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Osteonecrosis of the Hip | AVN

Classification

Ficat Classification

  • Professor RP Ficat; Ficat Classification of Osteonecrosis of the Hip Stage Description O
    • Normal hip with contra-lateral disease (Hungerford)
    I
    • Normal radiograph
    • Diagnosis following MRI, bone scan or histology
    II
    • Radiographic changes of repair (osteoporosis / sclerosis / cysts)
    • No osteochondral fracture
    • Head spherical
    III
    • Wedge shaped ↑ density
    • Mottled osteoporosis
    • Subchondral lucent line® Crescent sign
    • Head no longer spherical "out of round"
    • Usually affects antero-lateral area of femoral head (best seen on lateral view)
    IV
    • Marked changes with secondary degenerative changes in the joint
    • Collapse of subchondral bone & severe deformity of the head

    Steinberg Classification

    • Steinberg etal Steinberg Classification of Osteonecrosis of the Hip Stage Description 0
      • Normal hip with contra-lateral disease ( Hungerford)
      • Suspicion but unable to confirm
      I
      • Normal radiograph
      • Diagnosis following MRI, bone scan or histology
      II
      • Radiographic changes of repair (osteoporosis / sclerosis)
      • No osteochondral fracture
      • Head spherical
      III
      • Wedge shaped ↑ density
      • Mottled osteoporosis
      • Subchondral lucent line (Crescent sign)
      • Head no longer spherical "out of round"
      • Usually affects antero-lateral area of femoral head (best seen on lateral view)
      IV
      • Flattening of the femoral head
        • On AP or lateral XRAYS
        • Now irreversible changes
        • Symptomatic treatment until arthroplasty
      V
      • joint narrowing with or without
      • acetabular involvement
      VI
      • advanced degenerative changes
      • These stages are further divided into mild (A), moderate(B) or severe (C)
      Classification of Osteonecrosis of the Hip
      Stage Description
      1 + 2
      • A mild: less than 15% involvement of head on XR or MRI
      • B mod: 15- 30%
      • C severe: more than 30%
      3
      • A: subchondral collapse (crescent) less than 15% of artic surface
      • B: 15- 30%
      • C: more than 30%
      4
      • A: less than 15% of surface has collapsed + depression is less than 2 mm
      • B: 15- 30% collapsed or 2-4 mm depression
      • C: more than 30% collapsed or more than 4mm depression
      5
      • A,B or C average of femoral hd involvement as in stage 4
      • Head involvement = % of head on AP view x % head on lateral view
        • Eg 25 % involvement may be 50 % AP & 50 % lateral