Patients randomization and blinded injection preparation
Patients were allocated by simple randomization by a trained nurse into two equal groups (30 patients each). The patients, clinical examiner and sonographer were blinded to the type of injection given. The nurse prepared syringes containing either saline (2 ml of 0.9% NaCl) or L-GF (dissolved in 1 ml saline and 1 ml lignocaine), wrapped them up using opaque adhesive tape to conceal their content and labeled them with a name code of the patients.