Adductor Canal Block v. Bupivacaine for Total Knee Arthroplasty

Researchers from New York have examined the role of the adductor canal block in total knee arthroplasty (TKA).

Their study “Adductor Canal Block Compared with Periarticular Bupivacaine Injection for Total Knee Arthroplasty: A Prospective Randomized Trial” appears in the July 2018 edition of The Journal of Bone and Joint Surgery.

According to the study authors, “One hundred and fifty-five patients undergoing primary total knee arthroplasty under spinal anesthesia were randomized to 1 of 3 groups: ACB [Adductor Canal Block] alone (15 mL of 0.5% bupivacaine), PAI [peri-articular injection] alone (50 mL of 0.25% bupivacaine with epinephrine), and ACB+PAI.”

“The primary outcome in this study was the visual analog scale (VAS) pain score in the immediate postoperative period. Secondary outcomes included postoperative opioid use, activity level during physical therapy, length of hospital stay, and knee range of motion.”

“This randomized controlled clinical trial demonstrated significantly higher pain scores and opioid consumption after total knee arthroplasty done with an ACB and without PAI, suggesting that ACB alone is inferior for perioperative pain control. There were no significant differences between PAI alone and ACB+PAI with regard to pain or opioid consumption.”

Co-author, Matthew Grosso, M.D., with the Center for Hip and Knee Replacement, Columbia University Medical Center, New York, New York told OTW, “Pain control in total knee arthroplasty is continually evolving. Changes in the last decade have led to decreased pain, shorter length of hospital stay, faster return to activity, and overall improved outcomes.”

“However, there is still controversy regarding the optimal multimodal pain management strategy. Both adductor canal blocks and PAIs have gained popularity for reducing pain in the perioperative period. In this study, we wanted to determine which of these pain management strategies was more powerful, and whether there was any benefit to combining them.”

“We found that adductor canal block alone (without a peri-articular injection) was least effective in controlling pain and reducing opioid consumption. This suggested that periarticular injections are very effective in managing post-operative pain following TKA, and should be used in almost all cases.”

“There seemed to be a small benefit from combining adductor canal blocks with a peri-articular injection, although the results were not statistically significant.”

“Peri-articular injections are an effective method for improving perioperative pain control and should be used as standard practice in TKA. This will result in decreased pain and reduced opioid consumption for patients in the post-operative period. Adductor canal blocks can be considered as an adjunct to PAIs, but not as a stand-alone treatment.”

“Peri-articular injections and adductor canal blocks should be part of the standard discussion with patients regarding multimodal pain management following TKA. Patients should be counseled that utilizing peri-articular injections or adductor canal blocks with peri-articular injections will result in more comfort following surgery. This will allow them to take less opioid medication and have higher activity levels in the postoperative period.”