Prevalence of Osteonecrosis of the Femoral Head in High-Risk Male Patients with Severe COVID-19 Treated with High-Dose Corticosteroids: A Prospective Cohort Study Using Screening MRI-How Many Have Been Left Behind?

Objectives: The association between osteonecrosis (ON) and Coronavirus Disease of 2019 (COVID-19) was reported early during the pandemic. ON of the femoral head (ONFH) is particularly problematic, as it may destroy the joint and lead to arthroplasty, although early diagnosis and treatment might mitigate its progression. The aim of the present study was to quantify the prevalence of symptomatic and asymptomatic ONFH in patients with severe COVID-19 treated with high doses of corticosteroids during the first pandemic wave. Methods: For this prospective, observational, monocentric cohort study, patients were selected according to the risk factors described for severe acute respiratory syndrome coronavirus in 2002–2004 (SARS-1): young males (<61 years old), high cumulative cortisone doses (≥2 g), severe disease, and followed up clinically and with magnetic resonance imaging. ONFH was classified with the ARCO classification. Results: Out of 1944 patients admitted for COVID-19 from 23 February to 21 May 2020, 856 of 1944 were treated in ICU; 30/1944 were selected according to the inclusion criteria and 27 of 30 were enrolled. The mean age at admission was 54 years (range, 42–60). The mean dose of cumulative cortisone was 6.25 g (range, 2–16). A total of 4/27 (15%) patients had ONFH; only 2 of 4 (50%) were symptomatic, including 1 with multiple ON of major joints. Conclusions: A high-risk cohort of patients with COVID-19 and high doses of corticosteroids had a 15% rate of ONFH, and 2 years after the event, 50% of them were asymptomatic. For those patients, relying solely on clinical evaluation would risk underestimating ONFH, potentially influencing treatment and outcomes. Moreover, other joints might develop ON. The data collected in the present study can be considered for the management of long-COVID. The association between severe COVID-19, high doses of corticosteroids and ONFH suggests the need for focused clinical and magnetic resonance imaging, considering the high rate of asymptomatic patients.