METACARPAL TENOTOMY 207 



be slipped beneath this vessel, which occupies a rather su- 

 perficial location along the internal surface of the region. 



Second Step. — Disinfecting the Field. — The whole mid- 

 dle third of the metacarpal region is clipped, shaved and dis- 

 infected with mercuric chloride solution 1-500, and then 

 rinsed in alcohol. It may in addition be submitted to 

 a friction with boric acid and iodoform. It is important that 

 no infectious matter be carried into the recesses of this shel- 

 tered wound. 



Third Step.— Incising the Skin as a Point of Entrance.— 

 A small point of entrance for the bistoury is first made with 

 the point of the scalpel in the groove, between the perforans 

 tendon and great suspensory ligament. The exact location 

 of this point of entrance is important. It is made at the 

 posterior edge of the groove, not in its depths, so that the 

 bistoury can be passed downward and forward under the 

 great metacarpal artery, and internal metacarpal vein. If 

 the entrance point is made in the depths of the groove these 

 two vessels can hardly be avoided. 



Fourth Step. — Dividing the Tendons. — This step is ef- 

 fected with the special bistoury previously described. The 

 bistoury is passed through the entrance incision, antero-ex- 

 ternally; that is to say, forward and downward, so as to 

 glide under the great metacarpal artery, the internal meta- 

 carpal vein and internal plantar nerve. The blade is placed 

 flatwise against the tendon on its downward course. When 

 the blade is buried beyond its cutting portion it is first di- 

 rected straight through to the opposite side, until its point 

 is felt beneath the skin, and then turned, cutting edge against 

 the tendon. At the same moment the assistant holding the 

 rope is instructed to pull with his might to bring tension 

 upon the tendons as the bistoury divides them. It is ad- 

 visable to first divide only the perforans and then endeavor 

 to break down the deformity by force. If the adhesions do 

 not yield to the traction, the perforatus is then severed. 



Fifth Step. — Breaking Down the Adhesions. — Old de- 

 formities require the application of considerable force to re- 

 adjust them. If they do not yield to ordinary traction the 

 rope looped around the pastern is taken in both hands and 

 one foot is placed against the front of the fetlock. A steady 

 and forcible forward traction with the hands and a firm 

 backward pressure with the foot will usually bring the 

 fetlock to its normal angle without much ceremony. The 

 reposition is attended with a crunching sound caused by the 

 tearing of the adhesions. It sometimes happens that the 



