34 



THE INFERIOR EXTREMITY 



peroneal retinacula bind the tendons of the peronaeus longus 

 and brevis to the lateral surface of the calcaneus (Fig. 158). 



Intermuscular Septa. As the deep fascia of the leg passes 

 backwards over the fibular region, two strong intermuscular 

 septa are given off from its deep surface. These are dis- 

 tinguished as the anterior and posterior fibular septa. The 

 anterior fibular septum intervenes between the peroneal muscles 

 and the extensor muscles of the toes, and is attached to the 

 anterior crest of the fibula. The posterior fibular septum is 



interposed between the 

 peroneal muscles and the 

 muscles on the back of 

 the leg, and is attached 

 to the lateral crest of the 

 fibula. 



The leg is thus sub- 

 divided into three osteo- 

 fascial compartments, cor- 

 responding to the anterior, 

 lateral, and posterior 

 crural regions. The an- 

 terior compartment is 

 bounded by the investing 

 deep fascia, the anterior 



FIG. 152. Diagrammatic representation of fibular septum, the anterior 



the Fascia of the Leg. The fascia of the c , , . , r 



tibialis posterior is more a muscular P art of the medial surface 

 aponeurosis than a true fascial septum ; of the fibula (that part 

 but it is convenient for descriptive pur- 

 poses to regard it as one of the parti- 

 tions. 



which lies anterior to the 

 interosseous crest), the 

 interosseous membrane, 

 and the lateral surface of the tibia. The lateral compartment 

 is bounded by the lateral surface of the fibula, the investing 

 fascia, and the two fibular septa. The posterior compartment, 

 which will be studied later, is much the largest ; its walls are 

 formed by the posterior surface of the tibia, the posterior 

 part of the medial surface and the whole of the posterior 

 surface of the fibula, the interosseous membrane, the posterior 

 fibular septum, and the investing deep fascia. 



Dissection. The anterior compartment of the leg should 

 now be opened by the removal of the deep fascia. The transverse 

 and cruciate ligaments, however, must be retained, and their 

 borders should be separated artificially, by the knife, from the 



