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Introduction
  • Epidemiology
    • demographics
      • bimodal distribution
        • high energy blunt trauma for young patients
        • low energy (fall from standing height) for elderly patients
    • location
      • posterior wall fractures are most common
  • Pathoanatomy  
    • fracture pattern determined by
      • force vector
      • position of femoral head at time of injury
  • Associated conditions
    • orthopaedic manifestations
      • extremity injury (36%)
      • nerve palsy (13%)
      • spine injury (4%)
    • systemic injuries
      • head injury (19%)
      • chest injury (18%)
      • abdominal injury (8%)
      • genitourinary injury  (6%)
  • Classification Systems
    • Judet and Letournel
      • classifed as 5 elementary and 5 associated fracture patterns
    • AO/OTA Classification
Anatomy
  • Osteology
    • acetabular 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 
      • anastomosis 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 
  
• More common in elderly patients with fall from standing (most common in elderly is "anterior column + medial wall")
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 inonimate 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
        • lowest joint reactive forces seen with toe-touch weight bearing and passive hip abduction 
          • greatest joint contact force seen when rising from a chair on the affecdted extremity 
        • 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
        • pregnancy is not contraindication to surgical fixation  
      • outcomes
        • associated hip dislocations should be reduced within 12 hours for improved 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 
      • obturator oblique inlet 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
  • Intraarticular hardware placement
  • Abductor muscle weakness
 

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Questions (29)

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

QID:4572
1

Inlet pelvis

1%

(50/3870)

2

Outlet pelvis

2%

(64/3870)

3

Anteroposterior pelvis

1%

(31/3870)

4

Obturator oblique pelvis

83%

(3231/3870)

5

Iliac oblique pelvis

12%

(479/3870)

Select Answer to see Preferred Response

PREFERRED RESPONSE 4

The posterior wall is best visualized on the obturator oblique pelvic view.

The obturator oblique and iliac oblique views make up the Judet views that are used to evaluate acetabular fractures, along with a standard AP pelvis radiograph. The obturator oblique pelvic view is best to view the anterior column and posterior wall in detail. The iliac oblique shows the profile of involved iliac wing, the posterior column, and the anterior wall.

Letournel reviewed his classification and treatment protocols, based on his 22 years of experience at that time. He noted that perfect anatomical reduction of the acetabulum led to the best outcomes.

Patel et al reviewed of the Letournel classification, and they found moderate to high inter- and intra-observer reliability with this classification system. The presence of articular displacement, marginal impaction, incongruity, intra-articular fragments and osteochondral injuries to the femoral head were found to have less reliability (intra- and interobserver).

Illustration A shows a right-sided obturator oblique radiograph, while Illustration B shows a right-sided iliac oblique radiograph. Illustration C shows a diagram of the obturator oblique radiograph, with the radiographic lines marked out.

Incorrect Answers:
Answers 1: Inlet pelvic imaging is best for assessing pelvic ring injuries (rotation and anterior-posterior or medial-lateral translation).
Answers 2: Outlet pelvic imaging is best for assessing pelvic ring injuries (proximal-distal translation, rotation).
Answers 3: AP pelvis is a good screening tool for pelvic and acetabular fractures.
Answers 5: Iliac oblique pelvis is best for assessing the posterior column and anterior wall of the acetabulum.

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(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? Review Topic

QID:3445
FIGURES:
1

The Keith method

1%

(13/1552)

2

The Moed method

1%

(13/1552)

3

The Calkins method

1%

(14/1552)

4

Dynamic fluoroscopic examination of the hip under anesthesia

96%

(1491/1552)

5

A history of associated hip dislocation

1%

(18/1552)

Select Answer to see Preferred Response

PREFERRED RESPONSE 4

Dynamic fluoroscopic examination of the affected hip under anesthesia is considered the best method of predicting hip stability. Fragment size, which can be calculated using the Keith, Moed, or Calkins method, can be used to predict hip stability radiographically, however they are not as accurate. In general it is thought that posterior wall fractures involving less than 20% of the posterior wall are stable, whereas those involving greater than 40%-50% are unstable. Unfortunately, this leaves an indeterminent zone (20-40%) which does not provide guidance in treatment.

Moed et al retrospectively reviewed 33 patients with posterior wall fractures who underwent dynamic fluoroscopic stress testing and compared the results of this testing to the Moed, Calkins, and Keith method of hip stability prediction. They found that the Moed method is the only reliable technique that is predictive of hip stability for small fracture fragments while also being predictive of instability for large fracture fragments. However, they also stated that there remain a substantial number of fractures involving 20% or more of the posterior wall that are both stable and unstable by examination under anesthesia. Therefore, they recommend dynamic fluoroscopic examination for assessment of hip stability in the presence of a posterior wall fracture.

Tornetta et al conducted a study in which dynamic fluoroscopic stress views were taken of 41 acetabular fractures that met the criteria for non-operative management to determine subtle signs of instability. Of the 41 fractures, 38 were found to be stable and 91% of these had good or excellent outcomes at 2.7 years. They concluded that dynamic stress views can identify subtle instability in patients who would normally be considered for non-operative treatment.

incorrect answers:
1-> Keith Method - Depth of the fracture segment in injured hip is compared to the contralateral intact posterior wall depth at the level of the fovea

2-> Moed - Depth of the fracture segment in the injured hip is compared to contralateral posterior wall depth at the level of the greatest amount of fracture involvement

3-> Calkins - Length of posterior acetabular arc from each hip is compared at the level of the greatest amount of fracture involvement.




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(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? Review Topic

QID:3503
FIGURES:
1

Nonoperative management based on the size of the posterior wall fragment

9%

(132/1439)

2

Operative management based on the size of the posterior wall fragment

3%

(37/1439)

3

Operative management based on the history of hip dislocation

3%

(44/1439)

4

Dynamic fluoroscopic stress exam under anesthesia in the obturator oblique view

75%

(1082/1439)

5

Dynamic fluoroscopic stress exam under anesthesia in the iliac oblique view

10%

(141/1439)

Select Answer to see Preferred Response

PREFERRED RESPONSE 4

Joint stability is critical for successful nonoperative management of posterior wall acetabular fractures. Recent evidence has established that dynamic fluoroscopic stress examination is the best method to determine joint stability in the setting of a posterior wall fracture. The obturator oblique view allows for the best evaluation of hip joint stability during examination for posterior wall fractures.

Grimshaw and Moed retrospectively reviewed the results of patients with posterior wall acetabular fractures managed nonoperatively after evaluation with dynamic fluoroscopic stress tests. At two year follow up, all had good to excellent Merle d’Aubigne clinical scores for hip function and no evidence of post-traumatic hip arthritis on AP pelvis radiographs.

Tornetta retrospectively reviewed his results managing patients with dynamic fluoroscopic stress examination for acetabular fractures which met radiographic nonoperative criteria. Good-to-excellent clinical results were seen in 91% of patients managed nonoperatively.

Tornetta reviewed management of acetabular fractures and Tornetta and Mostafavi separately reviewed management of hip dislocations. In both articles, emphasis is placed on dynamic examination of posterior wall fractures as instability has been seen with fractures comprising as little as 15% of the posterior wall.

Illustration A demonstrates two fluoroscopic images from a dynamic stress exam of a patient with a posterior wall fracture. The image obtained in the obturator oblique view clearly demonstrates that the femoral head loses congruency with the acetabular dome.

Incorrect Answers:
Answers 1 & 2: Posterior wall fragment size less than 40% was historically used as an indirect measure of stability, however measurements of fragment size may be unreliable and instability has been seen with fractures much smaller than 40%
Answer 3: A history of hip dislocation was thought to indicate a more unstable fracture. In the level IV study by Grimshaw and Moed, patients with an associated hip dislocation who were stable under stress exam had no significant difference in outcome with nonoperative management.
Answer 5: The iliac oblique view is used to evaluate the anterior wall and posterior column. Displacement or instability of the posterior wall would not be seen with this view

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(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? Review Topic

QID:3571
1

Intraarticular penetration of the screw

15%

(216/1450)

2

Position of the screw cephalad to the sciatic notch

10%

(140/1450)

3

Screw starting point at the anterior inferior iliac spine

15%

(214/1450)

4

Screw starting point at the gluteal pillar

3%

(38/1450)

5

Screw position between the inner and outer tables of the ilium

57%

(833/1450)

Select Answer to see Preferred Response

PREFERRED RESPONSE 5

The obturator oblique-inlet view, as seen in Illustration A, best demonstrates the position of a supra-acetabular screw or pin relative to the tables of the ilium.

Starr et al review their initial results and technique of closed or limited open reduction and percutaneous fixation of acetabular fractures. They defined two groups of patients who may benefit from this technique; elderly patients with multiple comorbidities to facilitate early mobilization and restore hip morphology, and young patients with elementary fracture patterns and multiple associated injuries.

Starr et al describe their operative technique and outcomes for a case series of 3 patients using percutaneous acetabular fixation to augment open reduction of acetabular fractures. The authors state that, for placement of an anterior colum ramus screw, an iliac oblique-inlet (not obturator oblique-inlet) will ensure that the screw is within the medullary canal of the ramus and does not exit anterior or posterior.

Gardner and Nork describe a technique for placement of a large femoral distractor in the supra-acetabular region to compress displaced posterior pelvic ring injuries. They note that the obturator oblique-inlet view is necessary to view the entire length of the pin as well as to ensure that pin remains in bone.

Incorrect answers:
Answer 1: Relationshiop of the screw to the acetabulum is best evaluated with the obturator oblique-outlet view as well as the iliac oblique view
Answer 2: The iliac oblique view is used to ensure the trajectory of the screw is superior to the sciatic notch
Answer 3: The Obturator oblique-outlet view, otherwise known as the "teepee" or "tear drop" view, is used to identify the start for supra-acetabular implant placement
Answer 4: The gluteal pillar is not utilized as a start point when placing supraacetabular fixation, and the obturator oblique-inlet view would not be ideal to visualize this region of the pelvis

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(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? Review Topic

QID:3578
FIGURES:
1

Kocher-Langenbeck

14%

(202/1483)

2

Watson-Jones

2%

(36/1483)

3

Extended iliofemoral

9%

(134/1483)

4

Ilioinguinal

74%

(1102/1483)

5

Hardinge

0%

(7/1483)

Select Answer to see Preferred Response

PREFERRED RESPONSE 4

Figures A through C depict and AP pelvis and Judet views of a T-type fracture of the right acetabulum. The ilioinguinal approach provides access to the anterior wall and anterior column for fracture fixation, in addition to allowing fixation of the nondisplaced posterior transverse fracture line. The lateral femoral cutaneous nerve (LFCN) is at risk in the superficial part of the dissection. Another option for the approach would be the modified Stoppa, which would also allow excellent access to the anterior column as well as the internal aspect of the iliac wing and quadrilateral plate.

Illustration A shows the five basic and 5 associated acetabular fractures.

Incorrect Answers:
Answer 1. Kocher-Langenbeck: access for posterior wall and column fractures
Answer 2. Watson-Jones: anterolateral approach best for the hip, not the anterior column of the acetabulum.
Answer 3. Extended iliofemoral: visualization for both column fractures
Answer 5. Hardinge approach: lateral approach for THA

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(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? Review Topic

QID:3628
FIGURES:
1

Os acetabuli marginalis superior

97%

(1824/1871)

2

Fovea capitis

0%

(8/1871)

3

Myositis ossficans

1%

(15/1871)

4

Avascular necrosis.

0%

(9/1871)

5

Acetabular fracture

1%

(10/1871)

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PREFERRED RESPONSE 1

The patients hip radiograph demonstrates an os acetabuli marginalis superior which is a benign accessory ossification center found in the superior aspect of the acetabulum. This can be commonly confused with an acute fracture or avascular necrosis. Although the os acetabuli marginalis superior occasionally persists into adult life, it usually fuses to the acetabulum by the time an individual reaches age 20.

Caudle et al provide a case report of a a patient with a painful os acetabuli marginalis superior. This was successfully treated with resection of the fragment, and bone grafting. This was noted to be a very unusual source of hip pain in adolescents.

Incorrect Answers:
2-The fovea capitis is the depression on the head of the femur where the ligamentum teres inserts. This can appear as a small ossicle on the surface of femoral heads in skeletally immature patients. An example of this is shown in Illustration A.
3-Myositis ossificans is soft tissue calcification which develops after trauma, or more rarely, surgery. An example of myositis ossificans around the hip is shown in Illustration B.
4-Avascular necrosis of the femoral head classically occurs in patient with a history of alcoholism, steroid use, or sickle cell disease. Radiographs can demonstrate femoral head sclerosis, and eventually collapse of the articular surface. An example of femoral head AVN in a patient with sickle cell disease is shown in Illustration C.
5-Acetabular fractures occur in the setting of trauma, and are relatively rare in the pediatric population. An example of a left sided acetabular fracture is shown in Illustration D. Illustration E shows a right sided acetabular fracture through the triradiate cartilage.

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(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? Review Topic

QID:3664
1

Increased age

3%

(42/1367)

2

Increased hip flexion-extension arc

27%

(371/1367)

3

Immediate weight-bearing

10%

(132/1367)

4

Increased hip muscle strength

59%

(805/1367)

5

Decreased stride length

1%

(15/1367)

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PREFERRED RESPONSE 4

Patient functional outcomes after acetabular fractures have been shown to be related to postoperative hip strength, regardless of surgical approach.

The reference by Borrelli et al evaluated muscle strength and outcomes after acetabular surgery via an anterior approach. They report that hip extension strength was affected least (6%), whereas abduction, adduction, and flexion strength was affected to a greater degree. They note that hip muscle strength after operative treatment of a displaced acetabular fracture directly influences patient outcome.

The reference by Engsberg et al is a review of patients that underwent ORIF of acetabular fractures through anterior or posterior approaches. They report that maximizing hip muscle strength may improve gait, and improvement in hip muscle strength and gait is likely to improve functional outcome. Worsening functional outcomes were correlated with decreased gait kinematics and stride length.


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(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? Review Topic

QID:3273
1

Modified Stoppa approach

3%

(11/384)

2

Extended iliofemoral approach

1%

(4/384)

3

Kocher-Langenbeck approach

93%

(359/384)

4

Ilioinguinal approach

1%

(3/384)

5

Combined anterior and posterior approach

2%

(7/384)

Select Answer to see Preferred Response

PREFERRED RESPONSE 3

Operative treatment is indicated for most displaced acetabular fractures to allow early ambulatory function and to decrease the chance of post-traumatic arthritis. Among the various surgical approaches, the Kocher-Langenbeck allows direct exposure of both the posterior column and posterior wall. Indications for using this exposure include posterior wall fractures, posterior column fractures, combined posterior wall/posterior column fractures, and simple transverse fractures.


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(OBQ10.203) When placing a percutaneous retrograde pubic ramus 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? Review Topic

QID:3296
1

AP pelvis

0%

(1/512)

2

Outlet obturator oblique view

14%

(72/512)

3

Inlet iliac oblique view

71%

(362/512)

4

Iliac oblique view

4%

(22/512)

5

Obturator oblique view

10%

(53/512)

Select Answer to see Preferred Response

PREFERRED RESPONSE 3

As reviewed in the referenced article by Starr et al, when placing a retrograde pubic rami screw, the pelvic inlet iliac oblique view will best determine the anteroposterior placement of the screw in the pubic ramus. To ensure placement outside of the joint, the outlet obturator oblique is best, but all other views should be incorporated into determination of the position of fixation, as the corridor for this screw placement is quite narrow.

Illustration A shows a left sided inlet iliac view on a pelvic bone model.

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(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? Review Topic

QID:3251
FIGURES:
1

Posterior inferior

5%

(52/963)

2

Anterior superior

19%

(183/963)

3

Posterior superior

73%

(703/963)

4

Directly superior

2%

(16/963)

5

Anterior inferior

1%

(6/963)

Select Answer to see Preferred Response

PREFERRED RESPONSE 3

Figure A is an AP radiograph of a hip hemiarthroplasty.

Contact pressures from an insturmented hip endoprosthesis can have important implications in both implant positioning and rehabilitation protocols.

Hodge et al implanted a pressure-measuring Moore-type endoprosthesis in a patient who had sustained a displaced fracture of the femoral neck. They used this prosthesis to determine the measurement and telemetry of contact pressures in the hip for 36 months post-operatively. The highest pressure, eighteen megapascals, was recorded while the patient was getting up from a chair using the affected leg and was localized in the posterior superior portion of the acetabulum. This can be important in the post-operative care of acetabular fractures, as patients are at increased risk of loss of fixation with greater acetabular contact forces. Interestingly, peak pressures in vivo were found to be considerably higher than previously measured pressures in vitro.

Incorrect Answers:
1,2,4,5,-These regions of the acetabulum have less contact pressure compared to the posterior superior portion.


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(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? Review Topic

QID:2912
1

Pudendal

2%

(31/1531)

2

Deep illiac circumflex

3%

(45/1531)

3

Hypogastric

5%

(83/1531)

4

Obturator

89%

(1366/1531)

5

Testicular

0%

(2/1531)

Select Answer to see Preferred Response

PREFERRED RESPONSE 4

The "corona mortis" (translated as “crown of death”) artery is a vascular variant that joins the external illiac and the obturator artery as it crosses the superior pubic ramus. Tornetta et al did a study where "fifty cadaver halves were dissected to determine the occurrence and location of the corona mortis. Anastomoses between the obturator and external iliac systems occurred in 84% of the specimens. Thirty-four percent had an arterial connection, 70% had a venous connection, and 20% had both. The distance from the symphysis to the anastomotic vessels averaged 6.2 cm (range, 3-9 cm)." The corona mortis can be injured in superior ramus fractures and iatrogenically while plating pelvic ring injuries using the ilioinguinal approach.

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(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? Review Topic

QID:2925
FIGURES:
1

Both column

30%

(265/882)

2

Anterior column

1%

(5/882)

3

Anterior column posterior hemitransverse

5%

(44/882)

4

Transverse

62%

(548/882)

5

T-type

2%

(19/882)

Select Answer to see Preferred Response

PREFERRED RESPONSE 4

The radiograph in Figure A shows a transverse acetabulum fracture. The iliopectineal (anterior column) and ilioischial lines (posterior column) are interrupted, revealing bicolumnar involvement; however, this is different than the both column fracture, as a transverse pattern has articular surface still in continuity with the axial skeleton via the sacroiliac joint.

The referenced article by Patel et al showed a wide variation of inter and intra-observer agreement in interpreting radiographs of acetabular fractures, with high agreement for basic radiographic classification and only slight to moderate agreement for other radiologic variables such as impaction.

The other referenced article by Letournel is a great review article regarding the initial classification of these fractures as well as a quick summary of his outcomes.


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

QID:2950
1

Transtectal transverse acetabular fracture

7%

(110/1607)

2

Vertical shear pelvic ring injury

4%

(69/1607)

3

Displaced H-type sacral fracture

2%

(27/1607)

4

Both column acetabular fracture

85%

(1364/1607)

5

Anterior-posterior type III pelvic ring injury

2%

(34/1607)

Select Answer to see Preferred Response

PREFERRED RESPONSE 4

The pelvic spur sign is indicative of a both column acetabular fracture. It is best seen on an AP or obturator oblique x-ray. The spur is the intact portion of the ilium, still attached to the axial skeleton and seen posterosuperior to the displaced acetabulum (typically medially displaced).

Illustration A shows the spur sign (arrows) on a CT image, while illustration B shows an obturator oblique of the pelvis and the spur sign is shown with the long tailed arrow (on the left of the image).

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(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: Review Topic

QID:2957
1

Determination of surgical planning

1%

(6/498)

2

Intra-articular loose bodies

2%

(11/498)

3

Marginal impaction

2%

(12/498)

4

Fracture piece size and position

1%

(3/498)

5

Determination of pre-existing degenerative changes

93%

(463/498)

Select Answer to see Preferred Response

PREFERRED RESPONSE 5

CT scanning is indicated in acetabular fractures for determination of surgical approach and techniques, evaluation of marginal impaction and presence of intra-articular loose bodies (especially after hip dislocation), and evaluation of fracture piece sizes and relative positions.

Kellam et al reviewed their initial experience with CT scanning and acetabular fractures, and noted a 25% change in surgical planning when CT was utilized versus plain radiographs; they also noted the ability to detect marginal impaction and fracture size/position was improved with CT.


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

QID:2976
1

Transverse

6%

(98/1602)

2

Both column

76%

(1214/1602)

3

Anterior column posterior hemitransverse

12%

(187/1602)

4

Posterior column with posterior wall

4%

(72/1602)

5

Anterior column with anterior wall

2%

(26/1602)

Select Answer to see Preferred Response

PREFERRED RESPONSE 2

A both column acetabular fracture is defined as an acetabular fracture with no articular surface in continuity with the remaining posterior ilium (and therefore, axial skeleton). The spur sign is a radiological sign seen with these fractures, and is the posterio-inferior aspect of the intact posterior ilium. The spur sign and other radiographic findings consistent with a both column acetabular fracture can be seen in Illustration A (AP), Illustration B (obturator oblique), and Illustration C (iliac oblique).

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(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? Review Topic

QID:3011
FIGURES:
1

Decreased length of hospital stay

2%

(5/229)

2

Improved functional outcome

5%

(11/229)

3

Greater organ dysfunction

83%

(191/229)

4

Higher likelihood of being discharged to home as opposed to a rehab facility

4%

(10/229)

5

Improved fracture reduction

5%

(12/229)

Select Answer to see Preferred Response

PREFERRED RESPONSE 3

Early fixation of acetabular fractures is associated with lesser organ dysfunction, so therefore answer three is not true.

Plaisier et al showed the timing of acetabular and pelvic ring fracture fixation greatly impacted patient outcome. Patients who had fixation within 24 hours of injury showed shorter length of stay in the hospital and ICU (decreased number of ventilator days), improved functional outcomes including a highly likelihood of being discharged to home as opposed to a rehabilitation facility, and lesser organ dysfunction.

The reference by Matta et al is a classic article that shows that patients fixed within 3 weeks of injury showed both a higher rate of anatomical reduction and lower overall complication rate than patients with similar fracture patterns treated after 3 weeks.


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(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? Review Topic

QID:3030
FIGURES:
1

Anterior column posterior hemitransverse

18%

(283/1584)

2

Both column

76%

(1196/1584)

3

Transverse

1%

(20/1584)

4

Transverse with posterior wall

4%

(56/1584)

5

Anterior column

1%

(22/1584)

Select Answer to see Preferred Response

PREFERRED RESPONSE 2

Figures A through D show a comminuted both column acetabular fracture. In this injury, both columns are involved, with the acetabulum losing all connection to the axial skeleton (sacrum). This differentiates it from all other patterns, where at least part of the acetabular cartilage maintains connection to the sacrum.

Figure C shows the ischial spur, which is classically known as the spur sign and most easily seen on the obturator oblique radiograph.

Incorrect Answers:
Answer 1: This injury has axial skeleton attachment to the acetabular cartilage through the posterior column.
Answer 3: This injury has axial skeleton attachment to the acetabular cartilage through the anterior and posterior columns.
Answer 4: This injury has axial skeleton attachment to the acetabular cartilage through the anterior column as well as the posterior column, depending on fracture pattern.
Answer 5: This injury has no posterior column involvement, and therefore the posterior column maintains the axial skeleton attachment to the acetabulum.


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(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? Review Topic

QID:505
FIGURES:
1

Posterior wall

4%

(12/301)

2

Transverse

75%

(227/301)

3

Anterior wall

4%

(12/301)

4

Posterior column

2%

(7/301)

5

Both column

14%

(43/301)

Select Answer to see Preferred Response

PREFERRED RESPONSE 2

The axial CT cut and Judet radiographic view shown reveals a transverse fracture pattern according to the Letournel classification system. This can be determined by the fact that the articular surface of the acetabulum is attached to the intact portion of the ilium, which is connected to the axial skeleton posteriorly through the sacroiliac joint. This differs from a both-column fracture, in which the articular surface of the acetabulum has no attachments to the axial skeleton due to fracture line(s). The axial CT scan also shows a vertical fracture line which is typical of a transverse fracture pattern.

Durkee et al review the classification schemes for these injuries, as well as comment on the importance of quality images (Judet views, CT, etc).

Figures A and B show a transverse acetabular fracture with mild displacement.

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

QID:651
1

decreased chance of anatomic fracture reduction

86%

(252/293)

2

decreased risk of heterotopic ossification

1%

(3/293)

3

decreased rate of neurologic injury

0%

(1/293)

4

decreased rate of infection

0%

(1/293)

5

decreased rate of multi-organ failure

12%

(35/293)

Select Answer to see Preferred Response

PREFERRED RESPONSE 1

Madhu et al showed time to surgery was a significant predictor of radiological and functional outcome for both elementary and associated displaced fractures of the acetabulum. Both anatomic reduction and functional outcome significantly worsened as time to surgery increased. It was found anatomic reduction was more likely when surgery was within 15 days for elementary fracture and 5 days for associated.

Incorrect answers:
2: No data exists showing a decrease in heterotopic ossification as time to surgery increases.
3: Neurologic injury is more associated with the initial injury.
4,5: Multi-organ failure was not commented on, but infection showed a trend towards being more likely with longer time to surgery.


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(OBQ07.3) In Figure A, the two red arrows point to which of the following two arteries? Review Topic

QID:664
FIGURES:
1

Superior gluteal and pudendal

1%

(6/415)

2

Internal iliac and medial circumflex

1%

(3/415)

3

External iliac and deep femoral

4%

(17/415)

4

Obturator and external iliac

93%

(386/415)

5

Medial circumflex and inferior gluteal

0%

(2/415)

Select Answer to see Preferred Response

PREFERRED RESPONSE 4

The external iliac and obturator artery anastomose to form the corona mortis. During the Stoppa or ilioinguinal approach to the pelvis, you need to be careful of the corona mortis because the vessels can cause significant bleeding especially if they retract into the pelvis. In the Tornetta et al article, fifty cadaver halves were dissected to determine the occurrence and location of the corona mortis. Anastomoses between the obturator and external iliac systems occurred in 84% of the specimens. Thirty-four percent had an arterial connection, 70% had a venous connection, and 20% had both. The distance from the symphysis laterally to the anastomotic vessels averaged 6.2 cm. The Okcu et al article showed similar results in 150 cadavers: they found vascular anastomoses between the obturator and external iliac systems in 61% of the sides, and anastomotic veins in 52% of the exposures. The mean distance between the anastomotic arteries and the symphysis pubis was 6.4 cm, and 5.6 cm for the communicating veins. There seemed to be no significant difference between genders in the incidence of corona mortis and the distance between communicating vessels and the symphysis pubis.


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(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? Review Topic

QID:759
1

Posterior wall/ posterior column

4%

(12/323)

2

Transverse

6%

(19/323)

3

T-Type

8%

(26/323)

4

Anterior column/ posterior hemitransverse

8%

(26/323)

5

Both columns

74%

(239/323)

Select Answer to see Preferred Response

PREFERRED RESPONSE 5

There are 5 simple and 5 associated fracture types according to the classification system created by Judet and Letournel. The key feature which distinguishes both column fractures from other associated types is that all articular segments are detached from the intact portion of the ilium, which remains attached to the sacrum through the SI joint.

Although the transverse plus posterior wall, T-shaped, and anterior plus posterior hemi-transverse fractures all show involvement of the anterior and posterior columns, they are not “both columns” because a portion of the articular surface remains in its normal position, attached to intact ilium.

The intact ilium is responsible for the "spur sign" noted most prominently on the obturator oblique radiograph.

Illustration A demonstrates the 10 types of acetabular fractures as created by Judet and Letournel. Illustration B is an example of a both column acetabular fractures as seen on the obturator oblique radiograph.

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(OBQ07.114) An 74-year-old community-ambulating male presents with complaints of right hip pain for 4 months. He does not recall any specific trauma though his pain is quite severe at this point. A radiograph is shown in Figure A. What is the most appropriate definitive treatment for this patient? Review Topic

QID:775
FIGURES:
1

Skeletal traction

3%

(15/473)

2

Conservative treatment with delayed physical therapy and shoe lifts

3%

(13/473)

3

Open reduction and internal fixation

30%

(142/473)

4

Right hip reconstruction

63%

(298/473)

5

Closed reduction and percutaneous fixation

1%

(5/473)

Select Answer to see Preferred Response

PREFERRED RESPONSE 4

The patient described in this question has sustained an insufficiency fracture of the right acetabulum that has been neglected. Total hip arthroplasty (THA), with use of flanged and/or custom acetabular components as needed, is necessary to reconstruct the acetabulum and address the significant femoral head damage.

Total hip arthroplasty as the primary treatment for acetabular fracture remains controversial. Osteopenia, pre-fracture hip arthritis and significant chondral impaction injuries make osteosynthesis difficult and more prone to failure. In the elderly patient with these injury characteristics or delayed presentation, THA may be a preferred first procedure as it can definitively address these issues.

Weber et al reviewed delayed THA in acetabular fractures that had previously undergone open reduction internal fixation, and reported a 78% 10-year survival rate, with worse outcomes in patients < 50 years old, males, weight >80kg, and patients with large residual segmental acetabular defects.

Jiminez et al review the the use of THA after acetabular fractures, either in a delayed or acute fashion. They note that THA as an acute treatment of acetabular fractures is rarely indicated: "Circumstances in which this may be a consideration include certain pathologic fractures, patients with pre-existing symptomatic hip arthritis who are already candidates for hip arthroplasty prior to injury, and rare instances of associated femoral side injuries, including head-splitting fractures that preclude a satisfactory operative result or significantly displaced ipsilateral femoral neck fractures."

Mears reviews acute THA in osteopenic acetabular fractures, with presentation of treatment algorithms and techniques, including conservative treatment, minimally invasive fixation, conventional fixation, acute and delayed THA.

Figure A shows a delayed-presentation right acetabular fracture with significant femoral head impaction injury and acetabular protrusio. Illustration A shows an algorithm for treatment of acetabular fractures in osteopenic patients.

Incorrect answers:
Answer 1: Traction would be acceptable if the patient had an unacceptable medical risk for surgery
Answer 2: Conservative treatment inappropriate unless patient not a surgical candidate for medical reasons
Answer 3: Several injury factors make this choice more prone to failure (1) delayed presentation, (2) osteopenia, (3) femoral head injury, (4) medial roof impaction
Answer 5: Close reduction may improve the protrusio if the fracture is still mobile but cannot address the significant chondral injury.

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

QID:891
1

Increased age

24%

(84/348)

2

Intraoperative complications

5%

(18/348)

3

Ipsilateral femoral head injury

10%

(36/348)

4

Involvement of both columns

56%

(195/348)

5

Non-anatomic fracture reduction

4%

(15/348)

Select Answer to see Preferred Response

PREFERRED RESPONSE 4

Negative outcome factors have been shown to include: increasing patient age, time from injury to surgery (>3 weeks), intraoperative complications, femoral head bone or cartilage injury, and fracture reduction > 1-2mm from anatomic. Choice of surgical approach has not been shown to affect patient outcomes.

The referenced study by Matta evaluated outcomes of displaced acetabular fractures. The overall clinical result was excellent for 104 hips (40 per cent), good for ninety-five (36 per cent), fair for twenty-one (8 per cent), and poor for forty-two (16 per cent). The clinical result was related closely to the radiographic result. These findings indicate that in many patients who have a complex acetabular fracture the hip joint can be preserved and post-traumatic osteoarthrosis can be avoided if an anatomical reduction is achieved.


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(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? Review Topic

QID:162
1

hip flexion, knee extension

2%

(27/1728)

2

hip extension, knee extension

2%

(39/1728)

3

hip flexion, knee flexion

5%

(86/1728)

4

hip extension, knee flexion

91%

(1569/1728)

5

the pressure does not vary based on position

0%

(2/1728)

Select Answer to see Preferred Response

PREFERRED RESPONSE 4

In the cited study, researchers measured tissue fluid pressure within the sciatic nerve in cadaveric specimens using a pressure transducer. The hip and knee were taken through a combination of ranges and found that the clinically relevant increase in pressure happened with the hip flexed at 90 degrees and the knee fully extended. They concluded that increased intraneural pressure was related to excursion of the nerve as linear distance between the greater sciatic notch and the distal leg increase. Hence, according to the question stem, to avoid traction injury, the reverse position should be implemented (hip extension and knee flexion).


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

QID:352
FIGURES:
1

Ilioischial line

2%

(6/354)

2

Posterior column

5%

(19/354)

3

Posterior wall

85%

(301/354)

4

Anterior wall

8%

(27/354)

5

Sacroiliac joint

0%

(1/354)

Select Answer to see Preferred Response

PREFERRED RESPONSE 3

Letournel and Judet developed a schematic representation of the acetabulum as being contained within asymmetric long anterior and short posterior arms of an inverted “Y”.

On the bony pelvis, the ilioischial component becomes that posterior column and the iliopectineal line becomes the anterior column. The Judet-Letournel classification system is based on this scheme. By careful evaluation of landmarks on a standard AP pelvis radiograph, as well as on 45-degree oblique obturator and iliac views, the extent of injury can be determined accurately.

The AP view usually demonstrates the six fundamental landmarks relatively well as seen in illustration A. The obturator oblique view reveals additional information about the anterior column and posterior wall(see illustration A(B), B). In an obturator oblique view the x-ray beam is centered on and almost perpendicular to the obturator foramen. The iliac oblique view visualizes the posterior column and anterior wall (illustration A(C), C). This view also shows the best detail of the iliac wing as the radiographic beam is roughly perpendicular to the iliac wing. Inclusion of the opposite hip is essential for evaluation of symmetrical contours that may have slight individual variations and to evaluate the width of the normal articular cartilage in each view in a pelvic series (AP, Judet's) .

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(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? Review Topic

QID:45
FIGURES:
1

Ilioinguinal

45%

(129/287)

2

Hardinge

1%

(2/287)

3

Iliofemoral

36%

(103/287)

4

Watson-Jones

2%

(7/287)

5

Kocher-Langenbeck

16%

(46/287)

Select Answer to see Preferred Response

PREFERRED RESPONSE 3

The radiograph and CT images shown in A-D show an acute both column acetabular fracture with segmental posterior column comminution. For difficult fractures with anterior displacement in which access to the entire anterior column is required, the ilioinguinal or Stoppa approach is ideal. These approaches allow access to the anterior column as far as the symphysis and includes the quadrilateral plate. Most both-column fractures can also be managed through these approaches, but only if the posterior fragment is large and in one piece. In this case, the posterior column is in several pieces and requires either two approaches or an extended approach, such as the iliofemoral. The original description of the ilioinguinal approach makes intraarticular visualization of the hip impossible. If visualization of the joint is required, a T extension of the incision just medial to the anterior-superior iliac spine can be made. Most surgeons accept that the joint is reduced when the fracture lines inside the pelvis are reduced, and thus this extension is very rarely used.

The extended iliofemoral approach gives excellent visualization of the outer table of the ilium, the superior dome, and the posterior column. The anterior column can be visualized to the iliopectineal eminence. The exposure is similar to that provided by the triradiate approach with the additional benefit of access to the bone above the sciatic notch. The approach can be extended to provide exposure to the iliac fossa; however, this is very rarely necessary and should be avoided. Extending the approach to the inside of the pelvis greatly increases the risk of devascularizing segments of the acetabulum.


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

QID:1073
1

Fracture line crossing the acetabulum with disruption of the iliopectineal and ilioischial lines

81%

(244/300)

2

Disruption of the iliopectineal and ilioischial lines, with extension into the iliac wing and obturator ring

4%

(12/300)

3

Disruption of the iliopectineal and ilioischial lines, with extension into the obturator ring

6%

(17/300)

4

Isolated disruption of the iliopectineal line, with an intact ilioischial ine

5%

(14/300)

5

Isolated disruption of the ilioischial line, with an intact iliopectineal ine

4%

(12/300)

Select Answer to see Preferred Response

PREFERRED RESPONSE 1

Transverse acetabular fractures separate the innominate bone into two fragments, the superior iliac and the inferior ischiopubic, by a single fracture line that crosses the acetabulum horizontally. The iliopectineal and ilioischial lines are disrupted on the AP pelvis radiograph. Axial CT scan of this fracture pattern at the level of the dome will show a vertical anterior to posterior fracture line. Illustrations A-C show AP and Judet pelvic radiographs of a transverse fracture. Illustration D demonstrates the axial CT appearance of this fracture type. Answer choice 2 is describing a both column injury or anterior column posterior hemitransverse, and answer choice 3 describes a T-type fracture pattern. Answer choices 4 and 5 describe an anterior column and posterior column injury respectively. Judet et al provide one of the first comprehensive reviews on acetabular surgical approaches, fracture types, and radiographic anatomy. Illustration E demonstrates the acetabular classification scheme developed by Judet.

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(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? Review Topic

QID:1198
FIGURES:
1

Ilioinguinal

3%

(29/1130)

2

Kocher-Langenbeck

89%

(1006/1130)

3

Stoppa

3%

(33/1130)

4

Stoppa with lateral window

3%

(31/1130)

5

Extended iliofemoral

3%

(29/1130)

Select Answer to see Preferred Response

PREFERRED RESPONSE 2

The images demonstrate a posterior column acetabular fracture. These are best surgically treated with a Kocher-Langenbeck approach, which allows access to the posterior column and posterior wall. Figure A shows disruption of the ilioischial line with an intact iliopectineal line which is diagnostic of this fracture pattern. The CT image in Figure D shows the characteristic horizontal (coronal) orientation of the column fracture when viewed on an axial CT. Illustration A shows the radiographic landmarks used in diagnosing acetabular fractures. Illustrations B and C show the orientation of column and wall fractures respectively. Ilioinguinal and Stoppa approaches allow access for anterior column fixation and symphysis fixation respectively. The extended iliofemoral approach can be used to treat both column injuries, but has high rates of post-operative heterotopic ossification.

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(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? Review Topic

QID:1205
FIGURES:
1

Degree of displacement seen on preoperative AP pelvis view

1%

(16/1544)

2

Degree of displacement seen on preoperative Judet views

5%

(75/1544)

3

Degree of displacement seen on preoperative pelvic CT scan

12%

(184/1544)

4

Degree of displacement seen on postoperative Judet views

13%

(204/1544)

5

Degree of displacement seen on postoperative pelvic CT scan

69%

(1063/1544)

Select Answer to see Preferred Response

PREFERRED RESPONSE 5

Moed et al performed a study to determine the clinical outcome in patients in whom a displaced fracture of the posterior wall of the acetabulum had been treated by open reduction and internal fixation. They were able to show good to excellent clinical results for patients who underwent anatomic reduction and internal fixation of posterior wall acetabulum fractures as assessed using radiographs. Fractures in elderly patients and patients who sustained extensive comminution were more likely to have worse clinical result.

In a separate study, Moed et al. evaluated the results of 67 patients who underwent ORIF of a posterior wall fractures by assessing the accuracy of postoperative AP pelvis, obturator oblique films, iliac oblique films, and CT scans. They found that postoperative pelvic CT scan was the most accurate way to judge final fracture reduction and was able to pick up residual fracture displacements that were not seen on postoperative plain radiographs. They concluded that the accuracy of reduction as assessed on postoperative CT scan was the most reliable indicator of clinical outcomes.


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