Background & Aims
The efficacy of lumbar epidural steroid injection (ESI) varies, and there are no established clinical parameters to reliably predict a favorable response to ESI. This prospective observational study aimed to investigate clinical factors and magnetic resonance imaging (MRI) findings that can predict a favorable outcome following ESI in patients with low back pain (LBP) and/or sciatica.
Methods
A total of 120 patients diagnosed with lumbosacral radiculopathy underwent transforaminal epidural steroid injections (TFESI). At each epidural level, 5.0 mg of a dexamethasone mixture in 2.0% lidocaine and 0.5% bupivacaine was injected. At the 2-week follow-up, a favorable response to ESI was defined as either a reduction in pain or an improvement in the Oswestry disability index (ODI) score of more than 50.0%. Data collection encompassed information regarding pain location, pain duration, body mass index (BMI), the presence of a straight leg raising test (SLRT), motor weakness, neurogenic claudication, and the severity of MRI imaging. The incidence of spinal surgery following ESI was recorded for up to 12 months. The primary outcomes were the clinical presentations and MRI findings of the favorable and poor responders. The secondary outcomes were the duration of pain reduction greater than 50% following TFESI and the incidence of spinal surgery following the procedure.
Results
A favorable response was observed in 60.8% of patients, while 39.2% of patients exhibited poor responses at 2 weeks post-ESI. There were no significant differences in pain characteristics, clinical presentations, or MRI findings, except for the extent of central canal stenosis. Poor responders displayed severe central canal stenosis, whereas good responders showed a statistically significant presence of mild central canal stenosis (P<0.01). Favorable responders experienced a notable 29-week period of pain reduction (95%CI 10.3–47.8), along with a significantly lower incidence of surgery at 12 months (13.7%) (P<0.01). 51.1% of poor responders ultimately required surgical intervention at 12 months. The mean pain score differences of 3.5 out of 10 post-TFESI represented the optimal values for sensitivity and specificity in forecasting good responder status.
Conclusions
The existence of severe central canal stenosis is a significant predictor of an unfavorable response following TFESI. Approximately 60% of patients experiencing LBP and/or sciatica exhibit a positive response, resulting in reduced surgical rates of 37.4% at 12 months.
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Presenting Author
Pornpan Chalermkitpanit
Poster Authors
Pornpan Chalermkitpanit
MSc.
Chulalongkorn University
Lead Author
Topics
- Specific Pain Conditions/Pain in Specific Populations: Low Back Pain