Effect of multiple analgesic pathways including local infiltration analgesia, peripheral nerve blocks, and intrathecal morphine for controlling pain after total knee arthroplasty

Background We questioned whether the triple analgesic pathways procedure via local infiltration analgesia (LIA), peripheral nerve blocks, and intrathecal morphine (ITM) is superior to LIA only for controlling pain after Total Knee Arthroplasty (TKA). Methods This retrospective study included 192 primary TKA patients. Group A (76 patients) received LIA only, Group B (61 patients) had ITM, adductor canal block and LIA, while Group C (55 patients) received ITM, femoral nerve block and LIA. A propensity score-matched analysis was used to compare visual analog scales (VAS) for pain intensity, total amount of morphine consumption (TMC), angle of knee flexion, and length of hospital stay (LHS). Results Group A showed significantly higher VAS than Group B at 12 h (4.27 +/- 2.70 vs 2.42 +/- 2.35) and 18 h (4.24 +/- 2.35 vs 2.18 +/- 2.02), and significantly higher than Group C at 6 h (3.46 +/- 3.07 vs 0.60 +/- 1.50), 12 h (4.27 +/- 2.70 vs 0.89 +/- 1.48), and 18 h postoperative (4.24 +/- 2.35 vs 1.82 +/- 2.18). However, the VAS of Group C and B converged to equalize with Group A after 12 and 18 h, respectively. The TMC at 48 h postoperative of Group A was higher than that of Group B (p < 0.01). Nevertheless, there was no difference between groups in terms of knee flexion and LHS, except the LHS of Group B was longer than Group A (p = 0.04). Conclusion Triple analgesic pathways could provide a better initial analgesic profile. However, the pain seems to be rebound after resolution of nerve block and ITM, with potentially longer LHS.