E2413. Musculoskeletal Manifestations of Sickle Cell Disease: A Pictorial Essay
  1. Gisela Andrade; Hospital Prof. Doutor Fernando Fonseca
  2. Joana Granadas; Hospital Prof. Doutor Fernando Fonseca
  3. Carlos Casimiro; Hospital Prof. Doutor Fernando Fonseca
  4. Sérgio Ferreira; Hospital Prof. Doutor Fernando Fonseca
Sickle cell disease (SCD) is an inherited blood disease due to a mutation in the beta-globin chain gene, causing the production of an abnormal HbS hemoglobin. When deoxygenated, HbS molecules tend to form large and rigid polymers that distort red blood cells (RBC) into a sickled shape. Sickled RBC tend to occlude small vessels at low oxygen tension. Sickled RBC are also susceptible to phagocytosis by macrophages, causing chronic hemolytic anemia. Skeletal and muscular involvement in SCD is very common and a major source of morbidity and disability. This involvement reflects the presence of two main pathologic processes, chronic hemolytic anemia and microvascular occlusion. This work intends to review and illustrate the wide range of musculoskeletal abnormalities that can be encountered in patients with SCD.

Educational Goals / Teaching Points
To review and illustrate the spectrum of musculoskeletal imaging findings in sickle cell disease.

Key Anatomic/Physiologic Issues and Imaging Findings/Techniques
Manifestations of sickle cell disease, including musculoskeletal, usually start after six months of age when the fetal hemoglobin levels begin to fall. Occlusion of the bone microvasculature causes ischemic osteonecrosis, which affects predominantly vulnerable areas without collateral blood flow, such as the femoral head. Ischemia also predisposes to infection, causing osteomyelitis and septic arthritis, and may result in growth disturbances due to premature epiphyseal closure. Chronic hemolytic anemia is responsible for the development of marrow hyperplasia, reconversion of yellow marrow to red marrow and extramedullary hematopoiesis due to an increased demand for hematopoiesis. Imaging modalities, particularly magnetic resonance imaging (MRI), are essential for the diagnosis and follow-up of these abnormalities.

A wide spectrum of musculoskeletal pathologies is associated with SCD and many have characteristic radiographic appearances. Their recognition is essential to early treatment and prevention of long-term complications.