TIBIO-FIBULAR JOINTS 427 



distal part of each of the opposing surfaces of the bones is 

 articular and coated with cartilage continuous with the 

 cartilage on the distal ends of the tibia and fibula where they 

 take part in the formation of the ankle joint ; in other cases 

 articular cartilage is entirely absent. The surfaces of the 

 proximal part of the syndesmosis are always rough, and are 

 held together by an exceedingly strong interosseous ligament. 



In addition to the important interosseous ligament three 

 other ligaments are present : 



1. Lig. malleoli lateralis anterius (O.T. Ant. inf. tibio-fibular ligament). 



2. Lig. malleoli lateralis posterius (O.T. Post. inf. tibio-fibular ligament). 



3. Distal ligament of the lateral malleolus. 



The anterior and posterior ligaments are flat strong bands 

 which pass from the tibia to the fibula, in an oblique direc- 

 tion, laterally and distally. 



The distal part of the posterior ligament forms a strong 

 narrow band of yellowish fibres, which takes a transverse 

 course on the back of the joint and is firmly attached to 

 both tibia and fibula, filling up the interval between them. 

 It constitutes a part of the tibio-fibular socket for the 

 talus at the ankle joint (Figs. 192 and 193); and on the 

 proximal aspect of the articular surface of the talus, the 

 area over which it plays is usually easily distinguished. This 

 portion of the posterior ligament is called the distal ligament 

 of the lateral malleolus. 



Dissection. To see the interosseous ligament of the tibio- 

 fibular syndesmosis the bones of the leg may be sawn through 

 about two inches from the distal end of the tibia, and then 

 divided with the saw proximo-distally in a vertical-transverse, 

 or frontal direction. This cut should be planned so as to pass 

 through the tibio-fibular syndesmosis. The short strong fibres 

 of the interosseous ligament will then be seen, and also the short 

 narrow articular interval between the distal portions of the 

 opposing surfaces of the bones when that interval is present. If 

 a cavity is present in the distal part of the joint the synovial layer 

 of the capsule of the ankle joint is prolonged proximally over 

 w the inner surface of those parts of the ligaments of the tibio- 

 fibular syndesmosis which help to form the boundaries of the 

 cavity. 



ARTICULATIONS OF THE FOOT. 



The articulations of the foot are very numerous. They 

 consist of: 



