Table 1. Literature Map.
TFEI = Transforaminal epidural injections; ILEI = Interlaminar lumbar epidural injections; CEI = Caudal epidural injections; LEI = Lumbar epidural injections; NA = Not available; FU = Follow-up.
| Study | Study Design | Injection | Mean Age | Sample Size | Gender (%) | Diagnosis | Pain Duration (Weeks) | Maximum FU (Months) | |
| Females | Males | ||||||||
| Sayegh (2009) [25] | Prospective, randomized, double-blind clinical trial | CEI without steroid | 49.12 | 183 | 32.78% | 67.23% | Lumbar radicular pain and sciatica | >4 | 12 |
| Ghahreman (2010) [3] | Prospective, randomized study | TFEI with steroid | 49.5 | 150 | 40.66% | 59.30% | Lumbar disc herniation | 12 | 12 |
| Manchikanti (2014 A) [17] | Randomized, controlled, double-blind, active control trial | TFEI with or without steroids | 42.85 | 120 | 50% | 50% | Lumbar disc herniation and radiculitis | 24 | 24 |
| Manchikanti (2014 B) [12] | Randomized, controlled, double-blind, active control trial. | LIEI with or without steroids | 44.5 | 120 | 69.20% | 30.80% | Lumbar disc herniation and radiculitis | 24 | 24 |
| Manchikanti (2011) [21] | Randomized, controlled, double-blind trial | CEI without steroid | 45.85 | 120 | 65% | 35% | Lumbar disc herniation and radiculitis | 24 | 12 |
| Manson (2013) [18] | Retrospective | TFEI with steroids | 45.8 | 91 | 41.75% | 58.24% | Lumbar disc herniation and/or radiculopathy | 6 | 26.6 |
| Manchikanti (2008) [26] | A randomized, double-blind, equivalence trial. | CEI without steroid | 47.05 | 84 | 66.60% | 33.33% | Lumbar disc herniation and radiculitis | 24 | 12 |
| Owlia (2007) [28] | Comparative study | LEI with steroid | 38.2 | 84 | 57.14% | 42.80% | Lumbar radicular pain | >2 | 3 |
| Kennedy (2014) [1] | Multicenter, double-blind, prospective, randomized trial | TFEI with steroids | 35.75 | 78 | 34.61% | 65.38% | Unilateral radicular pain | 8 | 6 |
| Manchikanti (2010) [23] | Randomized, double-blind, controlled trial | LIEI with injections | 41.95 | 70 | 65.71% | 34.26% | Lumbar radicular pain | 24 | 12 |
| Helvoirt (2014) [16] | Prospective cohort study | TFEI with steroids | 47.3 | 69 | 50.70% | 49.30% | Lumbar disc herniation | 20 | 12 |
| Rados (2011) [22] | Randomized prospective study | TFEI & LIEI with steroid | 49.2 | 64 | 35.90% | 64.10% | Chronic lumbar radicular pain caused by herniated disc | 12 | 6 |
| Spijker-Huiges (2014) [2] | Randomized controlled trial | TFEI with steroids | 43.7 | 63 | 47.61% | 52.38% | Lumbosacral radicular syndrome | 2-4 | 13 |
| Gomez (2007) [27] | Retrospective | LIEI with steroid | 47 | 60 | 50% | 50% | Lumbosciatic pain | 24-48 | 6 |
| Baral (2011) [20] | Prospective observational study | TFEI with steroid | 41.04 | 50 | 48% | 52% | Lumbar disc herniation | NA | 6 |
| Kawu (2012) [19] | Prospective-controlled observational study | TFEI & LIEI with steroids | 47.6 | 49 | NA | NA | Lumbar disc herniation | 31.2 | 6 |
| Schaufele (2006) [29] | Retrospective | LIEI Versus TFEI without steroid | NA | 40 | NA | NA | Lumbar intravertebral disc herniation | 2-48 | 12 |
| Laiq (2009) [24] | Quasi-experimental study | LEI with steroid | 40.5 | 25 | 68% | 32% | Lumbar radicular pain | 2 | 6 |
| Yang (2006) [30] | Prospective | TFEI with steroid | 50 | 19 | 42.10% | 57.89% | Sciatica with unilateral symptoms | 8-96 | 24 |