Background: Although intraoperative periarticular multi-drug injection has been used for postoperative pain control after total knee arthroplasty (TKA), the injection has the inherent shortcoming of limited acting time. This randomized controlled trial was performed to assess whether adding percutaneous periarticular multi-drug injection at the day following TKA would improve the postoperative pain relief.
Methods: A total of 43 participants were randomly assigned to receive additional periarticular injection at 08:30, postoperative day 1 or no additional injection. The multi-drug solution including 40 mg of methylprednisolone, 150 mg of ropivacaine, and 0.1 mg of epinephrine was infiltrated into the muscle belly of the vastus medialis. In both groups, patients were treated with intraoperative periarticular multi-drug injection and postoperative intravenous and oral nonsteroidal anti-inflammatory drugs. We did not use any narcotic pain medications postoperatively. The primary outcome was the patients' global assessment of postoperative pain at rest measured using a visual analog scale (VAS) and quantified as the area under the curve (AUC) of serial assessments until 20:00, postoperative day 5.
Results: The mean AUC for the postoperative pain VAS at rest was 1616 ± 1191 in patients received the additional periarticular injection versus 2808 ± 1494 in those received no injection (mean difference, - 1192; 95% confidence interval, - 2043 to - 340; p = 0.007). No wound complication or surgical site infection was observed in either groups.
Conclusions: Adding percutaneous periarticular multi-drug injection at the day following TKA may provide better postoperative pain relief. Further studies are needed to confirm the safety of the percutaneous injection.
Trial registration: University Hospital Medical Information Network UMIN000029003 . Registered 5 September 2017.
Keywords: Knee; Multimodal; Opioid; Pain management; Primary arthroplasty.