Steinberg staging of avascular necrosis

At and about the time when Ficat and Arlet in the late 70s brought out their system of classification, Steinberg and colleagues proposed a system which also incorporates quantitative assessment of femoral head involvement. This is primarily useful in standardizing reporting of direct comparison between series of studies of the same patient.


Stage 0

  • normal or non-diagnostic radiograph, bone scan and MRI

Stage I

  • normal radiograph, abnormal bone scan and/or MRI

Stage II

  • abnormal radiograph showing ‘cystic’ and sclerotic changes in the femoral head

Stage III

  • subchondral collapse showing a ‘crescent’ sign

Stage IV

  • flattening of the femoral head

Stage V

  • joint narrowing with or without acetabular involvement

Stage VI

  • advanced degenerative changes

Extent of femoral head involvement is graded as follows

  • Stage I and II
    • A, mild: <15% head involvement in radiograph or MRI
    • B, moderate: 15% to 30%
    • C, severe: >30%
  • Stage III
    • A, mild: subchondral collapse (crescent) beneath <15% articular surface
    • B, moderate: crescent beneath 15% to 30%
    • C, severe: crescent beneath >30%
  • Stage IV
    • A, mild: 15% surface has collapsed, depression <2mm
    • B, moderate: 15% to 30%  collapsed or 2-4mm depression
    • C, severe: >30% collapsed or >4mm depression
  • Stage V
    • A, B or C: average of femoral head involvement, as determined in stage IV and estimated acetabular involvement

Read more

Steinberg, Marvin E., G. D. Hayken, and D. R. Steinberg. “A quantitative system for staging avascular necrosis.” Bone & Joint Journal 77.1 (1995): 34-41.