Wednesday, September 26, 2018 2:00 PM – 3:00 PM Increasing Value: Lumbar Spine Surgery: 66. Cost-benefit analysis of intraoperative EMG for pedicle screw placement in routine lumbar fusions

Abstract

BACKGROUND CONTEXT Advances in intraoperative neuromonitoring have increased the safety and shown clear benefit for complex spine cases. However, controversy exists regarding the utility of intraoperative EMG for identification of pedicle wall breaches for uncomplicated posterolateral lumbar fusions. PURPOSE To perform a cost-benefit analysis of pedicle screw stimulation via triggered EMG in routine lumbar pedicle screw cases. STUDY DESIGN/SETTING Prospective case series. PATIENT SAMPLE Patients undergoing primary instrumented posterior lumbar fusion with pedicle screws from L1 to S1. OUTCOME MEASURES EMG screw stimulation, need for screw repositioning, variable direct cost. METHODS A prospective study was conducted at single institution. Patients undergoing instrumented posterolateral lumbar fusion were monitored with intraoperative triggered EMGs. Pedicle screws were placed freehand from L1 to S1 by attending physicians and spine fellows. Concern for pedicle breach was identified with a screw stimulation value less than 10 mA. RESULTS There were 145 cases with a total of 725 pedicle screws placed. Mean age was 57.8±14.2 years, OR time was 238±95 minutes, EBL was 426.8±354.3cc. Mean number of surgical levels fused was 2.7±1.1. 686 (95%) screws stimulated at >10 mA and 39 (5%) screws stimulated at CONCLUSIONS Only 1% of the 725 lumbar pedicle screws placed in 8 of 145 cases required repositioning. Due to the infrequency of pedicle wall breaches and the cost of ION, the utility of this modality in straightforward lumbar fusions should be critically evaluated. FDA DEVICE/DRUG STATUS This abstract does not discuss or include any applicable devices or drugs.