Abstract:

Objective  To explore the analgesic effect of different approaches(transtrochanteric planar approach and transpopliteal approach) of sciatic nerve block applied to patients with ankle fracture during surgery, and their impact on stress state.

Methods  A total of 78 patients with ankle fractures were selected, and based on the random number table method, they were divided into group A(sciatic nerve anesthesia block via the greater trochanter plane approach) and group B(sciatic nerve anesthesia block via the upper popliteal approach), with 39 cases in each group. Nerve block-related indicators, visual analogue scale（VAS） scores for pain at different time points after surgery, and muscle strength of the posterior femoral muscles at 8 h after surgery were compared, and the occurrence of adverse reactions was recorded.

Results  Onset time of sensory block, operation time of nerve block, depth of sciatic nerve, the dosage of intraoperative fentanyl and the VAS score at 8 h after surgery were significantly lower in group B than in group A, and the difference was statistically significant(P＜0.05). At 15 min and 30 min after anesthesia, the systolic blood pressure, diastolic blood pressure and heart rate of group B were significantly lower than those of group A, with significant difference(P＜0.05). The differences of interaction between groups, time points and time points between groups were statistically significant(P＜0.05). The overall muscle strength of the posterior femoral muscles of group B was significantly higher than that of group A at 8 h after surgery, and the difference was statistically significant(P＜0.05). No adverse reactions occurred in the two groups.

Conclusion  Compared with the greater trochanter approach, the upper popliteal approach for sciatic nerve block is simpler and has a more significant analgesic effect, and it can better retain the muscle strength of the posterior femoral muscles.

Key words: ankle fracture, sciatic nerve, sonication