Spinal somatosensory evoked potential evaluation of acute nerve-root injury associated with pedicle-screw placement procedures

An experimental study

I. Ming Jou, Che-Chia Hsu, Tai Chang Chern, Wen Yi Chen, Yuan Chang Dau

Research output: Contribution to journalArticle

4 Citations (Scopus)

Abstract

Pedicle screws for spinal fixation risk neural damage because of the proximity between screw and nerve root. We assessed whether spinal somatosensory evoked potential (SSEP) could selectively detect pedicle-screw-related acute isolated nerve injury. Because pedicle screws are too large for a rat's spine, we inserted a K-wire close to the pedicle in 32 rats, intending not to injure the nerve root in eight (controls), and to injure the L4 or L5 root in 24. We used sciatic-nerve-elicited SSEP pre- and postinsertion. Radiologic, histologic, and postmortem observations confirmed the level and degree of root injury. Sciatic (SFI), tibial (TFI), and peroneal function indices (PFI) were calculated and correlated with changes in potential. Although not specific for injuries to different roots, amplitude reduction immediately postinsertion was significant in the experimental groups. Animals with the offending wire left in place for one hour showed a further non-significant deterioration of amplitude. Electrophysiologic changes correlated with SFI and histologic findings in all groups. SSEP monitoring provided reliable, useful diagnostic and intraoperative information about the functional integrity of single nerve-root injury. These findings are clinically relevant to acute nerve-root injury and pedicle-screw insertion. If a nerve-root irritant remains in place, a considerable neurologic deficit will occur.

Original languageEnglish
Pages (from-to)365-372
Number of pages8
JournalJournal of Orthopaedic Research
Volume21
Issue number2
DOIs
Publication statusPublished - 2003 Mar 25

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Somatosensory Evoked Potentials
Wounds and Injuries
Irritants
Sciatic Nerve
Neurologic Manifestations
Spine
Pedicle Screws

All Science Journal Classification (ASJC) codes

  • Orthopedics and Sports Medicine

Cite this

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title = "Spinal somatosensory evoked potential evaluation of acute nerve-root injury associated with pedicle-screw placement procedures: An experimental study",
abstract = "Pedicle screws for spinal fixation risk neural damage because of the proximity between screw and nerve root. We assessed whether spinal somatosensory evoked potential (SSEP) could selectively detect pedicle-screw-related acute isolated nerve injury. Because pedicle screws are too large for a rat's spine, we inserted a K-wire close to the pedicle in 32 rats, intending not to injure the nerve root in eight (controls), and to injure the L4 or L5 root in 24. We used sciatic-nerve-elicited SSEP pre- and postinsertion. Radiologic, histologic, and postmortem observations confirmed the level and degree of root injury. Sciatic (SFI), tibial (TFI), and peroneal function indices (PFI) were calculated and correlated with changes in potential. Although not specific for injuries to different roots, amplitude reduction immediately postinsertion was significant in the experimental groups. Animals with the offending wire left in place for one hour showed a further non-significant deterioration of amplitude. Electrophysiologic changes correlated with SFI and histologic findings in all groups. SSEP monitoring provided reliable, useful diagnostic and intraoperative information about the functional integrity of single nerve-root injury. These findings are clinically relevant to acute nerve-root injury and pedicle-screw insertion. If a nerve-root irritant remains in place, a considerable neurologic deficit will occur.",
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Spinal somatosensory evoked potential evaluation of acute nerve-root injury associated with pedicle-screw placement procedures : An experimental study. / Jou, I. Ming; Hsu, Che-Chia; Chern, Tai Chang; Chen, Wen Yi; Dau, Yuan Chang.

In: Journal of Orthopaedic Research, Vol. 21, No. 2, 25.03.2003, p. 365-372.

Research output: Contribution to journalArticle

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