Use of reduced-dose periarticular injection for pain management in simultaneous bilateral total knee arthroplasty.

We investigated the safety and efficacy of the bilateral periarticular multimodal drug injection (PMDI) at a reduced dosage in patients undergoing simultaneous bilateral total knee arthroplasty (SBTKA). In total, 45 patients undergoing SBTKA received 65 mL PMDI in each knee (reduced-dose group). The incidence of drug-related adverse effects and wound complications were evaluated. Pain levels during the night of the operation and postoperative day 1 and opioid consumption during the first 24 hours after surgery were compared with the regular-dose group of 55 patients undergoing SBTKA who received 100 mL of PMDI in 1 knee. No patient experienced a serious drug-related adverse effect or wound complication. Blood levels of ropivacaine were observed to be lower than a toxic level throughout the monitored period in all patients examined. Patients in the reduced-dose group experienced less pain during the night of operation, but a similar pain level at postoperative day 1.