Sciatic obturator femoral technique versus spinal anaesthesia in patients undergoing surgery for fixation of open tibial fractures using Ilizarov external fixator. A randomised trial

BACKGROUND: Peripheral nerve block is preferable for lower extremity surgery because it sufficiently blocks pain pathways at different levels providing excellent anaesthesia at the site of surgery. We designed this study to compare the efficacy and safety of SOFT block (sciatic-obturator-femoral technique) compared with spinal anaesthesia in patients undergoing surgery for fixation of open tibial fractures using Ilizarov external fixator. METHODS: One hundred and seven patients ASA I, II scheduled for fixation of open tibial fractures using Ilizarov external fixator. The patients were randomly allocated to receive either spinal anaesthesia or SOFT block. In spinal anaesthesia group, patients received spinal anaesthesia with hyperbaric bupivacaine 0.5% (7. 5-10mg). In SOFT group, patients received SOFT block with bupivacaine 0.25%. Primary endpoint included the duration of analgesia. The secondary endpoints included patient satisfaction scores, visual analogue scores, incidence of adverse events as vomiting, systemic toxicity from local anaesthetic drug and time to first effect of the techniques. RESULTS: The duration of SOFT block and time to first analgesic dose in SOFT group was significantly longer (p < 0.001). There was no significant difference between the study groups regarding satisfaction scores, the incidence of cardiovascular collapse, seizures and paraesthesia. Pain scores were significantly lower in SOFT group at 3,6,12 h postoperative (p < 0.001). The time to the first effect was significantly longer in SOFT group (p < 0.001). CONCLUSION: SOFT is a feasible technique of local anaesthesia for control of postoperative pain with unremarkable adverse events compared with spinal anaesthesia, in patients undergoing fixation of tibial fractures using Ilizarov external fixator. TRIAL REGISTRATION: This trial was retrospectively registered at ClinicalTrials.gov. registry number: NCT03450798 on February 20, 2018.