Steinberg staging of osteonecrosis of the femoral head

Steinberg staging of osteonecrosis of the femoral head is a commonly used system (at the time of writing, mid-2016) similar to the Ficat and Arlet staging. 

It is based on the radiographic appearance and location of lesion. It primarily differs from the other systems by quantifying the involvement of the femoral head which allows direct comparison between series¹. Seven stages of involvement are identified. Following staging, the extent of involvement of the femoral head is recorded as mild, moderate or severe. 

Classification 

• stage 0: normal or non-diagnostic radiographs, MRI and bone scan of at-risk hip (often contralateral hip involved, or the patient has risk factors and hip pain)

• stage I: normal radiograph, abnormal bone scan and/or MRI

• stage II: cystic and sclerotic radiographic changes

• stage III: subchondral lucency or crescent sign

• stage IV: flattening of the femoral head, with depression graded into:

  • mild: <2 mm 

  • moderate: 2-4 mm

  • severe: >4 mm

• stage V: joint space narrowing with or without acetabular involvement

• stage VI: advanced degenerative changes

Quantification of the extent of involvement is necessary for stages I to V:

• stage I and II

  • A: mild: <15% head involvement as seen on radiograph or MRI

  • B: moderate: 15-30%

  • C: severe: >30%

• stage III

  • A: mild: subchondral collapse (crescent) beneath <15% of articular surface

  • B: moderate: crescent beneath 15-30%

  • C: severe: crescent beneath >30%

• stage IV

  • A: mild: <15% of surface collapsed or <2 mm depression

  • B: moderate: 15-30% collapsed or 2-4 mm depression

  • C: severe: >30% collapsed or >4 mm depression

• stage V

  • A, B, or C: average of femoral head involvement, as determined in stage IV, and estimated acetabular involvement

See also

• osteonecrosis

• osteonecrosis of the femoral head

• Ficat and Arlet classification 

• Mitchell classification