Bilateral Avascular Necrosis of the Femoral Head in a Patient With Sickle Cell Trait: A Case Report.

Sickle cell trait (SCT), historically regarded as a benign carrier state, may nonetheless be associated with severe complications such as bilateral avascular necrosis (AVN) of the femoral head in select individuals. This risk is often underrecognized, particularly in regions with high SCT prevalence, leading to delayed diagnosis and management. We report the case of a 43-year-old Yemeni man who presented with progressive bilateral hip pain over eight months without traditional risk factors except smoking. His family history was notable for sickle cell disease and trait. Physical examination revealed painful, restricted hip movement and mild splenomegaly. Laboratory testing confirmed SCT with an HbS level of 33.9% and a normal hemoglobin concentration of 16.5 g/dL. Initial radiographs were unremarkable, but MRI demonstrated bilateral femoral head AVN with marrow edema and subchondral changes. While alternative causes, including thrombophilia, were not fully excluded, conservative management was unsuccessful due to poor adherence, necessitating surgical referral. In conclusion, this case adds to emerging evidence that SCT may contribute to severe orthopedic morbidity in the presence of additional risk factors such as smoking. We advocate for a high index of suspicion for established causes of AVN and early MRI in symptomatic patients to prevent diagnostic delay and irreversible joint damage.