Spine Journal: Article on Safe Thoracic Pedicle screw placedment

Thoracic pedicle screw placements especially the upper thoracic levels do not have specific  muscle innervation making it difficult to test pedicle screws, in other words it is not as discrete as you can do a test on for example Deltoid (Cervical) or Tibialis anterior (lumbar). The following article though

Spine (Phila Pa 1976). 2012 

Safe pedicle screw placement in thoracic scoliotic curves using t-EMG: stimulation threshold variability at concavity and convexity in apex segments.

de Blas G, Barrios C, Regidor I, Montes E, Burgos J, Pizá-Vallespir G, Hevia E.

Source

Department of Clinical Neurophysiology, Hospital Ramón y Cajal, Madrid, Spain.

Abstract

STUDY DESIGN:

A cross-sectional study of nonconsecutive cases (level III evidence).

OBJECTIVE:

In a series of young patients with thoracic scoliosis who were treated with pedicle screw constructs, data obtained from triggered electromyography (t-EMG) screw stimulation and postoperative computed tomographic scans were matched to find different threshold limits for the safe placement of pedicle screws at the concavity (CC) and convexity (CV) of the scoliotic curves. The influence of the distance from the medial pedicle cortex to the spinal cord on t-EMG threshold intensity was also investigated at the apex segment.

SUMMARY OF BACKGROUND DATA:

Whether the t-EMG stimulation threshold depends on pedicle bony integrity or on the distance to neural tissue remains elusive. Studying pedicle screws at the CC and CV at the apex segments of scoliotic curves is a good model to address this issue because the spinal cord is displaced to the CC in these patients.

Mar 15;37(6):E387-95. doi: 10.1097/BRS.0b013e31823b077b.

Lumbar Fusion & Analgesic related Death?

In one of the latest issue of "Spine" (Spine: 1 April 2009 - Volume 34 - Issue 7 - pp 740-747doi: 10.1097/BRS.0b013e31819b2176Surgery), a study related to lumbar fusion and analgesic death been analyzed and reported. The authors claim that the risk of death was higher in those patients who received instrumentation and especially inter vertebral cage placement when compared to bone only fusion??. Though I have not heard any perioperative death or even serious consequences in huge number of spine cases we did in the recent past, this report is a caution to look into the analgesic effect spine fusion, streamlining the usage of analgesics that are less toxic is extremely important.

Mortality After Lumbar Fusion Surgery
Juratli, Sham Maghout MD, MPH; Mirza, Sohail K. MD, MPH; Fulton-Kehoe, Deborah PhD, MPH; Wickizer, Thomas M. PhD; Franklin, Gary M. MD, MPH

Abstract

Study Design. Retrospective population-based cohort study.

Objective. To describe mortality after lumbar fusion surgery in Washington State workers' compensation claimants in the perioperative period and beyond.

Summary of Background Data. Although lumbar fusion surgery can be associated with serious complications, perioperative mortality is generally considered rare. Population-based mortality estimates have been limited to surgery in older adults.

Methods. We identified all Washington State workers' compensation claimants who underwent fusion between January 1994 and December 2001 (n = 2378) and assessed the frequency, timing, and causes of death. Mortality follow-up was concluded in 2004. Death was ascertained from Washington State vital statistics records and from the workers' compensation claims database. Poisson regression was used to obtain age- and gender-adjusted mortality rates. Years of potential life lost, percent of potential life lost, and mean potential life lost were calculated for the leading 5 causes of death and we calculated the risk of death associated with selected predictors.

Results.

Among the 2378 lumbar fusion subjects in the study cohort, 103 were deceased by 2004. The 3-year cumulative mortality rate was 1.93% (95% confidence interval, 1.41%-2.57%). The 90-day perioperative mortality rate was 0.29% (95% confidence interval, 0.11%-0.60%). The risk of perioperative mortality was positively associated with repeat fusions. The age- and gender-adjusted all-cause mortality rate was 3.1 deaths per 1000 worker-years (95% confidence interval, 0.9-9.8).

Analgesic-related deaths were responsible for 21% of all deaths and 31.4% of all potential life lost.

The risk of analgesic-related death was higher among workers who received instrumentation or intervertebral cage devices compared with recipients of bone-only fusions (1.1% vs. 0.0%; P = 0.03) and among workers with degenerative disc disease (age- and gender-adjusted mortality rate ratio, 2.71) (95% confidence interval, 1.17-6.28).

The burden was especially high among subjects between 45 and 54 years old with degenerative disc disease (rate ratio, 7.45).

Conclusion. Analgesic-related deaths are responsible for more deaths and more potential life lost among workers who underwent lumbar fusion than any other cause. Risk of analgesic-related death was especially high among young and middle-aged workers with degenerative disc disease.

© 2009 Lippincott Williams & Wilkins, Inc.

You do Spine surgery and Do not monitor nerves..Why?

Neuro monitoring (a.k.a.: Neurophysiologic Intraoperative Monitoring) may be one of the most exciting and important €œold€ innovations to come into spine and neuro surgery in decades.

Think of it, what surgeon would dare operate without blood gas monitoring? Or blood pressure monitoring?

So why operate without nerve monitoring?

We recently talked with Debra Zacharko, who teaches neuro monitoring for NeuroMatrix in Atlanta. She described a case in which one of her clients scheduled a straightforward laminectomy and declined to use neuro monitoring. €œSo, I told him that I'€™d perform the monitoring for free,€ said Zacharko, €œand when I showed him the wave form tapes

he was amazed to see how much nerve irritation there is even in a simple laminectomy.€