Triggered electromyography (tEMG) in the lumbar spine ItÌs reliable? Correlation of tEMG with postoperative CT images in lumbar instrumentation. / Electromiografía evocada (tEMG) en la columna lumbar. ¿Es confiable? Correlación de tEMG con imágenes de TC posoperatorias en la instrumentación lumbar.
Rev Esp Cir Ortop Traumatol
; 66(2): 143-148, 2022.
Article
in En, Es
| MEDLINE
| ID: mdl-35404792
ABSTRACT
INTRODUCTION:
Instrumentation with pedicle screws (PS) can compromise the adjacent neural structures. Triggered electromyography (tEMG) is a modality of intraoperative neuromonitoring, used to assist in the placement of these. The objective of the present study is to evaluate the reliability of this tool.METHOD:
Retrospective review of patients underwent posterior lumbar fusions from January 2017 to December 2019, correlating postoperative CT images (postop CT) with tEMG results for each PS with a threshold of 10mA, establishing sensitivity and specificity of this tool. Diagnostic test and receiver operating characteristic curve were performed to evaluate the area under the curve.RESULT:
A total of 275 PS were evaluated between L1 to S1; 5 PS showed concordance for an inadequate trajectory, while 10PS, with tEMG <10mA, were correctly positioned. The postoperative CT identified 17 pedicle gaps not noticed by the tEMG. Sensitivity and specificity were 23% (95% CI 8-45) and 96% (95% CI 93-98), respectively, with a PPV of 33.3% and a NPV of 93.6%. The area under the curve was 0.74 (95% CI 0.62-0.86) with a cut-off point of 24mA, showing a sensitivity of 77% (95% CI 0.55-0.92) and specificity of 69% (95% CI 0.63-0.75).CONCLUSION:
Given its low sensitivity, we do not recommend tEMG as the sole test in the verification of PS. We recommend using a cut-off point ≤8mA as it demonstrated the highest levels of sensitivity and specificity. We do not recommend using high thresholds to increase sensitivity.
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Type of study:
Prognostic_studies
Language:
En
/
Es
Journal:
Rev Esp Cir Ortop Traumatol
Year:
2022
Document type:
Article
Affiliation country:
Chile