Gonyautoxins 2/3 Local Periarticular Injection for Pain Management after Total Knee Arthroplasty: A Double-Blind, Randomized Study

The purpose of this study was to compare the efficacy of periarticular infiltration of gonyautoxin 2/3 (GTX 2/3) and a mixture of levobupivacaine, ketorolac, and epinephrine for pain management after total knee arthroplasty (TKA). Forty-eight patients were randomly allocated to receive periarticular infiltration of 40 µg GTX 2/3 (n = 24) diluted in 30 mL of sodium chloride 0.9% (study group) or a combination of 300 mg of levobupivacaine, 1 mg of epinephrine, and 60 mg ketorolac (n = 24) diluted in 150 mL of sodium chloride 0.9% (control group). Intraoperative anesthetic and surgical techniques were identical for both groups. Postoperatively, all patients received patient-controlled analgesia (morphine bolus of 1 mg; lockout interval of 8 minutes), acetaminophen, and ketoprofen for 72 hours. A blinded investigator recorded morphine consumption, which was the primary outcome. Also, the range of motion (ROM) and static and dynamic pain were assessed at 6, 12, 36, and 60 hours after surgery. The incidence of adverse events, time to readiness for discharge, and length of hospital stay were also recorded. The median of total cumulative morphine consumption was 16 mg (range, 0–62 mg) in the GTX 2/3 group and 9 mg (range, 0–54 mg) in control group, which did not reach statistical difference (median test, p = 0.40). Furthermore, static and dynamic pain scores were similar at all time intervals. GTX 2/3 was inferior in range of motion at 6 and 12 hours; nevertheless, we noted no difference after 36 hours. No differences between groups were found in terms of complications, side effects, or length of hospital stay. No significant differences were found between groups in terms of breakthrough morphine requirement. However, local anesthetic use resulted in an increased ROM in the first 12 hours. This prospective randomized clinical trial shows that GTX 2/3 is a safe and efficient drug for pain control after TKA; nevertheless, more studies using GTX 2/3 with larger populations are needed to confirm the safety profile and efficiency. This is level 1 therapeutic study, randomized, double-blind clinical trial.

Effectiveness of Periarticular Infiltration of the Knee during Total Knee Arthroplasty for Postoperative Pain Management

Background: Different treatment regimens of analgesia, nerve blocks and epidurals are used for pain relief in Total Knee Arthroplasty (TKA). Local infiltration analgesia (LIA) is one of the modalities in which a cocktail combination of different medicines is infiltrated locally into the capsule, surrounding tissues or intraarticular joint space. This study aims to analyze the effectiveness of periarticular injection of combination drugs (Bupivacaine, Ketorolac and Morphine) during TKA for postoperative pain management. Methods: Total of 150 patients who underwent primary unilateral TKA were randomly categorized into 2 groups (75 each). Group A (control group) didn’t receive intraoperative periarticular injection but Group-B received the intraoperative injection of combined local analgesics and anaesthetics (Bupivacaine, Ketorolac and Morphine). Pain following surgery at 0, 1, and 2 postoperative days were recorded with visual analogue scale (VAS) whereas Knee Society Score was used to evaluate the pain and function pre-operative and 3 months’ post-operative. Statistical analysis was done using SPSS software. Results: Patients receiving periarticular infiltration of combination drugs intraoperatively had lower VAS for postoperative pain (p < 0.001) and this group also showed reduced need of analgesia postoperatively. Conclusions: Periarticular infiltration of knee during Total Knee Arthroplasty is effective in management of postoperative pain Keywords: Periarticular; Total Knee Arthroplasty; combination drugs; postoperative pain

Comparison of Periarticular Infiltration and Combination Delivery of Local Anesthetics for Reducing Pain and Opioid Consumption after Total Knee Arthroplasty

Surgical-site delivery of local anesthetics decreases pain and opioid consumption after total knee arthroplasty (TKA). The optimal route of administration is unknown. We compared local anesthetic delivery using periarticular soft-tissue infiltration to delivery using a combination of preimplantation immersion and intra-articular injection (combination treatment). The records of patients who underwent unilateral, cemented, primary TKA with spinal anesthesia and adductor canal blocks at a single Veterans Affairs Medical Center were retrospectively reviewed. Three subgroups were compared, including controls who did not receive additional local anesthetics, patients who received periarticular infiltration, and patients who received combination treatment. Mean daily pain scores and mean 24-hour opioid consumption on postoperative days (PODs) 0 and 1 were calculated, and analysis of variance was used to assess for significant differences. Factors that were associated with lower pain scores and opioid consumption were then identified using multivariate stepwise regression. There were 26 controls, 25 periarticular infiltration patients, and 39 combination patients. The periarticular infiltration cohort had significantly lower mean pain scores and opioid consumption than controls on POD 0, but not on POD 1. The combination cohort had significantly lower mean pain scores and opioid consumption than controls on PODs 0 and 1. There were no significant differences between the infiltration and combination groups on either day. Multivariate regression analysis showed that infiltration was associated with significantly decreased opioid consumption on both days and decreased pain on POD 0. Combination treatment was associated with significantly decreased pain and opioid consumption on both days. Both local anesthetic periarticular infiltration and combination treatment are associated with decreased pain and opioid consumption after TKA. The stronger effects of the combination treatment compared with periarticular infiltration on POD 1 suggests that combination delivery may have a longer duration of action.