questions
31

Acetabular Fractures

Topic updated on 08/13/14 4:51pm
Introduction
  • Epidemiology
    • bimodal distribution
    • high energy blunt trauma for young patients
    • low energy (fall from standing height) for elderly patients
  • Pathoanatomy
    • fracture pattern determined by
      • force vector
      • position of femoral head at time of injury
  • Associated conditions
    • 50% will have injury to another organ system 
    • associated lower extremity injury most common (36%)
Anatomy
  • Osteology
    • inclination & anteversion
      • mean lateral inclination of 40 to 48 degrees
      • anteversion of 18 to 21 degrees
    • column theory 
      • acetabulum is supported by two columns of bone 
      • form an "inverted Y" 
      • connected to sacrum through sciatic buttress
        • posterior column
          • comprised of
            • quadrilateral surface
            • posterior wall and dome
            • ischial tuberosity
            • greater/lesser sciatic notches
        • anterior column
          • comprised of
            • anterior ilium (gluteus medius tubercle)
            • anterior wall and dome
            • iliopectineal eminence
            • lateral superior pubic ramus
  • Vascular
    • corona mortis 
      • anastamosis of external iliac (epigastric) and internal iliac (obturator) vessels
      • at risk with lateral dissection over superior pubic ramus
Letournel Classification

 
Illus.
AP
Obt.Obl.
Iliac.Obl.
CT
Comments
Elementary
Posterior wall 
 x
• Most common
• "gull sign" on obturator oblique view
Posterior column 
• check for injury to superior gluteal NV bundle
Anterior wall
 
 x
• Very rare
Anterior column 
x
 x
 x
 x
• More common in elderly patients with fall from standing
Transverse    
 x
 x
 x
 x

• Axial CT shows anterior to posterior fx line 
• Only elementary fx to involve both columns

Associated
Associated Both Column 

  Characterized by dissociation of the articular surface from the inominate bone  
• will see "spur sign" on obturator oblique
 

Transverse + Post. Wall

 x
  • Most common associated fx
T Shaped

 x
x

• May need combined approach
Anterior column or wall + Post. hemitransverse
x
x

• Common in elderly patients

Post. column + Post. wall
x
x
x
x
• Only associated fracture that does not involve both columns
 
Imaging
  • Radiographs
    • recommended views
      • AP pelvis, Judet views, inlet and outlet if concerned for pelvic ring involvement
    • 6 radiographic landmarks of the acetabulum 
      • iliopectineal line (anterior column)
      • ilioischial line (posterior column)
      • anterior rim
      • posterior rim
      • teardrop 
      • weight bearing roof
    • superior acetabular rim may show os acetabuli marginalis superior which can be confused for fracture in adolescents 
    • Judet views (45 degree oblique views)
      • obturator oblique 
        • shows profile of obturator foramen 
        • shows anterior column and posterior wall 
      • iliac oblique 
        • shows profile of involved iliac wing
        • shows posterior column and anterior wall 
    • roof arc measurements
      • show intact weight bearing dome if > 45 degrees on AP, obturator, and iliac oblique
      • not applicable for associated both column or posterior wall pattern because no intact portion of the acetabulum to measure
  • CT scan
    • important to 
      • define fragment size and orientation
      • identify marginal impaction 
      • identify loose bodies
      • look for articular gap or step-off
Treatment
  • Nonoperative
    • protected weight bearing for 6-8 weeks
      • indications
        • minimally displaced fracture (< 2mm)
        • < 20% posterior wall fractures
          • treatment based on size of posterior wall is controversial
          • exam under anesthesia using fluoroscopy best method to test stability 
        • femoral head remains congruent with weight bearing roof (out of traction)
        • both column fracture with secondary congruence (out of traction)
        • displaced fracture with roof arcs > 45 degrees in AP and Judet views
        • relative contraindications to surgery
          • morbid obesity
          • open contaminated wound
          • presence of DVT
      • technique
        • close radiographic follow-up
        • skeletal traction rarely indicated as definitive treatment
  • Operative treatment
    • open reduction and internal fixation
      • indications
        • displacement of roof (>2mm)
        • posterior wall fracture involving > 40-50%
        • marginal impaction
        • intra-articular loose bodies
        • irreducible fracture-dislocation
      • outcomes
        • clinical outcome correlates with quality of articular reduction
          • earlier operative treatment associated with increased chance of anatomic reduction  
          • postoperative CT scan is most accurate way to determine posterior wall accuracy of reduction which has greatest correlation with clinical outcome 
        • greatest stress on acetabular repair occurs when rising from a seated position using the affected leg, and occurs in the posterior superior portion of the acetabulum 
        • functional outcomes most strongly correlate with hip muscle strength and restoration of gait postoperatively
    • open reduction and internal fixation with acute total hip arthroplasty 
      • indications
        •  significant osteopenia and/or significant comminution
      • outcomes
        • up to 78% 10-year implant survival noted
        • worse outcomes in males, patients <50 years old or >80kg, or if a significant acetabular defect remains
    • percutaneous fixation with column screws
      • indications
        • anterior column screws
Techniques
  • Percutaneous fixation with column screws
    • approach
      • anterograde (from iliac wing to ramus)
      • retrograde (from ramus to iliac wing)
      • posterior column screws
    • imaging
      • obturator oblique best view to rule out joint penetration
      • inlet iliac oblique view best to determine anteroposterior position of screw within the pubic ramus 
      • inlet obturator oblique view best to determine position of a supraacetabular screw within tables of the ilium 
  • ORIF
    • approaches
      • approach depends on fracture pattern
      • two approaches can be combined
Approaches
Indications
Risks
Anterior Approach (Ilioinguinal) topic

• anterior wall and anterior column 
• both column fracture
• posterior hemitransverse

• femoral nerve injury
• LFCN injury
• thrombosis of femoral vessels
• laceration of corona mortis in 10-15%.   

Posterior Approach (Kocher-Langenbach) topic

• posterior wall and posterior column fx  
• most transverse and T-shaped
• combination of above 

• increased HO risk compared with anterior approach 

• sciatic nerve injury (2-10%)  
• damage to blood supply of femoral head (medial femoral circumflex)

Extensile Approach (extended iliofemoral) topic

• only single approach that allows direct visualization of both columns
• associated fracture pattern 21 days after injury
• some transverse fxs and T types 
• some both column fxs (if posterior comminution is present)

• massive heterotopic ossification
• posterior gluteal muscle necrosis

Modified Stoppa Approach topic • access to quadrilateral plate to buttress comminuted medial wall fractures • Corona mortis must be exposed and ligated in this approach
 
Complications
  • Post-traumatic DJD
    • most common complication
    • anatomic reduction essential to prevent
    • treat with hip fusion or THA
  • Heterotopic Ossification
    • highest incidence with extensile approach
      • treat with
        • indomethacin x 5 weeks post-op
        • low dose external radiation (no difference shown in direct comparison)
    • lowest incidence with anterior ilioinguinal approach
  • Osteonecrosis
    • 6-7% of all acetabular fractures
    • 18% of posterior fracture patterns
  • DVT  and PE
  • Infection
  • Bleeding
  • Neurovascular injury
  • Intrarticular hardware placement
  • Abductor muscle weakness

 

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Qbank (31 Questions)

TAG
(OBQ12.212) The posterior wall of the acetabulum is best visualized on which of the following radiographic views? Topic Review Topic

1. Inlet pelvis
2. Outlet pelvis
3. Anteroposterior pelvis
4. Obturator oblique pelvis
5. Iliac oblique pelvis

PREFERRED RESPONSE ▶
TAG
(OBQ11.22) A 34-year-old male presents with the right posterior wall acetabular fracture shown in Figure A. What is the most accurate method to test for hip stability in this patient? Topic Review Topic
FIGURES: A          

1. The Keith method
2. The Moed method
3. The Calkins method
4. Dynamic fluorscopic examination of the hip under anesthesia
5. A history of associated hip dislocation

PREFERRED RESPONSE ▶
TAG
(OBQ11.80) A 35-year-old male undergoes closed reduction under sedation in the emergency department for a posterior hip dislocation with an associated posterior wall fracture. The post-reduction CT is seen in Figure A. What is the appropriate next step in management of this injury? Topic Review Topic
FIGURES: A          

1. Nonoperative management based on the size of the posterior wall fragment
2. Operative management based on the size of the posterior wall fragment
3. Operative management based on the history of hip dislocation
4. Dynamic fluorscopic stress exam under anesthesia in the obturator oblique view
5. Dynamic fluorscopic stress exam under anesthesia in the iliac oblique view

PREFERRED RESPONSE ▶
TAG
(OBQ11.148) A 35-year-old male suffers an anterior column acetabular fracture during a motor vehicle collision, and subsequently undergoes percutaneous acetabular fixation. Intraoperatively, fluoroscopy is positioned to obtain an obturator oblique-inlet view while placing a supraacetabular screw. Which of the following screw relationships is best evaluated with this view? Topic Review Topic

1. Intraarticular penetration of the screw
2. Position of the screw cephalad to the sciatic notch
3. Screw starting point at the anterior inferior iliac spine
4. Screw starting point at the gluteal pillar
5. Screw position between the inner and outer tables of the ilium

PREFERRED RESPONSE ▶
TAG
(OBQ11.155) A 74-year-old man falls, sustaining the injury shown in Figures A through C. In surgical planning, what is the best surgical approach to treat this injury? Topic Review Topic
FIGURES: A   B   C      

1. Kocher-Langenbeck
2. Watson-Jones
3. Extended iliofemoral
4. Ilioinguinal
5. Hardinge

PREFERRED RESPONSE ▶
TAG
(OBQ11.205) A 14-year-old presents on the request of her pediatrician for evaluation of her left hip. The patient reports having a recent history of lower abdominal pain, and as part of the work-up a KUB radiograph was obtained. The abdominal work-up was negative, and her pain has since resolved, however, the pediatrician noted an abnormal radiographic finding in the left hip and requested a formal orthopedic evaluation. The patient denies any history of hip trauma or pain. A left hip radiograph is shown in Figure A, and the the abnormality in question is indicated by the white arrow. The radiographic finding is most consistent with which of the following? Topic Review Topic
FIGURES: A          

1. Os acetabuli marginalis superior
2. Fovea capitis
3. Myositis ossficans
4. Avascular necrosis.
5. Acetabular fracture

PREFERRED RESPONSE ▶
TAG
(OBQ11.241) A 32-year-old male sustains a posterior wall acetabulum fracture as the result of a high-speed motor vehicle collision. Improved patient-reported outcomes after surgical treatment are associated with which of the following variables? Topic Review Topic

1. Increased age
2. Increased hip flexion-extension arc
3. Immediate weight-bearing
4. Increased hip muscle strength
5. Decreased stride length

PREFERRED RESPONSE ▶
TAG
(OBQ10.180) A 35-year-old male sustains a posterior column/posterior wall acetabular fracture. Which of the following is the preferred approach for open treatment of this injury? Topic Review Topic

1. Modified Stoppa approach
2. Extended iliofemoral approach
3. Kocher-Langenbeck approach
4. Ilioinguinal approach
5. Combined anterior and posterior approach

PREFERRED RESPONSE ▶
TAG
(OBQ10.203) When placing a percutaneous retrograde pubic rami screw for fixation of an acetabular fracture, which of the following radiographic views can best ensure that the screw does not exit the posterior aspect of the superior pubic ramus? Topic Review Topic

1. AP pelvis
2. Outlet obturator oblique view
3. Inlet iliac oblique view
4. Iliac oblique view
5. Obturator oblique view

PREFERRED RESPONSE ▶
TAG
(OBQ10.268) A 78-year-old male undergoes the procedure shown in Figure A for treatment of a femoral neck fracture. As the patient passes through mid-rise during sitting to standing using the affected leg, what portion of the acetabulum experiences the highest contact pressures? Topic Review Topic
FIGURES: A          

1. Posterior inferior
2. Anterior superior
3. Posterior superior
4. Directly superior
5. Anterior inferior

PREFERRED RESPONSE ▶
TAG
(OBQ09.99) During the ilioinguinal approach to the pelvis, the corona mortis artery must be identified and ligated if present. The corona mortis artery joins the external illiac artery with which other major artery? Topic Review Topic

1. Pudendal
2. Deep illiac circumflex
3. Hypogastric
4. Obturator
5. Testicular

PREFERRED RESPONSE ▶
TAG
(OBQ09.112) A 33-year-old male sustains the injury seen in Figure A as a result of a high-speed motor vehicle collision. Based on this image, what is the most likely acetabular fracture pattern? Topic Review Topic
FIGURES: A          

1. Both column
2. Anterior column
3. Anterior column posterior hemitransverse
4. Transverse
5. T-type

PREFERRED RESPONSE ▶
TAG
(OBQ09.137) The pelvic spur sign on plain radiography is indicative of the following injuries? Topic Review Topic

1. Transtectal transverse acetabular fracture
2. Vertical shear pelvic ring injury
3. Displaced H-type sacral fracture
4. Both column acetabular fracture
5. Anterior-posterior type III pelvic ring injury

PREFERRED RESPONSE ▶
TAG
(OBQ09.144) A computed tomography (CT) scan has been shown to be indicated for evaluation of all of the following aspects of acetabular fractures, EXCEPT: Topic Review Topic

1. Determination of surgical planning
2. Intra-articular loose bodies
3. Marginal impaction
4. Fracture piece size and position
5. Determination of pre-existing degenerative changes

PREFERRED RESPONSE ▶
TAG
(OBQ09.163) An acetabular fracture with all segments of the articular surface detached from the intact posterior ilium is defined as what fracture pattern? Topic Review Topic

1. Transverse
2. Both column
3. Anterior column posterior hemitransverse
4. Posterior column with posterior wall
5. Anterior column with anterior wall

PREFERRED RESPONSE ▶
TAG
(OBQ09.198) A 25-year-old male is involved in a motor vehicle accident and presents with the injury shown in Figure A. Early fixation of this fracture pattern is associated with all of the following EXCEPT? Topic Review Topic
FIGURES: A          

1. Decreased length of hospital stay
2. Improved functional outcome
3. Greater organ dysfunction
4. Higher likelihood of being discharged to home as opposed to a rehab facility
5. Improved fracture reduction

PREFERRED RESPONSE ▶
TAG
(OBQ09.217) A 22-year-old female is involved in a motor vehicle collision and sustains the injury shown in Figures A through D. According to these images, what is the acetabular fracture classification? Topic Review Topic
FIGURES: A   B   C   D    

1. Anterior column posterior hemitransverse
2. Both column
3. Transverse
4. Transverse with posterior wall
5. Anterior column

PREFERRED RESPONSE ▶
TAG
(OBQ09.223) A patient wakes up with a foot drop following open reduction internal fixation of a posterior wall/posterior column acetabular fracture. What position of the leg causes the highest intraneural pressure in the sciatic nerve? Topic Review Topic

1. hip and knee extension
2. hip flexion to 90, knee extension
3. hip internal rotation, knee flexion to 90
4. hip and knee flexion to 90
5. hip extension, knee flexion to 90

PREFERRED RESPONSE ▶
TAG
(OBQ08.119) A 42-year-old female sustains the injury seen in the computed tomography images seen in Figures A and B. According to the Letournel classification, what is the injury pattern shown? Topic Review Topic
FIGURES: A   B        

1. Posterior wall
2. Transverse
3. Anterior wall
4. Posterior column
5. Both column

PREFERRED RESPONSE ▶
TAG
(OBQ08.265) Which statement is true with respect to acetabular fracture surgery as the time between injury and surgery increases? Topic Review Topic

1. decreased chance of anatomic fracture reduction
2. decreased risk of heterotopic ossification
3. decreased rate of neurologic injury
4. decreased rate of infection
5. decreased rate of multi-organ failure

PREFERRED RESPONSE ▶
TAG
(OBQ07.3) In Figure A, the two red arrows point to which of the following two arteries? Topic Review Topic
FIGURES: A          

1. Superior gluteal and pudendal
2. Internal iliac and medial circumflex
3. External iliac and deep femoral
4. Obturator and external iliac
5. Medial circumflex and inferior gluteal

PREFERRED RESPONSE ▶
TAG
(OBQ07.98) Which of the following associated type acetabular fracture patterns is defined based on the fact that all articular segments are detached from the intact portion of the ilium, which remains attached to the sacrum through the sacroiliac joint? Topic Review Topic

1. Posterior wall/ posterior column
2. Transverse
3. T-Type
4. Anterior column/ posterior hemitransverse
5. Both columns

PREFERRED RESPONSE ▶
TAG
(OBQ07.114) An 84-year-old community-ambulating female sustains a comminuted left acetabular fracture as a result of a fall from standing height. A radiograph is shown in Figure A. What is the most appropriate definitive treatment for this patient? Topic Review Topic
FIGURES: A          

1. Skeletal traction
2. Conservative treatment with delayed physical therapy and shoe lifts
3. Open reduction and internal fixation
4. Open reduction and internal fixation with acute total hip arthroplasty
5. Closed reduction and percutaneous fixation

PREFERRED RESPONSE ▶
TAG
(OBQ07.230) All of the following have been shown to negatively affect clinical outcomes in treating displaced acetabular fractures, EXCEPT: Topic Review Topic

1. Increased age
2. Intraoperative complications
3. Ipsilateral femoral head injury
4. Involvement of both columns
5. Non-anatomic fracture reduction

PREFERRED RESPONSE ▶
TAG
(OBQ06.51) A 25-year-old patient presents with a posterior wall/ posterior column acetabular fracture. She is scheduled for open reduction internal fixation through a posterior approach. What position of the leg exerts the least amount of intraneural pressure on the sciatic nerve? Topic Review Topic

1. hip flexion, knee extension
2. hip extension, knee extension
3. hip flexion, knee flexion
4. hip extension, knee flexion
5. the pressure does not vary based on position

PREFERRED RESPONSE ▶
TAG
(OBQ06.166) What acetabular component is best appreciated on an obturator oblique radiograph of the pelvis as seen in Figure A? Topic Review Topic
FIGURES: A          

1. ilioischial line
2. posterior column
3. posterior wall
4. anterior wall
5. sacroiliac joint

PREFERRED RESPONSE ▶
TAG
(OBQ05.8) A 32-year-old male sustains the injury shown in Figure A through D as the result of a high-speed motor vehicle collision. This particular injury is best treated with which of the following single approaches? Topic Review Topic
FIGURES: A   B   C   D    

1. Ilioinguinal
2. Hardinge
3. Iliofemoral
4. Watson-Jones
5. Kocher-Langenbeck

PREFERRED RESPONSE ▶
TAG
(OBQ05.187) When viewing pelvic injury radiographs, which of the following describes the findings diagnostic of an isolated transverse acetabular fracture? Topic Review Topic

1. Fracture line crossing the acetabulum with disruption of the iliopectineal and ilioischial lines
2. Disruption of the iliopectineal and ilioischial lines, with extension into the iliac wing and obturator ring
3. Disruption of the iliopectineal and ilioischial lines, with extension into the obturator ring
4. Isolated disruption of the iliopectineal line, with an intact ilioischial ine
5. Isolated disruption of the ilioischial line, with an intact iliopectineal ine

PREFERRED RESPONSE ▶
TAG
(OBQ04.93) A 45-year-old male is involved in a motor vehicle accident and sustains the injury shown in Figures A-D. Which of the following is the most appropriate approach for surgical fixation of this fracture? Topic Review Topic
FIGURES: A   B   C   D    

1. Ilioinguinal
2. Kocher-Langenbeck
3. Stoppa
4. Stoppa with lateral window
5. Extended iliofemoral

PREFERRED RESPONSE ▶
TAG
(OBQ04.100) A 47-year-old male sustains an isolated posterior wall acetabulum fracture after a motor vehicle collision and undergoes open reduction and internal fixation. Post-operative radiographs are shown in Figure A. Which of the following has been shown to correlate most closely with good outcomes following ORIF of posterior wall fractures? Topic Review Topic
FIGURES: A          

1. Degree of displacement seen on preoperative AP pelvis view
2. Degree of displacement seen on preoperative Judet views
3. Degree of displacement seen on preoperative pelvic CT scan
4. Degree of displacement seen on postoperative Judet views
5. Degree of displacement seen on postoperative pelvic CT scan

PREFERRED RESPONSE ▶



Cases

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