The effects of adding local infiltration analgesia of the knee to a multimodal pain protocol for total arthroplasty: A matched pair retrospective study

Background: We hypothesize that the addition of local infiltration analgesia (LIA) to a multimodal pain protocol will reduce the total amount of opioids consumed for acute pain control post total knee arthrolplasty (TKA). Methods: This study was a retrospective, matched pair study including patients who had primary TKA. All patients included in the analysis had preoperative oral celecoxib and acetaminophen, had single-dose spinal anesthetic with intrathecal morphine, and had intravenous patient-controlled analgesia with an opioid agent in addition to gabapentin and celecoxib in the first 48 h. Patients whose charts were excluded from the study had revision TKA, received opioid therapy prior to the surgery, were classified as American Society of Anesthesiology (ASA) IV, and had general anesthesia. Fifty patients who underwent TKA and had LIA were matched for age, body mass index (BMI), and gender with patients who did not receive LIA. The primary outcome measures were total doses of opioids consumed post TKA. Results: Patients receiving LIA consumed on average significantly less intravenous (IV) morphine equivalents than patients not receiving LIA, with a mean difference (±SD) of 88.9 ± 15.6 mg IV morphine equivalents. Furthermore, pain control was better in the LIA group. The incidences of nausea and vomiting, pruritis, and excessive sedation were higher in the non-LIA group compared to the LIA group. There was no difference in the hospital length of stay between both groups. Conclusions: The addition of LIA to our multimodal pain protocol for TKA was associated with a reduction in total opioid consumption.