The addition of continuous wound infusion of local anaesthetics to local infiltration in the management of postoperative pain and rehabilitation after total hip arthroplasty: a double-blind randomized controlled trial.

BACKGROUND: Total hip arthroplasty is one of the most common procedures in orthopedic surgery. We hypothesized that local infiltration of analgesia and continuous wound infusion of anesthetics in the first 72 hours after surgery could provide more effective postoperative analgesia with better rehabilitation. METHODS: A double-blind, randomized, controlled study was conducted with 96 patients who underwent total hip arthroplasty. The patients were randomized to receive either a local infiltration analgesia and continuous wound infusion of anesthetics or a local infiltration analgesia and continuous wound infusion of saline solution. The patients in both groups received subarachnoid anesthesia and a local infiltration analgesia. A multihole catheter was placed next to the implant and connected to an electronic pump containing a 300-mL solution of 0.2% levobupivacaine (experimental group) or saline (control group). RESULTS: A total of 96 consecutive patients were enrolled and randomized. Of these, 48 patients received local infiltration analgesia and continuous wound infusion of local anesthetics, and the remainder received local infiltration analgesia and continuous wound infusion of saline solution. The analysis showed a significant main effect of treatment on the postoperative incident of pain (F-treat(1,F-93)=22.62, P=0.000) and on resting pain during the post-surgery follow-up (F-treat(1,F-93)=15.62, P=0.0002). The pain scores during the rehabilitation period were significantly less in the experimental group. Analgesic consumption was less in the experimental group. CONCLUSIONS: The addition of continuous wound infusion of anesthetics to local infiltration analgesia provided an extended analgesic effect associated with good rehabilitation performance.