1. X-rays: Pelvis, Hip & Shoulder
Feb. 22, 2006
J. Huffman, PGY-1
Thanks to Dr. J. Lord
Also thanks to Moritz, Adam and Steve Lan for some borrowed slides and images

2. Goals:
As per instructions, this is a radiology talk ONLY. The focus is on reading as many films as possible.
Therefore, try your best to describe what you see as you would when on the phone with a consultant.
No epidemiology
No management
No associated injuries (i.e. vascular injury with pelvic #)

3. Outline Pelvis Hip Shoulder Anatomy Views Classification of fractures
Practice
Hip
Fractures
Dislocations
Shoulder
Anatomy
Views
Dislocations
Fractures
Practice

4. Pelvis: Anatomy Pelvis = sacrum, coccyx + 2 inominate bones
Inominate bones = ilium, ischium, pubis
Strength from ligamentous + muscular supports

5. Pelvis: Anatomy Anterior Support: Posterior Support: ~40% of strength
Symphysis pubis
Fibrocartilaginous joint covered by ant & post symphyseal ligaments
Pubic rami
Posterior Support:
~60% of strength
Sacroiliac ligament complex
Pelvic floor
Sacrospinous ligament
Sacrotuberous ligament
Pelvic diaphragm
Sacrospinous resists external rotation
Sacrotuberous resists rotational and vertical shearing forces

6. Pelvis: Anatomy Very strong posterior ligaments
Disruption of these is the cause of mechanical instability
Arteries and veins lie adjacent to posterior arch

7. Pelvis: Anatomy Divided into 3 columns: Anterior superior column
(= ilium)
Anterior inferior column
(= pubis)
Posterior Column
(= ischium)
Ant superior column is the primary wt bearing structure
The ant inferior column is thin and easily fractured
The post column is thick and strong bust most commonly fractured

8. Pelvis: Imaging Plain films CT scans AP Inlet view / Outlet view
Judet view (oblique – shows columns, acetabulum)
AP alone ~90% sensitive; combined w/ inlet/outlet views ~94%
Limited in ability to clearly delineate posterior injuries
Pelvic films are NOT necessary in pts with normal physical exam, GCS >13, no distracting injury and not intoxicated
At least one study shows clinical exam reliable in EtOH
Gonzalez et al. J Am Coll Surg. 2002; 194: 121-5
CT scans
Evaluates extent of posterior injury better
Superior imaging of sacrum and acetabulum
More detailed info about associated injuries
EtOh levels up to 104 mmol/l, most were > 21.7
Prospective study of 2176 consecutive blunt trauma pts of which 4.5% had pelvic #’s
AP plevis alone missed more injuries than clinical exam even in intoxicated pts
On the other hand, plain films can help to predict bleeding complications and should be done if pelvis is suspected to be busted as the first step in the work up

9. 6 lines of the pelvis:
1. Iliopubic (arcuate) line – disruption indicates ant column injury
2. Ilioischial line which defines the posterior column
3. Teardrop or Roentgenographic U formed by roof of acetabaulum and ilioischial spine defines quadrangular plate – disruption means intraplevic penetration
4. Roof of acetabulum
5. Post rim of acetabulum
6. Ant rim of acetabulum
7. Shenton’s line = medial femoral shaft  obturator foramen: disruption in hip dislocation or femoral neck #’s

11. Pelvis: Imaging - Acetabulum
Arcuate line
Ileoischial line
Radiographic U (teardrop)
Acetabular roof
Anterior lip of acetabulum
Posterior lip of acetabulum

12. Pelvis: Imaging - Acetabulum

13. Pelvis: Imaging – Normal Inlet

14. Pelvis: Imaging – Normal Outlet

15. Pelvis: Imaging Radiographic clues to posterior arch fractures:
L5 transverse process avulsion* (iliolumbar ligament)
Avulsion of the lower, lateral sacral lip* (sacrotuberous ligament)
Ischial spine avulsion* (sacrospinous ligament)
Assymmetry of sacral foramina
Displacement at the site of a pubic ramus fracture
Ist 2 always denote mechanical instability

16. Pelvis: Fracture Classification Systems
2 most common are Tile and Young systems
Tile Classification system:
Advantages
Comprehensive
Predicts need for operative intervention
Disadvantages
Does NOT predict morbidity or mortality
Young Classification System:
Based on mechanism of injury  predicts ass’d injury
Estimates mortality
Excludes more minor injuries

17. Tile Classification System
Type A:
Stable: Posterior structures intact
Type B:
Partially stable: Posterior structures incompletely disrupted
Type C:
Unstable: Posterior structures completely disrupted
*Each type further classified into
3 sub-types based on fracture.

18. Tile Classification System
Type A: Stable pelvis: post structures intact
A1: avulsion injury
A2: iliac wing or ant arch #
A3: Transverse sacrococcygeal #

19. Tile Classification System
Type B: Partially stable pelvis: incomplete posterior structure disruption
B1: open-book injury
B2: lateral compression injury
B3: contralateral / bucket handle injuries

20. Tile Classification System
Type C: Unstable pelvis: complete disruption of posterior structures
C1: unilateral
C2: bilateral w/ one side Type B, one side Type C
C3: bilateral Type C

21. Young Classification System
Lateral Compression
Anteroposterior Compression
Vertical Shear
Combination
*LC and APC further classified into 3
sub-types based on fracture
Pros and cons to each – Tile is comprehensive but Youngs predicts mortality, GU complications and risk of bleeding

22. Young Classification System:
Lateral Compression (50%)
transverse # of pubic rami, ipsilateral or contralateral to posterior injury
LC I – sacral compression on side of impact
LC II – iliac wing # on side of impact
LC III – LC-I or LC-II on side of impact w/ contralateral APC injury

23. Young Classification System:
AP Compression (25%)
Symphyseal and/or Longitudinal Rami Fractures
APC I – slight widening of the pubic symphysis and/or anterior SI joint
APC II – disrupted anterior SI joint, sacrotuberous, and sacrospinous ligaments
APC III – complete SI joint disruption w/ lateral displacement and disruption of sacrotuberous and sacrospinous ligaments

24. Young Classification System:
Vertical Shear (5%)
Symphyseal diastasis or vertical displacement andteriorly and posteriorly
Combined Mechanism
combination of injury patterns

25. Young Classification System: Morbidity and Mortality

26. Type A1 avulsion
Tile A1

27. Tile B1
Tile B1 / Young APC II

28. Pubic ramus # = Tile A2
Tile C1/ Young VS

29. Tile A1

30. No Fracture, just an IUD

31. Tile B3 / Young APC

32. Right iliac wing # also called Duverney
Tile A2 / Young LC II

33. No #, just SC air from rib fractures

34. Pelvis: Acetabular Fractures
Four Categories:
Posterior lip fracture
Commonly assoc. w/ posterior hip dislocation
Central or transverse fracture
Fracture line crosses acetabulum horizontally
Anterior column fracture
Disrupts arcuate line, ileoischial line intact, U displaced medially
Posterior column fracture
Ileoischial line disrupted and separated from the U
Judet (oblique views) or CT helpful if suspicious

35. Pelvis: Imaging - Acetabulum

36. Focus on the acetabular fractures.
Posterior Column #

37. Posterior Column #

38. Anterior Column #

39. Bilateral Anterior Column #

40. Posterior Lip #

41. Central (Transverse) fracture

42. Proximal Femur & Hip

43. Proximal Femur & Hip: Injuries
Fractures:
Femoral neck, intertrochanteric, femoral head, greater & lesser trochanter, subtrochanteric
Dislocations:
Anterior, posterior, central, (inferior)
Any elderly pt c/o hip, thigh or knee pain has a proximal femur fracture until proven otherwise
Femoral neck & intertrochanteric #’s account for 90% of hip #’s

44. Proximal Femur: Anatomy
Ward’s Triangle

45. Proximal Femur: ImagesAP
Internal rotation!
Lateral
Cross-table Lateral
Frog-leg Lateral

46. Proximal Femur: Images
Cross-table lateral view
* = ischial tuberosity

47. Proximal Femur: Fracture Classification
Relationship to capsule
Intracapsular, extracapsular
Anatomic location
Neck, trochanteric, intertrochanteric, subtrochanteric, shaft
Degree of displacement

48. Proximal Femur: Approach to the film
Shenton’s Line
Femoral neck #
Dislocation
‘S’ and ‘Reverse S’ patterns
Position of lesser trochanter
Femoral head size
Trace trabecular groups

49. Left posterior dislocation – note Shenton’s line

50. Proximal Femur: Approach to the film
Lowell’s ‘S’ patterns

51. Impacted femoral neck #

52. Hip: Dislocations Etiology Types: Orthopedic emergencies:
Adults: high energy mechanism (MVA)
Elderly, prosthetic joints, kids < 6yo: minor mech
Types:
Posterior >> anterior > central (> inferior)
Orthopedic emergencies:
Urgent reduction after ABC’s / stabilization
Significant neurovascular complications
Often multiple associated injuries
Mandate CT post-reduction
CT post reduction for intra-articular #’s, acetabular #’s

53. Hip: Dislocation imaging
Plain Films: ant vs. post dislocations
Femoral head size
Posterior dislocation  femoral head smaller
Lesser trochanter visibility
Post dislocation  adduction & internal rotation, lesser trochanter not seen
Ant dislocation  external rotation; lesser trochanter clearly visible CT
Indicated for more detailed evaluation of femoral neck, intra-articular #’s, and acetabulm

54. Anterior dislocation

55. Posterior dislocation
Lesser trochanter

56. Proximal Femur: Fractures
Femoral head fracture:
Usually 2° to dislocation
Pipkin classification
Femoral neck fracture:
Can be subtle (check lines, ‘S’)
Describe as nondisplaced (15-20%) vs displaced
Intertrochanteric fracture:
High energy or weak bone
Classify according to number of bone fragments (e.g. two-part)

58. Displaced femoral neck fracture

59. Nondisplaced femoral neck #

60. Two-part intertrochanteric fracture

61. Three-part intertrochanteric #

62. Proximal Femur: Fractures
Isolated trochanter fracture:
Rare (women more than men)
Direct fall or avulsion by iliopsoas
Outpt management
Subtrochanteric fracture:
#’s b/w lesser trochanter & point 5 cm distal
Common site for pathologic fractures
Vague symptoms
Occult fracture:
~%5 of hip fractures not seen radiographically

63. Isolated greater trochanter #

64. Isolated lesser trochanter #

65. Subtrochanteric fracture

66. Proximal Femur & Hip
Practice

67. Intertrochanteric fracture 2° to mets from prostate CA

68. Pipkin III femoral head fracture and posterior dislocation

69. AC separation Clavicle fracture Scapula fracture Shoulder dislocation

70. Shoulder: Anatomy 3 bones: 3 joints: 1 articulation: Clavicle Humerus
Scapula
3 joints:
Acromioclavicular
Glenohumeral
Sternoclavicular
1 articulation:
Scapulothoracic

71. Shoulder: Anatomy

72. Shoulder: Anatomy

73. Shoulder: Images True AP Lateral (transcapular) Axillary AC view
Should see no overlap of humerus over the glenoid
Lateral (transcapular)
Scapula looks like a ‘Y’)
Axillary
Best “true lateral” view of the shoulder
AC view
100° abduction

74. More useful for soft-tissue evaluation
Shoulder: Images
Internal rotation
External rotation
More useful for soft-tissue evaluation

75. Normal True AP of the Shoulder

76. Normal lateral film of the shoulder

78. Normal axillary film of the shoulder

79. Trauma Axillary View:     - does not require abduction of the arm (nor removal from sling);     - the patient leans backward;     - the x-ray plate is placed directly under the shoulder, and the x-ray tube             is positioned directly above;

80. AC Separation: Classification
Type I
Sprain of the AC joint
CC distance maintained (N = 11-13mm)
Type II
AC ligaments disrupted
Joint space widened
CC distance maintained
Clavicle rides upward (<50% its width)

81. AC Separation: Classification
Type III (and IV, V, VI)
Complete disruption of AC and coracoclavicular ligaments as well as muscle attachements
Joint space widened
CC space is increased
(5mm difference from uninjured side)
Clavicle is displaced

82. Type III AC separation – AC view (100° Abduction)

83. Clavicle Fracture Classified anatomically:
Medial third (5%) – direct blow to the anterior chest
Middle third (80%) – direct force to lateral aspect of shoulder
Lateral third (15%) – direct blow to the top of shoulder
Lateral to the coracoclavicular lig. (stable)
Medial to the coracoclavicular lig. (tend to displace)
Involves the articular surface

84. Fracture of the middle third of the clavicle

85. Comminuted fracture of the middle third of the clavicle

86. Distal third clavicle fracture – type II

87. Scapula Fracture Classified Anatomically:
Acromion process, scapular spine or coracoid process
Scapular neck involved
Intra-articular fractures of the glenoid fossa
Scapular body involved (most common)

88. Type I scapular fracture (coracoid fracture)

89. Type III scapular fracture

90. Comminuted, type III scapular fracture

91. Shoulder: Dislocation
Classification
Anterior (95-97%)
Subcoracoid (most common)
Subglenoid
(1/3 associated with # greater tuberosity, or # glenoid rim)
Subclavicular
Intrathoracic
Also important to note primary vs. recurrent

92. Anterior dislocation - subcoracoid

93. Shoulder: Dislocation
Classification – cont’d
Posterior
Subacromial (98% of posterior dislocations)
Subglenoid
Subspinous
Inferior (Luxatio Erecta) - rare
superior - rare

94. Shoulder: Dislocation
Signs of posterior shoulder dislocation:
↑distance from anterior glenoid rim and humeral head
“rim” sign
Humeral head internally rotated
“Light bulb” or “drum stick” sign
True AP shows humeral/glenoid overlap
Impaction # of the anteromedial humeral head
“reverse Hill-Sachs deformity”  “Trough sign”

95. Posterior dislocation
Arrow = impaction # of anteromedial humeral head

96. Posterior dislocation
Note the humeral head roatation

97. Posterior dislocation – lateral view

98. Posterior dislocation – axillary view

99. Shoulder: Dislocation
Associated fractures:
Compression # of the posterolateral aspect of the humeral head
“Hill-Sachs deformity”
11-50% of anterior dislocations
Anterior glenoid rim fracture
“Bankart’s fracture”
~5% of cases
Avulsion fracture of the greater tuberosity
~10-15% of cases

100. Anterior dislocation
Arrow = # of the posterolateral aspect of humerus

101. Post-reduction film
Avulsion # of the greater tuberosity

103. Shoulder
Practice

104. Clavicle fracture – distal third – type II

105. Scapula fracture – type III

106. AC separation - grade I

107. Anterior shoulder dislocation

108. Posterior dislocation (False AP – note overlap)