Local infiltration vs epidural analgesia for postoperative pain control after total knee or hip arthroplasty: A meta-analysis of randomized controlled trials.

BACKGROUND Inconsistent results have been obtained regarding postoperative pain control using local infiltration and epidural analgesia for patients after total knee or hip arthroplasty (TKA and THA). We therefore conducted a meta-analysis of randomized controlled trials (RCTs) to assess the efficacy and safety of local infiltration vs epidural analgesia for TKA and THA. METHODS Electronic searches were conducted on PubMed, EmBase, and the Cochrane library to identify eligible RCTs conducted up to February 2020. Weighted mean difference (WMD) and relative risk with 95% confidence interval (95%CI) were applied to calculate pooled effect estimates between local infiltration and epidural analgesia using the random-effects model. RESULTS Seven RCTs including a total of 412 TKA patients, and three RCTs including a total of 200 THA patients were selected for this meta-analysis. We noted that local infiltration was associated with lower visual analog scale (VAS) scores at rest after 48 hours (WMD: -1.31; 95%CI: -2.44 to -0.18; P = .024) and 72 hours (WMD: -0.95; 95%CI: -1.39 to -0.52; P < .001) for patients with TKA, while local infiltration significantly reduced VAS scores at rest after 12 hours for patients with THA (WMD: -1.00; 95%CI: -1.49 to -0.51; P < .001). Moreover, local infiltration was associated with lower VAS scores during movement after 48 hours in TKA patients (WMD: -1.08; 95%CI: -1.86 to -0.29; P = .007), while there were higher VAS scores during movement after 24 hours for patients with THA (WMD: 1.06; 95%CI: 0.67 to 1.45; P < .001). Furthermore, we noted that local infiltration was associated with higher flexion angles compared with epidural analgesia after 24 hours (WMD: 7.11; 95%CI: 2.30-11.93; P = .004), 48 hours (WMD: 6.69; 95%CI: 3.78 to 9.59; P < .001), and 72 hours (WMD: 5.19; 95%CI: 0.95-9.44; P = .016). There were no significant differences between local infiltration and epidural analgesia for the length of hospital stay, nausea, or wound infection. CONCLUSIONS Local infiltration is superior to epidural analgesia for postoperative pain control after TKA, whereas for THA patients inconsistent results were obtained at various times.