Endocrine Abstracts

Background: Avascular necrosis of the femoral head (AVNFH) is a disorder caused mainly by chronic glucocorticoid use. Systemic corticosteroid (CS) therapy was widely used in patients with mild or moderate SARS-CoV 2 infection despite lack of clinical benefits. However, emerging evidence suggests that COVID-19 infection can cause long-term effects, affecting different body systems, known as ‘long COVID-19’¹. One such sequela is AVNFH, although the link between AVNFH and SARS-CoV 2 infection has not been fully documented. We describe two cases of AVNFH following COVID-19 infection who received high-doses of CS.

Case study: The first case is that of a 17-year-old female patient, with history of non-Hodgkin lymphoma (NHL) stage III, treated with intensive chemotherapy, according to a specific protocol, which included dexamethasone (an approximate dose of 120 mg prednisone equivalent per day). Six months later, she received Prednisone, 50 mg/day for fourteen days for moderate COVID-19 infection. After three months, she was referred to our hospital with severe bilateral hip joint pain. Magnetic resonance imaging (MRI) of the hip showed AVNFH: on the right, stage IV and on the left, stage III according to FICAT and ARLET classification. The patient received one intravenous (iv) ibandronate injection, but the treatment was discontinued at the indication of her paediatric oncologist. Bilateral total hip arthroplasty was planned. The second case is that of a 16-year-old female patient with history of myasthenia gravis for which she received Prednisone, 45 mg/day, initiated in January 2022. Three months later, she developed severe SARS-CoV 2 infection, so the dose of Prednisone was increased at 50 mg/day. She was referred to our clinic after three months, presenting cushingoid phenotype and severe thoracic back pain caused by vertebral compression fracture at T4 and T8 level. She underwent progressive dose reduction of CS until cessation and was treated with iv ibandronate. One year later, after a mild COVID-19 infection, she experienced severe bilateral hip joint pain. MRI of the hip revealed bilateral AVNFH (right>left), stage II-III according (FICAT and ARLET classification). Treatment with iv bisphosphonate was continued and hyperbaric oxygen therapy was performed.

Conclusions: AVNFH in patients surviving COVID-19 could be considered a multifactorial problem and additional research is needed to establish a risk stratification and long-term follow-up protocol for these patients in order to properly diagnose and treat them.

Reference: 1. Davis HE et al: Long COVID: major findings, mechanisms and recommendations. Nat Rev Microbiol. 2023 Mar;21(3):133–46.