Aim: In subjects with acute sciatica (≤ 4 weeks duration), this is a pilot comparative effectiveness study to evaluate feasibility and to determine final sample size for a future adequately powered randomised controlled trial of (i) CT-guided transforaminal lumbosacral epidural steroid injection, and (ii) oral dexamethasone, in a masked (blinded), randomised, sham injection and oral placebo controlled trial.