Staging System of Steinberg et al for Imaging Studies of Avascular Necrosis in the Femoral Head (University of Pennsylvania System)

Description

Steinberg et al developed a staging system for avascular necrosis of the femoral head based on changes seen on imaging studies. This can help standardize the initial description of a lesion and changes that develop over time. The authors are from the University of Pennsylvania.

Changes on Imaging Studies	Stage
normal radiograph, normal bone scan and MRI	0
normal radiograph, bone scan and/or MRI abnormal	I
cystic and sclerotic changes in the femoral head	II
subchondral collapse (crescent sign) without flattening	III
flattening of the femoral head	IV
joint narrowing or acetabular changes	V
advanced degenerative changes	VI

Stages I through V were subgroup based on anatomic changes.

Stage	Parameter Studied
I	femoral head
II	femoral head
III	articular surface
IV	articular surface
V	articular surfaces

Substage for Groups I, II, III, and V

Extent of Change	Percentage	Substage
mild	< 15%	A
moderate	15 - 30%	B
severe	> 30%	C

Substage for IV

Extent of Change	Percentage	Depression in Surface	Substage
mild	< 15%	< 2 mm	A
moderate	15 - 30%	2 - 4 mm	B
severe	> 30%	> 4 mm	C

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Description

Specialty

ICD-10