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EASILY MISSED FOOT AND ANKLE
FRACTURES
NORDIC TRAUMA COURSE 2016, AARHUS
Ken F. Linnau, MD, MS
Emergency Radiology
Harborview Medical Center – University of Washington
Seattle, WA
Thanks to
Claire K Sandstrom
Harborview Medical Center
Seattle, WA
TARSAL STRESS FX
How many of these radiographs are normal?
Metatarsal stress fractures
• Metatarsals are most common site of stress fracture
• Occur with activity done in excess: hiking, running, marching
• May occur after foot surgery
• Often not evident on initial radiographs
Metatarsal stress fractures: options
• Re-image with radiographs in 7-10
days: cheap
• Bone scan: sensitive
• MRI: fancy, not cheap, sensitive
45 YOF W FOOT PAIN AFTER RUNNING
Sag STIR
Ax T1
Ax T2 FS
Sag T1
34 yom calcaneus fx pinned 2 wks ago,
continued pain
Stress fractures in the foot:
• Any bone except phalanges.
• Metatarsal (2nd and 3rd ): fluffy periosteal reaction.
• Calcaneus: narrow bands of sclerosis @ tuberosity.
• Talus: notoriously missed: consider MRI.
• Navicular: fracture is typically sagittal in orientation:
• External oblique view or CT or MRI.
22 yo bicyclist who crashed
How many fractures do you see?
22 yo bicyclist who crashed
22 yo bicyclist who crashed
The same bicyclist 10 days later
The same bicyclist 10 months later
Tarso-metatarsal (TMT) fracture -
dislocation (Lisfranc)
• Due to forced plantar flexion, twist or
crush.
• Transverse metatarsal ligaments II – V.
• Skip MT I-II (arrow).
• Oblique Lisfranc ligament (yellow).
• Base of MT II locked in mortise
between medial and lateral cuneiform
25 yof car vs. bulldozer
Lisfranc fracture-dislocation:
Unique osseous and ligamentous anatomy
• Predisposition for MT I- II separation
• More disruption with high-energy
• Divergent
• Homolateral
• Radiographic clues
22 yof jumped from 9ft
Click to add text
Stress views!
Every year in July…..
22 yof jumped from 9ft
Stress views:
• Warranted if tender or swollen
• Early diagnosis improves
outcomes of Lisfranc fx
• Ankle block or anesthetic
• Forefoot abduction with fulcrum
at calcaneo-cuboid joint
• Operative indication if TMT joint
displacement > 2 mm
22 yof jumped from 9ft
Lisfranc injury?
Click to add text
45 yof fall from standing height
No Lisfranc on CT!
Metadiaphyseal fracture of the 5th MT
(Jones)
• 1.5 - 2 cm from base of MT V
• Extra-articular
• Propensity for non-union
• Distinguish from avulsion
• Os vesalianum
• Sesamoid of peroneus
tendon
• Common in running athletes
• Inversion or stress-related
46 yo man
persistent
pain
6 weeks
after fall
What o’clock is the important abnormality?
46 yom, ankle pain 6 weeks post fall
46 yom, ankle pain 6 weeks post fall
46 yom, ankle pain, post op
Lateral process of the talus
• Always inspect carefully, if swelling inferior to lat. malleolus
• Fractures usually only seen on AP view
• Contains the lateral portion of posterior facet
• If untreated: premature subtalar osteoarthritis
• Snowboarder fracture
24 yom, basketball injury
Fibula Fx
High Fibula Fx 6 cm above malleolus tip
Post mal Fx
Pron-Ext Rotation Stage IV
NO post mal Fx
Pron-Ext Rotation Stage III
Low Fibula Fx at or below
tibial plafond
Spiral (Low ant/High
post)
Med mal Fx or deltoid lig tear
Sup-Ext Rotation Stage IV
NO med mal fx or deltoid lig tear
Post mal Fx
Sup-Ext Rotation Stage III
NO post mal Fx
Sup-Ext Rotation Stage II
Oblique (Low med/High
lat)
Pron-Abduction
Stage III
Transverse
Med mal Fx (vertical)
Sup-Adduction Stage II
NO med mal Fx
Sup-Adduction Stage I
Modified from
Arimoto HK and Forrester DM. Classification of Ankle
Fractures: An Algorithm. AJR 135:1057-1063 (1980)
http://www.ajronline.org/cgi/reprint/135/5/1057.pdf
Weber B Weber A
Weber C
Joseph Yu’s checklist for low-energy ankle
trauma:
Medial malleolus (1)
Lateral malleolus (2)
Anterior tibial tubercle (3)
Posterior tibial malleolus (4)
Talar dome (5)
Lateral talar process (6)
Posterior talar process (7)
Dorsal to talonavicular joint (8)
Anterior calcaneus process (9)
Calcaneal insertion of ext dig
brev (10)
Base of 5th MT (11)
Emergency Radiology (2009) 16: 309-318
24 yof rock climber: fall
Click to add text
Which side is abnormal?
Click to add text
24 yof rock climber: fall
Joseph Yu’s checklist for low-energy ankle
trauma:
Medial malleolus (1)
Lateral malleolus (2)
Anterior tibial tubercle (3)
Posterior tibial malleolus (4)
Talar dome (5)
Lateral talar process (6)
Posterior talar process (7)
Dorsal to talonavicular joint (8)
Anterior calcaneus process (9)
Calcaneal insertion of ext dig
brev (10)
Base of 5th MT (11)
Emergency Radiology (2009) 16: 309-318
24 yof rock climber: fall
Osteochondral defects:
• Talar dome (5)
• Most common talus fracture
• ¼ lateral, ¾ medial
• MRI can be helpful to assess
stage of injury
24 yof rock climber: fall
Posterior process of the talus (7):
• Medial and lateral tubercles form groove
for flexor hallucis tendon.
• Injury presents with posteromedial pain.
• Os trigonum = unfused lat tubercle.
• Completely corticated
• Synchondrosis anteriorly
• Differentiating os from fracture: CT, MR.
27 yof rolled her ankle
How many fractures do you see?
27 yof rolled her ankle
Anterior process of the calcaneus
(9):
• Insertion of the bifurcate ligament
• Stabilizer of plantar and dorsal
flexion.
• Avulsion fractures uncommon
• Often initially missed.
• Oblique views, CT, MR may help.
• DDX: os calcaneus secundarius
Joseph Yu’s checklist for low-energy ankle
trauma:
Medial malleolus (1)
Lateral malleolus (2)
Anterior tibial tubercle (3)
Posterior tibial malleolus (4)
Talar dome (5)
Lateral talar process (6)
Posterior talar process (7)
Dorsal to talonavicular joint (8)
Anterior calcaneus process (9)
Calcaneal insertion of ext dig
brev (10)
Base of 5th MT (11)
Emergency Radiology (2009) 16: 309-318
Summary:
Stress fractures are often initially radiographically inapparent
Lisfranc fracture dislocations can be subtle, but require
surgery
Talar fractures: lateral process fractures are often subtle,
scrutinize the AP view.
Joe’s ankle check list: try it, you may like it.
Selected references:
1. Digiovanni CW, Benirschke SK, Hansen ST. Foot Injuries. In:
Browner BD, Jupiter JB, Levine AM, editors. Skeletal Trauma: WB
Saunders; 2003. p. 2466.
2. Nathan R, Ingraham C. Lower Extremity Trauma. In: Bittle MM,
Gunn ML, Gross JA, Stern EJ, editors. Trauma Radiology Companion.
2nd ed: Lippincott Williams & Wilkins; 2012. p. 376-410.
3. Rogers LF. The Foot. Radiology of Skeletal Trauma: Churchill
Livingston; 2002. p. 1319.
4. Yu JS, Cody ME. A template approach for detecting fractures
in adults sustaining low-energy ankle trauma. Emerg Radiol.
2009;16(4):309-18. Epub 2009/02/19.