Background and aims Retrospective data and prior studies suggest a synergistic analgesic effect of an adductor canal blockade (ACB) added to local infiltration analgesia (LIA) compared to LIA alone. Our hypothesis was that physical therapy (PT) milestones would be reached earlier with ACB + LIA than LIA alone.

Methods After IRB approval, patients scheduled for unilateral primary TKA were randomized to receive either ACB or a sham block (saline) in addition to the LIA administered by the surgeon. Exclusion criteria included significant systemic disease, substance abuse and chronic pain. Spinal anesthetic and postoperative pain management were standardized. ACB was performed at the mid-thigh level with 30 mL of 0.25% bupivacaine with 1:200,000 adrenaline. LIA was performed by the surgeon using bupivacaine, ketorolac, adrenaline and morphine, as well as liposomal bupivacaine.

Data collected included passive and active ROM of the knee in flexion and extension; 2-minute walk test; total distance ambulated on the day of surgery and the first and second post-operative days; and pain NVS before, during and after physical therapy sessions.

Results Preliminary results of 63 patients out of 150 planned are reported. Pain scores, measured as an AUC for the initial 48 hours, were not different between groups. However, total distance ambulated and 2-minute walk tests were lower in the group that received the ACB in addition to LIA at each of the time points.

Conclusions While these interim results remain to be confirmed, the data suggest that LIA alone is preferable to LIA + ACB.