350 Anatomy Applied to Medicine and Surgery. 



in the treatment of popliteal aneurism by means of forced 

 flexion. Hence, flexion and extension of the limb may 

 predispose towards popliteal aneurism by frequently al- 

 tering the size of the vessel. (2) The absence of mus- 

 cles closely surrounding and, therefore, supporting the 

 artery. (3) The alteration in the current of the blood, 

 the result of the division of the artery, at this point, into 

 two large branches. (4) The curve in the artery the 

 femoral portion of the popliteal space is deeper than the 

 tibial, hence, it follows, that the vessel must suddenly 

 curve backwards, from the femur, to arrive at the higher 

 plane on the tibia. 



Operations. Tenotomy of the hamstring muscles 

 may be performed for pseudo-ankylosis, when these 

 tendons are permanently contracted, and, when this oper- 

 ation is employed, the tendons are generally divided on a 

 level with the most prominent part of the femoral con- 

 dyles. When the bicipital tendon is to be divided,the sharp 

 tenetome is introduced on the inner side of, and close to the 

 tendon, and the blunt tenetome, following it, is turned to- 

 wards and divides the tendon. In the insertion of the 

 sharp tenetome it is essential that both this tendon and 

 the external popliteal nerve, that runs along its inner and 

 posterior border, should be clearly identified. As a rule, 

 when the conditions demand a tenotomy of the biceps, the 

 latter is so prominent, that the nerve is left behind, i.e., is 

 more deeply situated, with reference to the tendon, than 

 usual, but, even though this is likely to be the case, yet 

 the normal relation of nerve and tendon should be kept in 

 mind when operating on the latter. When the semi- 

 tendinosus and the semi-membranosus are to be divided, 

 the knife should be introduced at a spot, opposite the site 

 of the incision, employed for the division of the biceps. 



