Papers of the Week

Pain after total knee arthroplasty (TKA) is a prevalent condition. This study compared the effectiveness of tapentadol extended release (ER) 50 mg x 2, oxycodone controlled release (CR) 10 mg x 2 and placebo; as added to a multimodal analgesic regime both in-hospital and at home the first week after TKA. The study was randomized and blinded for investigators, staff, outcome assessors and patients. Follow-up included pain intensity on mobilization, pain at rest, worst pain in the previous 24 hours, and adverse effects measured on 0-10 numeric rate scales. A total of 134 patients in three study groups received their allocated intervention and were included in the analysis. The primary outcome pain on mobilization the 7 first postoperative days reported as mean pain Area Under the Curve (AUC) was 528.1 (SD 267.5, IQR 356.6 to 665.4) for placebo, 427.2 (SD 203.9, IQR 303.6 to 544.3) for tapentadol ER and 507.9 (SD 243.7, IQR 292.4 to 686.8) for oxycodone CR (p=0.12). With the exception of constipation being less prevalent in the tapentadol ER group (p=0.02), we found no significant differences between treatment groups for the secondary outcomes. Tapentadol ER as an add-on to multimodal analgesia did not significantly improve pain relief when compared to oxycodone CR or placebo. Constipation was lowest in the tapentadol ER group.