High-volume local infiltration analgesia combined with intravenous or local ketorolac+morphine compared with epidural analgesia after total knee arthroplasty.

Background: Recently, high-volume local infiltration analgesia (LIA) in total knee arthroplasty (TKA) has been introduced, but dosage, timing, and effects of adjuvants are still debated.

Methods: We randomized 102 patients undergoing TKA to receive either epidural analgesia (EDA group) or LIA (ropivacaine 150 mg and epinephrine 0.5 mg) combined with ketorolac 30 mg and morphine 5 mg given either locally (LIA group) or i.v. (LIAiv group). Epidural analgesia was maintained for 48 h. Intra-articular re-injection via a catheter with ropivacaine 142.5 mg and either intra-articular or i.v. ketorolac 30 mg was given 24 h after surgery. Pain scores, morphine consumption, side-effects, and readiness for hospital discharge were studied.

Results: At discharge from the postoperative anaesthetic care unit, verbal pain scores were lower in the EDA group (P=0.004), but discharge was delayed [difference 101 min, 95% CI: (23, 178), P=0.007]. Group LIA reported lower pain scores at rest beyond 24 h after surgery [mean VAS (sd) at 24/48/72 h: LIA group 16/12/10 (14)/(13)/(11); LIAiv group 22/18/15 (17)/(15)/(12); EDA group 27/30/21 (21)/(29)/(19)]. Both the LIA and the LIAiv groups were mobilized faster and were earlier ready for hospital discharge [3.5 days (LIA group) vs 4 days (LIAiv group) vs 5.5 days (EDA group); P<0.001]. Cumulated morphine consumption (72 h) was lowest for the LIA group [80 vs 101 mg (EDA group) vs 118 mg (LIAiv group), P=0.007].

Conclusions: LIA with local adjuvants compared with epidural analgesia results in reduced opioid consumption, faster mobilization, and earlier readiness for hospital discharge. Ketorolac and morphine are more efficient when given locally than systemically. The study has been registered at clinicaltrials.gov (NCT00562627) before onset of participant enrolment: http://clinicaltrials.gov/ct2/show/NCT00562627?term=spreng&rank=2 (April 21, 2010).