RESECTION OF PLEXOR PEDIS PERFORANS TENDON. 1057 



border of the navicular bone with one steady cut. The portion of 

 the aponeurosis thus freed is next divided along the middle line from 

 before backwards as far as the upper margin of the navicular bone, 

 the margins are reflected and each is carefully dissected free. Again 

 grasping the knife with both hands, the operator makes a semi- 

 circular sweeping cut along the edge of the semi-lunar crest, thus 

 dividing the lower insertion of the aponeurosis into the os pedis. 

 The pieces are then removed. 



The fibro-cartilage covering the lower surface of the navicular 

 bone is next removed by the vigorous use of the curette. If the 

 primary injury extend to the point of insertion of the plantar 

 aponeurosis the terminal fibres of the tendon must be carefully removed 

 and the semi-lunar crest curetted, care being taken, however, not to 

 open the joint between the navicular bone and the os pedis. If, 

 however, the insertion of the aponeurosis is healthy the semi-lunar 

 crest should not be touched ; the fibrous layer which covers it soon 

 becomes vascular, and granulates rapidly provided it be protected 

 from infection. Wherever necrosis exists it is absolutely imperative 

 to remove the whole of the diseased tissue, and, in fact, to encroach 

 a little on the adjoining healthy parts. To overlook a fragment of 

 diseased tissue is to risk the necessity for operating anew and under 

 much more difficult conditions. The cavity is sponged with a 10 per 

 cent, solution of chloride of zinc, rinsed with carbolic solution, 

 powdered with iodoform, salol or calomel, firmly packed with masses 

 of tow, moistened with carbolic or sublimate, and a moist dressing 

 applied over all. French operators touch any point in the wound which 

 may appear likely to undergo retrogressive changes with tincture of 

 iodine. The space is filled with tow, partly to check the bleeding 

 which follows removal of the tourniquet, partly to restore the fibro- 

 fatty frog and its sensitive covering to their normal position. Next 

 day the dressing is removed, the wound rinsed out with disinfectants, 

 and the dressing renewed, but the cavity is only loosely filled with 

 carbolic tow or jute. This second dressing remains in position eight 

 to ten days, provided it is not wet through with discharge, and 

 neither fever nor severe pain has set in. In the interval the walls 

 of the space have everywhere become covered with granulations — - 

 in favourable cases without any trace of pus formation. The 

 dressing is then renewed every four or five days ; and as the cavity 

 fills with granulations, less material is used. Finally, healing be- 

 comes complete ; the frog may possibly appear rather shortened, 

 but, as a rule, no other deformity remains. French and German 

 operators often return horses to work in four tc six weeks, but 



R.S. 3 Y 



