238 THE INFERIOR EXTREMITY 



pubic tubercle, (2) through the medium of the lacunar ligament 

 to the medial part of the pectineal line. The inguinal 

 ligament pursues an oblique course between its iliac and pubic 

 attachments, and at the same time describes a gentle curve, the 

 convexity of which is turned distally. By its distal border it 

 affords attachment to the iliac part of the fascia lata, and 

 when that is divided it loses its curvature. 



The ligamentum lacunare (O.T. Gimbernafs ligament) is a 

 small triangular piece of aponeurosis which occupies the interval 

 between the medial part of the inguinal ligament and the medial 

 inch of the pectineal line being attached by its margins to 

 both. Its base, which looks laterally, is sharp, crescentic, and 

 free, and abuts against the femoral sheath. The lacunar 

 ligament occupies a very oblique plane ; its femoral surface 

 looks distally and laterally, whilst its abdominal surface is 

 directed upwards and medially (Fig. 109). 



Dissection. The exposure of the femoral sheath is the next 

 step in the dissection of the thigh. To display it the iliac portion 

 of the fascia lata must be partially reflected. Divide the superior 

 horn of the lateral crescentic margin of the fossa ovalis, and 

 then carry the knife laterally along the lower border of the 

 inguinal ligament, so as to sever the attachment of the fascia 

 lata to that thickened band. The incision should extend to 

 within an inch of the anterior superior spine of the ilium. The 

 piece of fascia marked out by the incision above, and by the 

 lateral free margin of the fossa ovalis medially, must be carefully 

 raised from the subjacent femoral sheath and thrown distally 

 and laterally. On the removal of a little loose fat, the femoral 

 sheath will be brought into view as it enters the thigh under 

 the inguinal ligament. Isolate it carefully from adjacent and 

 surrounding parts, by carrying the handle of the knife gently 

 round it as far as possible. Insinuate the handle of the knife, first 

 between the sheath and the inguinal ligament, next between 

 the sheath and the lacunar ligament^ which lies medial to it, 

 and finally behind the sheath along the front of the pectineal 

 fascia. Laterally and posteriorly the sheath is fused with the 

 iliac fascia 1 on the psoas muscle, and in that situation it will 

 be necessary to use the edge of the knife before the sheath can 

 be isolated (Fig. in). 



Femoral Sheath. The funnel-shaped appearance of the 

 femoral sheath will now be apparent the wide mouth of 

 the membranous tube is directed upwards towards the 

 abdomen, whilst the narrow distal part gradually closes 



1 Do not confuse the iliac fascia with the iliac part of (he fascia lata. 

 The iliac fascia is a fascia which descends from the abdomen on the anterior 

 surfaces of the psoas and iliacus muscles. The iliac part of the fascia lata is 

 part of the deep fascia of the thigh (see p. 229). 



