History of cancer Unexplained weight loss Immunosuppression Urinary infection Intravenous drug use Prolonged use of corticosteroids Back pain not improved with conservative management History of significant trauma Minor fall or heavy lift in a potentially osteoporotic or elderly individual Acute onset of urinary retention, overflow incontinence, loss of anal sphincter tone, or fecal incontinence Saddle anesthesia Global or progressive motor weakness in the lower limbs