pelvic trauma (incl. femoral head and hip dislocation)

Question 1

Sacral Fractures

1. Common in pelvic ring injuries ( _____%)
2. ____% are associated with neurologic injury
3. Frequently missed:
   ◾___% in patients who are neurologically intact
   ◾___% in patients who have a neurologic deficit

Answer 1

** Under-diagnosed and often mistreated fractures that may result in neurologic compromise **

1. 30-45%
2. 25%
3. Frequently missed
   ◾75% in patients who are neurologically intact
   ◾50% in patients who have a neurologic deficit

Question 2

Sacral Fractures

1. Epidemiology
2. Prognosis
   a. Presence of a __________ is the most important factor in predicting outcome
   b. Mistreated fractures may result in? (4)

Answer 2

Epidemiology
◾Young adults: as a result of high energy trauma
◾Elderly: as a result of low energy falls

2. Prognosis
   a. Neurologic deficit

b. Mistreated fractures may result in: 
◾lower extremity deficits
◾urinary dysfunction
◾rectal dysfunction
◾sexual dysfunction

Question 3

Sacral Fractures

Classification

Answer 3

Denis classification [Zone 1 - 3]

Zone 1= lateral to foramina
◾most common (50%) ◾nerve injury rare (5%) ◾usually occurs to L5 nerve root

Zone 2= through foramina
◾may be stable OR unstable
◾Zone 2 fx with shear component HIGHLY UNSTABLY

Zone 3=medial to foramina into the spinal canal
◾ highest rate of neuro deficit (60%) ◾bowel, bladder, and sexual dysfunction

Other Fracture patterns include
(i) Transverse (◦higher incidence of nerve dysfunction)

(ii) U-type sacral fractures (◦results from axial load ◦represent spino-pelvic dissociation ◦high incidence of neurologic complications)

Question 4

Sacral Fractures

Radiographs

1. only show ____% of sacral fractures
2. Recommended views (3)
3. Additional views (1)
4. Findings (2)

Answer 4

1. 30%
2. Recommended views
   ◾AP pelvis
   ◾Inlet view= best assessment of sacral spinal canal and superior view of S1
   ◾Outlet view= provides true AP of sacrum
3. Additional views
   ◾cross-table lateral
4. Findings
   ◾L4 or L5 transverse process fractures
   ◾asymmetric foramina

** MRI when neural comprimise is suspected **

Question 5

Sacral Fractures: Treatment

Op vs non-op

Answer 5

1. Nonoperative: indications
   ◾<1 cm displacement and no neurologic deficit
   ◾insufficiency fractures
2. Operative: Indications
   ◾displaced fractures >1 cm (incl. late displacement)
   ◾soft tissue compromise
   ◾persistent pain after non-operative management
3. Surgical fixation with decompression: Indications
   ◾any evidence of neurologic injury

Question 6

Sacral Fractures : Surgical treatment

1. Options include (4)

Percutaneous screw fixation
◾Screws may be placed as sacroiliac, trans-sacral or trans-iliac trans-sacral ◾useful for sagittal plane fractures

Beware of:
2. _______ nerve root

3. _________ of fracture
4. May cause _________

Answer 6

1. (i) Percutaneous screw fixation (ii)Posterior tension band plating (iii) Iliosacral and lumbopelvic fixation (iv)Decompression of neural elements

Beware of :
2. L5 nerve root

3. Avoid overcompression of fracture
4. May cause iatrogenic nerve dysfunction

*** Note: ◾does not allow for removal of loose bone fragments ◾do not use in osteoporotic bone

Question 7

Ilium Fractures

stable or unstable generally?

Typical pattern ?

Assoc with ? [3]

Answer 7

• Most are unstable fractures
• Typically progress from iliac crest to greater sciatic notch
• Iliac wing fractures have high incidence of associated injuries
  ◦open injuries
  ◦bowel entrapment
  ◦soft tissue degloving

Question 8

Ilium Fractures

Anatomy - Osteology

1. pelvic girdle is comprised of :
2. ilium
   a. 2 important anterior prominences
   ◾anterior-superior iliac spine (ASIS) ◾origin of: [2]
   ◾anterior-inferior iliac spine (AIIS) ◾origin of: [2]
3. Posterior prominences
   a. Posterior-superior iliac spine (PSIS) : located 4-5 cm lateral to the ___ spinous process

Answer 8

1. pelvic girdle is comprised of
   ◾sacrum
   ◾2 innominate (coxal) bones
   ◾each formed from the union of 3 bones: ilium, ischium, and pubis

2a. origin of sartorius and transverse and internal abdominal muscles
2b. origin of direct head of rectus femoris and iliofemoral ligament (Y ligament of Bigelow)

3. Posterior prominences
   a. posterior-superior iliac spine (PSIS)
   ◾located 4-5 cm lateral to the S2 spinous process
   b. posterior-inferior iliac spine (PIIS)

Question 9

Ilium Fractures

1. Treatment : Nonoperative
   ◾indications
2. Operative
   ◾indications

Answer 9

Treatment
•Nonoperative ◦mobilization with an assist device ◾indications
◾nondisplaced fractures
◾isolated iliac wing fractures

•Operative ◦open reduction and internal fixation ◾indications
◾displaced fractures of ilium

Question 10

Ilium Fractures

classification

Answer 10

No specific classification for iliac wing fractures

Generally described as specific subtypes of more common classification systems

Question 11

Ilium Fractures

Tile Classification

Answer 11

Tile Classification
◾stable (intact posterior arch)
◾A1-1: iliac spine avulsion injury
◾A1-2: iliac crest avulsion
◾A2-1: iliac wing fractures often from a direct blow

◾partially stable (incomplete disruption of posterior arch)
◾B2-3: incomplete posterior iliac fracture

◾unstable (complete disruption of posterior arch)
◾C1-1: unilateral iliac fracture

Question 12

Ilium Fractures

Operative Techniques

Wound Management

1. evaluate all wounds for: [2]

Answer 12

Operative Techniques

Wound Management
1. evaluate all wounds for
◾soft tissue disruption or internal degloving injury
◾possible soft tissue or bowel entrapment in the fracture site

Addit:
◦ prophylactic antibiotics as appropriate
◦ serial debridements as necessary

Question 13

Ilium Fractures

Operative Techniques

Open Reduction Internal Fixation

1. approach [3]
2. Timing

Answer 13

1. approach
   i. posterior approach
   ii. ilioinguinal approach
   iii. Stoppa approach (lateral window)
2. Recommend early reconstruction
   ◾single pelvic reconstruction plate or lag screw along the iliac crest
   ◾supplemented with a second reconstruction plate or lag screw at the level of the pelvic brim or sciatic buttress
   ◾ coordination with trauma team
   • injury to bowel may require diversion procedures
   • plan surgical intervention with trauma team to minimize recurrent trips to the operating room

Question 14

Ilium Fractures

Complications [4]

Answer 14

1. Malunion with deformity of the iliac wing
2. Internal iliac artery injury
3. Bowel perforation
4. Lumbosacral plexus injury

Question 15

SI Dislocation & Crescent Fractures

Spectrum of injuries that include [3]

Answer 15

Spectrum of injuries that include

1. incomplete (Sacroiliac) SI dislocation
   ◾rotationally unstable
2. complete SI dislocations
   ◾vertically and rotationally unstable
3. SI fracture-dislocation (crescent fracture)

Question 16

SI Dislocation & Crescent Fractures

Spectrum of injuries: details

1. incomplete (Sacroiliac) SI dislocation
2. complete SI dislocations
3. SI fracture-dislocation (crescent fracture)

Answer 16

incomplete (Sacroiliac) SI dislocation
◾posterior SI ligaments remain intact
◾rotationally unstable

complete SI dislocations
◾posterior SI ligaments ruptured
◾vertically and rotationally unstable

SI fracture-dislocation (crescent fracture)
◾iliac wing fracture that enters the SI joint
◾injury to posterior ligaments vary
◾combination of vertical iliac fx and SI dislocation
◾posterior ilium remains attached to sacrum by posterior SI ligaments
◾anterior ilium dislocates from sacrum with internal rotation deformity
◾when ilium fragment remains with sacrum it is termed a crescent fracture

Question 17

SI Dislocation & Crescent Fractures

1. mechanism of injury
2. pathoanatomy
   a. pelvic stability determined by:

•Prognosis is primarily based on:

Answer 17

1. mechanism of injury
   ◾lateral compression force
   ◾usually high energy

2a. degree of injury to posterior structures
2b. Iliac wing fractures may be associated with open wounds and may involve bowel entrapment
3. Prognosis - primarily based on accurate and stable reduction of SI joint

Question 18

SI Dislocation & Crescent Fractures

Classification

Answer 18

No classification system specifically for SI injury

◦ included in Young- Burgess and Tile classification of pelvic fractures

◦ crescent fractures described as LC-2 injury according to Young-Burgess

Question 19

SI Dislocation & Crescent Fractures

1. Treatment : Operative
   a. details - acute management
   b. indications for ORIF
2. Anterior ring ORIF
   ◾indications
3. Anterior and posterior ring ORIF
   ◾indications
4. ORIF of ilium
   ◾indications

Answer 19

1a. immediate skeletal traction
1b. indications ◾vertical translation of the hemipelvis

2. anterior ring ORIF ◾indications ◾incomplete SI dislocations with pubic symphyseal diastasis
3. anterior and posterior ring ORIF ◾indications ◾complete SI dislocations ◾vertically unstable require anterior and posterior pelvic ring fixation
4. ORIF of ilium ◾indications ◾crescent fracture ◾required to restore posterior SI ligaments and pelvic stability

Question 20

SI Dislocation & Crescent Fractures

Complications [3]

Answer 20

• DVT ◦35%-50%
• Neurological injury
• Loss of reduction and failure of fixation

Question 21

Hip Dislocation

1. Epidemiology / incidence
2. mechanism
3. Hip joint inherently stable due to ?

Answer 21

1. Epidemiology ◦rare, but high incidence of associated injuries
   ◦mechanism is usually young patients with high energy trauma

2. Hip joint inherently stable due to ◦bony anatomy
◦soft tissue constraints including 
◾labrum
◾capsule 
◾ligamentum teres

Question 22

Hip Dislocation

anatomic classification

Answer 22

Anatomic classification
1. Posterior dislocation (90%)
◾occur with axial load on femur, typically with hip flexed and adducted (axial load through flexed knee - eg. dashboard injury)
◾position of hip determines associated acetabular injury (increasing flexion and adduction favors simple dislocation)

2. anterior dislocation
   ◾associated with femoral head impaction or chondral injury
   ◾occurs with the hip in abduction and external rotation
   ◾inferior (“obturator”) vs. superior (“pubic”) ◾hip extension results in a superior (pubic) dislocation ◾Clinically hip appears in extension and external rotation
   ◾flexion results in inferior (obturator) dislocation ◾Clinically hip appears in flexion, abduction, and external rotation

Question 23

Hip Dislocation

Posterior dislocation (90%)

assoc with ? [5]

Answer 23

2. Associated with 
◾osteonecrosis
◾posterior wall acetabular fracture
◾femoral head fractures
◾sciatic nerve injuries 
◾ipsilateral knee injuries (up to 25%)

Question 24

Hip Dislocation

Treatment : Emergent

1. closed reduction within ____ hours
2. Indications
3. contraindications

Answer 24

1. 6 hrs
2. indications ◾acute anterior and posterior dislocations
3. contraindications
   ◾ipsilateral displaced or non-displaced femoral neck fracture

Question 25

Hip Dislocation Rx Operative open reduction and/or removal of incarcerated fragments 1. indications

Answer 25

``` indications ◾irreducible dislocation ◾radiographic evidence of incarcerated fragment ◾delayed presentation ◾non-concentric reduction ◾should be performed on urgent basis ```

Question 26

Hip Dislocation Rx Operative ORIF ◾indications

Answer 26

``` indications ◾associated fractures of : i. acetabulum ii. femoral head iii. femoral neck -> should be stabilized prior to reduction ```

Question 27

Hip Dislocation Complications 1. Post-traumatic arthritis a. up to __% for simple dislocation, markedly increased for complex dislocation Femoral head osteonecrosis 2a. Femoral head osteonecrosis = __to__% incidence 2b. AVN Increased risk with _______ ? 3. Sciatic nerve injury a. __to__% incidence b. associated with _______ 4. Recurrent dislocations a. less than ___%

Answer 27

1a up to 20% for simple dislocation, markedly increased for complex dislocation 2a. 5-40% incidence 2b. Increased risk with increased time to reduction 3a. 8-20% incidence 3b. associated with longer time to reduction 4. Recurrent dislocations ◦less than 2%

Question 28

Acetabular Fractures

Answer 28

a

Question 29

Femoral head fractures

Answer 29

a

Question 30

Pelvic Ring Fractures 1, Mechanism 2. Mortality rate __to__% for closed fractures, as much as ___% for open fractures 3. ________ is leading cause of death overall 4. increased mortality associated with: (5)

Answer 30

1. Mechanism typically high energy blunt trauma 2. Mortality rate 15-25% for closed fractures, as much as 50% for open fractures 3. hemorrhage is leading cause of death overall ◾closed head injury is the most common for lateral compression injuries 4. Increased mortality associated with ◾systolic BP <90 on presentation ◾age >60 years ◾increased Injury Severity Score (ISS) or Revised Trauma Score (RTS) ◾need for transfusion > 4 units ◾higher Young-Burgress classification grade

Question 31

Pelvic Ring Fractures Associated injuries ``` ◦chest injury in up to __% ◦long bone fractures in __% ◦sexual dysfunction up to __% ◦head and abdominal injury in __% ◦spine fractures in __% ```

Answer 31

◦chest injury in up to 63% ◦long bone fractures in 50% ◦sexual dysfunction up to 50% ◦head and abdominal injury in 40% ◦spine fractures in 25%

Question 32

Pelvic Ring Fractures Prognosis : high prevalence of poor functional outcome and chronic pain 1. poor outcome associated with : (7)

Answer 32

``` 1. poor outcome associated with ◾SI joint incongruity of > 1 cm ◾high degree initial displacement ◾malunion or residual displacement ◾leg length discrepancy > 2 cm ◾nonunion ◾neurologic injury ◾urethral injury ```

Question 33

Pelvic Ring Fractures Pediatric pelvic ring fractures children with open triradiate cartilage have different fracture patterns than do children whose triradiate cartilage has closed ◾if triradiate cartilage is open ?

Answer 33

◾if triradiate cartilage is open the iliac wing is weaker than the elastic pelvic ligaments, resulting in bone failure before pelvic ring disruption ◾for this reason fractures usually involve the pubic rami and iliac wings and rarely require surgical treatment

Question 34

Pelvic Ring Fractures Radiographs : inlet 1. technique 2. Ideal for visualising ?

Answer 34

1. technique ◾xray beam angled 40° caudad (may be as little as 25 degrees) ◾adequate image when S1 overlaps S2 body 2. ideal for visualizing ◾anterior or posterior translation of the hemipelvis ◾internal or external rotation of the hemipelvis ◾widening of the SI joint ◾sacral ala impaction

Question 35

Pelvic Ring Fractures Radiographs : outlet 1. technique 2. Ideal for visualising ?

Answer 35

1. outlet technique ◾xray beam angled ~40° cephalad (may be as much as 60 degrees) ◾adequate image when pubic symphysis overlies S2 body 2. ideal for visualizing ◾vertical translation of the hemipelvis ◾flexion/extension of the hemipelvis ◾disruption of sacral foramina and location of sacral fractures

Question 36

Pelvic Ring Fractures Classification : Tile Classification

Answer 36

Tile classification A: stable ◾A1: fracture not involving the ring (avulsion or iliac wing fracture) ◾A2: stable or minimally displaced fracture of the ring ◾A3: transverse sacral fracture (Denis zone III sacral fracture) B - rotationally unstable, vertically stable ◾B1: open book injury (external rotation) ◾B2: lateral compression injury (internal rotation) ◾B2-1: with anterior ring rotation/displacement through ipsilateral rami ◾B2-2-with anterior ring rotation/displacement through contralateral rami (bucket-handle injury) ◾B3: bilateral C - rotationally and vertically unstable ◾C1: unilateral ◾C1-1: iliac fracture ◾C1-2: sacroiliac fracture-dislocation ◾C1-3: sacral fracture ◾C2: bilateral with one side type B and one side type C ◾C3: bilateral with both sides type C

Question 37

Pelvic Ring Fractures Classification :Young-Burgess Classification

Answer 37

1. APC APC I (Symphysis widening < 2.5 cm) APC II Symphysis widening > 2.5 cm. Anterior SI joint diastasis . Posterior SI ligaments intact. Disruption of sacrospinous and sacrotuberous ligaments.) APC III (Disruption of anterior and posterior SI ligaments (SI dislocation). Disruption of sacrospinous and sacrotuberous ligaments.APCIII associated with vascular injury) 2. Lateral Compression (LC) i. LC type 1 Oblique or transverse ramus fracture and ipsilateral anterior sacral ala compression fracture ii. LC type 2 Rami fracture and ipsilateral posterior ilium fracture dislocation (crescent fracture iii.LC type 3 Ipsilateral lateral compression and contralateral APC (windswept pelvis). Common mechanism is rollover vehicle accident or pedestrian vs auto. 3. Verical Shear (VS) Posterior and superior directed force. Associated with the highest risk of hypovolemic shock (63%); mortality rate up to 25%

Question 38

Pelvic Ring Fractures Bleeding & Initial Treatment 1. Bleeding Source (broad) [5] 2. common sources of hemorrhage (Pelvis) a. b. 3. uncommon sources of hemorrhage a.

Answer 38

``` 1. Bleeding Source ◦intraabdominal ◦intrathoracic ◦retroperitoneal ◦extremity (thigh compartments) ◦pelvic ``` 2. common sources of hemorrhage a. venous injury (80%) (shearing injury of posterior thin walled venous plexus) b. bleeding cancellous bone 3. uncommon sources of hemorrhage a) arterial injury (10-20%) ◾superior gluteal most common (posterior ring injury, APC pattern ◾internal pudendal (anterior ring injury, LC pattern) ◾obturator (LC pattern)

Question 39

Pelvic Ring Fractures External fixation 1. indications 2. contraindications

Answer 39

1. indications ◾pelvic ring injuries with an external rotation component (APC, VS, CM) ◾unstable ring injury with ongoing blood loss 2. contraindications ◾ilium fracture that precludes safe application ◾acetabular fracture

Question 40

Pelvic Ring Fractures External fixation: technique 1. Pin insertion: supra-acetabular pin 2. AIIS pins can place the _________ nerve at risk 3. _______ screws with internal subcutaneous bar may be used 4. Pin insertion: superior iliac crest pin 5. Superior iliac crest pin insertion

Answer 40

1. Pins inserted into ilium ◾supra-acetabular pin insertion ◾single pin in column of supracetabular bone from AIIS towards PSIS --> obturator outlet view helps to identify pin entry point --> iliac oblique view helps to direct pin above greater sciatic notch --> obturator oblique inlet view helps to ensure pin placement within inner and outer table 2. lateral femoral cutaneous nerve 3. pedicle screws 4. Superior iliac crest pin insertion ◾multiple half pins in the superior iliac crest ◾place in thickest portion of ilium (gluteal pillar) ◾may be placed with minimal fluoroscopy

Question 41

Pelvic Ring Fractures Nonoperative : weight bearing as tolerated 1. indications (4)

Answer 41

1. Mechanically stable pelvic ring injuries including i.) LC1 ◾anterior impaction fracture of sacrum and oblique ramus fractures with < 1cm of posterior ring displacement ii.) APC1 ◾widening of symphysis < 2.5 cm with intact posterior pelvic ring iii.) isolated pubic ramus fractures iv.) parturition-induced pelvic diastasis ◾bedrest and pelvic binder in acute setting with diastasis less than 4cm

Question 42

Pelvic Ring Fractures Operative: ORIF 1. indications [6]

Answer 42

1. indications ◾symphysis diastasis > 2.5 cm ◾SI joint displacement > 1 cm ◾sacral fracture with displacement > 1 cm ◾displacement or rotation of hemipelvis ◾open fracture ◾chronic pain and diastasis in parturition-induced diastasis or acute setting >6cm

Question 43

Pelvic Ring Fractures Operative: ORIF Techniques 1. Anterior ring stabilization 2. Anterior and posterior ring stabilization a) necessary in _____ injuries b. Ipsilateral acetabular and pelvic ring fractures - fix which first

Answer 43

Anterior ring stabilization ◾Single superior plate ◾apply through rectus-splitting Pfannenstiel approach ◾may perform in conjunction with laparotomy or GU procedure 2a. vertically unstable injuries 2b. reduction and fixation of the pelvic ring should be performed first

Question 44

Pelvic Ring Fractures Operative: ORIF Techniques: Posterior ring stabilization

Answer 44

1. anterior SI plating ◾risk of L4 and L5 injury with placement of anterior sacral retractors 2. iliosacral screws (percutaneous) ◾good for sacral fractures and SI dislocations ◾safe zone is in S1 vertebral body -> outlet radiograph view best guides superior-inferior screw placement -> inlet radiograph view best guides anterior-posterior screw placement ◾L5 nerve root injury complication with errors in screw placement ◾entry point best viewed on lateral sacral view and pelvic outlet views ◾risk of loss of reduction highest in vertical sacral fracture patterns 3. Posterior SI "tension" plating ◾can have prominent HW complications

Question 45

Pelvic Ring Fractures Complications

Answer 45

1. Neurologic injury ◦L5 nerve root runs over sacral ala joint ◦may be injured if SI screw is placed to anterior ◦anterior subcutaneous pelvic fixator may give rise to LFCN injury (most common) or femoral nerve injury 2. DVT and PE ◦DVT in ~ 60%, PE in ~ 27% ◦prophylaxis essential ◾mechanical compression ◾pharmacologic prevention (LMWH or Lovenox) ◾vena caval filters (closed head injury) 3. Chronic instability ◦rare complication; can be seen in nonoperative cases ◦presents with subjective instability and mechanical symptoms ◦diagnosed with alternating single-leg-stance pelvic radiographs ``` 4. Infection ◦risk factors include: ◾obesity ◾diabetes ◾delay in treatment ◾open fracture ```

Question 46

Pelvic Ring Fractures Complications Urogenital Injuries

Answer 46

•Present in 12-20% of patients with pelvic fractures ◦higher incidence in males (21%) •Includes ◦posterior urethral tear (most common urogenital injury with pelvic ring fracture) ◦bladder rupture (may see extravasation around the pubic symphysis ; associated with mortality of 22-34%) •Diagnosis ◦made with retrograde urethrocystogram ◦indications for retrograde urethrocystogram include ◾blood at meatus ◾high riding or excessively mobile prostate ◾hematuria