Eleven RCTs and five non-randomised studies were included in the review. Most studies evaluated long-term response of at least six months; only two RCTs evaluated short-term response of less than six months. Seven RCTs were judged as high quality. All five non-randomised studies were judged as moderate quality.
Disc herniation and radiculitis (six RCTs and two non-randomised studies, 794 participants):
Four of the six RCTs that evaluated caudal epidural steroid injections assessed long-term outcomes. Three out of the four RCTs that evaluated long-term response showed positive results in pain relief and/or improvement in functional status for caudal epidural steroid injections compared with controls. One RCT showed negative or unclear results. Two RCTs that evaluated short-term response showed positive results for local anaesthetic and steroids. Two non-randomised studies evaluated long-term response and only one study showed positive response for caudal epidural injections.
Axial pain (one RCT and one non-randomised study, 217 participants):
One RCT that evaluated caudal epidural steroid injections in axial or discogenic pain showed positive long-term results for local anaesthetic with steroid compared with local anaesthetic only. One non-randomised study showed negative long-term results for caudal epidural steroid injections.
Spinal stenosis (one RCT and two non-randomised studies, 411 participants):
One RCT showed positive long-term results for caudal epidural steroid injections compared with control. Only one out of two non-randomised studies showed positive long-term results for caudal epidural steroid injections.
Post surgery syndrome (three RCTs, 238 participants):
One RCT showed equivalent long-term results for local anaesthetic and steroids compared with local anaesthetic only. One RCT assessed forceful epidural injections with steroid and sodium chloride solution and showed positive results in the forceful group and negative results with injection of only methylprednisolone. One RCT assessed hypertonic sodium chloride solution and hyaluronidase and showed positive long-term results when hyaluronidase was used.