Test Your Skill In Reading Pediatric Ankles
Radiology Cases in Pediatric Emergency Medicine
Volume 3, Case 5
Alson S. Inaba, MD
Loren G. Yamamoto, MD, MPH
Kapiolani Medical Center For Women And Children
University of Hawaii John A. Burns School of Medicine
     This case consists of 16 ankle radiograph sets.  
Limited histories will be provided in most of them.  
When lateral views are shown, the heel is to the left of 
the image and the toes point toward the right on the 
image.

Case A:
     18-year old male with an inversion injury.

View Case A.






Interpretation of Case A
     AP and lateral views are displayed.  The AP view 
shows a fracture of the lateral cortex of the distal fibula.  
The lateral view shows an oblilque fracture through the 
distal fibula.  The AP view shows a black crescent in 
the tibia which is an artifact from poor film handling.  
There is a slight irregularity of the medial metaphysis of 
the distal tibia, however, the patient is not tender there.
     Impression:  Oblique fracture of the distal fibula.


Case B:
     This is a 6-year old male who sustained an inversion 
injury 6 hours prior to the ED visit.  He was initially 
limping, but he is now walking normally.  There is 
minimal tenderness of the lateral malleolus.

View Case B.







Interpretation of Case B
     AP, lateral, and mortise views are displayed.  There 
is a small bony density contiguous with the medial 
malleolus which is probably a developmental variant in 
view of his tenderness over the lateral malleolus only.  
This is very faint, best seen on the AP view and 
posteriorly (left) on the lateral view.  To see it best, turn 
down the room lights and adjust the brightness and 
contrast on your monitor.
     Impression:  Probably normal ankle.  Small bony 
density contiguous with the medial malleolus, probably 
a developmental variant.


Case C:
     This is a 14-year old male who sustained a twisting 
injury playing football when he stepped into a hole.  He 
has tenderness over his medial malleolus and is unable 
to bear weight.

View Case C.







Interpretation of Case C
     AP and lateral views are displayed.  The AP view 
shows a very slight lucency above the medial malleolus.  
It can be seen at the medial edge of the tibial 
metaphysis just above the physis.  The lateral view is 
positioned such that the heel is on the left and the toes 
are on the right.  This lateral view shows the fracture 
better along the anterior distal tibia.
     Impression:  Probable non-displaced medial 
malleolus (tibial metaphysis) fracture.


Case D:
     14-year old male with an ankle injury.

View Case D.







Interpretation of Case D
     AP, mortise, and lateral views are displayed.  There 
is a vertical lucency through the distal tibial epiphysis 
extending from the physis to the mortise joint space.
     Impression:  Salter Harris Type III fracture of the 
distal tibia.  


Case E:
     This is a 10-year old male who twisted his ankle 
skateboarding.  He complains of pain over his lateral 
malleolus.  There is tenderness and moderate swelling 
over the lateral malleolus.

View Case E.







Interpretation of Case E
     AP and mortise views are shown here.  There are 
no definite abnormalities on this radiograph.  The 
lucency above the medial malleolus at the medial tibial 
metaphysis does not represent a fracture since the 
patient is not tender there.
     Impression:  Normal ankle radiographs.
     However on closer examination of this patient, he is 
not tender over the tip of the fibula, he is mostly tender 
over the fibular physis raising the possibility of a 
non-displaced Salter Harris Type I fracture through the 
fibular physis.  This is a clinical diagnosis, not a 
radiographic diagnosis.  Such injuries should be 
splinted and followed clinically.  For a more in-depth 
review of the Salter-Harris fracture classifications, refer 
to Case 18 in Volume 1.
     Clinical Impression:  Rule out a non-displaced Salter 
Harris Type I fracture of the distal fibular physis.


Case F:
     A TV set fell on the lower leg of this 18-month old.

View Case F.







Interpretation of Case F.
     AP and lateral views are displayed.  There are 
disruptions in the cortices of the distal fibular and tibial 
metaphyses.  These are torus fractures of the distal 
fibula and tibia.  There is a second fracture of the fibula 
more proximal (upper portion of the image) with a 
modest degree of medial angulation (i.e., angle points 
to the medial side) seen best on the AP view.
     Impression:  Torus fractures of the fibula and tibia.   
Angulated fracture of the distal fibular diaphysis.


Case G:
     This is an 18-year old male with an ankle inversion 
injury.  He is tender over the distal aspect of the lateral 
malleolus.

View Case G.







Interpretation of Case G.
     AP, mortise, and lateral views are displayed.  There 
is a small bony density adjacent to the tip of the lateral 
malleolus.  This could represent an avulsion fracture of 
distal fibula or an accessory ossicle.  Since clinically he 
is tender in this area, this probably represents a small 
avulsion fracture of the tip of the fibula.
      Impression:  Small avulsion fracture of the distal 
fibula.


Case H:
     This is a 23-year old male who severely twisted his 
ankle.  He was running and he stepped into a deep 
hole.

View Case H.







Interpretation of Case H.
     AP, mortise, and lateral views are displayed.  There 
is an oblique, slightly displaced fracture of the distal 
portion of the shaft of the fibula.  There may be minimal 
widening of the medial aspect of the ankle mortise.  A 
small avulsion fracture is noted between the dome of 
the talus and the medial malleolus.  This small fragment 
is best seen on the AP view just inside the medial 
malleolus.  This may be hard to see.  You may have to 
enlarge the image, turn down the room lights, and 
adjust the contrast and brightness on your monitor.
     Impression:  Oblique fracture of the distal fibula and 
a small avulsion fracture which projects between the 
medial malleolus and the dome of the talus.


Case I:
     This is an 8-year old male who injured his ankle 
while skateboarding.  He has tenderness over his 
medial malleolus.

View Case I. 







Interpretation of Case I.
     AP and mortise views are displayed.  There is an 
irregularity of the tip of the medial malleolus.  This may 
represent a normal developmental variant of 
ossification.  However, it may represent a fracture.  A 
comparison view of his other ankle is needed for 
confirmation.  Since he is tender over his medial 
malleolus, one must assume that this is a fracture until 
proven otherwise.
     Impression:  Irregularity of the tip of the medial 
malleolus representing a fracture or a normal variant.


Case J:
     This radiograph was copied off a 35mm slide.  There 
was no patient identifying information on the slide so 
the patient's age and history are not available.

View Case J. 







Interpretation of Case J.
     AP, mortise, and lateral views are displayed.  There 
is an obvious fracture through the medial malleolus.  
Note that this fracture is obvious on the mortise view, 
but very subtle on the AP view.  This fracture might 
have been missed if a mortise view was not obtained.
     Impression.  Medial malleolus fracture.
Note:  This is NOT a Salter-Harris type III fracture since 
the fracture line does not extend into the physis (growth 
plate).  Salter-Harris fractures, by definition, must 
involve the physis.


Case K:
     This is a 17-year old male who twisted his ankle 
during a soccer game.  He was initially ambulatory, but 
he could not bear any weight on his injured ankle the 
next day.  He has tenderness over the lateral aspect of 
his ankle.

View Case K.







Interpretation of Case K.
     AP, mortise, and lateral views are displayed.  There 
is a fracture through the distal fibula.  Although the 
growth plate is almost closed, this is still technically a 
Salter Harris Type I fracture through the physis.  It is 
radiographically visible because it is slightly displaced 
as a widening of the physis.  It is not easily seen on the 
AP view, but it is more obvious on the mortise view.  
This fracture might have been missed if a mortise view 
was not obtained.  A normal closure of the growth plate 
will sometimes have this appearance.  Comparative 
views or stress views are required to confirm this 
radiographically.
     Impression:  Probable distal fibula fracture.


Case L:
     This is a 10-year old male who was struck by a car.  
He has evident injuries of his head, neck, abdomen, 
pelvis, and lower extremities.  Only his ankle 
radiographs are displayed here.

View Case L.







Interpretation of Case L.
     AP, mortise, and lateral views are displayed.  There 
are obvious comminuted fractures of the distal one-third 
of his fibula and tibia visible at the top of the image.  He 
may also have a medial malleolus fracture.  The medial 
malleolus fracture is best seen on the AP view.  There 
is a subtle lucency through the end of the medial 
malleolus.  There is an irregularity of the posterior tibia 
seen best on the lateral view.  This lateral view is 
positioned so that the heel is to the left and the toes are 
to the right.  The posterior metaphysis adjacent to the 
growth plate appears irregular.  This is probably not a 
fracture.  Note that a similar finding is visible on the 
lateral view in image B [Click on B].
     Impression:  Comminuted fractures of the distal 
one-third of the fibula and tibia.  Possible medial 
malleolus fracture.


Case M:
     This is a 3-year old female who sustained an 
inversion injury while running downhill.  She is limping 
and has tenderness over her lateral malleolus.

View Case M.







Interpretation of Case M.
     AP, mortise, and lateral views are displayed.  There 
are no definite bony abnormalities seen on these 
radiographs.  It is possible that he may have a slight 
distortion of the distal fibular metaphysis (proximal to 
the physis).
     There is some controversy as to whether the distal 
fibular epiphysis is slightly angulated or if this is a 
normal appearance.  According to our radiology editor, 
this is not necessarily radiographically abnormal (i.e., a 
normal fibula can have this appearance)..
     On closer examination, her pain is mostly over the 
fibular physis rather than the tip of the fibula.  Because 
of this, she is suspected as having a Salter Harris
Type I fracture through the fibular physis or the fracture 
of the fibular metaphysis.  She is placed in a splint and 
is followed clinically.
     Impression:  Probably normal ankle radiographs.  
Rule out fracture of the fibular metaphysis and/or a 
Salter Harris Type I fracture of the distal fibular physis.


Case N:
     This is a 13-year old male "sprained" his ankle at a 
baseball game.  There is obvious swelling about the 
ankle joint.

View Case N.







Interpretation of Case N.
     AP, mortise, and lateral views are displayed.  There 
is a vertical lucency through the distal tibial epiphysis 
extending from the ankle joint to the tibial physis.  It 
does not appear to extend into the metaphysis.
     Impression:  Salter Harris Type III fracture of the 
distal tibia.


Case O:
     This is a 9-year old female who fell off a second 
floor balcony at school, landing on her feet.

View Case O.







Interpretation of Case O.
     AP, mortise, and lateral views are displayed.  The 
lateral view also includes her foot.  There are multiple 
lucencies evident in her calcaneus.  The tibial physis 
does not appear to be widened or compressed.  There 
are no definite bony abnormalities of the ankle.  
However, in addition to being tender over her foot, she 
is also tender over her medial malleolus.  The 
mechanism of injury suggests the possibility of a Salter 
Harris Type V fracture of the distal tibial physis.  This is 
often not a radiographic diagnosis, but rather a clinical 
one based on examination findings and the mechanism 
of injury.  This type of injury may cause a growth arrest 
in a portion of the growth plate causing a valgus or 
varus deformity.
     Impression:  Multiple calcaneal fractures.  Rule out 
Salter Harris Type V fracture of the distal tibia.


Case P:
     This is a 23-year old female college student who 
twisted her ankle while jogging down a hill.  She has 
swelling and tenderness over her lateral malleolus.

View Case P.







Interpretation of Case P.
     AP, mortise, and lateral views are displayed.  There 
is an oblique fracture through the posterolateral aspect 
of the lateral malleolus.  This fracture has occurred 
through the fused growth plate which remains weaker 
than the surrounding bone for the next several years 
following closure.  The distal fibular physis usually fuses 
by age 20 years and the distal tibial physis usually 
fuses by age 18 years.
     Impression:  Lateral malleolus fracture.

Return to Radiology Cases In Ped Emerg Med Case Selection Page

Return to Univ. Hawaii Dept. Pediatrics Home Page

Web Page Author:
Loren Yamamoto, MD, MPH
Associate Professor of Pediatrics
University of Hawaii John A. Burns School of Medicine
loreny@hawaii.edu