236 



FEMORAL ARTERY. 



by the state of the vessel and by the position of 

 the limb ; when the artery is empty, they are 

 less marked than when it is full ; and when 

 the limb is extended, they are removed; when 

 flexed, they are reproduced ; while in some 

 subjects again, they appear to be absent, the 

 line of the vessel's course being almost direct. 

 The degree to which the artery passes back- 

 ward is not equally great at all parts of its 

 course: in its upper half, i.e. from Poupart's 

 ligament until it lies upon the adductor longus 

 muscle, the vessel inclines much more back- 

 ward than in the remainder, and at the same 

 time describes a curve concave forward, but 

 both the latter particulars are more remarkable 

 when the thigh is flexed, and in thin subjects, 

 than when the limb is extended and in sub- 

 jects which are in good condition ; in the last 

 case the vessel is supported and held forward 

 by the deep fat of the groin situate behind it. 

 In its lower half the artery inclines less back- 

 ward, being supported by the muscles against 

 which it rests. 



The femoral artery is also described as in- 

 clining inward * during its descent ; but this 

 statement requires correction, or at least ex- 

 planation. The vessel certainly does incline 

 inward at some parts of its course, and for the 

 most part it does so as it descends from the 

 os innominatum into the inguinal space, form- 

 ing thereby the curvatures which have been 

 mentioned ; but the general direction of it is 

 either slightly outward, or at the most directly 

 downward, not inward : the opinion that it is 

 inward has arisen, it is to be supposed, from 

 a partial view of its course, which, in conse- 

 quence of its serpentine direction, is likely to 

 mislead, and is at variance with that of the 

 popliteal artery, (the lower part of the same 

 vessel,) which is decidedly outward. In order 

 to be assured of the true direction of the 

 vessel, the writer has tested it carefully by 

 means of the plumb-line, and he has always 

 found that it inclined somewhat outward from 

 the perpendicular: the degree, however, to 

 which the proper femoral artery does so, is not 

 considerable, though sufficient to place the 

 matter beyond doubt. 



It is to be borne in mind that, in determin- 

 ing the direction of the vessel's course, the 

 limb must be placed in the bearing which it 

 holds naturally in the erect posture, inasmuch 

 as an inclination to either side will influence 

 materially the direction of the artery : thus an 

 inclination of the limb inward will at once 

 give it the same tendency, and render it spiral, 

 both which conditions are removed by placing 

 the limb in its ordinary position. 



In consequence of the course which the 

 vessel pursues, and of the oblique position of 

 the femur conjointly, the femoral and popliteal 

 arteries hold very different relations to the shaft 

 of that bone ; the former, in the first stage of 

 its course, being in a plane anterior to the 

 femur, and in the middle of the limb being 

 upon its inside ; while the latter is situate be- 

 hind the bone, and at the inferior part of the 



* Boyer, Cloquct, Harrison. 



popliteal region corresponds to the axis of its 

 shaft: hence the artery is said* to pass some- 

 what in a spiral manner in reference to the 

 thigh bone; but this is incorrect, the spiral 

 course being only apparent and resulting from 

 the combined effect of the obliquity of the 

 artery itself backward and outward, and of the 

 shaft of the femur inward and forward : that 

 this is so may be satisfactorily shewn by the 

 application of the plumb-line to the course of 

 the artery, upon the different aspects of the 

 limb ; from which it will appear that, allow- 

 ance being made for the serpentine deviations 

 already adverted to, the general course of the 

 vessel is, guam proximl, straight, and that it 

 cannot, at all with propriety, be said to be 

 spiral, this being not a real but an apparent 

 direction, the result of the circumstances which 

 have been mentioned. 



The point at which the femoral artery com- 

 mences is referred by most writers to Poupart's 

 ligament; this method of demarcation is at- 

 tended with the inconvenience, that during life 

 the exact situation of the ligament is difficult 

 to determine, inasmuch as it does not run 

 direct from one attachment to the other, and 

 that in dissection its position is immediately 

 altered on the division of its connections with 

 the adjoining fascia; : hence the student, not 

 having a fixed point of reference, is often at a 

 loss to distinguish between the iliac and femo- 

 ral arteries, and mistakes affecting the relations 

 of the most important branches of those vessels 

 are liable to be made. For those reasons it 

 appears to me that it would be much pre- 

 ferable to select some fixed and unchanging 

 point to which to refer the commencement of 

 the artery ; and for this purpose I would 

 suggest the ilio-pectineal eminence of the os 

 innominatum, which, to the student at least, 

 if not to the practical surgeon, will afford an 

 unerring guide to the distinction of the one 

 vessel from the other; the femoral artery, at 

 its entrance into the thigh, being situate im- 

 mediately external to the inferior part of that 

 prominence,f with which point the middle of 

 the line connecting the anterior superior spi- 

 nous process of the ilium and the symphysis 

 of the pubis will also be found to correspond. 

 The precise situation of the vessel is referred 

 by some to the centre of Poupart's ligament, 

 or a point midway between the anterior supe- 

 rior spinous process of the ilium and the 

 spinous process of the pubes ; by others to a 

 point midway between the spinous process of 

 the ilium and the symphysis of the pubes. 

 With regard to this question it is to be ob- 

 served that the relation of the artery to the 

 points between which it is situate is not strictly 

 the same in all instances ; that in some it will 

 be found to correspond to the former, and in 

 others to the latter account; but that the latter 

 relation appears to prevail in so much the 

 greater number, that it ought to be adopted as 

 the rule. According to Velpeau it is distant 

 two inches and a quarter from the spinous pro- 



* Harrison, op. cit. p. 137. 



t This point will be discussed again. 



