THE FIBULA. 



113 



The superior exiremiiy, or head, somewhat expanded, presents a small 

 oval eartilaginoiis surface looking upwards and inwards, which articu- 

 lates with the external tuberosity of the tibia, and externally to this a 



Fig. 



Fig. 101. Fig. 102. 

 S ^ 5. ' 



i 



101. — Right Fibula from the outside axd 



BEFORE. (A. T.) * 



1, shaft showing the oblique grooves of the peronei 

 muscles on the outer anterior surface ; 2, head ; 3, its 

 projection, giving insertion to the tendon of the biceps 

 femoris ; 4, malleolus externus or lower end, the figiu-e 

 is placed opposite its anterior or oblique edge ; above this 

 is seen the triangular subcutaneous surface of the bone. 



Fig. 102. — Right Fibula from the inside and 

 BEHIND. (A. T.) ^ 

 5, the obliqus surface of articulation with the tibia 

 superiorly ; 6, points to the internal or interosseous 

 ridge ; 7, the triangular rough surface for the lower 

 interosseous ligament ; 8, the external malleolar surface 

 for articulation with the astragalus ; 9, groove behind 

 the malleolus externus for the tendons of the peronei 

 muscles ; at a little distance below 6, the nutritious 

 foramen. 



rough prominence directed upwards, to 

 which the tendon of the biceps muscle is at- 

 tached : its external surface is subcutaneous ; 

 the rest is rough for ligaments. 



The mfcrior extremity, or external malleo- 

 lus, is larger than the head of the bone, and 

 longer and more prominent than the internal 

 malleolus ; internally it forms the outer limit 

 of the ankle joint, and presents a triangular 

 smooth surface for articulation with the as- 

 tragalus, bounded posteriorly by a rough 

 depression where the transverse ligament is 

 attached : its anterior border, after project- 

 ing rather abruptly forwards, slopes down- 

 wards and backwards ; its posterior border 

 presents a shallow groove traversed by the 

 tendons of the peronei muscles ; while 

 externally it is convex and subcutaneous, 

 and a triangular subcutaneous surface is 

 continued up from it for an inch or two on 

 the shaft. 



The shaft is irregularly three-sided and 

 twisted. One surface, from which the pe- 

 ronei muscles take origin, looks forward at the 

 commencement, then turning outwards and backwards, is continued 

 behind the subcutaneous space of the lower end to the groove behind the 

 malleolus. Another surface, looking backwards in the upper half of its 

 extent, winds inwards and terminates above the articular sru-face of the 

 malleolus ; near its upper end this surface is rough, giving attach- 

 ment to the soleus muscle, and in the rest of its extent it is occupied 

 by the flexor longus pollicis. The remaining part of the siuface of 

 the bone, internal, turns forward inferiorly, and terminates on the 

 anterior margin of the malleolus ; it is divided by a longitudinal line, 



VOL. I. I 



