190 



THE SKELETON 



biceps tendon and the fibular (long external) collateral ligament of the knee-joint, 

 medially it presents a round or oval facet [facies articularis capituli], directed 

 upward, forward, and medially, for articulation with the lateral condyle (tuber- 

 osity) of the tibia. The margin of the facet gives attachment to the articular 

 capsule of the superior tibio-fibular articulation. Posteriorly, the head rises into 

 a pointed apex (styloid process), which affords attachment to the short lateral 

 ligament of the knee-joint, and on the lateral side, to part of the biceps tendon. 



The posterior aspect of the head gives attachment to the soleus, the lateral aspect, extend- 

 ing also in front of the eminence for the biceps, to the peroneus longus; from the anterior aspect 

 fibres of the extensor digitorum longus arise, whilst the medial side lies adjacent to the tibia. 



The shaft [corpus fibulae], in its upper three-fourths, is quadrangular, possessing 

 four borders and four surfaces, whereas its lower fourth is flattened from side to 

 side, so as to be somewhat triangular. The borders and surfaces vary exceed- 

 ingly so that their description is difficult. The anterior crest (or antero-lateral 

 border) commences in front of the head and terminates below by dividing to 

 enclose a subcutaneous surface, triangular in shape, immediately above the 



Fig. 227.- 



-The Upper End of the Left Fibula to show Muscular and Ligamentous 

 Attachments X 2. (G. J. Jenkins.) 



Anterior superior tibio-fibular liga 

 ment 



Fibular collateral ligament 

 Biceps 



Styloid process 



^ Facet for tibia 



i Capsule of superior tibio- 

 fibular joint 



Short 

 lateral ligament 



Posterior superior tibio- 

 fibular ligament 



lateral malleolus. It gives attachment to a septum separating the extensor 

 muscles in front from the peronei muscles on the lateral aspect. The interosseous 

 crest (or antero-medial border), so named from giving attachment to the interos- 

 seous membrane, also commences in front of the head, close to the anterior crest, 

 and terminates below by dividing to enclose a rough triangular area immediately 

 above the facet for the talus (astragalus) ; this area gives attachment to the inferior 

 interosseous ligament, and may present at its lower end a narrow facet for articula- 

 tion with the tibia. The medial crest (or postero-medial border), sometimes 

 described as the oblique line of the fibula, commences at the medial side of the 

 head and terminates below by joining the interosseous crest, in the lower fourth 

 of the shaft. It gives attachment to an aponeurosis separating the tibialis 

 posterior from the soleus and flexor hallucis longus. The lateral crest (or postero- 

 lateral border) runs from the back of the head to the medial border of tlie peroneal 

 groove on the back of the lower extremity; it gives attachment to the fascia sepa- 

 rating tlic peronei from the flexor muscles. 



'J'hc anterior or extensor surface is the interval between the interosseous and 

 anterior crests. In the ui)per third it is extremely narrow, but broadens out 

 h)elow, where it is slightly grooved longitudinally. It affords origin to three 

 muscles: laterally, in the upper two-thirds, to the extensor digitorum longus, and, in 

 the lower third, to the peroneus tcrtivs; medially, in the middle third, also to the 

 extensor hallucis longus. The medial surface, situated between the interosseous 

 and medial crests, is narrow above and below, and broadest in the middle. It 

 is grooved and sometimes crossed obliquely by a prominent ridge, the secondary 

 oblique line of the filjula; tlie surface gives origin to the tibialis posterior, and the 

 ridge to a tendinous septum in the substance of the muscle. The posterior surface 



