Ultrasound-guided genicular nerves block: an analgesic alternative to local infiltration analgesia for total knee arthroplasty

Abstract

BACKGROUND Standard analgesic strategies for total knee arthroplasty employ local infiltration analgesia. Blockade and radiofrequency ablation of the genicular nerves are effective treatments for patients with chronic pain because of knee osteoarthritis. OBJECTIVE To test the noninferiority of the analgesic effect of genicular nerves block in comparison with local infiltration analgesia after 24 h of total knee arthroplasty. DESIGN Prospective cohort study. SETTING Perioperative setting. PATIENTS Thirty-five patients scheduled for total knee arthroplasty were prospectively included in the study and compared with 35 patients in a retrospective cohort. INTERVENTION Genicular nerve blocks in the prospective cohort were compared with local infiltration analgesia in the retrospective cohort. MAIN OUTCOME MEASURES The pain numeric rating scale and the cumulative opioid consumption in oral morphine equivalents during the first 24 h. RESULTS We conducted propensity score-matched analyses of patients using acute postoperative pain-related risk covariates. After one-to-one propensity score matching, 21 patients were included in the local infiltration analgesia group and 21 in the genicular nerve block group. The median difference in numeric rating score at rest at 24 h was −0.99 [95% confidence interval (CI), −1.99 to 0.5, P = 0.012] on the unmatched cohort and −1.9 (95% CI, −2 to 0, P = 0.002) on the matched cohort (meeting the noninferiority criteria, Δ=1). The median difference in cumulative opioid consumption was 2.5 mg (95% CI, −13.5 to 2.5, P < 0.001) for the unmatched cohort and 4.99 mg (95% CI, −11.5 to 2.5, P < 0.001) on the matched group (meeting the noninferiority criteria, Δ = 21 mg). CONCLUSION Local infiltration analgesia and genicular nerve block are comparable in terms of analgesic results. Therefore, genicular nerves block is an alternative to local infiltration analgesia in patients undergoing total knee arthroplasty. TRIAL REGISTRATION Clinicaltrials.gov identifier: NCT04024319.

Ultrasound‐guided genicular nerves block vs. local infiltration analgesia for total knee arthroplasty: a randomised controlled non‐inferiority trial

“…This limit is below the clinician‐perceived minimal clinically important difference recently reported by Laigaard et al. [10, 16, 25, 26]. Likewise, it has been suggested recently that quality of recovery measurement should be performed routinely [27].…”

“…The absence of clinical overt foot drop was particularly important, despite using somewhat larger volumes than previously described in the chronic pain setting (4 ml vs. 0.5–1 ml per nerve). Though reassuring, our study was not designed to detect a postoperative block of the common fibular nerve, so our results must be interpreted with caution [10, 20]. To that end, considering how problematic foot drop is in the context of total knee arthroplasty, caution is advised not to exceed local anaesthetic volume and to discuss with the surgical team any clinical signs of foot drop.…”

“…A 22‐gauge, 50‐mm needle (Stimuplex Ultra 360, B Braun Medical AG, Melsungen, Germany) was inserted using an out‐of‐plane technique as described by Pietrantoni et al. [10]. In contrast to the classic approach, five nerves (superior medial; superior lateral; inferior medial; inferior lateral; and recurrent tibial genicular branches) were infiltrated with 20 ml ropivacaine 0.2% with adrenaline 10 μg.ml −1 (4 ml per nerve) (Fig.…”

“…If the genicular arteries were not visualised, bone and muscular structures were used as anatomical landmarks, and the needle was placed against the bony surface. These structures were (in relation to each nerve) [10]: between vastus medialis and femoral periosteum, just cranial to the medial femoral condyle for the superior medial genicular nerve; between vastus lateralis and femoral periosteum, just cranial to the lateral femoral condyle superior lateral genicular nerve; medial and lateral sides of tibial tuberosity for the inferior medial and the recurrent tibial genicular nerves, respectively; and cranial to fibular head, in contact with the tibial periosteum for the inferior lateral genicular nerve.…”

“…Ultrasound-guided genicular nerves block is a technique that has been effectively used for a variety of chronic knee pain conditions and is a promising analgesic technique in surgical and acute pain settings [7,8]. It provides analgesia by selectively targeting sensory branches from the knee capsule but, unlike LIA, allows a reduction in local anaesthetic volume by depositing it near the genicular nerves under ultrasound guidance (150 ml vs. 20 ml) [9][10][11][12][13].…”