Corticosteroid-induced Osteonecrosis of the Femoral Head: Detection, Diagnosis, and Treatment in Earlier Stages

Liu, Li-Hua; Zhang, Qing-Yu; Sun, Wei; Li, Zi-Rong; Gao, Fu-Qiang

MRI has the highest sensitivity and specificity and is unanimously considered as the gold standard modality in the diagnosis of ONFH currently. Monitoring of high-risk patients with periodic hip MRI would help diagnose necrosis in its early stage. [40] The radiologic features correspond to the underlying pathology. The typical change in T1 imaging is a single density line that represents the separation of the normal and necrotic bones, while that in T2 imaging with another high signal line represents the granulation tissue with an increased vascularity. Bone marrow edema on MRI should be considered as a marker for potential progression to advanced osteonecrosis and is different from transient osteonecrosis of the hip and BEM syndrome. A previous case report indicated that osteonecrosis could possibly occur within 3 weeks after initiation of high-dose corticosteroid therapy. [41] MRI evaluation may be useful in following the progression of ONFH. A long-term prospective study showed that serial MRI evaluation might be useful in following up the progression of small asymptomatic lesions of ONFH in patients with SARS. [42] MRI also helps quantify the area and extent of ONFH in different planes and could also be used to guide treatments as a validated technique in following up patients. A previous study appraised the accuracy and limitations of the diagnostic methods for ONFH identification. [43] MRI may improve staging, investigate radiologically occult collapse, depict other causes of disability and pain, assess prognosis, and evaluate treatment; new MRI techniques need further investigations. A skilled and experienced physician should correlate MRI imaging with histologic changes in conjunction with a comprehensive clinical evaluation of patients for an earlier diagnosis.