“…The causes found are the following: Surgical: laminectomy, 3 discectomy, 4 arthrodesis, 5,6 scoliosis, 7 exeresis of calcified yellow ligaments, 8 vascular surgery, 9,10 use of surgicel. 11,12 Interventionist techniques: vertebroplasty, 13 arterial embolization, 14 epidural anesthesia, 15 intramuscular injections, 16 acupuncture. 17 Drugs: platelet antiaggregants, 18 acenocumarol, 19 tumor necrosis factor.…”