Past medical history includes known neck or back disorders (including osteoporosis, osteoarthritis, disk disorders, and recent or remote injury) and surgery, risk factors for back disorders (eg, cancers, including those of the breast, prostate, kidney, lung, and colon as well as leukemias), risk factors for aneurysm (eg, smoking, hypertension), risk factors for infection (eg, immunosuppression; IV drug use; recent surgery, hemodialysis, penetrating trauma, or bacterial infection); and extra-articular features of an underlying systemic disorder (eg, diarrhea or abdominal pain, uveitis, psoriasis).