Does Adding an IPACK Block to the Suprainguinal Fascia Iliaca Block Improve the Quality of Analgesia in Patients Undergoing Knee Arthroplasty under Spinal Anesthesia? A Retrospective Cohort Study.

Background and Objectives: Total knee arthroplasty (TKA) is a commonly performed orthopedic procedure, and is often accompanied by significant postoperative pain. The supra-inguinal fascia iliaca block (SIFIB), similar to an anterior lumbar plexus block, is frequently used in hip surgeries. The interspace between the popliteal artery and capsule of the posterior knee (IPACK) block is a regional anesthesia technique that targets the posterior innervation of the knee capsule. This retrospective study aimed to compare the analgesic effects of SIFIB and SIFIB + IPACK on patients undergoing TKA under spinal anesthesia. Materials and Methods: This retrospective study revealed the data collected from a tertiary hospital. Patient data were gathered for individuals who underwent unilateral TKA under spinal anesthesia during the period between 1 January 2023 and 1 September 2023. Inclusion criteria comprised patients falling within ASA class I-III, those following a standardized perioperative analgesia regimen, and individuals receiving opioids via a patient-controlled analgesia device (PCA) as part of their postoperative pain management strategy. Patients were grouped as SIFIB and SIFIB + IPACK according to the performed regional anesthesia technique. Results: In the study, the data of 88 patients in total, 61 in the SIFIB group and 27 in the IPACK group, were analyzed. The 24 h cumulative morphine consumption was similar in the SIFIB and SIFIB + IPACK groups (10.62 ± 6.58 mg vs. 12.55 ± 8.84 mg, respectively; p : 0.258). The NRS scores of the groups were similar in all time frames. Conclusions: Our study reveals that combining IPACK with SIFIB in the multimodal analgesia plan does not provide additional benefits in terms of postoperative opioid consumption and pain scores in patients undergoing unilateral THA under spinal anesthesia.