Table 5.
Description of study characteristics of randomized controlled epidural trials assessing the efficacy of lumbar transforaminal epidural injections in lumbar disc herniation.
| Study | Study characteristics | Methodologic quality score | Number of patients | Interventions | Outcome measures | Pain and function improvement | Improvement | Comment(s) | ||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 3 months | 6 months | 12 months | Short term | Long term | ||||||||
| (≤ 6 months) | > 6 months | ≥ 12 months | ||||||||||
| Cohen et al. [25] (2012) | RA, PC, F | 10/12 | Total = 84 Saline = 30 Corticosteroid = 28 Etanercept = 26 |
Steroids, etanercept, or saline Number of injections = 1–2 |
Pain relief, ODI, global perceived effect | Steroids = 50% Etanercept = 42% Saline = 43% |
Steroids = 29% Etanercept = 38% Saline = 40% |
Steroids = NA Etanercept = NA Saline = NA |
N | N | NA | Although this was a well-conducted study, it was not a true placebo study. Even though there was no significant difference, the authors concluded epidural steroid injections may provide short-term pain relief for some. The included patients had subacute sciatica. |
| Ghahreman et al. [40] (2010) | RA, PC, F | 12/12 | Total = 150 5 groups with 28, 37, 27, 28, 30 |
Steroids with saline vs local anesthetic vs intramuscular steroids vs Intramuscular saline Number of injections = 1–3 |
At least 50% pain relief | TF saline = 19% TF local anesthetic = 7% TF epidural = 54% |
NA | NA | Steroids = Y Local anesthetic and saline = N |
NA | NA | First study of its nature with a true placebo evaluation showing short-term improvement |
| Karppinen et al. [55, 56] (2001) | RA, PC, F | 11/12 | Total = 160 Methylprednisolone-bupivacaine = 80 Saline = 80 |
Sodium chloride solution or methylprednisolone (40 mg) and bupivacaine (5 mg) Number of injections = 1 |
VAS, ODI, Nottingham Health Profile, cost, physical examination | NA | SI in both groups | SI in both groups | U | U | U | An ineffective or inappropriate placebo design, without applicable results |
| Jeong et al. [51] (2007) | RA, AC, F | 9/12 | Total = 193 G = 104 PG = 89 |
0.5 mL bupivacaine hydrochloride and 40 mg 1 mL triamcinolone Number of injections = 1 |
VAS | PG = 88.4% G = 70.9% |
PG = 60.4% G = 67.2% |
NA | Y | Y | NA | Moderate-quality study showing mid-term improvement |
| Riew et al. [111, 112] (2006, 2006) | RA, AC, F | 8/12 | Total = 55 Bupivacaine = 27 Bupivacaine + steroid = 28 |
Bupivacaine 0.25% or bupivacaine with 6 mg betamethasone Number of injections = 1–4 |
North American Spine Society Outcome Instrument, operative treatment considered as failure of injection treatment | NA | NA | 33% vs 71% (avoided surgery) | Steroids = Y Local anesthetic = U |
Steroids = Y Local anesthetic = U |
Steroids = Y Local anesthetic = N |
Surgery avoided in 33% of bupivacaine group and 71% in steroid group |
| Ng et al. [96] (2005) | RA, AC, F | 11/12 | Total = 86 Bupivacaine = 43 Bupivacaine + steroid = 43 |
Bupivacaine only or bupivacaine with methylprednisolone Number of injections = 1 |
VAS, ODI, change in walking distance, claudication, satisfaction of the outcome | Bupivacaine = 47.5% Bupivacaine + steroid = 41.5% |
NA | NA | Steroids = Y Local anesthetic = N |
NA | NA | Small study with short-term followup showing improvement |
| Lee et al. [63] (2009) | RA, AC, F | 7/12 | Total = 93 IL = 34 TF = 59 |
Interlaminar vs transforaminal epidural injections 4 mL (TF) Number of injections = 1–3 |
NRS, PSI | Roland Pain Score: TF = 3.34–1.59 IL = 3.25–1.57 |
NA | NA | Y | NA | NA | Study with short-term followup showing improvement |
| Ackerman and Ahmad [1] (2007) | RA, AC, F | 7/12 | Total = 90 Caudal = 30 IL = 30 TF = 30 |
Steroid and saline with local anesthetic Number of injections = 1–3 |
Pain relief | Caudal = 57% IL = 60% TF = 83% |
Caudal = 57% IL = 60% TF = 83% |
NA | Y | P | NA | Study showing mid-term improvement |
| Park et al. [97] (2010) | RA, AC, F | 7/12 | Total = 106 Dexamethasone = 53 Triamcinolone acetate = 53 |
Dexamethasone or triamcinolone acetate with lidocaine Number of injections = 1 |
VAS, Short MPQ, ODI | Dexamethasone = 40% Triamcinolone = 71% |
NA | NA | Y | NA | NA | Short-term improvement with triamcinolone compared to dexamethasone |
| Rados et al. [107] (2011) | RA, AC, F | 8/12 | Total = 64 IL = 32 TF = 32 |
IL vs TF Number of injections = 1–3 |
VAS, ODI, disability scores | TF = 53% IL = 75% |
TF = 53% IL = 75% |
NA | Y | Y | NA | Study showing mid-term improvement |
| Tafazal et al. [121] (2009) | RA, AC, F | 10/12 | Total = 76 Bupivacaine = 34 Bupivacaine + steroid = 42 |
Bupivacaine with methylprednisolone Number of injections = 1–3 |
VAS, ODI, LBOS, Modified Somatic Perception Questionnaire, MZD | VAS and ODI changes: Bupivacaine = 24.3 and 13.8 Bupivacaine + steroid = 27.4 and 13.6 |
Y | NA | Y | Y | Y | Study showing long-term improvement |
RA = randomized; PC = placebo control; F = fluoroscopy; AC = active control; G = ganglionic; PG = preganglionic; IL = interlaminar; TF = transforaminal; ODI = Oswestry Disability Index; NRS = Numeric Rating Scale; PSI = Patient Satisfaction Index; MPQ = McGill Pain Questionnaire; LBOS = Low Back Outcome Score; MZD = Modified Zung Depression; NA = not applicable; SI = significant improvement; Y = yes; N = no; U = unclear.