TENOTOMY OF THE PERFORATUS 127 



A second method of performing this operation is to make the 

 cutaneous incision about three-quarters of an inch further forward, 

 i.e., in a hne with the incision for plantar neurectomy. The hps 

 of the incision are separated and the vessels and nerves on the inner 

 side of the limb drawn well forward with the thumb, whilst those 

 on the outer side are pressed forward with the fingers, as in the 

 first method. The tenotome is then introduced in front of the 

 perforans tendon, behind the nerve and vessels. The manner of 

 introducing the instrument is exactly similar to that adopted in the 

 first method, i.e., with the flat surface of the blade directed towards 

 the tendon. But when the instrument is turned the cutting edge 

 of the blade is directed backwards, so that "the tendon is cut through 

 by an antero-posterior incision. 



One of the difficulties attending this method is that the operator is 

 very liable to cut into the perforatus tendon whilst severing that of the 

 perforans. On the other hand, the method possesses a distinct advantage 

 over the first method, inasmuch as there is much less likelihood of the 

 vessels or nerves beinjr damaged. 



TENOTOMY OF THE PERFORATUS 



This operation is indicated when the affection which leads to the 

 production of the symptoms already described may be fairly accurately 

 diagnosed as being confined to this tendon. 



It may, however, be necessary to perform it when, owing to mis- 

 taken diagnosis, tenotomy of the perforans alone has been ineffective. 

 There is very little difference between the method of severing this 

 tendon and the first method described of performing tenotomy of the 

 perforans. The incision is made at the same seat, i.e., between the two 

 tendons, and the blunt-pointed tenotome is introduced in an exactly 

 similar manner. But the tenotome is turned in the opposite direction. 



