Pediatric Sickle Cell Disease Musculoskeletal

  • Etiology:
    — Sickling of red blood cells leads to anemia which leads to marrow hyperplasia and marrow reconversion and extra-medullary hematopoiesis
    — Vascular occlusion leads to bone infarcts and osteonecrosis
    — Osteomyelitis due to Salmonella (most common) and Staphylococcus aureus
  • Imaging Radiograph:
    — Dactylitis
    — Marrow hyperplasia: Long bones – widening of metaphyses and widening of trabeculae and thinning of cortex and osteopenia, skull – widened diploic spaces
    — Bone infarct or avascular necrosis: In proximal femur and proximal humerus and distal femur and proximal tibia, lucency and sclerosis of medullary bone, cortical bone infarct leads to periosteal reaction, H-shaped vertebra due to infarct of central part of vertebral body
    — Infection: See erosions and lysis and periosteal reaction
  • Imaging MR: Infarction versus infection appear similar on MR as marrow edema and extra-osseous fluid collections but infarction has high signal intensity on T1WI with fat saturation due to packed red blood cells
  • DDX:
  • Complications: Bone infarct, avascular necrosis
  • Treatment:
  • Clinical:
    — Bone pain can be caused by infarct or avascular necrosis or osteomyelitis
    — Osteomyelitis is 50 times less common than osteonecrosis
    — Suspect osteomyelitis if patient does not respond to conservative management or has asplenia or impaired complement and phagocytic activity

Radiology Cases of Sickle Cell Disease Musculoskeletal

Radiology Cases of Sickle Cell Disease Causing H-Shaped Vertebral Bodies

Radiograph of sickle cell disease of the spine
Lateral radiograph of the thoracic spine shows multiple H-shaped vertebral bodies.
CXR of acute chest syndrome
CXR AP (left) shows a dense opacity in the left lower lobe which on the lateral (right) is seen to be located posteriorly, causing a spine sign. The lateral radiograph also shows the T8 and T10 vertebral bodes to be H-shaped.
CXR of H-shaped vertebral bodies in sickle cell disease
CXR AP (left) shows opacity in the left lower lobe that on the lateral (middle) is located posteriorly (spine sign). The vertebral bodies (right) have an H-shaped appearance throughout the thoracic and lumbar spine.

Radiology Cases of Sickle Cell Disease Causing Calvarial Thickening

CT of calvarial thickening due to marrow hyperplasia in a patient with sickle cell disease
Axial (above left), coronal (above right) and sagittal (below) CT without contrast of the skull shows diffuse massive thickening of the diploic space of the skull.