Threaded pins and wires are commonly used in orthopedic practice and their migration intra- or post-operatively may be responsible for potentially serious complications. Vascular and visceral injury from intra-pelvic pin or guide-wire migration during or following hip surgery has been reported frequently in the literature and may result in progression through soft tissues with subsequent perforation of organs and vessels. In this report, we describe an autopsy case involving a 40-year old man suffering from chronic low back pain due to sacroiliac joint disruption. The patient underwent minimally invasive sacroiliac joint arthrodesis. Some intra-operative bleeding was noticed when a drill was retrieved, though the patient died postoperatively. Postmortem investigations allowed the source of bleeding to be identified (a perforation of a branch of the right internal iliac artery) and a potentially toxic tramadol concentration in peripheral blood to be measured.