Test yourself: X-ankle
Case Study 1.
A construction worker (38 years) fell from a scaffolding. Examination reveals an abnormal position of the right ankle. In the trauma room, an AP image and lateral image of the ankle are made.
Figure 1. AP image and lateral image of the right ankle.
Both images reveal a high fibular fracture. The lateral image also reveals a fracture of the posterior malleolus.
The medial clear space seems slightly widened. The abnormal articulation between the tibia and talus is clearly visible on the lateral image in particular.
Weber C fracture (pronation-exorotation stage IV fracture) with dislocated ankle fork.
♦ Figure 1. Answer: Weber C fracture.
Case Study 2.
A 25-year-old woman sprains her ankle while playing hockey. She reports her “ankle twisted inward”. She can hardly use her foot anymore after the event.
An x-ray is made (fig. 2).
Figure 2. Mortise and lateral image of the left ankle.
Normal ankle fork. No widening of the clear spaces.
A fracture line from the base of metatarsal V can be seen at the edge of the image.
Fracture of metatarsal V base.
Note: the above fracture is associated with an inversion trauma. You should therefore always check the entire image!
♦ Figure 2. Answer: fracture of MT-V base.
Case Study 3
An 8-year-old boy jumped from a wall (about 1-2 m high) and hurt his right leg. The right ankle is swollen significantly and the child no longer wants to stand on his right leg.
Figure 3. Mortise and lateral image of the right ankle.
The AP image reveals no abnormalities.
A fracture line can be seen on the lateral image under the epiphyseal plate (= epiphysis), there is no evident dislocation.
The fracture does not continue above the epiphyseal plate (= metaphysis).
Fracture of distal tibia, Salter Harris III.
♦ Figure 3. Answer: fracture of distal tibia, Salter Harris III.
Case Study 4.
A 59-year-old man jumped from a ladder, a height of about 1.5 m.
He can no longer use his left foot.
Figure 4. Axial calcaneus, lateral image and AP image.
Symmetrical ankle fork. No evident fracture at the level of the ankle. A lucent line at the dorsal side of the calcaneus can be seen on the lateral image. Trabeculation is also disrupted at the anterior side (particularly at the level of the neutral triangle). Also note the limited loss of height of the calcaneus (Böhler's angle is reduced).
Additional findings: enthesopathy of Achilles tendon.
Comminuted intra-articular calcaneal fracture of the corpus continuing to posterior.
♦ Figure 4. Answer: comminuted intra-articular calcaneal fracture.
Case Study 5.
A 34-year-old man slips while jogging and falls. He reports his right ankle “doubled” on him; everything happened so quickly that the man does not know exactly what type of movement the ankle made.
The ankle can hardly bear any weight and particularly the lateral and posterior side of the ankle are painful upon examination.
An ankle x-ray is made.
Figure 5. Mortise image and lateral image of the right ankle.
There is no obvious soft tissue swelling at the lateral malleolus or medial malleolus.
The ankle fork is symmetrical. No cortical interruptions are visible. There is a rounded structure on the lateral image posterior of the talus. This is an os trigonum and is one of the many accessory ossicles (= normal variation) in the ankle.
The patient was discharged with a diagnosis of contusion and a pressure bandage was applied.
♦ Figure 6. Answer: os trigonum. No fracture.