In such cases we ourselves have derived benefit from a regular flushing of the sinuses with a 1 in 2,000 solution of perchloride of mercury, introduced by means of a glass syringe, followed later by flushing in the same manner with a 1 in 40 solution of carbolic acid, the hollow of the heel meanwhile being kept clean with an antiseptic pad and bandage, or by liberal applications of an antiseptic powder.

The septic materials are in this way destroyed, and the wound heals without further complication.  We must admit, however, that the cure of the lesion is generally at the expense of slight lameness, due, in all probability, to inflammatory tissue adhesions between the flexor perforans and the perforatus, and to a partial destruction of the synovial membrane of the sheath.

If, in spite of the antiseptic irrigations, the fistula persists, then nothing remains but to resort to excision of the aponeurosis, as described on p. 222.

When Necrosis of the Lateral Cartilage is present.—­In this case we may at first try the ordinary treatments of poulticing; and blistering, of antiseptic caustic injections, and of plugging.  In some cases a cure is effected.  Should these fail, however, and we intend to see the finish of our case, then operative measures must be determined on.  This means cutting down upon the diseased cartilage, and either removing the necrosed portion, or excising the cartilage in its entirety.

The latter method is seldom practised in this country.  As it is the most radical of the two, however, we shall describe it here first.

Extirpation of the Lateral Cartilage.—­The operation of extirpating the lateral cartilage is by no means a new one, being introduced, according to Zundel, by the senior Lafosse in 1754.  It consisted in removing a portion of the wall by grooving and stripping it, and of excising the exposed cartilage by means of a sage-knife.

As to what portion of, and how much of the horn of, the quarter should first be removed, and as to what particular direction each groove should take, opinion among the older writers varied considerably.  This we know now is not an important matter, and it is sufficient to say that the first preliminary is a thinning down of the horn of the quarter with the rasp over the position occupied by the cartilage.  At the present time there are two or three modifications of the operation as originally introduced.  In all, however, the preliminary steps are the same.  We shall therefore describe them collectively, as applying correctly to either of the three methods of operating we are about to show.

Preparation of the Subject and Preliminary Steps in the Operation.—­On the day previous to the operation the horn of the wall immediately over the cartilage must be so thinned with a rasp as to yield readily to pressure of the thumb in any position.  It should be so thin as to only just avoid wounding the sensitive structures below.