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 haemorrhage after the initial shock has passed off. (3) Secondary haemorrhage 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 anaesthetic 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.