Abstract

The target of the present study is dual. First, to test the hypothesis of combined nerve block addressing different sites of nerve course can result in more successful distribution and prolongation of block whenever lower concentration local anesthetic mixture is used. Secondly to compare effectiveness of combined Adductor Canal and i-PAK Blocks versus Combined Adductor Canal and Periarticular Injection Blocks for ameliorating postoperative ACL Reconstruction Surgery pain.

Material and methods: The study is a Prospective, randomized cohort study: After IRB (Institutional Review Board) and committee approval was obtained, Patients aged 18-75years undergoing ACL Reconstruction Surgery over the period of one year and included 246 patients which were randomly allocated to either Combined Adductor Canal and i-PAK Blocks (group A), or Combined Adductor Canal and Periarticular Injection Blocks (group B) groups, each had 123 patients at the end of the study. Informed consent for this study was taken from the patient. This is a scientific abstract with no patient protected health information. A standard local anesthetic mixture was used throughout the study. The mixture of Ropivacaine 3.75% with 4mg of dexamethasone in a total volume of 42ml of mixture. There is no off-label medications included. No promotional content of a commercial entity is included (brand/trade/product names, photos, logos, company names, etc.).

Results: This study of the U/S guided comparison of combined Adductor Canal and i-PAK Blocks versus Combined Adductor Canal and Periarticular Injection Blocks For ACL Reconstruction Surgery demonstrates that of combined Adductor Canal and i-PAK Blocks results in prolongation of the time before request for first analgesia rescue (h) (statistically significant) indicated by higher readings in group A compared to group B .

Statistically significant difference was also observed comparing the two groups concerning the total pethidine consumption (mg) in the first 48 post-operative hours with much reduction of the total dose in group A together compared to group B.

Postoperative VAPS at rest and on walking were reduced after of combined Adductor Canal and i-PAK Blocks at all-time points assessed compared to group B.

Discussion: The combination of distal blocks is having the advantage of being safer approach away from critical structures and allows preservation of proximal muscle function. The inability to move due to the motor block of proximal and distal musculature has been shown to decrease patient satisfaction. Distal peripheral nerve blocks are superior at preserving motor function of the operative limb. A recent randomized controlled trial addressing this subject in the upper extremity (comparing ultrasound guided supraclavicular plexus block with distal peripheral nerve blocks for outpatient hand surgery) Showed better strength preservation and greater patient satisfaction with distal blocks. Using multiple points of blocking the nerves to reach the sensory terminals supplying the knee region with motor sparing effect can be achieved using lower anesthetic concentrations. Moreover, combined nerve block addressing different sites of nerve course targeting those which are mainly sensory can result in more successful analgesia and sparing of motor branches of mixed nerves. The validation of the present study results essentially requires further large RCT of adequate sample size.

Conclusion:This study reiterates the importance of tackling multimodal approach in regional techniques which probably will have a place in tailoring patient and surgical pain relief needs. The best approach should be tailored to suit specific surgery whenever possible. Combined Adductor Canal and i-PAK Blocks is better than Combined Adductor Canal and Periarticular Injection Blocks for ACL Reconstruction Surgery concerning postoperative pain.

Keywords

ACL, anterior cruciate ligament; FNB, femoral nerve block; ACB, adductor canal block, vastus medialis nerve, anesthetic, chronic narcotic, pethidine consumption, Periarticular Injection Blocks