Abstract
BACKGROUND: This study aimed to evaluate the efficacy and safety of ultrasound-guided lumbar plexus block (LPB) combined with transmuscular quadratus lumborum block (TQLB) at the L3 level using the Shamrock approach for total hip arthroplasty. METHODS: Eighty-four patients were enrolled and randomly assigned into three groups at a 1:1:1 ratio: P group (LPB at L3 level), TP group (T12 paravertebral block combined with LPB at L3 and L4 levels) or PQ group (LPB combined with TQLB at L3 level). The primary outcome was the effective rate of sensory block, assessed via the cutaneous sensory block area. The secondary outcomes included postoperative pain intensity, intraoperative sufentanil consumption, incidence of hypotension, procedure time of block and complications. RESULTS: The PQ group achieved a significantly higher effective rate of 67.6% compared to the P group, which was at 7.1% (p < 0.001), though lower than the TP group (89.3%, p = 0.051). The PQ group demonstrated significantly lower postoperative visual analogue scales (VAS) during movement compared to the P group (PACU: p = 0.009; 6 h: p = 0.046; 24 h: p = 0.006). However, no significant differences were observed between the PQ and TP groups under any condition (rest or movement). Sufentanil consumption remained comparable across the three groups. Notably, the PQ group experienced a lower frequency of intraoperative hypotension compared to the TP group (p = 0.028). Regarding procedure time, the PQ group exhibited a significantly lower mean value compared to the TP group, but it was higher than that in the P group (p < 0.001). Furthermore, no clinical signs of local anaesthetic systemic toxicity, nerve injury, haematoma or epidural block were observed in any of the groups. CONCLUSIONS: The combined technique may provide effective block with fewer technical challenges and hypotension risks compared to multi-level LPB, making it a feasible alternative for perioperative pain management in total hip arthroplasty. Trial registration ClinicalTrials.gov, NCT04266236. Registered on 10 February 2020. CLINICALTRIALS: gov PRS: Record Summary NCT04266236.