No Additive Analgesic Effect of Interspace Between Popliteal Artery and Capsule of the Knee Block Over Local Infiltration Analgesia Only Around Arthrotomy Site in Bilateral Total Knee Arthroplasty.

Study Summary

45 patients with bilateral primary knee osteoarthritis undergoing one-stage bilateral total knee arthroplasty (TKA) were randomized so that one knee received Local Infiltration Analgesia only around the Arthrotomy site (LIAA) alone and the contralateral knee received LIAA+interspace between the Popliteal Artery and the Capsule of the Knee (iPACK). The primary outcome of interest was postoperative pain assessed using the visual analogue scale (VAS) for the anterior and posterior aspects of the knee. Secondary outcomes of interest included knee flexion angle, active straight leg raise, operative duration, drain output, and patient knee preference at discharge. Outcomes were assessed from 6 to 96 hours postoperatively. Overall, the results of the study revealed no significant additive analgesic effect of iPACK over LIAA for anterior or posterior knee pain, and no differences in knee flexion or active straight leg raise. These findings suggest that when LIAA is performed in bilateral TKA, adding iPACK may not provide clinically meaningful benefit.