Lateral popliteal sciatic nerve block compared with ankle block for analgesia following foot surgery.

The purpose of this study was to compare postoperative analgesia after foot surgery in patients anaesthetised either with popliteal sciatic nerve block or ankle block. In a prospective study, 40 patients scheduled for foot surgery involving osteotomies were allocated randomly into one of two groups. Following induction of general anaesthesia, Group PS (n = 21) received a lateral popliteal sciatic nerve block and Group AB (n = 19) received an ankle block. Both groups received 20 ml bupivacaine 0.5% plain. In group PS 43% required morphine analgesia in the Post Anaesthetic Recovery Room (PAR) compared with 16% in group AB. Postoperative analgesia was assessed using VAS and a pain scale in the PAR and a questionnaire by telephone follow-up on the day after surgery. The ankle block appeared to be more reliable, providing more consistent analgesia in the PAR. Postoperative analgesia in Group PS lasted a median of 18.0 hr and in Group AB lasted 11.5 hr (P < 0.05). Both techniques provided effective analgesia after discharge home and high levels of patient satisfaction.