1. Lower Extremities
Second Part
Dr Mohamed El Safwany, MD.

2. Intended Learning Outcomes
The student should be able to understand radiological aspects related to lower limb trauma.

3. Knee Standard Xray projections: Special views
AP – evaluate joint space narrowing / calcifications
Lateral –evaluates .Patella / effusions
Special views
Sunrise / merchant view
Tangential / knee flexed/from top-down
Tunnel view
Knee more flexed, looking through the “tunnel created by the femoral condyles

5. Knee Most common reasons to order Knee X rays are: - trauma
- Degenerative changes
MRI:
Soft tissues: tendons, ligaments, menisci, and cartilage

6. Knee

7. The Knee Ligaments: Anterior Cruciate Ligament (ACL)
Posterior Cruciate Ligament (PCL)
Medial Collateral Ligament (MCL)
Lateral Collateral Ligament (LCL)

8. Knee Effusion X-ray findings: Best seen on Lateral view
Superior to Patella
Anterior to distal femur
Look for anterior displacement of fat line

9. Knee Effusion
MRI Sagittal
T2 weighted
image

10. Menisci
Crescent shaped fibrocartilagenous structures that are triangular in cross section.
These structures deepen the articular surface of the tibial plateau adding stability to the joint

11. Meniscal Tear Most Common injury to the knee requiring surgery
Medial meniscal tears occur 3 times more frequently than lateral meniscal tears
Locked knee requires urgent intervention

13. MRI ACL , PCL ACL Resist tibial anterior translation
PCL Resist tibial posterior
translation

14. MRI MCL
Resists Valgus Deformity and damaged by stress valgus

15. MRI LCL
Resists varus deformity and damaged by stress varus

16. ACL tear

17. ACL Tear

18. Posterior Cruciate Ligament Tear
Caused by hyperextension of knee or direct blow to anterior aspect of flexed knee (Dashboard)

19. Unhappy Triad
This is the term given to an injury where the ACL, MCL and Medial Meniscus are all three torn. 
The mechanism for this injury is usually a lateral blow to the knee with the foot fixed. 
1. ACL tear
2. MCL tear
3. Medial meniscus tear

20. Patellar Tendon Rupture
Exam:
Patient cannot actively extend knee
Palpable defect inferior to patella
Xray:

21. Patella Dislocation/ Subluxation
Lateral displacement of patella due to complete tear of medial patellar retinaculum

22. Patellar fractures Direct blow to patella – fall
Dark lines across the bone in x ray with sharp corners and edges
Repair by fixation pins and wire

23. Patellar fracture

24. Chronic Knee Pain Degenerative OA X ray findings
joint space narrowing (Medial common)
Spurs, osteophytes
Sclerotic bony margins

26. Loose body: disruption of cartilage , single broken piece.
If multiple pieces – synovial chondromatosis

27. Knee Replacement Indicated for severe DJD Includes:
Femoral condylar component
Proximal tibial component
Patellar component
AP view may look like components are not touching , the plastic component are not seen on X-ray

28. Artificial knee replacement

29. Foot Bones of the foot: 7 tarsals 5 metatarsals 14 phalanges Talus
Calcaneus
Navicular
Medial Cuneiform
Intermediate Cuneiform
Lateral Cuneiform
Cuboid
5 metatarsals
“rays of the foot”
14 phalanges

32. Plantar Fasciitis Plantar fasciitis is the most common foot problem.
It is caused by activity, overuse and aging.
Plantar fasciitis is an inflammation due to repeated overstretching of the plantar fascia ligament (fat pad of the foot), usually at the point where the fascia is attached to the calcaneus.

33. Plantar Fasciitis Contributing factors are:
flat feet
high arches
increasing age
sudden weight increase
sudden increase in activity level
running in sand
hereditary factors
Xray: May reveal bony spur at same site
Ultrasound and MRI may help diagnosis

34. Calcaneal bony spur

35. Hallux Valgus Most common deformity of the foot
Results in excessive valgus angulation of the big toe
The anatomical deformity consists of:
Increased forefoot width
Lateral deviation of the hallux
Prominence of the first metatarsal head

37. Lisfranc Injury
Fracture and lateral dislocation of 2nd, 3rd,4th and 5th metatarsals relative to the tarsal bones

38. Jones Fracture/Dancers fracture
Transverse fracture of the 5th metatarsal at the junction of the proximal metaphysis & diaphysis

40. Avulsion Fracture of the base of the 5th Metatarsal

41. Avulsion Fracture of the base of the 5th Metatarsal

42. Comminuted Fracture of proximal phalanx of great toe
XR:
AP/lat/oblique

43. Fractures of phalanges of lesser toes
XR:
AP/lat/obliq

44. Stress fracture
Callus

45. Calcaneus Fractures May be intraarticular or extraarticular
fall or twisting injury & pain localized to hind foot
XR:
AP/lat/obliq/ axial heel
Should have CT scan to review extent of fracture
Also do Xray of Lumbar spine due to associated fractures
Midfoot-metatarsals, forefoot -phalanges

47. Calcaneal Fracture
X ray CT
Internal
Fixation

48. Ankle sprains Inversion injury= injures lateral structures of ankle
ligament sprained=
1. Anterior talofibular ligament (front) - tears first
2. Posterior talofibular ligament (back) - tears second
3. Calcaneofibular ligament (middle) - tears last US

50. Ankle fractures Malleolar fractures
Ankle inversion injury:
Horizontal fibular fracture and oblique medial malleolus fracture
Ankle eversion fracture:
Horizontal medial malleolus fracture with oblique fibular fracture

51. Malleolar fracture-inversion injury

52. Ankle fractures

53. Achilles Tendonitis
Pain at achilles tendon, increased by running decreased by rest
Pain is often worse following activity, rather than during
Often palpable thickening over tendon or peritendinous tissues
Poor planterflextion.

54. Achilles Tendon Rupture

55. Tibial Shaft Fractures
Mechanisms of injury
1. direct trauma
2. indirect trauma: associated with rotary & compressive forces as a fall
Exam:
Pain, swelling, deformity
XRay:
AP/lateral tibia ,fibula

56. Tibial Shaft Fractures

57. Tibial Plateau Fractures
Involve proximal articular surface of tibia
Exam:
Pain localized to proximal tibia, swelling
Imaging:
X-Ray :AP, lateral knee
CT scan

58. Schatzker’s Classification
Schatzker I
Lateral split
Schatzker II
Split with depression
Schatzker III
Pure lateral depression
Schatzker IV
Pure medial depression
Schatzker V
Bicondylar
Schatzker VI
Split extends to metadiaphysis

59. Tibial Plateau Fracture
axial CT
coronal
X Ray

60. Question
What are the radiographic findings of patellar tendon rupture?

61. Assignments
5 Students will be selected for assignments.

62. Suggested Readings
Sutton’s Radiology

63. Thank You