Comparison of the ultrasound-guided single-injection femoral triangle block versus adductor canal block for analgesia following total knee arthroplasty: a randomized, double-blind trial.

PURPOSE: The aim of the study is to compare the femoral triangle (FT) and adductor canal (AC) blocks in terms of the analgesic efficacy and ambulatory outcomes in the context of multimodal analgesia following total knee arthroplasty (TKA).

METHODS: Patients presenting for TKA were assigned to a preoperative ultrasound-guided single-injection FT or AC block. Combined spinal and epidural anesthesia with bupivacaine was administered for TKA. Perioperatively a multimodal analgesic regimen was applied up to 48 h after surgery. The primary outcome was the average pain score during movement in the first 24 h postoperatively. The secondary outcomes included pain scores at rest and during movement at postoperative predetermined time points, cumulative opioid consumption in oral morphine equivalents, functional mobility measured by the timed "Up and Go" (TUG) test and muscle strength in the lower extremity.

RESULTS: Ninety-eight patients completed the study. Patients in the FT group had lower median pain scores during movement in the first 24 h postoperatively than those in the AC group (1.3 [1.0-3.3] vs. 3.0 [1.7-4.3]; median difference: - 1.0, adjusted 95% CI from - 1.7 to - 0.3, P = 0.010). There were significant differences in the pain scores at rest and during movement at 12 and 24 h postoperatively between the two groups (P = 0.008 and 0.005, respectively). Cumulative oral morphine equivalent consumption in the first and second 24 h postoperatively, Functional mobility reflected by the TUG test and muscle strength in the lower extremity showed no significantly statistically differences between the two groups.

CONCLUSIONS: The preoperative FT block provided improved analgesic outcomes without compromising functional mobility in the context of multimodal analgesia following TKA compared with the AC block.

TRIAL REGISTRATION: https://www.chictr.org.cn . Identifier: ChiCTR-INR-17012716.