1. Mark Wahba X-Ray rounds July 24th, 2003
Radiology of the Foot
Mark Wahba
X-Ray rounds
July 24th, 2003

2. Goals Approach to radiography of the foot
Become familiar with a Lisfranc injury
Become familiar with a Jones fracture

3. Outline Bones Views Important Points Lisfranc Joint Jones fracture
Films

4. The foot
28 bones
57 articulations

5. 3 anatomic and functional regions
Hindfoot: talus, calcaneus
Midfoot: navicular, cuboid, cuneiforms
Forefoot: metatarsals, phalanges, sesamoids

6. Bones

7. Bones

8. Accessory Ossification Centres
Normal
30% of population
Smooth corticated surfaces

9. Adequate views
Anterior-Posterior
Oblique
Lateral

10. AP

11. AP view
Medial margin of the base of the 2nd metatarsal is in line with the medial margin of the middle cuneiform
Base of the 3rd metatarsal is obscured
View 1st and 2nd MT, medial and middle cuneiform

12. AP alignment

13. Oblique

14. Oblique view
Medial margin of the base of the 3rd metatarsal should be in line with the medial margin of the lateral cuneiform
Base of the 2nd metatarsal is obscured
View 3,4,5 MT, lateral cunieform, navicular, cuboid

15. Oblique alignment

16. Lateral

17. Lateral
Hindfoot
Soft tissues
View articulations: CalCub, TN, NCun

19. Bohler’s Angle
Draw a line from the posterior aspect of the calcaneum to its highest midpoint
Draw a line from the anterior aspect of the calcaneum to its highest midpoint
Measured angle is from degrees

20. Bohler’s Angle

21. Jacques Lisfranc

22. Lisfranc Joint
named for Jacques Lisfranc ( ), a field surgeon in Napoleon's army
“described an amputation performed through this joint because of gangrene that developed after an injury incurred when a soldier fell off a horse with his foot caught in the stirrup”
refers to the articulation involving the first and second metatarsals with the medial and middle cuneiforms

24. Any injury to this area, whether dislocation or fracture-dislocation, is termed a Lisfranc injury
Initially missed 20% of the time
high risk of chronic pain and functional disability if they go unrecognized

26. Presentation Hx of Direct trauma
Hx of Indirect trauma: “force is transmitted to the stationary foot so that the weight of the body becomes a deforming force by torque, rotation or compression”
Pain in midfoot
Inability to weight bear, especially on toes
Lisfranc Injury of the Foot: A Commonly Missed Diagnosis, BURROUGHS et al., American Family Physician, July 1998, 58 no. 1 ,p.118

27. Why?
“While transverse ligaments connect the bases of the lateral four metatarsals, no ligament exists between the first and second metatarsal bases.  The joint capsule and dorsal ligaments form the only minimal support about the Lisfranc joint, creating a "weak link" that is prone to injury.”

28. Almost invariably involve metatarsal fractures
Usually the 2nd metatarsal
# cuboid, cuneiform, navicular occur in 39%
Weight bearing views are useful

29. Signs of a Lisfranc injury
The medial shaft of the 2nd metatarsal should be aligned with the medial aspect of the middle cuneiform on the AP view.
The medial shaft of the 3rd metatarsal should be aligned with the medial aspect of the lateral cuneiform on the oblique view.
The first metatarsal cuneiform articulation should have no incongruency.
The presence of small avulsed fragments ("fleck sign")should be sought in the medial cuneiform-second metatarsal space.
The naviculocuneiform articulation should be evaluated for subluxation.
Should be no "step-off" as each metatarsal shaft should never be more dorsal than its respective tarsal bone

30. AP

31. AP

32. Oblique view

33. Oblique view

34. lateral

35. lateral

36. Jones Fracture

37. Jones Fracture
“Sir Robert Jones described his own fracture of the fifth metatarsal in 1902, when he injured himself while dancing around a Maypole at a military garden party”
# at base of 5th metatarsal at metaphyseal-diaphyseal junction

39. w/in 1.5 cm distal to tuberosity of 5th metatarsal
Should not be confused w/ more common avulsion # of 5th metatarsal tuberosity
An oblique radiograph is essential to accurately assess this fracture

40. trauma site corresponds to the area between the insertion of the peroneus brevis and tertius tendons
peroneus tertius originates on anterior aspect of fibula
injury occurs when the ankle is plantar flexed and a strong adduction force is applied to the forefoot

42. Jones fracture

44. Ortho follow up
NWB cast 6-8 weeks
Notorious for nonunion and needing ORIF b/c of low vascularization and high stresses at this site

45. 5th metatarsal avulsion #

46. aka Dancer’s Fracture
Conservative treatment 4-6 wks
Cast, brace, crutches, wooden soled shoe

47. Thought to occur due to stress on the plantar aponeurosis causing an avulsion
Fractures of the Fifth Metatarsal Yu W. D. et al, THE PHYSICIAN AND SPORTSMEDICINE - VOL 26 - NO. 2 - FEBRUARY 98

48. Apophysis of 5th metatarsal
“bony outgrowth that has never been entirely separated from the bone of which it forms a part”
Found in the skeletally immature

49. Stress fracture
a stress phenomenon at the metaphyseal-diaphyseal junction
“severe intramedullary sclerosis, profound thickening of both the medial and lateral cortices, lucency in the lateral cortex”

50. Treat conservatively or operatively depending on activity level

51. Films

53. Lisfranc fracture/dislocation

57. Calcaneal fractures Most commonly fractured tarsal bone
25% have other lower extremity injury
thoracolumbar fractures occur in 10% of patients with calcaneal fractures

59. 1st metatarsal #
Lisfranc injury

64. Subtalar Dislocation
Disruption of talocalcaneal and talonavicular joints
No disruption of the tibiotalar joint
Closed reduction, ortho consult

69. Fracture Talus 2nd most common tarsal fracture
Mechanism: plantar or dorsi flexion plus inversion
High incidence of complications: AVN

72. Talus fractures talar neck excessive dorsiflexion of the ankle
stepping on brakes in MVA, snowboarders
AVN, subchondral collapse, degenerative arthritis
Need ortho consult in ED

75. Fracture of Navicular and Cuboid
Navicular # high risk of AVN (similar to scaphoid)
Most can have ortho F/U but if intra-articular should be seen in ED

77. Lisfranc dislocation

79. Jones fracture

81. Lisfranc fracture/dislocation

84. Fracture calcaneus

86. Lisfranc injury

87. Summary Know what to look at on each view
Know what to look for in Lisfranc Injuries
Know what to look for in a Jones fracture

88. end

89. References
Accident & Emergency Radiology A Survival Guide, Raby et al, 2001 Harcourt Publishers ltd Toronto Chapter 13
Pitfalls in Radiographic Interpretation, Part 2, Michelle Lin, MD,
Clinical Cases, Emedhom.com,
Lisfranc Injury of the Foot: A Commonly Missed Diagnosis, BURROUGHS et al., American Family Physician, July 1998, 58 no. 1 ,p.118
Rosen’s Emergency Medicine Concepts and Clinical Practice 5th ed., Marx et al. Mosby, Toronto, 2002 chapter 51
Wheeless' Textbook of Orthopaedics,
Fractures of the Proximal Fifth Metatarsal, STRAYER et al. American Family Physician, May 1999, 59 no.9 p.2516
Lisfranc Fracture Dislocation, Early J. S.
Fractures of the Fifth Metatarsal Yu W. D. et al, THE PHYSICIAN AND SPORTSMEDICINE - VOL 26 - NO. 2 - FEBRUARY 98
Pitfalls in the Radiologic Evaluation of Extremity Trauma:Part II. The Lower Extremity, SHEARMAN C. S. et al, American Family Physician March 1998