Effects of multi-site infiltration analgesia on pain management and early rehabilitation compared with femoral nerve or adductor canal block for patients undergoing total knee arthroplasty: a prospective randomized controlled trial

The aim of this study was to combine intra-articular and peri-articular with wound infiltration analgesia (multi-site infiltration analgesia, MIA) for patients undergoing total knee arthroplasty (TKA) and compare its pain management and early rehabilitation effect with the commonly used nerve block including adductor cannel block (FNB) and femoral nerve block (ACB).

We conducted a prospective randomized controlled trial and 77 patients were included for analysis. The patients were randomized over three groups. The first group (26 patients) received multi-site infiltration analgesia (MIA group), the second group (27 patients) received femoral nerve block (FNB group), and the third group (24 patients) received adductor cannel block (ACB group).

MIA showed better pain control at rest during the first 12 hours (p < 0.05 respectively) and less opioid consumption after operation than the other two groups (p < 0.05, respectively), but ACB and FNB revealed similar outcomes (p > 0.05). At the same time, there are no significant differences in pain score with activity, vital signs, and occurrence of complication (p > 0.05, respectively) among the three groups. When evaluated the early rehabilitation, MIA and ACB had similar outcomes on post-operative muscle strength (p > 0.05), but they showed better quadriceps strength when compared FNB (p < 0.05). Although the knee ROM of the patients with FNB showed better results (p < 0.05), their ambulation ability was inferior to those in MIA group (p < 0.05 and ACB group (p < 0.05) early after the operation, besides, MIA patients were superior to ACB patients (p < 0.05). Furthermore, MIA spent less time on operation and post-operative hospital stays when compared with FNB and ACB (p < 0.05, respectively), while the ACB and FNB were without significant difference (p < 0.05, respectively).

ACB was not inferior to FNB on pain control, but it was better on early mobilization. However, MIA that combine intra-articular and peri-articular with wound infiltration analgesia after TKA was more effective on pain control at rest, with better efficacy on early rehabilitation and easier to perform when compared with these commonly used nerve block. We recommended our MIA for pain relief and fast rehabilitation after TKA.