The study and application of intraoperative neurophysiological monitoring in oblique lateral interbody fusion combined with posterior transpedicle internal fixation / 中华骨科杂志

ABSTRACT

Objective To investigate a reliable and practicable model of intraoperative neurophysiological monitoring (IONM) in oblique lateral interbody fusion (OLIF) combined with posterior transpedicle internal fixation.Methods A total of 34 consecutive patients who underwent OLIF combined with posterior transpedicle internal fixation with IONM at the SRRSH from November 2014 to July 2016 were collected and follow-up at least for 3 months postoperative.The intraoperative somatosensory evoked potentials (SEP),motor evoked potentials (MEP),dermatomal somatosensory evoked potential (DSEP) and spontaneous electromyography (sEMG) were used and evaluated,besides,triggered electromyography (tEMG) was used to monitor the implantation of pedicle screws,the possible reasons and treating procedures of monitoring alerts were summarized.Results A total of 34 cases of patients were effectively monitored during OLIF combined with posterior transpedicle internal fixation.SEP monitoring was successful in all patients,and no abnormal SEPs were observed in all cases.DSEP monitoring was successful in 20 cases (58.8％),and no abnormal DSEPs were observed in these patients.MEP was successfully monitored in all cases,eliminating the anesthesia factor,no abnormal MEPs were observed in all cases.The sensitivity and positive predictive value of SEP,MEP,DSEP were 0％.3 cases had abnormal sEMG reactions during the channel establishment which disappeared after adjustment of channel,and 2 cases which appeared abnormal wave recovered after brief observation.Among the 5 patients with abnormal wave,one case got numbness,one patient felt pain in front of the thigh postoperative.Among the other 29 patients without abnormal wave during channel establishment,one case appeared numbness.These 3 patients with neurologic symptoms recovered in 3 months after conservative treatment.The sensitivity and specificity of sEMG was 66.7％ and 90.3％ respectively,negative predictive value and positive predictive value were 96.6％ and 40％ respectively.6 screws got tEMG response after tapping even the intensity was less than 10mA,which showed broken codex of pedicle according to postoperative CT scan.Cornclusion Intraoperative application of sEMG monitoring in OLIF can obviously reduce the incidence of the neurological deficit,which was an effective method,tEMG monitoring during lumbar pedicle screw fixation can detect the mal-positioned screws and protect the nerve roots.SEP,MEP and DSEP did not seem well suited for OLIF.