Randomised controlled trial of transforaminal injections for sciatica

Patients are randomised by random number allocation to one of five treatment groups. Each receives an injection under fluoroscopic guidance. In three groups the needle is placed in the intervertebral foramen that lodges the affected nerve. Respectively those groups are randomly injected with (1) 0.75ml of a local anaesthetic (0.5% bupivacaine) followed by a steroid preparation (1.75 ml triamcinolone 40mg/ml) or (2) 2ml bupivacaine 0.5% or (3) 2ml normal saline. In two other groups the needle is placed deeply in the back muscles opposite the segment affected by the disc herniation. They receive either 1.75 ml triamcinolone 40mg/ml or 2 ml normal saline. All patients receive at least one therapeutic injection, but are entitled to have one or two repeats of the allocated agent if their response is favourable but partial, and they wish to boost their response.