Bone marrow oedema on MR imaging indicates ARCO stage 3 disease in patients with AVN of the femoral head

Abstract

BME on MRI in AVN of femoral head indicates a subchondral fracture. BME in AVN of the femoral head represents ARCO stage 3/4 disease. CT identifies subchondral fractures and femoral head collapse better than MR imaging. This knowledge helps to avoid understaging and to trigger adequate treatment.

Effects of sclerotic changes on stress concentration in early‐stage osteonecrosis: A patient‐specific, 3D finite element analysis

“…Since ARCO Stages 1 and 2 have been defined as pre‐collapsed asymptomatic stages, patients with these stages show neither subchondral fracture on CT nor bone marrow edema on MRI, indicating the absence of collapse . Meanwhile, either subchondral fracture or bone marrow edema was reported in patients with ARCO Stage 3, which corresponds to the pre‐collapsed symptomatic stage . In this study, six hips without a sclerotic boundary were classified as Stage 1, 10 hips with a sclerotic boundary as Stage 2, and 35 hips with both a sclerotic boundary and minimal collapse (femoral head collapse <2 mm) as Stage 3.…”

“…In this study, we retrospectively reviewed the clinicoradiologic data of 398 patients who visited the Department of Orthopaedics at our hospital between January 2010 and December 2017. The inclusion criteria for this study were: (i) radiologic examinations of the hip joints, including computed tomography (CT) as well as magnetic resonance imaging (MRI) and plain radiographs performed with a standardized protocol at our institution, (ii) a diagnosis of ONFH based on both MRI and plain radiographs, (iii) femoral heads with a well‐preserved spherical shape or minimal collapse (femoral head collapse <2 mm), and (iv) an ONFH area occupying more than the medial two‐thirds of the weight‐bearing portion on mid‐coronal MRI according to the classification system of the Japanese Investigation Committee of Health and Welfare (JIC classification type C1/C2) . The exclusion criteria were: (i) a previous history of hip injury, (ii) congenital hip disease, (iii) lack of radiologic examination, and (iv) femoral heads with evident collapse (femoral head collapse ≥2 mm) or osteoarthritic changes.…”

“…The stage of ONFH was defined according to the classification of the Association Research Circulation Osseous (ARCO) . Since ARCO Stages 1 and 2 have been defined as pre‐collapsed asymptomatic stages, patients with these stages show neither subchondral fracture on CT nor bone marrow edema on MRI, indicating the absence of collapse . Meanwhile, either subchondral fracture or bone marrow edema was reported in patients with ARCO Stage 3, which corresponds to the pre‐collapsed symptomatic stage .…”

Femoral osteochondroplasty can be performed effectively without the risk of avascular necrosis or femoral neck fractures in an experimental ovine FAI model

“…For hypothesis 1, the presence of AVN was assessed according to internationally established criteria from the Association Research Circulation Osseous (ARCO) from 1994 11,12 . These criteria describe a stage-dependent multimodal classification using histology, conventional radiographs, CT and MRI.…”

Lantern-shaped screw loaded with autologous bone for treating osteonecrosis of the femoral head

“…Bone marrow oedema on magnetic resonance imaging (MRI) in the ONFH represents a secondary sign of subchondral fracture and thus indicates ARCO stage III [31]. The extent of the necrotic lesion within the femoral head was graded as Type A, B or C using the classification on the mid-coronal T1-weighted MRI scans.…”