Risk of cement leakage and pulmonary embolism by bone cement augmented pedicle screw fixation of the thoracolumbar spine

Abstract Background Cement augmented pedicle screw instrumentation (CAPSI) of the thoracolumbar spine is indicated in osteoporosis or osteopenia to improve pullout strength and biomechanical stability of pedicle screws (PS). Only few studies report on the incidence of pulmonary cement embolism or other complications associated with CAPSI. Purpose Aim of this retrospective study was to assess the rate of CAPSI associated complications. Study Design Retrospective cohort study. Patient Sample Patients who underwent CAPSI due to spinal tumors or degenerative spine disease. Outcome Measures Cement leakage, pulmonary cement embolism (PCE), mortality rate. Methods Our clinical database was reviewed for patients who underwent CAPSI between January 2012 and June 2015. A total of 165 patients (mean age 71 ± 11.2; range: 46-93 years; m=62, f=103) were included. Indications were osteoporotic fractures (n=40), spinal metastases (n=57), degenerative (n=49), infectious spine disease (n=5) or traumatic fractures (n=14) with an associated osteoporosis. Every patient received between 2 and 21 (mean 8 ± 3.3) cement augmented PS in the thoracolumbar and lumbosacral spine. Both, intraoperative cement leakage in prevertebral veins, the inferior vena cava and/or pulmonary arteries and leakage detected on postoperative imaging were evaluated. We assessed the incidence of clinically symptomatic and asymptomatic events. Results In 29 of 31 patients with intraoperative suspicion of cement leakage into prevertebral veins or the inferior vena cava on lateral fluoroscopy, which were without hemodynamic relevance, cement extrusion was confirmed on postoperative X-ray or CT scan. In three of eight patients with suspicion of pulmonary cement embolism (PCE), PCE was verified on thoracic CT. Four patients experienced life-threatening intraoperative hemodynamic reactions, either due to cement embolism (n=2; 1.2%) or anaphylactic shock (n=2; 1.2%) with need of intraoperative CPR in three cases. Two patients deceased due to fulminant PCE. Three patients with dyspnea one day after surgery were also confirmed with PCE on chest CT. In five patients an asymptomatic PCE was found incidentally on postoperative imaging. In additional 68 patients cement leakage into prevertebral veins or the ascending cava vein was found incidentally on postoperative spine X-ray or CT. Two out of 10 patients with intraspinal epidural cement leakage required revision surgery. 110 patients of the 165 patients (66.7%) ha