No superior method for analgesia after total knee arthroplasty: randomised controlled comparison of adductor canal block combined with iPACK block versus posterior capsule block

Abstract Objective The aim of this study compare the effectiveness of the space between the popliteal artery and the posterior knee capsule (iPACK) and posterior capsule injection (PCI) in patients with primary end stage knee osteoarthritis treated with total knee arthroplasty (TKA). Methods This was a double-blind, prospective, randomised trial. A total of 195 participants were randomly assigned to one of three groups: Group 1 with an adductor canal block (ACB) plus iPACK. Group 2 with ACB + PCI and a final control group with ACB only. All participants underwent primary total knee arthroplasty. Outcome measures comprised pain assessment using the Visual Analog Scale (VAS) and monitoring opioid analgesic consumption. VAS measurements were taken at the 1st, 6th, 12th, 24th, 48th, and 72nd hours, followed by the 10th day and the 12th week. Results Age, sex, BMI and side of surgery were analyzed and no significant differences were found. Groups ACB + iPACK and ACB + PCI exhibited significantly lower VAS scores compared to the control group at 3, 6, and 12 h after surgery, with group ACB + iPACK showing the lowest VAS scores among all groups. No significant difference in VAS values between groups was detected after 24 h postoperatively and after that. Significant differences were observed between groups in opioid consumption. The values for the first hour, first day, second day, and total consumption exhibited statistically significant differences between the groups. Conclusion Our study has shown that PCI in combination with ACB is not inferior to the iPACK technique. It is our belief that these combination techniques can be used in accordance with the surgeon’s experience and preference. It is important to remember that PCI is quicker and easier to perform without using ultrasonography.