MULTIMODAL ANALGESIA IN TOTAL KNEE ARTHROPLASTY

Purpose: After surgeons at a regional centre for orthopaedics began to use a simplified version of multimodal analgesia protocol in total knee arthroplasty (TKA), using intra-operative periarticular infiltration of bupivacaine and epinephrine, it was decided to review which methods of anaesthesia and analgesia were being used in the unit and how effective these were in terms of postoperative analgesic requirements and patient mobility. Methods: A retrospective casenote review was conducted of 67 consecutive patients undergoing primary TKA. Data were collected in the areas of demographics, anaesthetic analgesia, mobility and length of stay. Results: Of 67 patients, 31 received periarticular local anaesthetic, 23 underwent femoral nerve block and 13 had neither. Patients who had the periarticular injection required significantly less morphine. In addition, length of stay was shorter and mobility was achieved sooner in these patients. Discussion: Our technique of periarticular injection is the simplest to be described to date, using injection of bupivacaine and epinephrine alone. Unlike most previous studies, we have shown a significant improvement in postoperative mobility and a reduction in length of hospital stay, as well as confirming previous findings of a reduction in the use of opioids. This study also confirms the efficacy of bupivacaine in periarticular injections, as most previous trials have used ropivacaine, and shows that the technique is practical for use in an NHS orthopaedic unit. Conclusion: This study has described the use of a simple technique of analgesia by periarticular injection, which has reduced the amount of opiate analgesia required postoperatively, as well as showing benefits in mobility and length of hospital stay.