Comparison of peri- and intraarticular analgesia with femoral nerve block after total knee arthroplasty: a randomized clinical trial.

BACKGROUND: Postoperative pain after total knee arthroplasty (TKA) can be difficult to manage and may delay recovery. Recent studies have suggested that periarticular infiltration with local anesthetics may improve outcome.

METHODS: 80 patients undergoing TKA under spinal anesthesia were randomized to receive continuous femoral nerve block (group F) or peri- and intraarticular infiltration and injection (group I). Group I received a solution of 300 mg ropivacaine, 30 mg ketorolac, and 0.5 mg epinephrine by infiltration of the knee at the end of surgery, and 2 postoperative injections of these substances through an intraarticular catheter.

RESULTS: More patients in group I than in group F could walk < 3 m on the first postoperative day (29/39 vs. 7/37, p < 0.001). Group I also had significantly lower pain scores during activity and lower consumption of opioids on the first postoperative day. No differences between groups were seen regarding side effects or length of stay.

INTERPRETATION: Peri- and intraarticular application of analgesics by infiltration and bolus injections can improve early analgesia and mobilization for patients undergoing TKA. Further studies of optimal drugs, dosage, and duration of this treatment are warranted.