Cement Embolism into the Venous System after Pedicle Screw Fixation: Case Report, Literature Review, and Prevention Tips
An 87-year-old man diagnosed with spondylolisthesis due to a non-traumatic osteoporotic compression fracture of the 3rd lumbar vertebra was admitted to our hospital with severe low back pain associated with load-dependent bilateral buttock pain radiating also bilaterally into the L4 dermatome. Because of the advanced age of the patient, a conservative treatment including physiotherapy and mobilization with a stabilizing orthosis accompanied by oral analgesia was firstly conducted.\nDue to progression of pain and vertebral slipping after 6 consecutive months of conservative therapy, a minimal invasive dorsal instrumentation under general anesthesia was ultimately performed.\nWe chose a percutaneous dorsal approach with 4 stab incisions to insert the pedicle screws and both rods. Admittedly, the BMD was preoperatively not measured. Intraoperatively, a very low bone quality was noted so that pedicle screw augmentation with polymethylmethacrylate (PMMA) cement was conducted to increase the implants stability. Two cc of PMMA per pedicle were injected into the distal tip of the preformed screw hole and along its entire length at the level of the 2ed lumbar vertebral body (VB) under lateral and intermittent anteroposterior fluoroscopy control. Then, 6.5-mm-diameter and 50-mm-long pedicle screws were inserted.\nThree cc of PMMA per pedicle were injected into the 4th lumbar VB in the same previous manner. Afterwards, 7.5- mm-diameter and 50-mm-long pedicle screws were inserted. The intraoperative simultaneous fluoroscopy showed no cement extravasations at any time of the procedure. Finally, 90-mm-long rod was inserted to the left side and 80-mm-long rod to the right side; both were then tightened with 2 locking nuts each.\nAfter this procedure, clinical improvements in the form of alleviation of pain and rapid postoperative mobilization were achieved. A routine high resolution computed tomographic scan revealed postoperatively presence of cement in a left laterovertebral lumbar vein extending into the inferior vena cava. A small asymptomatic vascular epidural leak was also observed ( and ). The origin of the leak arose at the level of the augmentation in the 4th lumbar VB.\nThe patient denied any chest pain or dyspnea and he was not in respiratory distress with respiratory rat of 20/min. Findings of the postoperative cardiopulmonary examinations as well as chest radiograph were age-appropriate within normal ranges.\nAs thrombosis prophylaxis, the patient received subcutaneously a weight-based low molecular weight heparin and 100 mg/d acetylsalicylic acid orally. No cardiac or respiratory dysfunctions were noticed over the entire treatment period and the patient was discharged 2 weeks postinterventional. Clinically, the patient showed an uncomplicated 1-year follow-up.