BILATERAL AVASCULAR NECROSIS OF FEMORAL HEAD FOLLOWING COVID-19 INFECTION: CASE SERIES

: Introduction : Despite having a substantial impact on survivors’ mobility and leading to morbidity, musculoskeletal involvement was the post-COVID-19 infection sequelae area that received the least attention in the literature. Reviewing the COVID-19 histories of patients who visited a tertiary health center, the research is aimed at finding an as - sociation between COVID-19 infection and avascular femoral head necrosis, a condition brought on by insufficient blood flow. Avascular necrosis of the femoral head is a condition characterized by a restricted range of motion, pain, and disturbance of gait. It is brought on by insufficient blood flow. Case reports: We discussed several examples in which COVID-19 caused individuals to develop bilateral femoral head necrosis. When COVID-19 infection is the only factor present, and corticosteroids are used to treat it, avascular necrosis of the femoral head may become more prevalent. Detecting avascular necrosis of the femoral head in its early stages, hip MRI might reduce the patient’s disability and need for continuous treatment. Conclusion: Early identification and treatment of AVN patients reduce the need for surgery and the chance of disabilities.


INTRODUCTION
COVID-19 patients suffer a range of symptoms, including fever, sore throats, acute respiratory distress syndrome, thrombotic events, and acute myocardial infarction.These symptoms are only a few of the significant problems that result from the virus's systemic hyper-inflammation (1).According to the case report series by Agarwala et al, a lack of blood flow to the bone tissue causes avascular femoral head necrosis, which is characterized by bone marrow necrosis and osteocyte loss (2,3).For COVID-19 treating patients with hip pain, diagnostic information, and imaging recommendations are not yet available.Here, we present 3 cases of symptomatic femoral head necrosis that developed following COVID-19 treatment.

Case report No 1
On April 13, 2021, a 28-year-old female patient was diagnosed with COVID-19, for which she was admitted to an intensive care Karnataka Institute of Medical Science, India.She received 80 mg per day of intravenous methylprednisolone for a week while in the hospital.She had right hip joint ache four months after COVID-19.A local doctor treated her with analgesics for three months.She subsequently developed both hip and joint pain.AVN with oedema was seen in Magnetic Resonance Imaging (MRI) (Figure 1, 2, 3).She had a hybrid total hip replacement.

Case report No 2
On June 24, 2021, a male patient, 32 years old, was diagnosed with COVID-19 and was thereafter admitted to the hospital.He received intravenous (IV) methylprednisolone 80 mg/day for a week while in the hospital.He started experiencing right hip joint pain six months later.A nearby physician treated him with analgesics for eight months.He later developed both hip joint pain and stiffness as a result.Magnetic Resonance Imaging (MRI) revealed both femoral heads to have AVN.He underwent an uncemented total hip arthroplasty (Figure 4 and 5).

Case report No 3
On July 16, 2021, a male patient, 28 years old, was diagnosed with COVID-19 and was thereafter admitted to the Karnataka Institute of Medical Science and Hospital, India.He received intravenous (IV) methylprednisolone 80 mg/day for a week while in the hospital.He started experiencing right hip joint pain 14 months later.He later developed both hip and joint pain as a result.Magnetic Resonance Imaging (MRI) revealed both femoral heads to have AVN.He underwent core decompression with bone marrow aspirate infiltration (Figure 6 and 7).To exclude concomitant septic arthritis, hip aspiration was performed on patients who presented with increased inflammatory markers.Total hip arthroplasty was performed on both of our patients.

DISCUSSION
Ages 40 and under were the most often affected age group in this case series investigation, affecting all three individuals.The majority of COVID-19 infection patients are asymptomatic, but some have mild to severe symptoms that can affect several organ systems and lower quality of life.A hypercoagulable condition is brought on by COVID-19, which raises the possibility of thrombosis.Pro-inflammatory cytokines such as Interleukin (IL-1, IL-6, IL-17) and tumor necrosis factor-alpha, are increased according to immunological investigations (5).Vascular wall fragmentation, endothelial cell pyknosis, and karyorrhexis are the distinctive pathological characteristics.Small and medium-sized blood arteries are typically affected by neutrophilic infiltrates, which are the typical histological findings of vasculitis (6).Glucocorticoids impair the blood vessels' ability to respond to vasoactive chemicals, which results in vascular constriction that affects the femoral head and causes further femoral head ischemia."Micro RNA (miR)-596" is discovered to be up-regulated in instances of steroid-induced avascular necrosis femoral head (SANFH), which hinders the healing of osteonecrotic bone by preventing bone stromal cell proliferation and osteogenic differentiation (7).However, in the case report series of Agarwala et al., they reported that avascular femoral head necrosis developed in three patients who received corticosteroids in the treatment of COVID-19.The average time between the COVID-19 diagnosis to the start of AVN symptoms was 58 days (2).Li et al. looked into 1406 COVID-19 patients.One patient who had 1960 mg of methylprednisolone was found to have bilateral femoral head necrosis.According to observations in the literature, the average time it takes for AVN to manifest following corticosteroid medication is between 6 and 12 months (8).When 23 patients with AVN following COVID-19 were studied by Daltro et al., they discovered that 66% had moderate to severe COVID-19 infections and had received corticosteroid treatment.The remaining 33% had a mild COVID-19 past without using corticosteroids.Overall, they reported that in these 23 individuals, the median interval between COVID-19 infection and the start of AVN was 132.8 days (between 64 and 180) (9).

CONCLUSION
Since COVID-19 infection alone and corticosteroid medication administered in its treatment may increase the incidence of AVN, clinicians should be cau-

Learning objective
► Steroids are "life-saving in the treatment of COVID-19".
► Individuals with COVID-19 infection are more likely to develop avascular femoral head necrosis at minimal steroid dosages, and early presentation.
► Magnetic resonance imaging of the hips can be used to confirm a diagnosis if someone complains of hip and thigh discomfort.
► Advanced stage avascular femoral head necrosis can be effectively treated in individuals receiving total hip arthroplasty.

Declaration:
Human subjects: All participants in this study provided informed consent or waived it.The ethics committee of the KARNATAKA INSTITUTE OF MEDICAL SCIENCES approved 728/2021-22.The institutional ethics committee gave its approval to the project.

1
Department of physical medicine and rehabilitation (PMR), Karnataka Institute of medical sciences, Hubli, India 2 Department of orthopaedics, Karnataka Institute of medical sciences, Hubli, India Figure 1.X-ray of pelvis and both hips AP view