Hip Arthroscopy in Staging Avascular Necrosis of the Femoral Head

ABSTRACT: The purposes of this study were to
evaluate how accurately current imaging modalities
predict the quality of the articular surface
in avascular necrosis (AVN) of the femoral head
and to provide arthroscopic correlation to current
staging modalities. An arthroscopic classification
system, derived from the work of Marcus
et al, was used to prospectively stage the articular
surface in 23 hips with AVN using plain
radiographs, magnetic resonance imaging (MRI),
and arthroscopy. There was little correlation
between all three diagnostic modalities. These
findings were not statistically significant. Patients
with stage IV disease had the widest variation
in the appearance of the articular surface.
This study shows poor correlation in the staging
of AVN using current imaging techniques.
Magnetic resonance imaging has been shown to
be inadequate at assessing the articular cartilage.
Therefore, either arthroscopy or direct
visualization is required for accurate evaluation
and staging, especially in stage IV disease.