Department of Orthopaedic Surgery, Inje University College of Medicine, Seoul Paik Hospital, Seoul, South Korea.
Department of Orthopaedic Surgery, Lenox Hill Hospital, Northwell Health, New York, NY.
J Arthroplasty. 2020 Apr;35(4):933-940. doi: 10.1016/j.arth.2019.11.029. Epub 2019 Nov 27.
The Association Research Circulation Osseous (ARCO) presents the 2019 revised staging system of osteonecrosis of the femoral head (ONFH) based on the 1994 ARCO classification.
In October 2018, ARCO established a task force to revise the staging system of ONFH. The task force involved 29 experts who used a web-based survey for international collaboration. Content validity ratios for each answer were calculated to identify the levels of agreement. For the rating queries, a consensus was defined when more than 70% of the panel members scored a 4 or 5 rating on a 5-point scale.
Response rates were 93.1%-100%, and through the 4-round Delphi study, the 1994 ARCO classification for ONFH was successfully revised. The final consensus resulted in the following 4-staged system: stage I-X-ray is normal, but either magnetic resonance imaging or bone scan is positive; stage II-X-ray is abnormal (subtle signs of osteosclerosis, focal osteoporosis, or cystic change in the femoral head) but without any evidence of subchondral fracture, fracture in the necrotic portion, or flattening of the femoral head; stage III-fracture in the subchondral or necrotic zone as seen on X-ray or computed tomography scans. This stage is further divided into stage IIIA (early, femoral head depression ≤2 mm) and stage IIIB (late, femoral head depression >2 mm); and stage IV-X-ray evidence of osteoarthritis with accompanying joint space narrowing, acetabular changes, and/or joint destruction. This revised staging system does not incorporate the previous subclassification or quantitation parameters, but the panels agreed on the future development of a separate grading system for predicting disease progression.
A staging system has been developed to revise the 1994 ARCO classification for ONFH by an expert panel-based Delphi survey. ARCO approved and recommends this revised system as a universal staging of ONFH.
美国骨坏死研究协会（ARCO）基于 1994 年 ARCO 分类，提出了 2019 年修订的股骨头坏死（ONFH）分期系统。
2018 年 10 月，ARCO 成立了一个工作组来修订 ONFH 的分期系统。该工作组由 29 名专家组成，通过网络调查进行国际合作。为了确定各回答的内容效度比，计算了每个回答的内容效度比。对于评分查询，当超过 70%的小组成员在 5 分制上的评分达到 4 或 5 分时，就定义为达成共识。
应答率为 93.1%-100%，通过四轮德尔菲研究，成功修订了 1994 年 ARCO 分类的 ONFH。最终的共识结果得出了以下四期系统：Ⅰ期-射线照相正常，但磁共振成像或骨扫描阳性；Ⅱ期-射线照相异常（骨硬化、局灶性骨质疏松或股骨头囊性改变的细微征象），但无软骨下骨折、坏死部分骨折或股骨头扁平的证据；Ⅲ期-射线照相或计算机断层扫描可见软骨下或坏死区骨折。该期进一步分为Ⅲ A 期（早期，股骨头凹陷≤2mm）和Ⅲ B 期（晚期，股骨头凹陷>2mm）；Ⅳ期-射线照相有骨关节炎的证据，伴有关节间隙变窄、髋臼变化和/或关节破坏。这个修订的分期系统没有纳入以前的亚分类或定量参数，但专家组同意未来开发一个单独的分级系统来预测疾病进展。
一个分期系统已经通过专家小组的德尔菲调查来修订 1994 年 ARCO 分类的 ONFH。ARCO 批准并推荐该修订系统作为 ONFH 的通用分期。
