Abstract
Background: The Association Research Circulation Osseous developed a novel classification for early-stage (precollapse) osteonecrosis of the femoral head (ONFH). We hypothesized that the novel classification is more reliable and valid when compared to previous 3 classifications: Steinberg, modified Kerboul, and Japanese Investigation Committee classifications. Methods: In the novel classification, necrotic lesions were classified into 3 types: type 1 is a small lesion, where the lateral necrotic margin is medial to the femoral head apex; type 2 is a medium-sized lesion, with the lateral necrotic margin being between the femoral head apex and the lateral acetabular edge; and type 3 is a large lesion, which extends outside the lateral acetabular edge. In a derivation cohort of 40 early-stage osteonecrotic hips based on computed tomography imaging, reliabilities were evaluated using kappa coefficients, and validities to predict future femoral head collapse by chi-squared tests and receiver operating characteristic curve analyses. The predictability for future collapse was also evaluated in a validation cohort of 104 early-stage ONFH. Results: In the derivation cohort, interobserver reliability (k = 0.545) and intraobserver agreement (63%-100%) of the novel method were higher than the other 3 classifications. The novel classification system was best able to predict future collapse (P < .05) and had the best discrimination between non-progressors and progressors in both the derivation cohort (area under the curve = 0.692 [0.522-0.863], P < .05) and the validation cohort (area under the curve = 0.742 [0.644-0.841], P = 2.46 × 10−5). Conclusion: This novel classification is a highly reliable and valid method of those examined. Association Research Circulation Osseous recommends using this method as a unified classification for early-stage ONFH. Level of Evidence: Level III, diagnostic study.
Original language | English |
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Pages (from-to) | 1074-1082 |
Number of pages | 9 |
Journal | Journal of Arthroplasty |
Volume | 37 |
Issue number | 6 |
DOIs | |
State | Published - Jun 2022 |
Bibliographical note
Publisher Copyright:© 2022 Elsevier Inc.
Keywords
- avascular necrosis
- classification
- femoral head
- location
- osteonecrosis
- size