Should the lower end of the spinal cord be localized by MRI in all patients having low backache prior to spinal anesthesia?

Abstract

Objective: This study investigates the position of the lower end of the spinal cord conus in Chinese adults with low backache using MRI, to locate the safe puncture site for spinal anesthesia.

Methodology: Eight hundreds adults suffering from low backache were included in the study. Magnetic resonance imaging was used to localize the lower end of the spinal cord conus.

Results: Adult females’ conus positions were slightly lower than the males (median: L1:lower, quartile: L1:middle-L1:upper for females; median: L1:lower, quartile: L1:upper-L2 for males; P < 0.001). In addition our data showed that in 23.25% of patients the tip of the conus was located at the upper 1/3 level of L3. Pearson’s correlation analysis showed that when the study population was divided by age group (Group A = 30 years of age; Group B = 30-60 years old; Group C = more than 60 years of age), cone position was significantly lower in older patients (r = 0.113, P < 0.05).

Conclusion: Spinal puncture should not be performed higher than the L3-L4 intervertebral space in Chinese patients having low backache unless the position of the lower end of the spinal cord is identified by prior MRI.