['To compare the postoperative analgesic effects of 50 mg diclofenac p.o. before surgery and intra-articular ropivacaine injected after diagnostic day-case knee arthroscopy performed under spinal anesthesia.', 'In a randomized, double-blind investigation, 200 ASA physical status 1-2 outpatients, age 18-60 yr, received either 50 mg diclofenac p.o. or placebo one hour before operation (100 patients per group), and intraarticular injections of either 20 ml of ropivacaine 0.5% or 20 ml of saline 0.9% (50 patients in each premedication groups). Patients received 50 mg diclofenac p.o. prn and, if needed, 0.1 mg x kg(-1) oxycodone im for postoperative pain relief. Patients were discharged home with a supply of 50 mg diclofenac tablets and were given a sheet of paper with knee pain VAS scales and a questionnaire of analgesics taken. Patients rated their VAS scores eight hours after surgery and in the moming and at the end of the first and the second postoperative days, respectively.', 'The only statistically significant difference was found when the diclofenac groups were combined and compared with the combined placebo premedication groups. The VAS scores of knee pain at eight hours after the operation were 19+/-22 in the two diclofenac premedication groups and 32+/-28 in the two placebo groups (P = 0.001).'] Does diclofenac premedication but not intra-articular ropivacaine alleviate pain following day-case knee arthroscopy?