Background The prevalence of persistent or recurrent post-operative back or lower limb pain in patients who underwent discectomy or laminectomy is up to 15% and its management remains challenging. Post-operative peridural fibrosis secondary to scar formation is one of the major cause of recurrent pain symptoms in the legs after back surgery. We hypothesized that drugs targetting inflammatory-associated fibrotic processes may be of interest in this condition.
Objectives To assess the efficacy of tumor necrosis factor (TNF)-α inhibition with infliximab (IFX), as an anti-inflammatory and anti-fibrotic agent, in the treatment of post-operative peridural lumbar fibrosis-associated disabling chronic sciatica.
Methods A two-year double-blind, randomized, controlled study was conducted in a French tertiary care unit. Thirty-five patients presenting with post-operative peridural lumbar fibrosis-associated sciatica were randomized in two groups. The IFX group (N=17) was treated with a single intravenous infusion of 3 mg/kg IFX, and the placebo group (N=18) with a single saline serum infusion. The primary outcome was a 50% reduction in sciatica on visual analog scale (VAS) at day 10. Secondary outcomes were radicular and lumbar pain at day 0, 2 hours after infusion, and radicular and lumbar pain, Québec disability score, drug sparing effect, and tolerance, at days 10, 30, 90, and 180.
Results The two groups did not differ for baseline characteristics, except for radicular pain and neuropathic pain (VAS scores=55.0[50.0-70.0] in the placebo group vs 70[65.0-85.0] in the IFX group, and 45.0[41.0-73.0] vs 62.5[40.0-75.0], respectively). At day 10, no significant difference was found between placebo and IFX groups for the primary outcome (50% reduction in sciatica was observed in 3[17.6%] patients vs 5[27.8%], p=0.69, respectively). The frequency of patients reaching the Patient Acceptable Symptom State for radicular pain was significantly higher in the placebo than in the IFX group, 2 hours after infusion (12[70.6%] vs 5[27.8%], p=0.01, respectively). The two groups were comparable for all other secondary outcome measures.
Conclusions Treatment with a single 3 mg/kg IFX infusion for recurrent sciatica pain associated with post-operative peridural lumbar fibrosis does not significantly reduce radicular symptoms at day 10.
Disclosure of Interest None declared