i82 OPERATIVE TECHNIQUE. 



are passed at a distance of i^, inches from the margin of the wound 

 and comparatively deepl}' ; the number inserted naturally depends on 

 the size of the wound. A drainage-tube is then inserted and the 

 wound closed with closely placed interrupted sutures. Bayer insists 

 on the importance of drawing up a fold of skin, thus producing a ridge 

 h inch high before inserting these sutures. A large piece of iodoform 

 gauze is spread over the whole field of operation and fixed to the 

 rubber tubes used for securing the sutures of relaxation. The gauze 

 covers the drainage-tube. The horse is then allowed to rise and the 

 space marginated by the rubber tubes is protected with a pad of 

 dressing material which is caused to press on the wound by thrusting 

 broad strips of thin elastic wood, similar to that used in the manu- 

 facture of hat boxes, under the rubber tube on either side. This 

 brings the surfaces of the wound together and facilitates union. The 

 trifling local prominences caused by the stitches do not prevent the 

 application of a well-fitting collar and usually disappear in a month 

 or two. leaving a scarcely visible linear scar. 



The dressings used in fractures of hones may be divided into two 

 kinds, viz. those of a temporary character — termed provisional — and 

 those intended to be more lasting — permanent dressings. The choice 

 for the first dressing is often very restricted, and whatever first comes 

 to hand may require to be used. In this case broad strips of linen or 

 even of sacking are sometimes first applied as a padding and support, 

 and the splints, formed of flat pieces of wood, are applied on either side 

 of the long axis of the bone and fixed in position by cords or straps. 

 Pieces of wood may be replaced by bundles of straw. The broken 

 part being thus protected the horse should be removed as rapidly as 

 possible to the stable, and the permanent dressing applied. If time 

 permit the supporting pieces of wood maybe sewn between linen pads. 

 To increase the firmness of the dressing rolls of straw, lengths of sole 

 leather, straw board or bark or pieces of lead moulded to the shape of 

 the part, can be employed in place of wooden splints. 



Permanent dressings are prepared with starch, dextrin, plaster, 

 tripolith, glue, gutta-percha, plastic cardboard, and poroplastic felt. 

 When applying any of these care must be taken that the broken parts 

 are first replaced as nearly as possible in their natural positions, and 

 so retained until the dressing has become quite hard. The dressing 

 must not press unduly on any point as this would cause sloughing of 

 the skin, a complication specially liable to occur where prominent 

 bony processes have to be included in the dressing. The portions to 

 be covered and their immediate neighbourhood are therefore first 

 supported by the application of a sheet of linen, over which wadding 



