Pelvic radiograph (an approach)

  • trace the main pelvic ring and two obturator foramina
  • if a ring is disrupted, think fracture... then look for a second one
  • the sacroiliac joints should be symmetrical, joint space range 2-4 mm
  • the symphysis pubis joint space should be ≤ 5 mm
  • if either joint space is widened, think main pelvic ring fracture
  • trace Letournel lines: ileopectineal line, ilioischial line, acetabular roof, anterior rim, posterior rim, and teardrop
    • ileopectineal line disruption suggests an anterior column fracture
    • ilioischial line disruption suggests a posterior column fracture
    • teardrop displacement suggests an occult acetabular fracture
  • the arcuate lines should be smooth and symmetrical
  • If lines angulated, think sacral fracture
  • the cortex of femoral head, neck, greater, and lesser trochanter should be smooth with normal trabecular pattern on AP and lateral 
    • if cortical disruption, trabecular pattern disruption or transverse sclerosis, think fractured proximal femur
  • trace the Shenton line
    • If line disruption, think fractured proximal femur

Intracapsular:

  • fracture site within the joint capsule
    • subcapital (most common), transcervical, or basicervical
  • high risk of disruption of the blood supply to the femoral head
    • displaced intracapsular fractures are associated with delayed union, non-union, or avascular necrosis

Extracapsular:

  • fracture line distal to the attachment of the femoroacetabular joint capsule
    • intertrochanteric (most common) or subtrochanteric
  • 40% of all pelvic fractures
  • isolated fracture of superior or inferior ramus most common stable pelvic injury
  • mechanisms:
    • fall in elderly
    • exercise-induced stress fractures
  • more: pubic ramus fracture
  • fracture at one site often associated with a second
  • a double break represents an unstable injury
  • high energy blunt trauma
  • requires CT evaluation
  • more: complex pelvic ring fracture
  • bimodal distribution: young (high energy) and elderly (poor bone quality)
  • impaction of femoral head, lateral compression or axial loading
  • 75% associated with femoral head subluxation/dislocation; frequently comminuted
  • more: acetabular fracture
  • typically adolescent athletes
  • repeated or sudden muscle contraction
  • ischial tuberosity avulsion (hamstring insertion) most common
  • more: ischial tuberosity avulsion
  • common in pelvic ring fractures
  • mechanisms:
    • fall in elderly
    • high-energy blunt trauma
  • frequently missed
  • 25% associated with neurologic injury
  • more: sacral fracture
Approaches to radiographs
Share article

Article information

rID: 28680
Synonyms or Alternate Spellings:
  • Pelvis x-ray
  • Pelvis xray
  • Pelvis XR
  • Pelvic x-ray

Cases and figures

  • Drag
    Figure 1: three rings
    Drag here to reorder.
  • Drag
    Figure 2: joint spaces
    Drag here to reorder.
  • Drag
    Figure 3: acetabulum
    Drag here to reorder.
  • Drag
    Figure 4: acetabular radiological anatomy
    Drag here to reorder.
  • Drag
    Figure 5: sacral foramina
    Drag here to reorder.
  • Drag
    Figure 6: proximal femora
    Drag here to reorder.
  • Drag
    Figure 6: annotated pelvis
    Drag here to reorder.
  • Drag
    Case 1(a): subcaptial fractured neck of femur
    Drag here to reorder.
  • Drag
    Case 1(b): intertrochanteric fracture
    Drag here to reorder.
  • Drag
    Case 2: pubic ramus fracture
    Drag here to reorder.
  • Drag
    Case 3: complex open book fracture
    Drag here to reorder.
  • Drag
    Case 5: hip dislocation
    Drag here to reorder.
  • Drag
    Acetabular fractu...
    Case 4: acetabular fracture
    Drag here to reorder.
  • Drag
    Case 6: ischial tuberosity avulsion fracture
    Drag here to reorder.
  • Drag
    Case 7: Malgaigne fracture
    Drag here to reorder.
  • Drag
    Case 8: intertrochanteric fracture
    Drag here to reorder.
  • Updating… Please wait.
    Loadinganimation

    Alert accept

    Error Unable to process the form. Check for errors and try again.

    Alert accept Thank you for updating your details.