I Traumatic, posttraumatic, or injury related A Compression fracture B Muscle or ligamentous injury C Spondylolysis D Spondylolisthesis E Disc herniation F Spinal epidural hematoma II Infectious A Spinal Discitis Vertebral osteomyelitis a Bacterial b Tuberculosis Spinal epidural abscess B Nonspinal Appendicitis Cholecystitis Pancreatitis Pelvic inflammatory disease Pyelonephritis Pyomyositis Pneumonia Myalgias due to viral infection Herpes zoster III Reactive arthritis (collagen vascular disease) A Ankylosing spondylitis B Arthritis of IBD C Reactive sacroiliitis D Psoriatic arthritis IV Neoplastic A Osteoid osteoma B Leukemia C Lymphoma D Ewing sarcoma