Which pathologic fracture is most commonly associated with multiple myeloma?

• A. Vertebral fracture
• B. Acetabular fracture
• C. Humeral neck fracture
• D. Humeral shaft fracture

Answer: (A)

Vertebral fractures are the classic pathologic fracture seen with multiple myeloma because the disease causes osteolytic bone destruction, especially in the axial skeleton where marrow and trabecular bone are abundant. Malignant plasma cells stimulate osteoclast activity and suppress osteoblasts, leading to lytic lesions in the vertebral bodies. Under normal or even minor stress, these weakened vertebrae can collapse, producing vertebral compression fractures with back pain and height loss. While fractures can occur in other bones, such as the acetabulum or humeral regions, they are much less typical than vertebral involvement in myeloma.