Causes of bone infarction

Sickle Cell Disease

• Sickle cell disease (SCD) is a group of inherited red blood cell disorders.
• Abnormal hemoglobin causes the red blood cells to become rigid and sickle-shaped.
• These abnormal cells can occlude blood vessels, leading to ischemia (reduced blood flow) and infarction (death of tissue) in various organs, including bone.
• Bone infarcts in SCD typically manifest as painful bone crises, often affecting the long bones.
• The location and severity of infarcts can vary, affecting bone growth and development in children.

Excess Corticosteroids

• Prolonged or high-dose corticosteroid use can lead to bone tissue damage and the development of bone infarcts.
• Corticosteroids suppress the immune system, but also lead to a reduction in bone formation and an increase in bone resorption.
• Patients on long-term corticosteroid therapy have a significantly higher risk of osteoporosis and subsequent bone infarcts.
• Bone infarcts occurring due to steroid use often occur in the femoral head, spine, or pelvis.

Pancreatitis

• Acute or chronic pancreatitis can also cause bone infarction.
• Pancreatitis, inflammation of the pancreas, can be associated with systemic complications; including vascular damage and microvascular emboli (blood clots) and subsequently affecting blood supply to the bone.
• The exact mechanism is not fully understood, but the inflammatory process and systemic complications associated with pancreatitis seem implicated in the bone infarction.
• Bone infarcts, associated with infections and poor circulation in pancreatitis, are often clinically silent, requiring imaging diagnostics to be detected.

Caisson Disease ('The Bends')

• Caisson disease, also known as decompression sickness, can result in bone infarcts.
• This condition occurs when individuals exposed to high pressure (e.g., during deep-sea diving or tunnel construction) experience rapid decompression.
• Nitrogen bubbles form in the bloodstream, leading to impaired blood flow and potentially bone infarcts, particularly in the long bones.
• The resultant vascular compromise may lead to significant bone tissue damage.

Gaucher Disease

• Gaucher disease is a rare inherited lysosomal storage disorder.
• This condition affects the body's ability to break down certain fats, leading to their accumulation in various organs, including the bone marrow and bone structure.
• Accumulation of these fats can damage the bone marrow and blood vessels in the bone, which may lead to infarction.
• Bone infarcts in Gaucher disease occur due to the indirect damage from the storage disorder as it impacts vascular function.

Leukemia/Lymphoma

• Certain types of leukemia and lymphoma can cause bone infarction.
• These cancers frequently involve bone marrow and can impact the vascular supply to the bone; disrupting normal blood flow to the bone, with occlusion in blood vessels and potentially bone death.
• Tumors obstructing blood flow in bones can also contribute to the development of bone infarction.
• This effect is more prevalent in haematological malignancies that have spread to the bone, impacting bone marrow health and blood vessel function.

Explore the connections between sickle cell disease and the effects of corticosteroids on bone health. This quiz delves into how sickle-shaped red blood cells can cause complications like bone infarcts and the implications of long-term corticosteroid use on bone tissue. Test your understanding of these critical medical concepts.