Archives of Orthopaedic and Trauma Surgery - 2026-03-28 - Journal Article
Combined iPACK and adductor canal block versus two-level erector spinae plane block in elderly patients undergoing total knee arthroplasty: a randomized, triple-blinded clinical trial.
Pietraszek P, Reysner T, Gola W, Kluzik A, Perek A, Marszałek-Buko J, Reysner M
Topics
Key Takeaway
Combined iPACK + ACB reduced 48-hour opioid consumption by 3.2 mg MME versus two-level lumbar-sacral ESPB (9.7 vs 12.9 mg MME; p=0.035) in elderly TKA patients.
Summary Depth
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Summary
This single-center, triple-blinded RCT compared combined iPACK + ACB versus two-level lumbar-sacral ESPB (L1 and S1) in 60 patients aged 65-100 undergoing primary TKA under spinal anesthesia, using 0.2% ropivacaine 20 mL at each injection site. iPACK + ACB produced lower total opioid consumption (9.7 vs 12.9 mg MME; p=0.035), longer time to first rescue opioid (9.3 vs 8.5 h; p=0.026), lower NRS at 8 hours (2.6 vs 3.3; p=0.004), and lower 24-hour NLR (2.20 vs 2.61; p=0.002). Quadriceps strength (MRC grade 5) was preserved in both groups with no significant difference.
Key Limitation
Follow-up truncated at 48 hours provides no data on functional recovery, discharge readiness, or fall risk beyond the immediate postoperative period, which are the outcomes most relevant to elderly TKA patients.
Original Abstract
BACKGROUND
Effective postoperative pain management after total knee arthroplasty (TKA) in elderly patients is challenging because of their increased susceptibility to opioid-related adverse events. Motor-sparing regional anesthesia techniques such as the adductor canal block (ACB), the interspace between the popliteal artery and the posterior capsule of the knee (iPACK) block, and the erector spinae plane block (ESPB) may improve analgesia while preserving quadriceps strength and modulating the systemic stress response.
METHODS
In this single-center, prospective, randomized, triple-blinded trial, 60 patients aged 65–100 years undergoing primary TKA under spinal anesthesia were allocated to receive either combined iPACK + ACB (20 mL of 0.2% ropivacaine for each block) or a two-level lumbar–sacral ESPB at L1 and S1 (20 mL of 0.2% ropivacaine at each level). The primary outcome was total opioid consumption within 48 h, expressed in morphine milligram equivalents (MME). Secondary outcomes included time to first rescue opioid, Numerical Rating Scale (NRS) pain scores, neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), and quadriceps strength (Medical Research Council scale).
RESULTS
Compared with two-level ESPB, iPACK + ACB significantly reduced total opioid consumption (9.7 ± 5.4 vs 12.9 ± 6.9 mg MME; p = 0.0348) and prolonged the time to first rescue opioid (9.3 ± 4.3 vs 8.5 ± 3.4 h; p = 0.0263). NRS scores were lower at 8 h (2.6 ± 0.8 vs 3.3 ± 0.7; p = 0.0037), with no relevant differences thereafter. NLR at 24 h was significantly lower with iPACK + ACB (2.20 ± 0.41 vs 2.61 ± 0.45; p = 0.0015), whereas PLR did not differ. Quadriceps strength remained preserved (MRC 5) in both groups.
CONCLUSION
In elderly patients with TKA, combined iPACK + ACB provides more effective, opioid-sparing analgesia and attenuates the early inflammatory response compared with two-level lumbar–sacral ESPB, without compromising quadriceps motor function. Trial registration: ClinicalTrials.gov Identifier: NCT06470542.