Post-COVID avascular necrosis of the femoral head

Abstract

The severe acute respiratory syndrome (SARS) was a highly infectious pneumoni that emerged in Uzbekistan due to Covid-19 pandemic. A large number of SARS patients experienced large joint arthralgia, although this was, for the most part, not associate with any abnormality on magnetic resonance imaging. The main musculoskeletal complication of SARS were osteonecrosis and reduced bone mass, and these arose not from the disease per se but as a sequel to treatment of SARS with high-dose steroids. SARS patient were almost universally steroid naive with no other known predisposition to osteonecrosis. Prevalence of osteonecrosis in SARS patients treated with steroids ranged from 5% to 58%. Osteonecrosis most commonly affected the proximal femur and femoral condyles and was most strongly related to cumulative steroid dose and duration of steroid therapy. Most osteonecrotic lesions tended to improve with a reduction in lesion volume over a follow-up period of 5 years. The relative reduction in osteonecrotic lesion volume was greatest for smaller lesions.