Comparison of 2 Peripheral Nerve Blocks Techniques for Functional Recovery and Postoperative Pain Management After Total Knee Arthroplasty: A Prospective, Double-Blinded, Randomized Trial.

BACKGROUND Methods of pain management that have less effect on motor function after total knee arthroplasty (TKA) are needed to ensure early mobilization. We investigated whether the distal femoral triangle and distal adductor canal blocks are superior to the femoral nerve block regarding motor blockade at early postoperative hours. MATERIAL AND METHODS Patients scheduled for TKA under spinal anesthesia were blindly assigned into 2 groups. One group received the distal femoral triangle and distal adductor canal blocks and the other group received the femoral nerve block. In both groups, at 3, 6, 24, and 48 h after surgery motor blockade was evaluated with the Bromage scale. Secondary outcomes such as pain control efficacy and patient satisfaction were evaluated at 6, 24, and 48 h postoperatively using either the VAS scale or a 10-point scale. RESULTS We analyzed the outcomes of 77 patients. Better motor function at 3 and 6 h after TKA was observed in the distal femoral triangle and the distal adductor canal blocks group (37.7% vs 23.4%, p=0.032 and 49.4% vs 32.5%, p=0.002, respectively). At 24 h after the surgery, patients from the femoral nerve block group consumed significantly more rescue opioid analgesics (p=0.016). We found no significant differences in pain intensity and patient satisfaction at any timepoints after the surgery. CONCLUSIONS The distal femoral triangle and distal adductor canal blocks resulted in significantly better motor function at the first 3 and 6 h after total knee arthroplasty. At 24 h after surgery, rescue opioid doses in the femoral nerve block group were significantly higher.