the whole extent of the wound, and to remove any foreign body or blood-clot that may be in it. It is usually necessary to enlarge the wound, freely dividing injured fasciæ, paring away bruised tissues, and purifying the whole wound-surface. Any blood vessel that is punctured should be cut across and tied; and divided muscles, tendons, or nerves must be sutured. After hæmorrhage has been arrested, iodoform and bismuth paste is rubbed into the raw surface, and the wound closed. If there is any reason to doubt the asepticity of the wound, it is better treated by the open method, and a Bier's bandage should be applied.
Contused and Lacerated Wounds.—These may be considered together, as they so occur in practice. They are produced by crushing, biting, or tearing forms of violence—such as result from machinery accidents, firearms, or the bites of animals. In addition to the irregular wound of the integument, there is always more or less bruising of the parts beneath and around, and the subcutaneous lesions are much wider than appears on the surface.
Wounds of this variety usually gape considerably, especially when there is much laceration of the skin. It is not uncommon to have considerable portions of skin, muscle, or tendon completely torn away.
Hæmorrhage is seldom a prominent feature, as the crushing or tearing of the vessel wall leads to the obliteration of the lumen.
The special risks of these wounds are: (1) Sloughing of the bruised tissues, especially when attempts to sterilise the wound have not been successful. (2) Reactionary hæmorrhage after the initial shock has passed off. (3) Secondary hæmorrhage as a result of infective processes ensuing in the wound. (4) Loss of muscle or tendon, interfering with motion. (5) Cicatricial contraction. (6) Gangrene, which may follow occlusion of main vessels, or virulent infective processes. (7) It is not uncommon to have particles of carbon embedded in the tissues after lacerated wounds, leaving unsightly, pigmented scars. This is often seen in coal-miners, and in those injured by firearms, and is to be prevented by removing all gross dirt from the edges of the wound.
Treatment.—In severe wounds of this class implicating the extremities, the most important question that arises is whether or not the limb can be saved. In examining the limb, attention should first be directed to the state of the main blood vessels, in order to determine if the vascular supply of the part beyond the lesion is sufficient to maintain its vitality. Amputation is usually called for if there is complete absence of pulsation in the distal arteries and if the part beyond is cold. If at the same time important nerve-trunks are lacerated, so that the function of the limb would be seriously impaired, it is not worth running the risk of attempting to save it. If, in addition, there is extensive destruction of large muscular masses or of important tendons, or comminution of the bones, amputation is usually imperative. Stripping of large areas of skin is not in itself a reason for removing a limb, as much can be done by skin grafting, but when it is associated with other lesions it favours amputation. In considering these points, it must be borne in mind that the damage to the deeper tissues is always more extensive than appears on the surface, and that in many cases it is only possible to estimate the real extent of the injury by administering an anæsthetic and exploring the wound. In doubtful cases the possibility of rendering the parts aseptic will often decide the question for or against amputation. If thorough purification is accomplished, the success which attends conservative measures is often remarkable. It is permissible to run an amount of risk to save an upper extremity which would be unjustifiable in the case of a lower limb. The age and occupation of the patient must also be taken into account.
It having been decided to try and save the limb, the question is only settled for the moment; it may have to be reconsidered from day to day, or even from hour to hour, according to the progress of the case.
When it is decided to make the attempt to save the limb, the wound must be thoroughly purified. All bruised tissue in which gross dirt has become engrained should be cut away with knife or scissors. The raw surface is then cleansed with eusol, washed with sterilised salt solution followed by methylated spirit, and rubbed all over with “bipp” paste. If the purification is considered satisfactory the wound may be closed, otherwise it is left open, freely drained or packed with gauze, and the limb is immobilised by suitable splints.