To critically review the best available studies evaluating the efficacy of lumbosacral
transforaminal epidural steroid injections (TFESIs) in the treatment of radicular
pain.
MEDLINE, EMBASE, and the Cochrane database were searched for the period between 1950
and May 2008. Search terms included epidural steroid injection (ESI), transforaminal
ESI, foraminal ESI, selective nerve root block, nerve root injection (NRI), selective
NRI, periradicular infiltration, and periradicular injection. Randomized controlled
trials (RCTs), published in English, which evaluated the efficacy of fluoroscopically
guided TFESIs were reviewed.
Studies were analyzed with a quality checklist modeled after the 2001 CONSORT Statement:
Revised Recommendations for Improving the Quality of Reports of Parallel-Group Randomized
Trials. Nine studies were found to include a majority of these items.
Data included study design, inclusion criteria, symptom duration, randomization protocol,
blinding protocol, intervention, control, outcomes, follow-up, dropout, statistical
analysis, and conclusions.
Each article was assigned a level of evidence: I (high-quality RCT) or II (RCT with
<80% follow-up, no blinding or improper randomization). Studies were divided according
to control, and overall evidence was graded as A (good), B (fair), C (conflicting/poor
quality), or I (insufficient).
There is fair evidence supporting TFESIs as superior to placebo for treating radicular
symptoms. There is good evidence that TFESIs should be used as a surgery-sparing intervention,
and that TFESIs are superior to interlaminar ESIs (ILESIs) and caudal ESIs for radicular
pain. In patients with subacute or chronic radicular symptoms, there is good evidence
that a single TFESI has similar efficacy as a single transforaminal injection of bupivacaine
or saline. Future studies should address the ideal number of injections. While more
placebo-controlled trials are needed to conclusively define the role of TFESIs, current
studies support their use in the treatment of lumbosacral radicular pain.