740 
DISEASES OF THE HOCK. 
the os calcis and 1 full inch in front of the Achilles tendon an incision 2 
to 2| inches long is made parallel to the tendon. After ligaturing any 
bleeding vessels, two retractors are introduced into the wound and the 
edges drawn back to allow the subcutaneous tissue to be divided down to 
the underlying fascia. After again ascertaining by palpation the exact 
position of the nerve the fascia is divided in the same direction and to the 
same extent as the skin wound. A fragment of fascia about ^ inch wide 
may then be removed with scissors, whereupon the nerve, recognisable by 
its white colour and fibrous consistence, usually projects through the 
opening. A thread is passed under it with a blunt-pointed needle; the 
struggling which usually follows shows that the nerve has really 
been alighted on. A fragment an inch in length is then dissected 
free and divided as high up as possible with one stroke of the knife 
or with scissors. 
As healing by first intention is rather difficult to attain, sutures are 
only necessary where rather severe bleeding occurs. 
The formation of a neuroma on the central end of the divided nerve is 
uncommon, and when occurring is usually due to the fact that the end of 
the nerve has been left too long, so that it projects into the operation 
wound. Should it occur, however, it may necessitate a second operation 
for its removal, and in this event it is usually best to operate at a higher 
point, as the formation of fibrous tissue usually renders it difficult to find 
the divided end. 
Double neurectomy of the anterior and posterior tibial nerves is not 
