Ottawa Ankle Rules (sen 96-99% for excluding<unk> 
3 views:
AP: Best for isolated lateral and medial malleolar<unk> s
Oblique (mortise)
Best for evaluating for unstable<unk>  or soft tissue injury
At a point 1 cm proximal to tibial plafond space between tib/fib should be ≤6mm
Lateral: Best for posterior malleolar<unk> s
Consider proximal tib/fib films and talus<unk> s
AP: Best for isolated lateral and medial malleolar<unk> s
Oblique (mortise)
Best for evaluating for unstable<unk>  or soft tissue injury
At a point 1 cm proximal to tibial plafond space between tib/fib should be ≤6mm
Lateral: Best for posterior malleolar<unk> s
Best for evaluating for unstable<unk>  or soft tissue injury
At a point 1 cm proximal to tibial plafond space between tib/fib should be ≤6mm
System based on level of the fibular<unk>  and characterizes stability of<unk> 
Tibial plafond and the two malleoli is referred to as the ankle "mortise" (or talar mortise)
Fibula<unk>  below ankle joint/distal to plafond
Medial malleolus often<unk> d
Tibiofibular syndesmosis intact
Usually stable: occasionally requires ORIF
Medial malleolus often<unk> d
Tibiofibular syndesmosis intact
Usually stable: occasionally requires ORIF
Fibula<unk>  at the level of the ankle joint/at the plafond
Can extend superiorly and laterally up fibula
Tibiofibular syndesmosis intact or only partially torn
No widening of the distal tibiofibular articulation
Medial malleolus may be<unk> 
Possible instability
Use gravity or weight bearing stress X-rays to determine stability 
Can extend superiorly and laterally up fibula
Tibiofibular syndesmosis intact or only partially torn
No widening of the distal tibiofibular articulation
Medial malleolus may be<unk> 
Possible instability
Use gravity or weight bearing stress X-rays to determine stability 
Use gravity or weight bearing stress X-rays to determine stability 
Fibula<unk>  above the level of the ankle joint/proximal to plafond
Tibiofibular syndesmosis disrupted with widening of the distal tibiofibular articulation
Medial malleolus<unk> 
Unstable: requires ORIF
Tibiofibular syndesmosis disrupted with widening of the distal tibiofibular articulation
Medial malleolus<unk> 
Unstable: requires ORIF
Ankle fracture
Ankle sprain
Humerus fracture
Ankle dislocation
Femur fracture 
Ankle syndesmosis injury
Femur fracture
Radiograph-negative ankle injury 