Acetabulum fracture - Basics for Orthopod

1. Acetabulum fractures
Arun Upreti
Moderator- Prof. Dr. Suresh Uprety

2. Content
• Introduction
• Osteology
• Radiographic anatomy
• Fracture classification
• Management
• Complications

3. Introduction
• The management of acetabular fractures is one of the most complex aspect of
orthopedic surgery
• Complex high velocity injury, in a region of complex anatomy, complex
radiographic interpretation and surgical approaches
• Difficulty in accurately defining and classifying fracture pattern – protusio
fracture, central fracture dislocation, burst fracture, stove in hip(Matta 1986,
Tornetta 2001). These descriptions only simply describe author’s description
that there is displacement of acetabular fragment as well as femoral head.
• It presents long term problems for the patient of post traumatic arthritis due to
damage to hyaline cartilage or due to increased unit loading pressure between
femoral head and acetabulum(Matta 1986)

4. History
1964
1983
1993
“Their precise roentgenographic
descriptions and classifications has
provided the greatest contribution to
understanding and treatment of acetabular
fractures” Matta 1986

5. History
Defined radiographic anatomy of
acetabular fractures – x ray and operative
comparisons, lead lined x ray of pelvis.
Developed surgical approaches –
Ilioinguinal and Extended iliofemoral
through cadaveric dissections
Described surgical fixation of techniques –
lag screw followed by plate. Developed
reduction tools
Described short and long-term surgical
outcomes of patients

6. Acetabular anatomy: Osteology
• Cup shaped structures that
encloses the head of femur in
hip joint
• Lunate surface is the horse-shoe
shaped articular surface
• Acetabular fossa
• Judet – bony masses that limit
and support the acetabulum
• Anterior and Posterior column

7. Osteology

8. Acetabular Osteology
• Columns – Anterior, Posterior,
Superior (Rouviere 1940)
• Walls – Anterior and Posterior
• Posterior – Postero-superior and postero
inferior
• Quadrilateral surface or medial wall
• Dome of acetabulum

9. Anterior column
3 segments – Iliac, acetabular and
pubic segment
• Iliac – pelvic surface and external
surface, ASIS, AIIS
• Acetabulum – anterior half –
posterolateral, internal and
antero-superior surface
• Iliopectineal eminence – anterior
wall
• Pubis

10. Anterior wall
Iliopectineal eminence –
represents the anterior and
medial boundary of the
acetabulum
Iliopsoas runs just lateral to it

11. Posterior Column
• Ilio-ischial column – thick and good
solid material for IF
• Internal surface – quadrilateral
surface
• Posterior surface – posterior wall,
the sub cotyloid groove, retro
cotyloid surface
• Convex area arising from retro-
cotyloid space
• Anterolateral surface

12. Quadrilateral surface
• Flat plate of bone forming the
lateral border of true pelvic
cavity lying adjacent to medial
wall of acetabulum
• May be comminuted in elderly

13. Dome/Roof of the Acetabulum
• Anterior and Posterior column
confluence at mid point of anterior
column at angle of about 60
• Filled with compact bone
• Anatomical roof – 45 to 60 of
articular surface
• Weight bearing surface
• Anatomic restoration with
congruent reduction is goal of
treatment

14. Vascular anatomy

15. Medical Circumflex femoral artery

16. Neurovascular anatomy

17. Radiographic anatomy
• Three views should be routinely
obtained
-AP
-Obturator oblique
-Iliac oblique
- Inlet and Outlet views (Tornetta)
-Two third oblique views
-Judet views mixed with Inlet/Outlet
views for percutaneous fixation

18. Judet Views

19. Standard Radiographic views
Anterior column,
Posterior wall
Posterior column
Anterior wall
Iliac wing profile

20. Letournel’s radiographic landmarks
• Iliopectineal line (Innominate
line)
• Ilio-ischial line
• Tear drop
• Acetabular roof
• Anterior wall
• Posterior wall
“radiological line is produced by rays tangential to a bony
surface or crossing a border, and represents, truly, a line of
tangency; it must not be interpreted as a surface, of which it is
only an "optical" cuts”

21. Radiographs

22. Iliopectineal line
• Landmark for anterior column
• Anterior – pelvic brim
• Posterior – sciatic buttress and
roof of sciatic notch

23. Ilio-ischial line
• Landmark for the posterior column
• Created by the beam tangent to the
posterior surface of quadrilateral
surface
• Overlaps the teardrop
• Anterior limit – obturator foramen
• Posterior limit -1 finger breadth below
the ischial spine
• Radiologically – begins with IP line,
courses straight and ends at teardrop

24. Tear drop
• Obturator canal and
anteroinferior portion of
quadrilateral surface – medial
• Lateral limb –anterior inferior
cotyloid fossa
• Represents relationship between
columns

25. Roof

26. Anterior and posterior wall
Anterior wall – begins at external border of
the roof, more horizontal than posterior
border
Becomes continuous with the superior border
of obturator foramen(Acetabulo-obturator
line)
Acetabular articular surface lies just above the
midpoint
Posterior wall – Straight line ends at the ischial
tuberosity

27. Letournel’s 6 radiological landmarks

28. Iliac Oblique Radiograph
• Ilio-ischial line
• Anterior border of the
acetabulum

29. Obturator Oblique view
• Pelvic brim (IP line)
• Posterior border of acetabulum
• Obturator foramen
• Iliac wing

30. Radiographic anatomy

31. Radiological Landmarks

32. Mechanism of Injury

33. Fracture Classification

34. Elementary Patterns
Part or all of the one column
supporting the acetabulum as
been detached
Transverse fractures are
included on virtue of purity

35. Posterior wall fractures
• Most common type of
acetabular fracture
• Associated with posterior
dislocation
• Posterior wall is broken
• Other landmarks are intact

36. Anterior wall
• Counter part of anterior wall
fractures
• Anterior wall with
corresponding segment of
iliopectineal line
• Tear drop inwardly displaced
but maintains relationship
with IP line

37. Anterior column fractures
• Segment of the anterior
column is separated from
the innominate bone
• Head dislocates anteriorly
• Fracture starts at Iliac
crest(high), notch between
anterior iliac
spine(intermediate) or
iliopsoas grove(low) ends at
pubic ramus.

38. Anterior column fractures
• AP – break in iliopectineal line
• Tear drop is inwardly displaced
• Two breaks in anterior edge of the
innominate bone from iliac crest to
pubic ramus
• Other lines intact
• Associated with quadrilateral plate
fracture

39. Posterior column fractures

40. Transverse fractures
• Split the acetabulum in two
fragments – upper iliac and
lower ischiopubic
• Subclassified based on level
of fracture relative to
acetabular roof
• Infratectal
• Juxtatextal
• Transtectal

41. Transverse fractures

42. T-Type fractures
• Transverse fracture with vertical
fracture line through ischiopubic
segment

43. Both column

44. Associated type
• Posterior column and anterior hemi
transverse are group together as T-
shaped fractures
• Anterior wall and anterior wall/column
fractures are grouped together
• Anterior wall and Transverse; anterior
column and posterior hemi transverse
are grouped together under anterior
fracture and posterior hemi transverse –
same approach

45. Secondary congruence

49. Radiographic evaluation

50. Roof Arc Angle
• Three angles measured on
AP (A), iliac oblique (B),
and obturator oblique (C)
• Vertical line drawn through
center of acetabulum
• Another line, 45 degrees
from that starting at the
center of the acetabulum
• If fracture falls within the
angle drawn on any of the
views, considered to be in
weight-bearing dome
• Relative indication for
surgery
A B C

51. Role of CT Evaluation

52. CT – Axial cuts

53. CT Evaluation: Acetabulum
• Recognizing patterns
• Axial view
A. Column fractures: Horizontal
(coronal) orientation
B. Transverse: Vertical (sagittal
orientation)
C. Anterior wall: Oblique
• Travels anteriorly and medially
D. Posterior wall: Oblique
• Travels anteriorly and laterally
A B
C D

54. Role of CT
• Better characterizes fractures
• Marginal impaction
• Intra-articular fragments
• Fragment size
• Fragment displacement/rotation
• Reduction of femoral head
• Better identify minimally displaced
fractures
• Femoral head impaction

55. 3D Reconstruction

56. Treatment
• Initial treatment – ATLS
• Orthopaedics treatment an emergency when – open fractures,
irreducible fracture dislocation, vascular injury
• Skeletal traction – Non congruent hip or unstable hip
• Transfer to a facility with experienced acetabular surgeon

57. Non-Operative Management
• Non displaced or minimally displaced fractures
• Fractures without significant displacement in important region of the
hip(Roof Arc measurement), CT subchondral arc of 10mm
• Secondary congruence
• Medical comorbidities

58. Indication for surgery
• Incarcerated fragments
• 2mm or more displacement of dome
• Unstable femoral head – subluxation, posterior wall fractures >40%
size

59. Decision making in Acetabular fractures
• Individual patient factors, institutional factors and facture pattern
• Plan for early mobilization
• Surgery must be better than expected natural history of the condition
• “Operative problem unless specific criteria for Non-Operative
management is met”

60. Decision making in Acetabular fractures
Olson and Matta criteria for non operative management
• 10 mm CT subchondral arc
• 45 Roof Arc measurement
• 50% of articular surface of posterior wall intact in all section
• Congruent femoral head in all 3 views
• Fluoroscopically confirmed stable hip
• Not a both column fracture
• Can be used to determine for each fracture

61. Algorithm
(Except for
Both Column
fractures)

62. Algorithm
for both
column
fractures

63. Timing of the surgery
• Urgent – hip dislocation, open fracture, vascular compromise and
worsening neurological deficit
• Only when medically fit for surgery
• Ideally within 5 to 7 days
• As time passes reduction becomes difficult due to organized
hematoma, soft tissue contractures and early callus formation
• Elemental types – 5 days, others 15 days

64. Surgical Approach
• Posterior wall, posterior column, Transverse posterior wall, T shaped
fractures with posterior wall involvement or principally posteriorly
displaced and transverse fractures with posterior displacement
• Anterior approach for anterior wall, anterior column, anterior column
posterior hemi transverse, posterior hemi transverse

65. Surgical approach
Main surgical
approaches
•Ilioinguinal - Anterior
•Kocher-Langenback
– Posterior
•Stoppa -Emerging
Others –
•Extended iliofemoral
approach,
•Dual approaches

66. Ilioinguinal

68. Kocher-Langenbeck Approach

69. KL Modification – Trochanteric flip osteotomy

70. Stoppa’s Approach

71. Special equipment

72. Case example

73. Percutaneous fixation
Retrograde fixation of anterior
column
Anterograde fixation of posterior
column
Retrograde fixation of posterior
column

74. Surgical Outcome
• Fracture pattern – worse in associated pattern, Letorunel – worst
outcomes in posterior column/wall fracture
• Initial fracture displacement of 20mm
• Timing of surgery
• Surgeon experience
• Soft tissue
• Cartilage damage to acetabulum or femoral head
• Poor fracture reduction

75. Outcomes and Complications
• Reported overall mortality upto 2.5%
• Post-traumatic arthritis (17% in Letournel’s series)
• Infection
• Sciatic nerve injuries 10% to 15% trauma and 2 to 6% iatrogenic
• Heterotrophic ossification(HO) – 80% posterior approach. Indomethacin and
Radiation therapy.
• AVN – femoral head and posterior column of acetabulum

76. Summary
• Acetabular fractures are complex fractures
• Adequate management based on fracture classification based on radiographic findings
• Fracture pattern and displacement guide surgical approach
• Anatomic reduction of fracture and stability of hip are primary goals
• Surgery requires special equipment
• Outcomes improve with surgical expertise and experience
• Complications are common

77. Thank you
• Diomedes hefted a boulder in his
hands, flung it and truck Aeneas’s
thigh where the hip bone turns
inside the pelvis, and the joint they
called cup, it snapped the socket”
• ~Iliad Chapter 5

78. Next Presentation
• Adult pelvis fractures by Akash