Gabapentoids in knee replacement surgery: contemporary, multi-modal, peri-operative analgesia.

Pain remains a significant barrier to rapid patient recovery and rehabilitation post-surgery, particularly after joint replacement surgery. Historically, protocols used for peri-operative pain management have been largely reactive and dependent on opioid use, with adjunctive non-steroidal and other simple analgesia. This review explores the evidence supporting the use of gabapentoids (eg. Lyrica®) in surgical fields, then in orthopaedics more specifically, and finally in the targeted domain of total knee replacement (TKR) surgery. The concept of 'pre-emptive' analgesia is also explored. Gabapentoids have shown clinical value in reducing the patient-reported pain experience and also decreasing concurrent opioid requirements in the post-surgical period in a number of surgical areas, however there remains no consensus for their optimal use in patients undergoing knee arthroplasty. Reported adverse effects including sedation and potential respiratory depression should herald some caution, and monitored use in 'at risk' patient groups. There have been a small number of clinical trials conducted around the use of gabapentoids in TKR, however the validity and generalisability of these results have been limited by small sample sizes, and cross-study analysis is confounded by adoption of inconsistent analgesic protocols, non-comparable dosing regimes, poor (or absent) control selection, and cohort heterogeneity. High-quality trials are needed to allow the role of gabapentoids in multi-modal peri-operative analgesic pathways to be better defined, to permit wider endorsement for main-stream or standardised care.