title: Intraoperative monitoring with stimulus-evoked electromyography during placement of iliosacral screws. An initial clinical study.
abstract: A consecutive series of twenty-seven patients who had thirty acute unstable (type-C) fractures of the pelvic ring was studied prospectively to evaluate the use of stimulus-evoked electromyography to decrease the risk of iatrogenic nerve-root injury during the insertion of iliosacral screws. A prerequisite for inclusion in the study was a normal neurological status preoperatively; somatosensory evoked potentials were monitored to further document the neurological status both before and after insertion of the screw or screws. A total of fifty-one iliosacral screws were inserted, and a current threshold of more than eight milliamperes was selected as the level that indicated that the drill-bit was a safe distance from the nerve root. Four of the fifty-one screws were redirected because of information obtained with stimulus-evoked electromyography. Postoperatively, all patients had a normal neurological status. Computerized tomography, although not accurate for detailed measurements, demonstrated that all of the screws were in a safe, intraosseous position. Monitoring with stimulus-evoked electromyography appears to provide reliable data and may decrease the risk of iatrogenic injury to the nerve roots during operations on the pelvic ring.
authors.affiliation: Department of Orthopaedic Surgery, University Health Center, Detroit, Michigan 48201, USA.
authors.forename: B R
authors.initials: BR
authors.lastname: Moed
authors.forename: B K
authors.initials: BK
authors.lastname: Ahmad
authors.forename: J G
authors.initials: JG
authors.lastname: Craig
authors.forename: G P
authors.initials: GP
authors.lastname: Jacobson
authors.forename: M J
authors.initials: MJ
authors.lastname: Anders
mesh_terms: D000293:Adolescent; D000328:Adult; D001863:Bone Screws; D004576:Electromyography; D005073:Evoked Potentials, Somatosensory; D005260:Female; D005593:Fracture Fixation, Internal; D006801:Humans; D007085:Ilium / Q000000981:diagnostic imaging / Q000601:surgery*; D007431:Intraoperative Complications / Q000517:prevention & control; D008297:Male; D008875:Middle Aged; D016343:Monitoring, Intraoperative; D010384:Pelvic Bones / Q000293:injuries; D011446:Prospective Studies; D012447:Sacrum / Q000000981:diagnostic imaging / Q000601:surgery*; D013126:Spinal Nerve Roots / Q000293:injuries; D014057:Tomography, X-Ray Computed