ANKLE JOINT. 



inferior , and posterior inferior, which connect 

 the fibula to the tibia ; and from the posterior 

 surface of the end of the fibula, a ligament 

 called the transverse, passes to the posterior 

 part of the internal malleolus, which resembles 

 the marginal ligament of the glenoid cavity 

 and acetabulum ; for it enlarges the articulation 

 with the astragalus, while it serves as a liga- 

 ment to the tibia and fibula. There are some 

 short, strong fibres passing below and between 

 the opposite surfaces of the tibia and fibia, 

 called the inferior interosseous ligament. ' 



Articulation of the Leg, Foot, and Ankle Joint. 



It should be observed that the tibia and fibula are so firmly 

 connected with each other below, that they may be considered 

 as forming but one member of this articulation. 



Fig. 68.f The varied surfaces formed by 



the tibia and fibula and their two 

 malleolar processes, and by the as- 

 tragalus with its two lateral facets, 

 where it is contiguous to them, are 

 invested with the usual apparatus of 

 articulation. The synovial fluid is 

 generally observed to be very redun- 

 dant in this joint. There are four 

 ligaments which enter into this ar- 

 ticulation. 

 A triangular band of fibres called the internal lateral liga- 



* A posterior view of the ankle joint. 1. The lower part of the interosseous 

 membrane. 2. The posterior inferior ligament connecting the tibia and fibula. 

 3. The transverse ligament. 4. The internal lateral ligament. 5. The posterior 

 fasciculus of the external lateral ligament. 6. The middle fasciculus of the 

 external lateral ligament. 7. The synovial membrane of the ankle joint. 

 8. The os calcis. 



f An internal view of the ankle joint. 1. The internal malleolus of the tibia. 

 2, 2. Part of the astragalus ; the rest is concealed by the ligaments. 3. The os 

 calcis. 4. The scaphoid bone. 5. The internal cuneiforme bone. 6. The inter- 

 nal lateral or deltoid ligament. 7. The anterior ligament. 8. The tendo Achillis ; 

 a small bursa is seen interposed between this tendon and the tuberosity of the 

 os calcis. 



