Articular surfaces of ankle joint:-
The term ankle joint refers to specifically to the talocrural joint that is the articulation between teh distal tibia and fibula proximally and the body of the talus distally .
The ankle is synovial hinge joint with a joint capsule and associated ligaments
It is considered to have a single axis with one degree of freedom
Proximal articular surface :_
The proximal segment of the ankle is composed of concave surface of distal tibia and tibial fibular malleoli.
-these 3 facets form an almost continues concave joint surface that extends more distally on the fibular (lateral )side than on the tibial (medial side and more distally on the post margin of tibia than on the anterior margin .
-mortise the structure of the distal tibia and the malleoli resembles and is referred to as mortise .
- the proximal and distal tibio fibular joints are anatomically distinct from the ankle joint but functionally linked exclusively to the ankle joint.
-tibio fibular jt donot add any degree of freedom to the more distal ankle and foot
-fusio of radio ulnar joints would have a little effect on wrist range of motion whereas fusion of tibio fibular joints may impair normal ankle functions.
Distal articular surface :-
The body talus forms the distal articulation of ankle jt
The talus bone have 3 main components-head ,neck body
-the body of talus has three articular surface
1)large lateral facet fibula
2)smaller medial facet (tibia)
3)trochlear or superior facet
The large convex trochlear surface has a central groove that runs at the slight angle to the neck and head of talus
-the articular cartilage covering the trochlea is continues with the cartilage covering the more extensive lateral facet and the smaller medial facet
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