Rapidly destructive hip osteoarthritis: a diagnosis not to miss

This review illustrates the imaging features of rapidly destructive hip osteoarthritis (RDHO) across different imaging modalities. RDHO is a rare joint disease of unknown aetiology resulting in rapid deterioration of the hip joints. Patients often present with severe hip pain and can progress to complete joint destruction in 6 months to 3 years causing disability. Since its clinical and imaging features often overlap with other conditions, the diagnosis is easily missed in daily practice. The purpose of this paper is to outline the characteristic imaging features of RDHO, aiming to enhance awareness of this disease entity and promote timely treatment for patients. Sequential radiographs are particularly important in demonstrating the rapid progression of radiographic findings and with the early recognition of characteristic features, diagnosis can be made to avoid treatment delay. Although CT scan is not necessary for diagnosis, it is useful in evaluating the extent of joint destruction and guiding surgical planning. MRI can provide additional information and rule out other pathologies with similar symptoms. Overall, radiographs, CT and MRI are common modalities used in the evaluation of RDHO.