Inadvertent intradiscal contrast flow during lumbar transforaminal epidural steroid injections: a case series examining the prevalence of intradiscal injection as well as potential associated factors and adverse events.

OBJECTIVES: The primary aim was to evaluate the prevalence of inadvertent intradiscal injection during fluoroscopically guided contrast-enhanced lumbar transforaminal epidural steroid injections. The secondary aim was to determine if there are any risk factors for or adverse events as a result of inadvertent intradiscal contrast injection.

DESIGN: The study was a retrospective case series.

SETTING: The study was set in three outpatient spine care centers.

PATIENTS: A search was conducted in a database of spinal injection procedures from July 2000-May 2008. Fifteen cases of inadvertent intradiscal contrast flow were identified. These cases were matched with one control case with the same age, gender, level, and side of injection.

INTERVENTIONS: The prevalence of intradiscal contrast flow with lumbar transforaminal epidural steroid injection was calculated. Chart review of the cases and controls was performed. An independent, blinded examiner evaluated needle tip placement.

OUTCOME MEASURES: Frequency of intradiscal contrast flow during lumbar transforaminal epidural steroid injections and the relationship between the occurrence of intradiscal contrast flow with potential risk factors.

RESULTS: The prevalence of inadvertent intradiscal injection during lumbar transforaminal epidural steroid injections was 0.17%. All of the patients received prophylactic antibiotics after inadvertent disk injection, and there were no infectious or other complications identified.

CONCLUSIONS: Intradiscal contrast injection is an infrequently reported event during lumbar transforaminal epidural steroid injections. Our data support that the prevalence is very low and there might be an association with ipsilateral foraminal stenosis. Although there is potential for significant adverse complications with intradiscal injection, our data set did not show serious sequelae.