Partial Excision of the Lateral Cartilage. - Discarding the somewhat elaborate methods we have just described, there are English operators who removed the necrosed portion only of the cartilage, and do so in what appears at first sight a comparatively rough-and-ready manner.

The apparent roughness is that they do not concern themselves with conserving the coronary cushion, and hesitate but little in cutting portions of it bodily away. One would imagine that in this case the quarter of the side operated on would be always more or less bare of horn. Such, however, is not the case.

To perform this operation the animal is again cast and chloroformed. Some operators, however, use the stocks and dispense with the anaesthetic. The foot is first well cleaned with soap and water and a stiff brush, and the hair of the coronet over the seat of operation shaved. Again, too, the horn of the affected quarter is rasped until it yields easily to pressure of the thumb, and the whole of the foot washed in an antiseptic solution.

A probe is now inserted into the opening at the coronet, and the direction of the fistula noted, after which the foot is firmly secured, and an Esmarch bandage and tourniquet applied to the limb.

This done, a triangular or wedge-shaped portion of skin, coronary cushion, and thinned horn is removed with a strong sage-knife or scalpel.

The base of the wedge-shaped portion removed contains the opening of the fistula, and the apex of the wedge should reach to the bottom of the sinus (see Fig. 142).

After the horn is removed and the fistula followed up, it is sometimes found that what we at first thought was its end, it may now be continued in an altogether different direction.

It is again followed up with the probe, and the horn and sensitive structures excised until we are quite certain we have reached its furthest extent.

Attention should next be paid to the cartilage. Wherever spots of necrosis are found, as indicated by the pea-green colour of the affected parts, they must be carefully excised. Care should be taken in so doing to carry the line of excision some little distance around the visibly affected parts. This is done that we may be quite certain nothing at all remains calculated to give rise to further trouble.

It goes without saying that, in addition to the necrosed cartilage, all other diseased and necrotic tissues should also be removed. The os pedis is occasionally found necrotic just where the cartilage joins it, or it may be that a small portion of the sensitive laminae, by reason of its liver-red or even gray coloration, gives evidence of death of the part.

The former must be well curetted, and the latter cleaned carefully with a scalpel and forceps.

Fig. 142.   Partial Excision Of The Lateral Cartilage By Removing A Portion Of The Coronary Cushion

Fig. 142. - Partial Excision Of The Lateral Cartilage By Removing A Portion Of The Coronary Cushion. The Dotted Lines Show The Outline Of The Wedge-Shaped Portion Of Structures To Be Removed, Including Skin, Coronary Cushion, Horn, And Sensitive Laminae. A, The Opening Of The Fistula.

The operation finished, the foot is again douched in an antiseptic solution, the wound mopped dry with carbolized tow, dressed with either of the dressings described on page 358, and finally bandaged. The dressing should be changed every three days only, unless in the meanwhile pawing movements and other symptoms of distress indicate their removal.

The length of coronary cushion removed in this operation is from 1/4 to 1/2 inch (we ourselves, however, have seen it more), and yet its loss seems to occasion no serious after-trouble beyond a slight deformity of the parts beneath. The sensitive structures become sufficiently covered with horn, and the animal in nearly every case is returned to work, while in a great many instances he may also trot perfectly sound.

Simple though the operation may appear, and apparently rough in its method, it is nevertheless successful in effecting a cure in cases where blisters, plugging, injections, and other means have failed.

Mr. W. Dacre, M.R.C.V.S.,[A] after reading an article on the operation before the members of the Lancashire Veterinary Medical Association, says: 'My observations have not been based on a single case, and having had nine of them, and all of them successful, I felt it to be my duty to bring this subject before the Society.'

[Footnote A: Veterinary Record, vol. v., p. 407.]

Mr. T.W. Thompson, M.R.C.V.S.,[A] says: 'In a great number of cases I have removed a 1/2 inch of the coronary band.... I have performed the operation a great number of times, and have never seen a foot that has been damaged by it.'

[Footnote A: Ibid.]

Professor Macqueen[A] says: 'I do not spare the coronary band or sensitive laminae when I find those parts diseased. I do not unnecessarily damage those structures. At the same time, I am confident that excision of a piece of the coronary band or removal of a few sensitive laminae has not the untoward consequences so much dreaded in former days.'

[Footnote A: Ibid., p. 714.]

Mr. John Davidson, M.E.C.V.S.,[A] says: 'The treatment described, if carefully carried out and details attended to, will be found a success in dealing with the majority of cases of quittor. If I may be permitted to say so, without being considered boastful, I have yet to see the first case that has resisted the treatment.'

[Footnote A: Ibid., vol. xiv., p. 769.]

Should our case of quittor be complicated by caries of the bone, this must, where possible, be scraped or curetted until the whole of the diseased portion is removed, and a healthy surface is left. After-dressing must then be carried out as in other cases.

The treatment of ossified cartilage will be found under treatment of side-bones, and the methods of dealing with penetrated articulation and purulent arthritis are treated of in Chapter XII (Diseases Of The Joints[A]).