Can local infiltration analgesia increase satisfaction in postoperative short-term pain control in total knee arthroplasty?

BACKGROUND: One of the major challenges to total knee arthroplasty (TKA) is optimal pain control. Effective analgesia is capital in fast-track surgery programs to allow patient's early functional outcomes.

OBJECTIVES: Compare length of stay (LOS) short-term pain control, and patients' satisfaction at 1 month between local infiltration analgesia (LIA) combined with femoral nerve block (FNB) and FNB only in patients undergoing TKA.

PATIENTS AND METHODS: Two hundred and fifty-four patients were included in a randomized prospective study and distributed in two groups. The first group received an intraoperative LIA (150 mL mixture of ropivacaine 2.0 mg/mL + ketorolac 30 mg + adrenaline 10 μg/mL) combined to an FNB. The control group had only an FNB. Demographical data and visual analog scale (VAS) score were obtained preoperatively, at 36 h after surgery and at the 15-day follow-up. Patients' satisfaction at 1 month was also evaluated. Statistical analysis data was performed.

RESULTS: No differences in demographical data and preoperative VAS score were observed between both groups. LIA group had a lower VAS score at 36 h after surgery (1.34 ± 1.31 vs. 3.68 ± 1.932 in the control group, p = 0.00), but these differences were not maintained at the 15-day follow-up (4.51 ± 1.889 vs. 4.11 ± 1.940 in the control group, p > 0.05). LOS and patients' satisfaction were comparable between groups. Patients with LIA had no additional complications.

CONCLUSIONS: LIA is a safe adjuvant to FNB to reduce perioperative pain during the first 36 h after TKA. Its effects wean with time, but do cover the first crucial hours of rehabilitation in a fast-track program. LIA seems don't modify postoperative course nor patient's satisfaction at short-term follow-up. The final impact of LIA on surgical outcome is still to be determined.