Abstract:

BACKGROUND: Currently the ultrasound-guided continuous femoral nerve block has been widely used as a postoperative analgesia method after knee replacement surgery, but there are still some technical and practical details issues to be studied.
OBJECTIVE: To evaluate the effect of ultrasound-guided imaging and safety evaluation of different puncture techniques and needle choice in the ultrasound-guided continuous femoral nerve block after total knee arthroplasty.
METHODS: One hundred and sixty patients undergoing total knee arthroplasty were randomly divided into four groups, with 40 cases in each group. Continuous femoral nerve block was done after general anesthesia induction. Patients in each group were respectively punctured using 20 G needle (diameter 1.1 mm) out-of-plane approach, 20 G needle (diameter 1.1 mm) in-plane approach, 18 G needle (diameter 1.3 mm) out-of-plane approach, and 18 G needle (diameter   1.3 mm) in-plane approach. Patient-controlled analgesia pump was used 30 minutes before the end of surgery. The operating time of continuous femoral nerve block was recorded. The visual analogue scale scores at rest, active functional exercise and continuous passive movement state on 6, 24, 48, 72 hours after total knee arthroplasty were estimated. The presses of the pump, time of first walk, daily walk times and complication of continuous femoral nerve block were observed.
RESULTS AND CONCLUSION: The operating time of continuous femoral nerve block in group D was shorter than that in other groups (P < 0.05). There was no difference of visual analogue scale scores, the presses of the pump, time of first walk, and daily walk times among each group. The incidence of puncture site pain in group C was higher than that in other groups (P < 0.05). The best ultrasound imaging was obtained by using 18 G needle in-plane approach for ultrasound-guided continuous femoral nerve block after total knee arthroplasty, and the complication incidence was not increased.

Key words: Arthroplasty, Replacement, Knee, Analgesia, Femoral Nerve, Punctures