Pain management after total knee arthroplasty: A prospective randomized study

Total knee arthroplasty (TKA) is a common procedure for improving mobility and quality of life in patients with osteoarthritis. Postoperative pain control management after TKA is still a concern as it relates to patients satisfaction and functional recovery.Many anesthetic regimens and techniques have been explored to decrease postoperative pain and enhance the fast recovery after TKA. The aim of this study was to evaluate the best anesthetic treatment in pain control after TKA.

51 patients were included in a randomized prospective study and distributed in three groups. The first group (CG) in which no analgesic protocol was implemented (control group). The second group (LIA group) received an intraoperative local infiltration anesthesia (LIA) (60 ml mixture of two ropivacaine 75mg/10 mL + adrenaline 100μg/10 mL + physiological solution). The third group (FNB group) had only a femoral nerve block (FNB). Continuous outcomes including visual analogue scale (VAS) at 5,24,48 h and at 1 week, morphine consumption and range of motion (ROM) at 1,2,7 days.

There was significant difference between all groups (p < 0,001) in terms of the VAS score: at 5h after surgery (4.55,2.15,1.82); at 24h (4.15,2.65,3.36); at 48h (3.85,2.45,2.73); at 1 week (2.95,1.80, 1.64), respectively for groups CG, LIA, FNB.ROM was better in LIA and FNB groups than CG: at 1 die after surgery (44°,50°,54°); at 3 dies (69°,70°,71°); at 7 dies (91°,98°,98°), respectively for groups CG, LIA, FNB (p < 0,001).

LIA and FNB groups both showed a significant reduction at VAS score, better range of motion and less morphine consumption than CG (control group). LIA group has obtained a constant pain control in the postoperative days; FNB group had a good pain control in the hours after surgery, with a decrease in efficacy in the following days.

Further studies are still needed in order to define LIA as the reference pain management in TKA.