Pelvic trauma

Intro

• 5% mortality overall
• 20% mortality for complex pelvic fractures
• Up to 50% mortality if shocked on arrival and open fractures
• Stability provided by bones + sacrospinous, sacrotuberous and strong posterior sacroiliac ligaments
• Associated with:
  • Intra-abdominal injury 28%
  • Hollow viscous injury 13%
  • Rectal injury 5%
• Bladder lies close to pubic symphysis and rectum to the sacrum

Introduction

• Risk of mortality
  • SBP <90
  • Age >60
  • High trauma score
  • Transfusion >4 units
• Associated injuries
  • Chest injury (63%)
  • Long bone fracture (50%)
  • Sexual dysfunction (50%)
  • Head and abdominal injury (40%)
  • Spine fractures (25%)

Intro

• Acetabular anatomy
  • Superior iliac portion/superior dome = weight-bearing portion
  • Inner wall/pubis thin and easily damaged
  • Posterior/ischium thick
• Pelvic ring
  • Single break can yield a stable injury but two fractures in ring = unstable
• Vascular
  • Iliac artery and vein run near SI joints
  • Lumbosacral plexus or any of its branches/distal nerves can be injured with pelvic fracture

Clinical

• History
  • Mechanism and high suspicion
  • Ask about areas of pain, last urination/bowel opening, present bladder sensation and last solid/fluid intake
  • Determine last menses, pregnancy, PMHx, meds, allergies
• Exam
  • 93% sensitive for pelvic fracture in awake patient
  • Unexplained hypotension may be the only sign of a major pelvic disruption

Clinical

• Examination
  • Single pelvic spring (low sensitivity)
  • Positioning of lower limbs
  • Scrotal/labial/perineal haematoma/ecchymosis
  • Flank haematoma
  • Perineal lacerations
  • Lumbosacral plexus neurological exam
  • Rectal exam (sensation and tone)
  • Gross haematuria
  • Vaginal and rectal exams to rule out occult open fractures

Clinical

• Serious trauma
  • Check for pelvic/perineal ecchymoses
  • Destot’s sign (scrotal haematoma) indicates pelvic fracture
  • Leg length disparity or rotational deformity
  • FAST – Fluid in the pelvis may indicate a pelvic fracture
  • Do not perform compressive pelvic manoeuvres in a patient with shock or an obvious pelvic fracture
    • If stable or not obvious, can perform single pelvic spring test
  • PR +- proctoscopy/bimanual pelvic examination may be required to rule out an open fracture if evident
    • Loss of anal tone suggests spinal injury
  • Carefully evaluate lower limb pulses and sensation
  • If pelvic fracture found, assume intra-abdominal, retroperitoneal, gynaecological and urological injuries until proven otherwise

Clinical

• Stable with low mechanism
  • Examine entire spine and abdomen
  • Palpate for tenderness along pelvic bony structures, compress lateral to medial pelvis through iliac crests and greater trochanters
  • Compress pelvic ring AP through symphysis pubis and iliac crests
  • Evaluate lower limb pulses, motor function and sensation

Imaging

• Indications for plain pelvic X-ray
  • Unstable blunt trauma patient – can identify fracture quickly for early stabilisation and mobilisation of resources for angiography
  • Pelvic tenderness
  • Other finding on exam to suggest pelvic fracture
• Plain film not indicated if stable and undergoing CT abdo/pelvis anyway
• Plain film 85% sensitive for fractures in blunt trauma
• Contrast CT provides information on posterior pelvic ring ligamentous structures, contrast extravasation, pelvic haematoma and retroperitoneal bleeding
• Contrast extravasation is 80-90% sensitive for arterial bleeding
• In elderly patients
  • 50% of ‘isolated’ pubic rami fractures have associated posterior pelvic ring disruption on CT
  • 1/3 of ’isolated rami’ fractures in the elderly do not return to baseline or fail conservative pain therapy

Trace the anterior and posterior lines of the sacroiliac joint to identify it clearly. Can get confused with sacral ala fractures in LC I fractures.

Young-Burgess Classification

Young-Burgess Lateral Compression

• Type I: Oblique pubic ramus fracture with ipsilateral sacral ala compression fracture
• Type II: Oblique pubic ramus fracture with ipsilateral posterior ileal fracture dislocation (crescent fracture) 
• Type III: Ipsilateral LC fracture with contralateral APC fracture (windswept pelvis)

Lateral compression fractures

• Most common – 60-70%
• Overall mortality rate 8%
• At minimum, pubic ramus fractured
• As more force involved, sacroiliac joint is crushed, leading to disruption of posterior ligaments, fracture of sacrum and rotation of contralateral hemipelvis

AP compression (open-book)

• 25% of severe injuries
• Head-on MVA is classic example
• Splays pubic symphysis and ruptures sacral ligaments

Vertical shear

• Least common and seen in fall or jump from height
• 5% of fractures

Treatment

• Prevent movement of fracture segments
• Pelvic binder at level of greater trochanters (if open book or vertical shear)
  • Limits volume of pelvis and may help reduce blood loss
  • CI: Closed book lateral compression fractures
• Pelvis can accommodate 4L of blood
• Mostly venous bleeding and from mobile bone edges
• Predictors of need for transfusion or interventional/surgical haemorrhage control:
  • Initial Hct 0.30
  • Presence of pelvic haemorrhage on CT
  • SBP <90 on arrival
• BE >-6 or BE drop of >2 while in ED strongly correlates with need for either angiography or laparotomy

Treatment if haemodynamically unstable

• Carefully assess for other causes of bleeding
  • Need contrast trauma CT even if FAST negative as still likely to have visceral injury
• If FAST positive
  • Need CT to decide next treatment step
  • False positive rate for patients with pelvic ring disruption is up to 30%
    • Distorted anatomy, retroperitoneal blood, urine from ruptured bladder, pelvic haematomas can all lead to false positive FAST
    • Sensitivity 81% and specificity 87% for free peritoneal fluid (blood in 76% and urine in 19%)
  • If too unstable for CT go to laparotomy
• If FAST negative – Angiography (+- extraperitoneal packing if delay)
• Pelvic embolisation
  • No evidence of significant adverse effects aside from wound healing in big soft tissue trauma (esp. those with diabetes/PVD)

Treatment if unstable

• Extraperitoneal packing
  • Consider for unstable patients bleeding secondary to a significant pelvic fracture where angiography is not available, laparotomy is needed prior to angiography or patient is in extremis and needs stabilisation prior to angiography
  • Direct retroperitoneal packing during laparotomy is also an option
• External fixation
  • May be performed in ED, angiography suite or OT
  • Reduces bleeding from venous sources and cancellous bone
  • Does not offer any advantage over pelvic binding in initial management phase

Treatment if stable

• If other sources of bleeding excluded through CT or laparotomy:
  • Angiography with embolisation +- external fixation
• Embolisation effective for arterial bleeding and external fixation for venous bleeding
  • Both may be required to control haemorrhage
• Shock and death usually due to arterial bleeding (arterial seen in 10-15% of cases)
• Arteries involved:
  • Internal iliac branches
    • Superior gluteal artery and obturatory artery most commonly
• Contrast extravasation on CT is considered by many to be an indicator of arterial haemorrahge and indication for angiography +- embolisation
  • No intervention is needed for 50% of patients with blush on CT but no clinical signs of ongoing bleeding
• The need for arterial embolisation has a PPV of 39% for death in open pelvic fractures

Definitive care

• All pelvic fractures (apart from some isolated single bone fracture) require admission under orthopaedics
• Fractures that disrupt pelvic ring require ORIF within 5-14 days
• Complications
  • Nerve root injury
  • DVT (60%) and PE (27%)
  • Chronic instability
  • Urogenital injuries (10-20%)

Nerve root injuries

• Can occur due to:
  • Traction
  • Pressure from haemorrhage, callus or fibrous tissue
  • Impingement by bone fragments
• Deficits usually follow a nerve root pattern
• Lumbar nerve root injuries associated with SI dislocation/fracture and longitudinal displacement
• Sacral root injuries associated with transverse fractures of S1 and S2
• Anal wink reflex
  • Afferent pudendal nerve; Efferent S2-4
• Bulbocavernosus reflex
  • Afferent and efferent S1/2/3 all via pudendal nerve
• Cremasteric reflex
  • L1/2

Nerve root injuries

• L2 – Hip flexion – Anterior superior thigh
• L3 – Knee extension – Anterior middle thigh
• L4 – Knee extension – Medial shin
• L5 – Dorsiflexion of ankle – Top of foot
• S1 – Plantarflexion of ankle – Heel
• S2 – Knee flexion – Posterior calf and thigh
• S3 – Adduction of toes – Posterior buttocks
• S4 – Perianal region
• S5 – Perianal region

Avulsion and single bone pelvic fractures

• Conservatively managed as typically do not disrupt the pelvic ring
  • ASIS
  • AIIS
  • Ischial tuberosity
  • Pubic ramus
  • Body of ischium
  • Iliac wing*
  • Sacrum *
  • Coccyx
• Require analgesia, crutches, bed-rest or non-weight-bearing status and orthopaedic follow-up on an outpatient basis
• If found in the elderly, obtain a CT to detect occult posterior ligamentous disruption as this would alter management
• Isolated fractures of the sacrum or iliac wing suggest tremendous forces so look for other injuries very closely

Isolated pubic rami fractures

• Still result in increased rates of hospitalisation, morbidity and mortality at 1 year

Ilium fracture

• Mostly unstable
• Typically iliac crest to greater sciatic notch
• Associated injuries
  • Open injuries
  • Bowel entrapment
  • Soft tissue degloving
• Management
  • Non-operative
    • Non-displaced fractures
    • Isolated iliac wing fractures
  • Operative
    • Displaced fractures

Acetabular fractures

• May be very subtle on X-ray
• Can get Judet views if suspected (AP, 45 degree iliac oblique and 45 degree obturator oblique)
• CT is more sensitive and can give information on displacement of fracture fragments, degree of comminution and preoperative planning
• Require hospital admission under orthopaedics
• Look for visceral, neurovascular and other orthopaedic injuries
  • Sciatic nerve injury is common

Acetabular fracture

• Fracture pattern determined by force direction and position of femoral head at time
• Column theory
  • Acetabulum supported by 2 columns of bone
    • Posterior column
      • Quadrilateral surface
      • Posterior wall and dome
      • Ischial tuberosity
      • Greater/lesser sciatic notches
    • Anterior column
      • Anterior ilium
      • Anterior wall and dome
      • Iliopectineal eminence
      • Lateral superior pubic ramus

Sacroiliac dislocation and crescent fractures

• Incomplete SI dislocation
  • Posterior SI ligaments intact
  • Rotationally unstable
• Complete SI dislocations
  • Posterior SI ligaments disrupted
  • Vertically and rotationally unstable
• SI fracture-dislocation (Crescent)
  • Iliac wing fracture enters SI joint
  • Injury to posterior ligaments variable
  • Posterior ilium remains attached to sacrum by posterior SI ligaments
  • Anterior ilium dislocates from sacrum with internal rotation deformity

Sacroiliac dislocation and crescent fractures

• Mechanism
  • Lateral high energy compression
• Requires operative intervention

Sacral fracture

• Underdiagnosed and often mis-treated
• Seen in up to 45% of pelvic ring fractures
• 25% associated with neurological injury
• 75% missed if no neurological injury and 50% even if there is one
• Anatomy
  • L5 runs on top of sacral ala
  • S1-4 roots transmitted through sacral foramina
  • S1 and 2 most often injured
  • S2-5 important for anal sphincter tone, bulbocavernosus reflex and perianal sensation

Sacral fracture

• Denis classification
  • Zone 1: Lateral to foramina
    • Most common (50%), nerve injury rare (5% – L5 nerve root often)
  • Zone 2: Through foramina
    • Unstable if shear component
  • Zone 3: Medial to foramina into spinal canal
    • 60% have neurological deficit
    • Bowel/bladder/sexual dysfunction
• Transverse sacral fractures
  • Highest risk of nerve dysfunction
• U-type fractures
  • Axial loading forces
  • Spino-pelvic dissociation
  • High incidence of neurological complications

Sacral fracture

• Plain radiographs only show 30% of fractures
• Management
  • Non-operative
    • <1cm displacement and no neurology
  • Operative
    • Displaced >1cm
    • Neurological injury

Hip dislocation

• Posterior (90%)
  • Axial load on femur with hip flexed and adducted (dashboard injury)
  • Increasing flexion and adduction favours simple dislocation vs. complex fracture-dislocation
  • Associated with osteonecrosis, posterior wall acetabular fracture, femoral head fractures, sciatic nerve injuries and ipsilateral knee injuries (25%)
• Anterior (10%)
  • Associated with femoral head impaction
  • Hip in abduction and external rotation
  • May be inferior (obturator) or superior (pubic)
    • Hip extension results in superior (pubic) dislocation and presents in extension and external rotation
    • Hip flexion results in inferior (obturator) dislocation and presents in flexion, abduction and external rotation

Hip dislocation

• Examination
  • Posterior dislocation
    • Hip and leg in slight flexion, adduction and internal rotation
    • 10-20% sciatic nerve injury
    • Examine knee
    • CXR for possible aortic injury
  • Anterior dislocation
    • Oburator/inferior: Hip and leg in flexion, abduction and external rotation
    • Pubic/superior: Extension and external rotation

Hip dislocation

• Management
  • Non-operative
    • Emergent closed reduction within 6 hours for all acute anterior and posterior dislocations
    • Contraindicated for ipsilateral displaced or non-displaced femoral neck fracture
    • Technique:
      • Patient supine and traction in line with deformity regardless of direction of dislocation
    • Post-reduction CT to rule out fractures

Hip dislocation

• Complications
  • Post-traumatic arthritis (up to 20%)
  • Femoral head osteonecrosis (5-40%)
    • Increased risk with time to reduction
  • Sciatic nerve injury (8-20% incidence)
  • Recurrent dislocations (<2%)

Last Updated on March 27, 2024 by Andrew Crofton