Top

European Spine Journal

Published in:

01-09-2013 | Original Article

A CT-based study investigating the relationship between pedicle screw placement and stimulation threshold of compound muscle action potentials measured by intraoperative neurophysiological monitoring

Authors: Gerit Kulik, Etienne Pralong, John McManus, Damien Debatisse, Constantin Schizas

Published in: European Spine Journal | Issue 9/2013

Abstract

Purpose

Neurophysiological monitoring aims to improve the safety of pedicle screw placement, but few quantitative studies assess specificity and sensitivity. In this study, screw placement within the pedicle is measured (post-op CT scan, horizontal and vertical distance from the screw edge to the surface of the pedicle) and correlated with intraoperative neurophysiological stimulation thresholds.

Methods

A single surgeon placed 68 thoracic and 136 lumbar screws in 30 consecutive patients during instrumented fusion under EMG control. The female to male ratio was 1.6 and the average age was 61.3 years (SD 17.7). Radiological measurements, blinded to stimulation threshold, were done on reformatted CT reconstructions using OsiriX software. A standard deviation of the screw position of 2.8 mm was determined from pilot measurements, and a 1 mm of screw—pedicle edge distance was considered as a difference of interest (standardised difference of 0.35) leading to a power of the study of 75 % (significance level 0.05).

Results

Correct placement and stimulation thresholds above 10 mA were found in 71 % of screws. Twenty-two percent of screws caused cortical breach, 80 % of these had stimulation thresholds above 10 mA (sensitivity 20 %, specificity 90 %). True prediction of correct position of the screw was more frequent for lumbar than for thoracic screws.

Conclusion

A screw stimulation threshold of >10 mA does not indicate correct pedicle screw placement. A hypothesised gradual decrease of screw stimulation thresholds was not observed as screw placement approaches the nerve root. Aside from a robust threshold of 2 mA indicating direct contact with nervous tissue, a secondary threshold appears to depend on patients’ pathology and surgical conditions.

Darden BV, Wood KE, Hatley MK, Owen JH, Kostuik J (1996) Evaluation of pedicle screw insertion monitored by intraoperative evoked electromyography. J Spinal Disord 9:8–16PubMed

Whitecloud TS, Skalley TC, Cook SD, Morgan EL (1989) Roentgenographic measurement of pedicle screw penetration. Clin Orthop Relat Res 245:57–68PubMed

Okuyama K, Abe E, Suzuki T, Tamura Y, Chiba M, Sato K (1999) Posterior lumbar interbody fusion—a retrospective study of complications after facet joint excision and pedicle screw fixation in 148 cases. Acta Orthop Scand 70:329–334PubMedCrossRef

Pihlajamaki H, Myllynen P, Bostman O (1997) Complications of transpedicular lumbosacral fixation for non-traumatic disorders. J Bone Jt Surg (British Volume) 79B:183–189CrossRef

Thomsen K, Christensen FB, Eiskjaer SP, Hansen ES, Fruensgaard S, Bunger CE (1997) The effect of pedicle screw instrumentation on functional outcome and fusion rates in posterolateral lumbar spinal fusion: a prospective, randomized clinical study. Spine 22:2813–2822PubMedCrossRef

Esses SI, Sachs BL, Dreyzin V (1993) Complications Associated with the technique of pedicle screw fixation—a selected survey of Abs members. Spine 18:2231–2239PubMedCrossRef

Calancie B, Madsen P, Lebwohl N (1994) Stimulus-evoked EMG monitoring during transpedicular lumbosacral spine instrumentation—initial clinical-results. Spine 19:2780–2786PubMedCrossRef

Shi YB, Binette M, Martin WH, Pearson JM, Hart RA (2003) Electrical stimulation for intraoperative evaluation of thoracic pedicle screw placement. Spine 28:595–601PubMed

Bindal RK, Ghosh S (2007) Intraoperative electromyography monitoring in minimally invasive transforaminal lumbar interbody fusion. J Neurosurg Spine 6:126–132PubMedCrossRef

10.

Rodriguez-Olaverri JC, Zimick NC, Merola A, Vicente J, Rodriguez J, Tabuenca A, Loste A, Sunen E, Burgos J, Hevia E, Piza-Vallespir G (2008) Comparing the clinical and radiological outcomes of pedicular transvertebral screw fixation of the lumbosacral spine in spondylolisthesis versus unilateral transforaminal lumbar interbody fusion (TLIF) with posterior fixation using anterior cages. Spine 33:1977–1981PubMedCrossRef

11.

Glassman SD, Dimar JR, Puno RM, Johnson JR, Shields CB, Linden RD (1995) A prospective analysis of intraoperative electromyographic monitoring of pedicle screw placement with computed tomographic scan confirmation. Spine 20:1375–1379PubMed

12.

Gonzalez AA, Jeyanandarajan D, Hansen C, Zada G, Hsieh PC (2009) Intraoperative neurophysiological monitoring during spine surgery: a review. Neurosurg Focus 27:E6PubMedCrossRef

13.

Donohue ML, Murtagh-Schaffer C, Basta J, Moquin RR, Bashir A, Calancie B (2008) Pulse-train stimulation for detecting medial malpositioning of thoracic pedicle screws. Spine 33:E378–E385PubMedCrossRef

14.

Bose B, Wierzbowski LR, Sestokas AK (2002) Neurophysiologic monitoring of spinal nerve root function during instrumented posterior lumbar spine surgery. Spine 27:1444–1450PubMedCrossRef

15.

Gabriel C, Peyman A, Grant EH (2009) Electrical conductivity of tissue at frequencies below 1 MHz. Phys Med Biol 54:4863–4878PubMedCrossRef

16.

Anderson DG, Wierzbowski LR, Schwartz DM, Hilibrand AS, Vaccaro AR, Albert TJ (2002) Pedicle screws with high electrical resistance: a potential source of error with stimulus-evoked EMG. Spine 27:1577–1581PubMedCrossRef

17.

Holland NR (1998) Intraoperative electromyography during thoracolumbar spinal surgery. Spine 23:1915–1922PubMedCrossRef

18.

Fehlings MG, Brodke DS, Norvell DC, Dettori JR (2010) The evidence for intraoperative neurophysiological monitoring in spine surgery does it make a difference? Spine 35:S37–S46PubMedCrossRef

19.

Sutter M, Eggspuehler A, Grob D, Jeszenszky D, Benini A, Porchet F, Mueller A, Dvorak J (2007) The diagnostic value of multimodal intraoperative monitoring (MIOM) during spine surgery: a prospective study of 1,017 patients. Eur Spine J 16:S162–S170PubMedCrossRef

20.

Hilibrand AS, Schwartz DM, Sethuraman V, Vaccaro AR, Albert TJ (2004) Comparison of transcranial electric motor and somatosensory evoked potential monitoring during cervical spine surgery. J Bone Jt Surg (American Volume) 86A:1248–1253

21.

Rodriguez-Olaverri JC, Zimick NC, Merola A, De Blas G, Burgos J, Piza-Vallespir G, Hevia E, Vicente J, Sanper I, Domenech P, Regidor I (2008) Using triggered electromyographic threshold in the intercostal muscles to evaluate the accuracy of upper thoracic pedicle screw placement (T3–T6). Spine 33:E194–E197PubMedCrossRef

22.

Kim DH, Zaremski J, Kwon B, Jenis L, Woodard E, Bode R, Banco RJ (2007) Risk factors for false positive transcranial motor evoked potential monitoring alerts during surgical treatment of cervical myelopathy. Spine 32:3041–3046PubMedCrossRef

23.

Beatty RM, Mcguire P, Moroney JM, Holladay FP (1995) Continuous intraoperative electromyographic recording during spinal surgery. J Neurosurg 82:401–405PubMedCrossRef

24.

Lehman RA, Potter BK, Kuklo TR, Chang AS, Polly DW, Shawen SB, Orchowski JR (2004) Probing for thoracic pedicle screw tract violation(s)—is it valid? J Spinal Disord Tech 17:277–283PubMedCrossRef

25.

Raynor BL, Lenke LG, Kim Y, Hanson DS, Wilson-Holden TJ, Bridwell KH, Padberg AM (2002) Can triggered electromyograph thresholds predict safe thoracic pedicle screw placement? Spine 27:2030–2035PubMedCrossRef

26.

Bolger C, Brayda-Bruno M, Kaelin A et al (2003) A new device to detect iatrogenic initial vertebral cortex perforation: first clinical results [abstract]. Eur Spine J 12(1):S18

27.

Chaput CD, George K, Samdani AF, Williams JI, Gaughan J, Betz RR (2012) Reduction in radiation (fluoroscopy) while maintaining safe placement of pedicle screws during lumbar spine fusion. Spine 37(21):E1305–E1309PubMedCrossRef

Title: A CT-based study investigating the relationship between pedicle screw placement and stimulation threshold of compound muscle action potentials measured by intraoperative neurophysiological monitoring
Authors: Gerit Kulik
Etienne Pralong
John McManus
Damien Debatisse
Constantin Schizas
Publication date: 01-09-2013
Publisher: Springer Berlin Heidelberg
Published in: European Spine Journal / Issue 9/2013
Print ISSN: 0940-6719
Electronic ISSN: 1432-0932
DOI: https://doi.org/10.1007/s00586-013-2754-0

Keynote webinar | Spotlight on medication adherence

Springer Medicine

A CT-based study investigating the relationship between pedicle screw placement and stimulation threshold of compound muscle action potentials measured by intraoperative neurophysiological monitoring

Abstract

Purpose

Methods

Results

Conclusion

Keynote webinar | Spotlight on medication adherence

Springer Medicine

Abstract

Purpose

Methods

Results

Conclusion

Please log in to get access to this content

Other articles of this Issue 9/2013

Can decompression surgery relieve low back pain in patients with lumbar spinal stenosis combined with degenerative lumbar scoliosis?

Spinal alignment in low back pain patients and age-related side effects: a multivariate cross-sectional analysis of video rasterstereography back shape reconstruction data

Do physical activity level and body mass index predict recovery from persistent neck pain in men and women of working age? A population-based cohort study

Assessing the evolution of publications by Brazilian spine surgeons in the last decade

Tubular surgery with the assistance of endoscopic surgery via midline approach for lumbar spinal canal stenosis: a technical note

Percutaneous interspinous spacer versus open decompression: a 2-year follow-up of clinical outcome and quality of life