The Impact of Gabapentinoids on Pain-Related Outcomes after Knee and Hip Surgery: A Systematic Review with Meta-Analysis of Randomized Controlled Trials

Background: Postoperative pain remains a significant challenge after knee and hip surgeries, two of the most frequently performed procedures, preventing patients from seeking timely surgical help. Gabapentinoids, gabapentin, and pregabalin, have been gaining attention in postoperative pain management. Methods: We conducted a meta-analysis to evaluate the efficacy of gabapentinoids in pain management after knee and hip surgery. PubMed, Scopus, and Cochrane Library were searched for relevant randomized controlled trials (RCTs) published before January 2023. Results: Fifteen articles reporting 1320 patients were analyzed. Cumulative pain intensity at rest and on movement was lower in the experimental group with the mean difference (MD) = -0.30 [-0.55,-0.05], p-value = 0.02, and MD = -0.41 [-0.68,-0.13], p-value = 0.004, respectively. However, the difference was not clinically meaningful and lacked statistical significance at each time period. The gabapentinoid group required less opioid consumption in morphine equivalents (MD = -6.42 [-9.07, -3.78] mg, p-value < 0.001). There was a lower incidence of postoperative nausea in the experimental group with a risk ratio (RR) of 0.69 [0.55, 0.86], p-value < 0.001. A subgroup analysis showed that gabapentinoids reduced pain on movement on postoperative day two after total knee arthroplasty but not hip arthroplasty. There was insufficient data to examine the efficacy of gabapentinoids in the reduction of chronic postoperative pain in knee/hip surgery. Conclusions: Thus, gabapentinoids were associated with a reduction in postoperative pain intensity at rest and on movement, morphine consumption, and the incidence of postoperative nausea in the early postoperative period following knee and hip surgeries. However, pain reduction was not clinically relevant. Sedation has not been evaluated in this work and, if performed, this may have influenced the conclusions. An important limitation of this study is that different gabapentinoids, their administration times and dosages, as well as varying intraoperative management protocols, were pooled together.