P-029 - Is There Value in Using an Adductor Canal Catheter in Knee Arthroplasty? A Randomized Clinical Trial

Abstract Title: Is There Value in Using an Adductor Canal Catheter in Knee Arthroplasty? A Randomized Clinical Trial


Background: Total knee arthroplasty (TKA) is performed on approximately 800,000 patients annually in the U.S. (1), generally with excellent clinical outcomes (2). A key challenge with TKA is postoperative pain control for which oral analgesics, periarticular anesthetic injections, and local nerve blocks are often used (3,4). One strategy for prolonging the effect of nerve blocks is to insert an adductor canal catheter (ACC) that is attached to a reservoir of anesthetic solution with a pump that infuses the surgical area over a two-to-three-day period postoperatively. Despite the perceived logic of using the ACC and its very widespread use, its incremental effectiveness over routine periarticular injection has never been studied in a randomized trial, though the device is associated with considerable cost and inconvenience.

Purpose/Objectives: In an era of heightened awareness of the need to reduce low-value care in all aspects of medicine, assessment of the ACC is an archetypal example of the need to objectively study existing analgesic technologies and to re-evaluate the value of technologies as alternative clinical strategies evolve (5).


Methods: The ACC Effectiveness and Safety Study (ACCESS) was a randomized, open-label, two-arm, parallel-group noninferiority clinical trial of usual care with an ACC compared to usual care without an ACC among adult patients undergoing elective uncomplicated unilateral TKA; all patients received anesthetic periarticular injections during surgery (6). The noninferiority margin was established a priori by surveying orthopedists specializing in joint-replacement surgery; a consensus established the noninferiority margin as 2.0 points. Participants were randomized to the two treatment arms immediately prior to surgery; participants randomized to the ACC arm had their device implanted by an anesthesiologist according to usual clinical practice. Follow-up post-surgical outcomes were collected by a telephone call to participants on the second postoperative day and by a 15-day postoperative daily diary kept by participants. The primary outcome was the patient-reported pain level measured with the 11-level (0-to-10) numerical rating scale for pain on the second postoperative day. Secondary outcomes included daily pain scores for 15 days postoperatively, the daily and total number of oxycodone tablets consumed, hospital length-of-stay, and the frequency of "return-to-care" (emergency room visits and hospital readmissions) for the 7 and 30-day periods post-surgery.


Results: 126 patients were randomized in a 1:1 ratio to the two trial arms; 122 participants (97%) provided primary outcome data. The mean difference in pain scores on the second post-operative day (the primary outcome) was 1.06 points with a 95% confidence interval of 0.18 to 1.94; since the upper bound of this interval did not cross the predetermined noninferiority margin of 2.0 points, noninferiority was confirmed (p-value for noninferiority = 0.02). A mixed-effects regression model for 15-day pain scores showed the time-by-group interaction was significant (p = 0.04); a result that was not affected by adjustment for baseline demographics. There was no significant difference in the mean total number of opioid (oxycodone) tablets consumed over the 15-day postoperative period (46.0 tablets in the ACC-assigned group vs. 41.9 tablets in the non-ACC-assigned group, 95% CI for the difference: -18.0 to 9.7 tablets, p=0.55). There were no significant differences in hospital length-of-stay; same-day discharge occurred for 78% of all participants (48/63 (76.2%) in the ACC group and 50/63 (79.4%) in the non-ACC group, p=0.83). There was also no statistically significant difference in the frequency of return-to-care between the two study arms. Adjustment for baseline demographics did not alter these results.

Conclusions/Implications for future research and/or clinical care: We found that not using the ACC was noninferior to using the ACC, suggesting that the incremental benefit of the ACC was small and likely of insufficient magnitude to justify its routine use for patients undergoing TKA. Further trials may be helpful in defining the appropriate use of this costly technology (e.g., for particular subgroups); until such evidence becomes available, the value of the ACC for most patients remains in doubt. Other analgesic technologies that also lack high-quality evidence supporting their use should be subjected to similar tests of effectiveness and safety.


References: 1. American College of Rheumatology. Joint Replacement Surgery. https://rheumatology.org/patients/joint-replacement-surgery. Accessed January 23, 2024

2. Sloan, M., Premkumar, A. & Sheth, N. P. Projected Volume of Primary Total Joint Arthroplasty in the U.S., 2014 to 2030. J Bone Joint Surg Am 100, 1455–1460 (2018).

3. Kelley, T. C., Adams, M. J., Mulliken, B. D. & Dalury, D. F. Efficacy of multimodal perioperative analgesia protocol with periarticular medication injection in total knee arthroplasty: a randomized, double-blinded study. J Arthroplasty 28, 1274–1277 (2013).

4. Manickam, B. et al. Feasibility and efficacy of ultrasound-guided block of the saphenous nerve in the adductor canal. Reg Anesth Pain Med 34, 578–580 (2009).

5. Committee on the Learning Health Care System in America & Institute of Medicine. Best Care at Lower Cost: The Path to Continuously Learning Health Care in America. (National Academies Press (US), Washington (DC), 2013).

6. Kaiser Permanente. An Open-Label Randomized Noninferiority Clinical Trial of the Adductor Canal Catheter for Pain Control Post-Total Knee Arthroplasty. https://clinicaltrials.gov/study/NCT04639128 (2023).