Abstract
Objectives:
Pre- and Peri-Operative nerve blocks are traditionally administered by the anesthesia team as an adjunctive for operative pain management. Providing safe and effective peri-operative pain control helps to limit narcotic use by patient, postoperative nausea and improves post-operative patient flow through the PACU. Recently, there have been significant advancements in perioperative nerve blocks, local anesthesia, and multi-modal pain regimens to improve patient comfort and reduce reliance on opiate pain medications. Infiltration of 10 mL mixture of 30mL of 0.5% Marcaine, 20mL of 0.9% Normal Saline, 1mL of Morphine 10mg/1mL, and 1mL of Toradol 30mg/1mL between the popliteal artery and capsule of the knee or IPACK block has been described as a motor sparring nerve block which can provide effective analgesia following knee surgery and serve as an adjunct to commonly used adductor canal or femoral nerve blocks. We have recently reported on a posterior knee capsular block technique administered under direct arthroscopic visualization, intra-operatively by the orthopedic surgeon providing coverage identical to a traditional ultrasound guided Infiltration Between Popliteal Artery and Capsule of the Knee (IPACK Block). We have devised a simple, and reproducible technique for intraoperative, arthroscopic administration of local anesthetic in the space directly posterior to the knee capsule. This technique has been implemented by sports medicine orthopedic surgeons at our institution over the past couple of years. While the practice anecdotally seems to have improved post operative pain control in our patients, the safety and efficacy have not been formally studied. The purpose of this study is to investigate the effect of this practice on the post operative pain control as well as identify any adverse events over the period that this block was added to our standard practice.
Methods:
Electronic medical records of patients undergoing primary anterior cruciate ligament (ACL) reconstruction by three fellowship-trained sports medicine surgeons at our institution between March 2019 and February 2022 were retrospectively reviewed. Patients were included if they underwent primary arthroscopic assisted ACL reconstruction with or without concomitant meniscus procedure, chondroplasty, or microfracture. Patients who underwent revision ACL reconstruction, multi-ligament reconstruction, a concomitant realignment osteotomy, or a concomitant osteochondral allograft or meniscus allograft transplantation were excluded. Patients were divided into two groups according to the receival of arthroscopic IPACK block. All patients received a nerve block, but no patients received an IPACK done in the preoperative setting with anesthesia, any anesthesia IPACK block performed was in the PACU as a rescue block. The primary outcome was the need for a postoperative rescue nerve block. The secondary outcome was the incidence of complications related to the surgeon-directed IPACK block
Results:
Three hundred and twenty-five patients were included. Among them, 117 received the IPACK block and 208 did not receive it. There was no statistically significant difference in patient’s age and gender between the groups. There was a trend towards more rescue blocks in patients who did not receive the IPACK block compared to those who receive it (10.5% vs 6.8% respectively, p=0.264), and this trend reached the statistical significance when we looked at a subgroup of patients who received concomitant meniscus repair (17.4% vs 4.7% respectively, p=0.017). Logistic regression analysis showed that IPACK block decreased the risk of receiving a rescue block by approximately 50%. No complications related to IPACK block were reported.
Conclusions:
Implementing the arthroscopic assisted IPACK block reduced the need for postoperative rescue block in patients undergoing primary ACL reconstruction, and more significantly in those who had concomitant meniscus repair. It is a safe procedure with no reported complications or adverse events in our cohort. Implementation of the block adds very little time or cost to the surgical procedure. It has the potential to improve postoperative pain control, decrease reliance on postoperative opiate medications, facilitate early rehabilitation, and contribute to overall patient satisfaction after surgery.
