Spinal Stenosis Injections
Epidural steroid injections for treating spinal stenosis have been reported to be helpful in the short-term pain relief for some patients with lumbar spinal stenosis.11,12,17,18 However, few controlled trials have investigated the efficacy of epidural steroid injection in the treatment of lumbar spinal stenosis. Hoogmartens and Morelle17 and Rosen and coworkers18 retrospectively evaluated the effectiveness of epidural steroid injections and reported that approximately 50% of patients received short-term pain relief.
Much controversy exists with respect to the efficacy and patient satisfaction associated with steroid injections for lumbar spinal stenosis. Given the lack of research evidence for efficacy and the potential for complications, their use has been considered largely as an attempt to avoid surgery after the failure of other conservative management approaches.19,20,21
Injections for Sciatica Pain Relief
The anti-inflammatory effect of epidural injections is increasingly accepted as the probable mechanism of pain relief in patients suffering from sciatica, based on the neurogenic inflammatory basis for pain generation. There are now 18 randomized trials in the literature, with approximately half reporting a positive benefit. While most of the studies are for sciatica from herniated nucleus pulposus, one trial studied only patients with lumbar stenosis (Fukusaki) and one trial enrolled patients with both LSS and HNP (Cuckler).
Controversy Around Studies
Fukusaki reported some short term efficacy (three months) of epidural steroids. Cuckler concluded that the epidural steroids were no better than local anesthesia. Cuckler’s methods have been criticized, however, specifically his assumption that patients should expect to experience relief of symptoms within 24 hours or be considered treatment failures. The treatment regimen now recommended by NASS is an initial injection, after which the patient’s response is determined. It is current opinion that at least a week should pass after the initial injection before subsequent injections are considered, and there is no rationale for a series of injections without considering the response to the initial injection. In neither Cuckler’s study nor Fukusaki’s study was fluoroscopic guidance used. Instead, the loss of resistance (LOR) method was used for determining correct needle placement. This method has been shown to be less reliable for ensuring correct needle placement than fluoroscopic guided needle placement and current treatment guidelines strongly recommend the use of fluoroscopy.