Comparison of the analgesic effect between ultrasound-guided popliteal fossa superior and lower lateral approaches of the greater trochanter for sciatic nerve block in the elderly after total knee arthroplasty

ObjectiveTo investigate the effects of ultrasound-guided sciatic nerve block in total knee replacement.

MethodsOne hundred and twenty patients with unilateral total knee arthroplasty were divided into the group A and group B according to the random number table method(60 cases each group).The group A were treated with sciatic nerve block through the greater trochanteric lateral approach, and the group B were treated with sciatic nerve block through upper lateral popliteal approach.The sciatic nerve block index, sensory and r motor block onset time, maintenance time and block effects were compared between two groups.

ResultsThe operation time, number of punctures and puncture depth in group B were significantly less than those in group A(P < 0.01).The puncture success rate, block success rate and patient satisfaction in group B were significantly higher than those in group A(P < 0.01).There was no statistical significance in the onset and duration of block between two groups(P>0.05), and the block effect scores of sensory and motor in group B were significantly higher than those in group A(P < 0.01).There was no statistical significance in the VAS scores after 8 h of surgery between two groups(P>0.05).The muscle strength of the posterior femoris in the group B after 8h of operation achieved Ⅲ level and above, and which was significantly better than that in group A(P < 0.01).

ConclusionsThe ultrasound-guided upper lateral popliteal approach to sciatic nerve block after total knee arthroplasty is short puncture time, shallow penetration depth, high success rates of puncture and block, and good patient satisfaction and muscle strength of the posterior femoral muscle, which is worthy of clinical promotion.