Dexmedetomidine versus hyaluronidase along with lumbar transforaminal epidural steroid injection in failed back surgery: a randomized double-blind clinical trial.

Background: Failed back surgery syndrome is a common problem faced by chronic pain management specialists. Steroid-only epidural injections have modest efficacy because of excessive scarring. Epidural hyaluronidase (HA), functions as a depolymerizing agent, successfully breaking down adhesions and collagen bundles, whereas dexmedetomidine (DEX) helps to reduce inflammation.

Methods: The current study is a randomized, double blind, clinical trial. The study cohort included population with persistent (> 6 months) back and/or radicular lower limb pain after laminectomy. Group I (HA group) received bupivacaine 0.5% (5 mg), triamcinolone 40 mg, sterile saline (2 ml), and HA (1500 IU) instilled in 1 mL of distilled water. Group II (DEX group) received bupivacaine 0.5% (5 mg), triamcinolone 40 mg (1 ml), DEX (0.5 mcg/kg), and sterile saline (2 ml).

Results: Both groups showed significant reductions in VAS scores at all follow-ups compared to the pre-injection values. At 6 months, the DEX group experienced a significantly greater reduction in pain scores than the HA group (P = 0.003). In terms of the MODI, both groups showed significant reductions in disability scores at all follow-ups relative to the pre-injection values. The DEX group showed greater improvement in MODI values than the HA group. No significant complications were reported.

Conclusions: Both DEX and HA yielded significant improvements in pain and disability scores compared with pre-injection levels. The DEX group showed a more substantial and long-term reduction in both pain scores and disability index than the HA group.