Degree of postoperative pain, need for rescue analgesia,side effect profile of both groups, self-efficacy, expectancy, quality of life / health economics using EQ-5D Type of study: Prospective single blind RCT Planned number of subjects: 48 Study duration: 24 months Randomisation procedures Following informed consent, participants will be randomised into two groups. All IMP preparations for study will be coded so that participants have an equal chance of receiving one of the two IMPs. Randomisation will be carried out by computer program, and codes kept in pharmacy in a sealed envelope. All IMP's will be labelled to GCP standards.